New law for electricity from 2025: great opportunities for photovoltaics
On June 9, 2024, Swiss voters clearly approved the new electricity law with a vote share of 68% - a clear signal for the acceleration of the expansion of renewable energies. When the legislative changes come into force, the framework conditions will improve significantly, especially for photovoltaic systems. One challenge, however, is that the ordinances, i.e. the implementing provisions, have not yet been adopted. The following deadlines are planned for the provisions to come into force (from July 2024, subject to a decision by the Federal Council): Amendments to the Energy Act (without withdrawal tariffs) as of January 1, 2025, adoption of the ordinances in November 2024; Amendments to the Electricity Supply Act (and restart tariffs) as of January 1, 2026, ordinance issued in the first quarter of 2025; Amendments to the Spatial Planning Act as of July 1, 2025.
Below you will find an overview of the current state of knowledge on regulations that have a significant impact on photovoltaics (PV):
Whenever possible, it is advisable to use solar energy where it is generated, also to avoid overloading the electricity grids. In this context, there are two important innovations:
New: virtual RCPs (from 2025) In virtual associations for self-consumption (RCP), the use of connecting lines to the distribution network is also permitted for self-consumption. In addition, measurement data from different measuring devices can be virtually combined. This makes joint self-consumption - especially in existing buildings - easy to implement without replacing existing electricity meters and without replacing grid connections.
Self-consumption pools (RCP) are one of the instruments of the federal government’s Energy Strategy 2050 with the aim of increasing the share of renewable energy produced and consumed in Switzerland.
An RCP allows several tenants or owners of a property or adjacent buildings to come together in a single consumer community, supplied with energy generated by a common photovoltaic system and delivered through a single point connected to the local distribution company.
An RCP may consist of connected vertical supply points within a building and/or horizontal ones within a neighbourhood, provided that the production capacity of the shared facility is at least 10% of the capacity of the ‘connection to the community grid’ (above 30 kWp).
An RCP with an electricity consumption of more than 100 MWh/year (approx. 30 apartments) has the opportunity to access the free electricity market, like any large Swiss consumer.
The landowner is the sole contractual partner vis-à-vis the distribution system operator.
¹Energy Ordinance (EO), Art. 15, Paragraph 1
New: CELs (from 2026)Thanks to the new version of the Electricity Supply Act, participants in local electricity communities (CELs) can now use the public electricity grid at a reduced rate to supply each other with self-produced electricity from renewable energies. Participants in a CEL must be based in the same municipality, in the same sector and at the same grid level and be equipped with a smart meter. They remain customers of the distribution system operator (GRD).
The advantages at a glance: – Larger systems improve their profitability through more self-consumption. – More families and companies can benefit from cost-effective solar energy. – The participation of the population in projects is made easier.
Aspects that still need to be clarified: – Amount of the discount on the network usage fee. According to the draft regulation, this is 30% (or 15% if several network layers are used). – Minimum connected load of the system/production plants: According to the draft regulation, the minimum share of photovoltaic electricity production in relation to the connected load is 20%.
The remuneration paid by the distribution network operator (DSO) for the electricity fed into the grid is called the take-off tariff (also known as the “take-back tariff”). Currently, the level of this tariff varies considerably between the more than 600 GRDs in Switzerland (see www.pvtarif.ch).
New: Minimum feed-in tariffs From 2026, the remuneration for electricity from renewable sources will be based on the average quarterly market price at the time of feed-in to the grid. In addition, minimum tariffs are planned for systems with an output of up to 150 kW in order to protect against very low market prices. These minimum rates are based on the depreciation of the reference systems over their useful life.
The advantages at a glance: – Uniform framework conditions for all photovoltaic systems in Switzerland. – Protection against strong fluctuations in the electricity market.
Aspects still to be clarified: – Can a DSO pass on to its customers the additional costs of a tariff that is above the average quarterly market price? – Amount of the minimum remuneration.
A network usage tax must be paid for every kilowatt hour taken from the electricity grid - the current average price for households is 12.71 cents/kWh. Until now, only pump turbine power plants were exempt from this tariff.
New: Grid fee reimbursement for batteries From 2025, the grid fee for the electricity that a battery feeds into the grid will be reimbursed. For stationary storage systems, only the amount previously taken from the grid is reimbursed. For mobile storage systems (electric vehicles with bidirectional charging), the entire amount of energy is taken into account. It is expected that the exemption from paying the grid tax will apply from 2025, while the reimbursement for accumulators for self-consumption will only apply from 2026.
The advantages at a glance: – The use of energy storage systems is to be reduced. The load on the power grids becomes much more interesting. – Bidirectional charging of electric vehicles can be ideally combined with a photovoltaic system.
Aspects still to be clarified: – Some details on the implementation of the new rules have to be determined by the electricity industry and are not yet known. – Use of accumulators within a CEL
In order to avoid bottlenecks in distribution networks, it is becoming increasingly important that distribution network operators can use the flexibility of producers and operators of storage systems.
New: Clear rules on the use of flexibility. Distribution system operators must enter into agreements with owners who are willing to guarantee a certain degree of flexibility. This must be remunerated as soon as it accounts for more than 3% of the energy generated annually by the plant.
Large photovoltaic systems in rural areas often cannot be connected to the power grid because the grid connection cables are too weak. The costs for the necessary expansion of the connection lines are currently borne entirely by the system operators, which can lead to prohibitive costs.
New: Remuneration for the reinforcement of connecting lines is provided for the reinforcement of connecting lines of production plants with an output of more than 50 kW.
The advantages at a glance: Large systems with low production costs and low self-consumption benefit, for example, on agricultural roofs or on various infrastructures.
Aspects that still need to be clarified: The amount of the contribution. According to the consultation draft, it is 50 francs per kW of newly installed production capacity.
So far, the interest of distribution network operators in long-term solar power supply contracts has been limited. The situation could change from next year.
New: Minimum share of electricity from domestic and renewable sources. At least 20% of the electricity required for basic supply and at least 75% of the guarantees of origin in the standard electricity product of the network operators must come from domestic (national) sources and renewable sources.
The advantages at a glance: The demand for solar energy is expected to increase, at least among distribution system operators that do not operate large hydroelectric power plants.
There are already tenders for the one-off payment for systems without self-consumption with an output of 150 kW or more. What is new is that such systems can instead take part in an auction in return for a variable market premium.
The advantages at a glance: Instead of a one-time investment contribution, there is a guaranteed minimum remuneration for 20 years for the electricity produced.
Facade photovoltaic systems are becoming increasingly popular, but still account for less than half a percentage point of new photovoltaic systems. Facade systems have the advantage of generating over 40% of their production in the winter months.
New: More incentives, simpler approvals From January 1, 2025, the bonus for systems with an inclination angle of at least 75 degrees will be significantly increased. For integrated systems, the price will rise from 250 to 400 francs per kW of installed capacity, and for connected or isolated systems from 100 to 200 francs. This will encourage the installation of systems on the facade. The new version of the Spatial Planning Act will also come into force in mid-2025: In principle, no building permit procedure is required for facade systems. Instead, the already proven notification procedure for photovoltaic systems on roofs applies.
The advantages at a glance: The installation of solar systems on facades becomes more economically attractive and significantly easier.
Points still to be clarified: The consultation process for the new version of the spatial planning regulations is still ongoing. Therefore, the exact structure of the approval process for facade systems is not yet known.
At the launch of the web platform www.sonnendach.ch, the SFOE estimated the usable solar energy potential of Swiss buildings at around 67 terawatt hours (TWh) per year (50 TWh on roofs, 17 TWh on facades). An in-depth analysis by the ZHAW in 2022 showed a usable potential of 54 TWh on roofs.
A potential analysis outside buildings carried out by Meteotest (2019) on behalf of Swissolar revealed an additional potential of 10.5 TWh in parking lots and motorway embankments and 16.4 TWh in alpine areas that are pre-exposed outside the protection zones.
The total usable potential for annual solar power production in Switzerland is therefore almost 100 TWh.
In Switzerland, it is not possible to build large photovoltaic systems like the German ones, which produce less than 5 cents per kilowatt hour. Large photovoltaic systems on buildings in Switzerland produce 6-8 cents, while those on single-family homes produce around 15 cents/kWh. In addition, the purchase remuneration from distribution network operators generally does not cover the production costs of the solar power sold. Therefore, additional incentives for investors are required.
The one-off remuneration is a proven incentive for photovoltaic systems with self-consumption. Since 2023, it has been supplemented by the one-off high remuneration (up to a maximum of 60% of the investment costs) for systems without self-consumption, which is remunerated via an auction for systems with a size of 150 kW or more. This ultimately makes the construction of systems on noise barriers, warehouses, stable roofs, parking garage roofs or water basins interesting from an economic point of view. In addition, large alpine systems can be subsidized with up to 60% of the investment costs.
A newly installed solar system in Switzerland today causes 43 grams of CO2 equivalent per kilowatt hour (CO 2eq/kWh), which is three times less than the greenhouse effect of the electricity consumption mix in Switzerland. The energetic payback period of a solar system in Switzerland is around 15 months. During this time, the energy required for production is offset by the production of the system (comparison at primary energy level). Source: Treeze 2020, fact sheet on photovoltaic electricity. With a service life of around 30 years, a photovoltaic system therefore produces around 20 times more energy than is needed to manufacture it.
The installed photovoltaic capacity of 50 gigawatts (GW) that we propose corresponds to about five times the current peak production of the Swiss electricity grid. Even if photovoltaic systems never reach their maximum production at the same time, there will be surpluses that can be temporarily stored. Different storage periods must be distinguished:
Seasonal storage involves producing hydrogen through electrolysis. This can be stored directly or after further conversion steps as methane or liquid fuel. We are talking about "Power to X" and gases or synthetic fuels. These can be used in winter, for example, to operate combined heat and power plants or to operate heavy vehicles such as trucks or construction machinery. The management of reservoir power plants (including raising dams and building new reservoirs) also makes a significant contribution to seasonal storage. While solar energy covers a large part of summer demand, the water reserves in reservoirs can be conserved.
In terms of daily and weekly storage, the focus is on the storage of stationary batteries (preferably as a second life for electric cars) and the optimized self-consumption of electric cars and heat pumps. The latter offer the greatest benefit in the form of district storage, which at the same time helps to relieve the load on the power grids. Thanks to bidirectional charging, batteries in electric cars will quickly become more important. Pumping stations can also be used to exploit overproduction (e.g. at lunchtime).
If there is insufficient line capacity, the last resort is to dynamically regulate the photovoltaic production peaks at the connection point of the house.
Photovoltaic systems only deliver their nominal power for a few hours a year. In rural areas in particular, adapting line capacities to this peak production would have high cost consequences. It is therefore necessary to intensify efforts to use surplus electricity as decentrally as possible, both for charging batteries (in electric vehicles or in stationary solutions) and for the production of gas and synthetic fuels (Power-to-X).
To compensate, it should be possible to regulate the peak power at the grid connection point. This means that it is possible to install more PV energy in the existing grid than is currently available if local consumption is too low. The focus is on dynamic power control: the system operator himself ensures that the agreed maximum feed-in power at the grid connection point is not exceeded by controlling the loads. Local energy communities have dynamic energy control that includes entire districts. However, it is also conceivable that in areas with low grid capacity, the maximum power consumption at the grid connection point (where there is no corresponding control or battery on the inverter) is set to 70% of the nominal power. The resulting loss of production is only 1-3%, depending on the orientation of the system, and does not need to be compensated. It is important to note that flexibility depends on the manufacturer and must be compensated. Despite all these measures, selective grid expansions will still be necessary, especially in the agricultural sector. The conditions must be created so that this happens quickly.
Fixed battery storage systems can make a significant contribution to the efficient use of existing networks, especially if they are operated in a way that is beneficial to the grid and supply not just individual buildings but entire districts at suitable points in the grid. There is now little incentive for grid operators to build neighborhood storage systems or gas-fired power plants, as these - unlike pumped storage - are not exempt from the grid usage fee. However, grid operators may already pay private battery storage owners a fee for managing their storage batteries in such a way that they are useful for the grid.
The electrification of passenger transport is progressing rapidly. As a result, more and more mobile battery storage units are available. Today, they are mostly monodirectional, which means they can only use the peak production of solar systems. However, bidirectional charging is likely to become the standard soon, so that these accumulators1 can also make a significant contribution to securing supplies (day-night balancing). However, in order for these decentralized storage capacities to also be used to use excess solar power production, a significantly larger charging infrastructure is required than before.
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1 Swiss eMobility estimate: 2 million electric cars by 2035, which corresponds to a storage capacity of about 14.5 TWh, 22 GW
1. Morning time (6:00 a.m. – 10:00 a.m.): During this time, the demand for energy increases and prices tend to rise. Variation of the “variable transport tariff” component between 10.83 and 15.83 ct/kWh.
2. Solar band (10:00 - 17:00): This band takes into account energy production from solar sources and generally offers more competitive prices due to the abundant availability of renewable energy. Variation of the "Variable Transport Tariff" component between 5.83 and 10.83 ct/kWh.
3. Evening time (5:00 p.m. - 10:00 p.m.): Higher prices may apply at these times due to the increased energy demand. Variation of the "Variable transport tariff" component between 10.83 and 15.83 ct/kWh. In the case of accumulation, this tariff is limited to 10.83 ct/kWh, since exceeding solar band 2 supports the peak consumption that occurs between 5:00 p.m. and 10:00 p.m.
4. Night time (10pm – 6am): Prices are generally lower during these hours because there is less demand for energy. Variation of the “variable transport tariff” component between 5.83 and 10.83 cents/kWh.
On June 9, 2024, Swiss voters clearly approved the new electricity law with a vote share of 68% - a clear signal for the acceleration of the expansion of renewable energies. When the legislative changes come into force, the framework conditions will improve significantly, especially for photovoltaic systems. One challenge, however, is that the ordinances, i.e. the implementing provisions, have not yet been adopted. The following deadlines are planned for the provisions to come into force (from July 2024, subject to a decision by the Federal Council): Amendments to the Energy Act (without withdrawal tariffs) as of January 1, 2025, adoption of the ordinances in November 2024; Amendments to the Electricity Supply Act (and restart tariffs) as of January 1, 2026, ordinance issued in the first quarter of 2025; Amendments to the Spatial Planning Act as of July 1, 2025.
Below you will find an overview of the current state of knowledge on regulations that have a significant impact on photovoltaics (PV):
Whenever possible, it is advisable to use solar energy where it is generated, also to avoid overloading the electricity grids. In this context, there are two important innovations:
New: Virtual RCPs (from 2025) In virtual associations for self-consumption (RCP), the use of connecting lines to the distribution network is also permitted for self-consumption. In addition, measurement data from various measuring devices can be virtually combined. This makes joint self-consumption - especially in existing buildings - easy to implement without replacing existing electricity meters and without replacing grid connections.
Self-consumption pools (RCP) are one of the instruments of the federal government’s Energy Strategy 2050 with the aim of increasing the share of renewable energy produced and consumed in Switzerland.
An RCP allows several tenants or owners of a property or adjacent buildings to come together in a single consumer community, supplied with energy generated by a common photovoltaic system and delivered through a single point connected to the local distribution company.
An RCP may consist of connected vertical supply points within a building and/or horizontal ones within a neighbourhood, provided that the production capacity of the shared facility is at least 10% of the capacity of the ‘connection to the community grid’ (above 30 kWp).
An RCP with an electricity consumption of more than 100 MWh/year (around 30 apartments) has, like any large Swiss consumer, the opportunity to access the free electricity market.
The landowner is the sole contractual partner vis-à-vis the distribution system operator.
¹Energy Ordinance (EO), Art. 15, Paragraph 1
New: CELs (from 2026)Thanks to the new version of the Electricity Supply Act, participants in local electricity communities (CELs) can now use the public electricity grid at a reduced rate to supply each other with self-produced electricity from renewable energies. Participants in a CEL must be based in the same municipality, in the same sector and at the same grid level and be equipped with a smart meter. They remain customers of the distribution system operator (GRD).
The advantages at a glance: – Larger systems improve their profitability through more self-consumption. – More families and companies can benefit from cost-effective solar energy. – The participation of the population in projects is made easier.
Aspects that still need to be clarified: – Amount of the discount on the network usage fee. According to the draft regulation, this is 30% (or 15% if several network layers are used). – Minimum connected load of the system/production plants: According to the draft regulation, the minimum share of photovoltaic electricity production in relation to the connected load is 20%.
The remuneration paid by the distribution network operator (DSO) for the electricity fed into the grid is called the take-off tariff (also known as the “take-back tariff”). Currently, the level of this tariff varies considerably between the more than 600 GRDs in Switzerland (see www.pvtarif.ch).
New: Minimum feed-in tariffs From 2026, the remuneration for electricity from renewable sources will be based on the average quarterly market price at the time of feed-in to the grid. In addition, minimum tariffs are planned for systems with an output of up to 150 kW in order to protect against very low market prices. These minimum rates are based on the depreciation of the reference systems over their useful life.
The advantages at a glance: – Uniform framework conditions for all photovoltaic systems in Switzerland. – Protection against strong fluctuations in the electricity market.
Aspects still to be clarified: – Can a DSO pass on to its customers the additional costs of a tariff that is above the average quarterly market price? – Amount of the minimum remuneration.
A network usage tax must be paid for every kilowatt hour taken from the electricity grid - the current average price for households is 12.71 cents/kWh. Until now, only pump turbine power plants were exempt from this tariff.
New: Grid fee reimbursement for batteries From 2025, the grid fee for the electricity that a battery feeds into the grid will be reimbursed. For stationary storage systems, only the amount previously taken from the grid is reimbursed. For mobile storage systems (electric vehicles with bidirectional charging), the entire amount of energy is taken into account. It is expected that the exemption from paying the grid tax will apply from 2025, while the reimbursement for accumulators for self-consumption will only apply from 2026.
The advantages at a glance: – The use of energy storage systems is to be reduced. The load on the power grids becomes much more interesting. – Bidirectional charging of electric vehicles can be ideally combined with a photovoltaic system.
Aspects still to be clarified: – Some details on the implementation of the new rules have to be determined by the electricity industry and are not yet known. – Use of accumulators within a CEL
In order to avoid bottlenecks in distribution networks, it is becoming increasingly important that distribution network operators can use the flexibility of generators and storage operators.
New: Clear rules on the use of flexibility. Distribution system operators must enter into agreements with owners who are willing to guarantee a certain degree of flexibility. This must be remunerated as soon as it accounts for more than 3% of the energy generated annually by the plant.
Large photovoltaic systems in rural areas often cannot be connected to the power grid because the grid connection cables are too weak. The costs for the necessary expansion of the connection lines are currently borne entirely by the system operators, which can lead to prohibitive costs.
New: Remuneration for the reinforcement of connecting lines is provided for the reinforcement of connecting lines of production plants with an output of more than 50 kW.
The advantages at a glance: Large systems with low production costs and low self-consumption benefit, for example, on agricultural roofs or on various infrastructures.
Aspects that still need to be clarified: The amount of the contribution. According to the consultation draft, it is 50 francs per kW of newly installed production capacity.
So far, the interest of distribution network operators in long-term solar power supply contracts has been limited. The situation could change from next year.
New: Minimum share of electricity from domestic and renewable sources. At least 20% of the electricity required for basic supply and at least 75% of the guarantees of origin in the standard electricity product of the network operators must come from domestic (national) sources and renewable sources.
The advantages at a glance: The demand for solar energy is expected to increase, at least among distribution system operators that do not operate large hydroelectric power plants.
There are already tenders for the one-off payment for systems without self-consumption with an output of 150 kW or more. What is new is that such systems can instead take part in an auction in return for a variable market premium.
The advantages at a glance: Instead of a one-time investment contribution, there is a guaranteed minimum remuneration for 20 years for the electricity produced.
Facade photovoltaic systems are becoming increasingly popular, but still account for less than half a percentage point of new photovoltaic systems. Facade systems have the advantage of generating over 40% of their production in the winter months.
New: More incentives, simpler approvals From January 1, 2025, the bonus for systems with an inclination angle of at least 75 degrees will be significantly increased. For integrated systems, the price will rise from 250 to 400 francs per kW of installed capacity, and for connected or isolated systems from 100 to 200 francs. This will encourage the installation of systems on the facade. The new version of the Spatial Planning Act will also come into force in mid-2025: In principle, no building permit procedure is required for facade systems. Instead, the already proven notification procedure for photovoltaic systems on roofs applies.
The advantages at a glance: The installation of solar systems on facades becomes more economically attractive and significantly easier.
Points still to be clarified: The consultation process for the new version of the spatial planning regulations is still ongoing. Therefore, the exact structure of the approval process for facade systems is not yet known.
At the launch of the web platform www.sonnendach.ch, the SFOE estimated the usable solar energy potential of Swiss buildings at around 67 terawatt hours (TWh) per year (50 TWh on roofs, 17 TWh on facades). An in-depth analysis by the ZHAW in 2022 showed a usable potential of 54 TWh on roofs.
A potential analysis outside buildings carried out by Meteotest (2019) on behalf of Swissolar revealed an additional potential of 10.5 TWh in parking lots and motorway embankments and 16.4 TWh in alpine areas that are pre-exposed outside the protection zones.
The total usable potential for annual solar power production in Switzerland is therefore almost 100 TWh.
In Switzerland, it is not possible to build large photovoltaic systems like the German ones, which produce less than 5 cents per kilowatt hour. Large photovoltaic systems on buildings in Switzerland produce 6-8 cents, while those on single-family homes produce around 15 cents/kWh. In addition, the purchase remuneration from distribution network operators generally does not cover the production costs of the solar power sold. Therefore, additional incentives for investors are required.
The one-off remuneration is a proven incentive for photovoltaic systems with self-consumption. Since 2023, it has been supplemented by the one-off high remuneration (up to a maximum of 60% of the investment costs) for systems without self-consumption, which is remunerated via an auction for systems with a size of 150 kW or more. This ultimately makes the construction of systems on noise barriers, warehouses, stable roofs, parking garage roofs or water basins interesting from an economic point of view. In addition, large alpine systems can be subsidized with up to 60% of the investment costs.
A newly installed solar system in Switzerland today causes 43 grams of CO2 equivalent per kilowatt hour (CO 2eq/kWh), which is three times less than the greenhouse effect of the electricity consumption mix in Switzerland. The energetic payback period of a solar system in Switzerland is around 15 months. During this time, the energy required for production is offset by the production of the system (comparison at primary energy level). Source: Treeze 2020, fact sheet on photovoltaic electricity. With a service life of around 30 years, a photovoltaic system therefore produces around 20 times more energy than is needed to manufacture it.
The installed photovoltaic capacity of 50 gigawatts (GW) that we propose corresponds to about five times the current peak production of the Swiss electricity grid. Even if photovoltaic systems never reach their maximum production at the same time, there will be surpluses that can be temporarily stored. A distinction must be made between different storage periods:
Seasonal storage involves producing hydrogen through electrolysis. This can be stored directly or after further conversion steps as methane or liquid fuel. We are talking about "Power to X" and gases or synthetic fuels. These can be used in winter, for example, to operate combined heat and power plants or to operate heavy vehicles such as trucks or construction machinery. The management of reservoir power plants (including raising dams and building new reservoirs) also makes a significant contribution to seasonal storage. While solar energy covers a large part of summer demand, the water reserves in reservoirs can be conserved.
In terms of daily and weekly storage, the focus is on the storage of stationary batteries (preferably as a second life for electric cars) and the optimized self-consumption of electric cars and heat pumps. The latter offer the greatest benefit in the form of district storage, which at the same time helps to relieve the load on the power grids. Thanks to bidirectional charging, batteries in electric cars will quickly become more important. Pumping stations can also be used to exploit overproduction (e.g. at lunchtime).
If there is insufficient line capacity, the last resort is to dynamically regulate the photovoltaic production peaks at the connection point of the house.
Photovoltaic systems only deliver their nominal power for a few hours a year. In rural areas in particular, adapting line capacities to this peak production would have high cost consequences. It is therefore necessary to intensify efforts to use surplus electricity as decentrally as possible, both for charging batteries (in electric vehicles or in stationary solutions) and for the production of gas and synthetic fuels (Power-to-X).
To compensate, it should be possible to regulate the peak power at the grid connection point. This means that it is possible to install more PV energy in the existing grid than is currently available if local consumption is too low. The focus is on dynamic power control: the system operator himself ensures that the agreed maximum feed-in power at the grid connection point is not exceeded by controlling the loads. Local energy communities have dynamic energy control that includes entire districts. However, it is also conceivable that in areas with low grid capacity, the maximum power consumption at the grid connection point (where there is no corresponding control or battery on the inverter) is set to 70% of the nominal power. The resulting loss of production is only 1-3%, depending on the orientation of the system, and does not need to be compensated. It is important to note that flexibility depends on the manufacturer and must be compensated. Despite all these measures, selective grid expansions will still be necessary, especially in the agricultural sector. The conditions must be created so that this happens quickly.
Fixed battery storage systems can make a significant contribution to the efficient use of existing networks, especially if they are operated in a way that is beneficial to the grid and supply not just individual buildings but entire districts at suitable points in the grid. There is now little incentive for grid operators to build neighborhood storage systems or gas-fired power plants, as these - unlike pumped storage - are not exempt from the grid usage fee. However, grid operators may already pay private battery storage owners a fee for managing their storage batteries in such a way that they are useful for the grid.
The electrification of passenger transport is progressing rapidly. As a result, more and more mobile battery storage units are available. Today, they are mostly monodirectional, which means they can only use the peak production of solar systems. However, bidirectional charging is likely to become the standard soon, so that these accumulators1 can also make a significant contribution to securing supplies (day-night balancing). However, in order for these decentralized storage capacities to also be used to use excess solar power production, a significantly larger charging infrastructure is required than before.
---
1 Swiss eMobility estimate: 2 million electric cars by 2035, which corresponds to a storage capacity of approximately 14.5 TWh, 22 GW
1. Morning time (6:00 a.m. - 10:00 a.m.): In this range, the energy demand is The prices are rising and prices are trending upwards. Variation of the "variable transport tariff" component between 10.83 and 15.83 ct/kWh.
2. Solar band (10:00 - 17:00): This band takes into account energy production from solar sources and generally offers more competitive prices due to the abundant availability of renewable energy. Variation of the "Variable Transport Tariff" component between 5.83 and 10.83 ct/kWh.
3. Evening time (5:00 p.m. - 10:00 p.m.): Higher prices may apply at these times due to the increased energy demand. Variation of the "Variable transport tariff" component between 10.83 and 15.83 ct/kWh. In the case of accumulation, this tariff is limited to 10.83 ct/kWh, since exceeding solar band 2 supports the peak consumption that occurs between 5:00 p.m. and 10:00 p.m.
4. Nachtzeit (22:00 – 06:00 Uhr): In diesen Stunden sind die Preise im Allgemeinen niedriger, da weniger Energie nachgefragt wird. Variation der Komponente „Variabler Transporttarif“ zwischen 5,83 und 10,83 ct/kWh.On 9 June 2024, Swiss voters clearly approved the new Electricity Act with a vote share of 68% – a clear signal for the acceleration of the expansion of renewable energies. When the legislative changes come into force, the framework conditions will improve significantly, especially for photovoltaic systems. However, one challenge is that the ordinances, i.e. the implementing provisions, have not yet been decided. The following timeframes are planned for the entry into force of the provisions (as of July 2024, subject to decision by the Federal Council): Amendments to the Energy Act (without take-over tariffs) on 1 January 2025, adoption of ordinances in November 2024; Amendments to the Electricity Supply Act (as well as take-over tariffs) on 1 January 2026, adoption of ordinances in the first quarter of 2025; Amendments to the Spatial Planning Act on 1 July 2025.
Below is an overview of the current state of knowledge on the provisions that have a significant impact on photovoltaics (PV):
Whenever possible, it is advisable to consume solar energy where it is produced, also to avoid overloading electricity grids. There are two important innovations in this respect:
New: Virtual self-consumption pools (from 2025)With virtual self-consumption pools (RCP), the use of connection lines to the distribution grid is also permitted for self-consumption. In addition, the measurement data from several meters can be virtually combined. This means that shared self-consumption can be easily implemented - especially in existing buildings - without replacing existing electricity meters and without replacing grid connections.
Self-consumption pools (RCP) are one of the instruments promoted by the Confederation's Energy Strategy 2050 with the aim of increasing the share of renewable energy produced and consumed in Switzerland.
Through an RCP, several tenants or owners of a property or adjacent buildings can join together in a single consumption community, powered by energy produced by a shared photovoltaic system and supplied through a single point connected to the local distribution company.
An RCP can be made up of contiguous vertical supply points within a building and/or horizontal ones within a neighborhood, provided that the production power of the shared system is at least 10% of the power of the community's grid connection¹ (over 30kWp).
An RCP with an electricity consumption of over 100 MWh/year (about 30 apartments) has the possibility of accessing the free electricity market,like any large Swiss consumer.
The landowner is the sole contractual partner with the distribution network operator.
¹Energy Ordinance (Energy Ordinance), Art. 15, para. 1
New: CELs (from 2026)Thanks to the revised Electricity Supply Act, participants in local electricity communities (CELs) can now use the public electricity grid at a reduced tariff to supply each other with self-generated electricity from renewable energies. Participants in a CEL must be located in the same municipality, in the same sector and network level, and must be equipped with a smart meter. They remain customers of the distribution network operator (GRD).
The advantages at a glance: – Larger systems improve their economic efficiency thanks to greater self-consumption. – More households and businesses can benefit from low-cost solar energy. – It makes it easier for the population to participate in projects.
Aspects still to be clarified: – Amount of the discount on the network use fee. According to the draft ordinance, it is 30% (or 15% if several grid levels are used). – Minimum load connected to the production plant(s): According to the draft ordinance, the minimum level of photovoltaic electricity production in relation to the connected load is 20%.
The remuneration paid by the distribution network operator (DSO) for electricity fed into the grid is called the purchase tariff (also known as "take-back tariff"). The level of this tariff currently varies greatly among the more than 600 DSOs in Switzerland (see www.pvtarif.ch).
New: minimum unit take-back tariffs From 2026, the remuneration of electricity from renewable sources will be based on the average quarterly market price at the time of feed-in. In addition, minimum tariffs are planned for systems with a capacity of up to 150 kW, to protect against very low market prices. These minimum tariffs are based on the depreciation of the reference systems over their useful life.
The advantages at a glance: – Uniform framework conditions for all photovoltaic systems in Switzerland. – Protection from strong fluctuations in the electricity market.
Aspects still to be clarified: – Can a DSO pass on the additional costs of a tariff that is higher than the average quarterly market price to its customers? – Amount of the minimum remuneration.
A grid usage fee must be paid for every kilowatt hour drawn from the electricity grid - the current median price for households is 12.71 cents/kWh. Until now, only pumped-storage plants were exempt from this fee.
What's new: Refund of grid charges for batteries From 2025, the grid charge will be refunded for the electricity that a battery feeds into the grid. For stationary storage systems, only the amount previously taken from the grid will be refunded. For mobile storage systems (electric vehicles with bidirectional charging), the entire amount of energy will be taken into account. The exemption from the grid charge is expected to apply from 2025, while the refund for batteries with own consumption will only apply from 2026.
The advantages at a glance: – The use of battery storage systems to reduce the load on electricity grids becomes much more attractive. – Bidirectional charging of electric vehicles can ideally be combined with a photovoltaic system.
Still to be clarified: – Some details of the implementation of the new rules have to be defined by the electricity industry and are not yet known. – Use of storage batteries within a CEL
To avoid bottlenecks in distribution networks, it is becoming increasingly important for distribution network operators to be able to use the flexibility of producers and storage system operators.
New: Clear rules on the use of flexibility Distribution network operators must conclude agreements with owners who are willing to grant a certain amount of flexibility. This must be compensated as soon as it represents more than 3% of the annual energy produced by the plant.
Large-scale photovoltaic systems in rural areas often cannot be connected to the electricity grid because the grid connection cables are too weak. The costs for the necessary expansion of the connection lines have so far been borne entirely by the plant operators, which can lead to prohibitive costs.
New: Remuneration for the expansion of connection lines Contributions are planned for the expansion of connection lines for generation plants with an output of more than 50 kW.
The benefits in brief: Large systems with low production costs and low self-consumption, for example on agricultural roofs or on various types of infrastructure, will benefit.
Aspects still to be clarified: The amount of the contribution. According to the consultation draft, it is 50 Swiss francs per kW of new installed generation capacity.
So far, the interest of distribution network operators in long-term solar supply contracts has been limited. This could change from next year.
New: Minimum share of electricity from domestic and renewable sources At least 20% of the electricity required for basic supply and at least 75% of the guarantees of origin in the standard electricity product of the network operators must come from domestic (domestic) and renewable sources.
The advantages in brief:The demand for solar energy is set to increase, at least among distribution network operators who do not operate large hydroelectric plants.
There are already auctions for a one-off remuneration for plants without their own consumption with a power output of 150 kW or more. What is new is that such plants can instead participate in an auction for a floating market premium.
The advantages in brief:Instead of a one-off investment contribution, there is a minimum remuneration guaranteed for 20 years for the electricity produced.
Facade photovoltaic systems are becoming increasingly popular, but still account for less than half a percentage point of new photovoltaic systems. Facade systems have the advantage of generating more than 40% of their production in the winter months.
What's new: more incentives, simpler approvals From 1 January 2025, the bonus for systems with a tilt angle of at least 75 degrees will be significantly increased. For integrated systems, it will increase from 250 to 400 francs per kW of installed power, and from 100 to 200 francs for attached or free-standing systems. This will incentivise the construction of systems on façades. The revision of the Spatial Planning Act will also come into force in mid-2025: In principle, a building permit procedure will no longer be required for façade systems. Instead, the notification procedure that has already proven its worth for rooftop photovoltaic systems will apply.
The advantages at a glance: The installation of solar systems on façades will become more economically attractive and much simpler.
Aspects still to be clarified: The consultation procedure for the revision of the Spatial Planning Ordinance is still ongoing. The exact structure of the approval procedure for façade systems is therefore not yet known.
When launching the web platform www.sonnendach.ch, the SFOE estimated the exploitable solar energy potential of Swiss buildings at around 67 terawatt hours (TWh) per year (50 TWh on roofs, 17 TWh on facades). A more detailed analysis by the ZHAW in 2022 revealed a exploitable potential of 54 TWh on roofs.
An analysis of potentials outside buildings by Meteotest (2019) on behalf of Swissolar revealed an additional potential of 10.5 TWh on car parks and motorway embankments and 16.4 TWh on pre-exposed Alpine areas outside the protection zones.
The total exploitable potential for annual solar electricity generation in Switzerland is therefore almost 100 TWh.
Large-scale PV systems such as those in Germany, which produce at less than 5 euro cents per kilowatt hour, cannot be built in Switzerland. Large-scale PV systems on buildings in Switzerland produce at 6-8 cents, those on single-family homes at around 15 cents/kWh. In addition, the off-take remuneration of the distribution network operators usually does not cover the production costs of the sold solar electricity. Therefore, additional incentives for investors are needed.
The one-off remuneration is a proven incentive for PV systems with own consumption. Since 2023, it has been supplemented by the high one-off remuneration (up to a maximum of 60% of the investment costs) for systems without own consumption, which is paid out via an auction starting from a system size of 150 kW. This finally makes the construction of systems on noise barriers, warehouses, stable roofs, car park roofs or reservoirs economically attractive. In addition, large-scale Alpine systems can be subsidised up to 60% of the investment costs.
A newly installed solar system in Switzerland currently causes 43 grams of CO2 equivalent per kilowatt hour (CO 2eq/kWh), which is three times lower than the greenhouse effect of the electricity consumption mix in Switzerland. The energy payback period of a solar system in Switzerland is around 15 months. During this time, the energy required for production is compensated by the system's own production (comparison at primary energy level). Source: Treeze 2020, Factsheet on photovoltaic electricity. With a lifespan of around 30 years, a photovoltaic system therefore produces around 20 times more energy than is needed for its production.
The 50 gigawatts (GW) of installed photovoltaic capacity that we propose correspond to around five times the current peak production of the Swiss electricity grid. Even if photovoltaic systems will never reach their maximum production at the same time, there will be surplus production that can be temporarily stored. A distinction must be made between different storage periods:
For seasonal storage, hydrogen is produced through electrolysis. This can be stored directly or after further conversion steps as methane or liquid fuel. This is called "Power to X" and gas or synthetic fuels. These can be used in winter, for example, to operate CHP plants or to power heavy vehicles such as trucks or construction machinery. The operation of reservoir hydropower plants (including the raising of dams and the construction of new reservoirs) also contributes significantly to seasonal storage. While solar energy covers a large part of the summer demand, water reserves in reservoirs can be stored.
For daily and weekly storage, the focus is on stationary battery storage (preferably as a second life for electric cars), as well as optimised self-consumption by electric cars and heat pumps. The greatest benefits are provided by the latter in the form of neighbourhood storage systems, which at the same time help to relieve the load on electricity grids. Thanks to bidirectional charging, electric car batteries will quickly gain in importance. Pumped storage plants can also be used to make use of excess production (e.g. at midday).
In the event of a lack of line capacity, the last resort is the dynamic regulation of PV production peaks at the household connection point.
PV systems only deliver their nominal power for a few hours a year. Especially in rural areas, adjusting line capacities to this production peak would have major cost consequences. Efforts must therefore be stepped up to use excess electricity in the most decentralized way possible, both for charging batteries (in electric vehicles or stationary solutions) and for the production of gas and synthetic fuels (power-to-X).
For compensation purposes, it should be possible to regulate power peaks at the grid connection point. This means that more PV can be installed on the existing grid than currently if local consumption is too low. The focus is on dynamic power regulation: in this case, the plant operator himself ensures that the agreed maximum feed-in power at the grid connection point is not exceeded by controlling the loads. Local energy communities have dynamic power control with the inclusion of entire neighborhoods. However, it is also conceivable that in areas with low grid capacity, the maximum feed-in power at the grid connection point (where there is no corresponding control or battery on the inverter) is set at 70% of the nominal power. The resulting production loss is only 1-3%, depending on the orientation of the plant, and does not have to be compensated. It is important to note that flexibility depends on the manufacturer and must be compensated. Despite all these measures, selective grid expansions will still be necessary, especially in the agricultural sector. The conditions must be created for this to happen quickly.
Stationary battery storage systems can make a significant contribution to the efficient use of existing networks, especially if they are operated in a grid-serving manner and serve not just individual buildings, but entire districts at suitable points in the network. Today, network operators have virtually no incentive to build district storage systems or gas-fired power plants, since these - unlike pumped storage - are not exempt from the grid usage tariff. However, network operators could already pay private owners of battery storage systems a fee for operating their systems in a grid-useful manner.
The electrification of passenger transport is progressing rapidly. This means that more and more mobile battery storage systems are becoming available. Today, they are mostly unidirectional, i.e. they can only use the production peaks of solar systems. Soon, however, bidirectional charging is likely to become the standard, which means that these systems1 can also make a significant contribution to securing supply (day-night balancing). However, a much larger charging infrastructure is needed than is currently available, so that this decentralized storage capacity can be used to exploit surplus solar energy production.
---
1 Swiss eMobility estimate: 2 million electric cars by 2035, which roughly corresponds to a storage capacity of 14.5 TWh, 22 GW
1. Morning band (6:00 - 10:00): In this band, energy demand increases and prices tend to rise. Variation of the “Variable transport tariff” component between 10.83 and 15.83 cts/kWh.
2. Solar band (10:00 - 17:00): This band takes into account the production of energy from solar sources and usually offers more competitive prices thanks to the abundant availability of renewable energy. Variation of the “Variable transport tariff” component between 5.83 and 10.83 cts/kWh.
3. Evening band (17:00 - 22:00): During these hours, prices may be higher due to the increase in energy demand. Variation of the “Variable transport tariff” component between 10.83 and 15.83 cts/kWh. With storage, this tariff is limited to 10.83 cts/kWh because the surplus of solar band 2 supports the peak consumption that occurs between 5:00 p.m. and 10:00 p.m.
4. Night band (10:00 p.m. - 6:00 a.m.): During these hours, prices are generally lower, as energy demand is lower. Variation of the “Variable transport tariff” component between 5.83 and 10.83 cts/kWh.
On 9 June 2024, Swiss voters clearly approved the new Electricity Act with a vote share of 68% – a clear signal for the acceleration of the expansion of renewable energies. When the legislative changes come into force, the framework conditions will improve significantly, especially for photovoltaic systems. However, one challenge is that the ordinances, i.e. the implementing provisions, have not yet been decided. The following timeframes are planned for the entry into force of the provisions (as of July 2024, subject to a decision by the Federal Council): Amendments to the Energy Act (without take-back tariffs) on 1 January 2025, adoption of ordinances in November 2024; Amendments to the Electricity Supply Act (including take-back tariffs) on 1 January 2026, adoption of ordinances in the first quarter of 2025; Amendments to the Spatial Planning Act on 1 July 2025.
The following is an overview of the current state of knowledge on the provisions that have a significant impact on photovoltaics (PV):
Wherever possible, it is advisable to consume solar energy where it is produced, also to avoid overloading the electricity grids. There are two important innovations in this respect:
New: Virtual RCPs (from 2025)With virtual self-consumption groups (RCPs), the use of connection lines to the distribution network is also permitted for self-consumption. In addition, the measurement data from several meters can be virtually combined. This means that shared self-consumption can be easily implemented - especially in existing buildings - without replacing existing electricity meters and without replacing grid connections.
Self-consumption groups (RCPs) are one of the instruments promoted by the Confederation's Energy Strategy 2050 with the aim of increasing the share of renewable energy produced and consumed in Switzerland.
Through an RCP, several tenants or owners of a property or adjacent buildings can join together in a single consumption community, which is supplied with energy produced by a shared photovoltaic system and supplied via a single point of connection to the local distribution company.
An RCP may consist of adjacent vertical supply points within a building and/or horizontal ones within a district, provided that the production power of the shared system is at least 10% of the power of the community grid connection¹ (over 30kWp). An RCP
with an electricity consumption of over 100 MWh/year (around 30 apartments) has the possibility of accessing the free electricity market, like any large Swiss consumer.
The landowner is the sole contractual partner with the distribution network operator.
1Energy Ordinance (OEn), Art. 15, para. 1
New: CELs (from 2026)Thanks to the revision of the Electricity Supply Act, participants in local electricity communities (CELs) can now use the public electricity grid at a reduced rate to supply each other with self-generated electricity from renewable energies. Participants in a CEL must be located in the same municipality, in the same sector and network level, and must be equipped with a smart meter. They remain customers of the distribution network operator (GRD).
The advantages in brief: – Larger systems improve their economic efficiency thanks to greater self-consumption. – More households and businesses can benefit from low-cost solar energy. – It makes it easier for the population to participate in projects.
Aspects still to be clarified: – Amount of the discount on the grid usage fee. According to the draft ordinance, it is 30% (or 15% if several grid levels are used). – Minimum connected load to the generation plant(s): According to the draft ordinance, the minimum level of photovoltaic electricity production in relation to the connected load is 20%.
The remuneration paid by the distribution network operator (DSO) for electricity fed into the grid is called the purchase tariff (also known as the "take-back tariff"). Currently, the level of this tariff varies greatly among the more than 600 DSOs in Switzerland (see www.pvtarif.ch).
New: minimum single take-back tariffs From 2026, the remuneration for electricity from renewable sources will be based on the average quarterly market price at the time of feed-in. In addition, minimum tariffs are planned for systems with a capacity of up to 150 kW, in order to protect against very low market prices. These minimum tariffs are based on the depreciation of the reference systems over their useful life.
The advantages at a glance: – Uniform framework conditions for all photovoltaic systems in Switzerland. – Protection against strong fluctuations in the electricity market.
Aspects still to be clarified: – Can a DSO pass on the additional costs of a tariff that is higher than the average quarterly market price to its customers? – Amount of the minimum remuneration.
A grid use fee must be paid for every kilowatt hour drawn from the electricity grid - the current median price for households is 12.71 cents/kWh. Until now, only pumped-storage systems were exempt from this fee.
New: Reimbursement of grid fees for batteries From 2025, the grid fee will be reimbursed for the electricity that a battery feeds into the grid. In the case of stationary storage systems, only the amount previously drawn from the grid will be reimbursed. For mobile storage systems (electric vehicles with bidirectional charging), the entire amount of energy is taken into account. The exemption from the grid tax is expected to apply from 2025, while the reimbursement for batteries with own consumption will only apply from 2026.
The advantages at a glance: – The use of battery storage systems to reduce the load on electricity grids becomes much more attractive. – The bidirectional charging of electric vehicles can ideally be combined with a photovoltaic system.
Aspects still to be clarified: – Some details of the implementation of the new rules have to be defined by the electricity industry and are not yet known. – Use of storage batteries inside a CEL
To avoid bottlenecks in distribution networks, it is becoming increasingly important for distribution network operators to be able to use the flexibility of producers and storage system operators.
New: Clear rules on the use of flexibility Distribution network operators must conclude agreements with owners who are willing to grant a certain amount of flexibility. This must be compensated as soon as it represents more than 3% of the annual energy produced by the plant.
Large-scale photovoltaic systems in rural areas often cannot be connected to the electricity grid because the grid connection cables are too weak. The costs for the necessary expansion of the connection lines have so far been borne entirely by the plant operators, which can lead to prohibitive costs.
New: Remuneration for the expansion of connection lines Contributions for the expansion of connection lines are planned for production plants with an output of more than 50 kW.
The advantages at a glance: Large-scale systems with low production costs and low self-consumption, for example on agricultural roofs or on various types of infrastructure, will benefit.
Still to be clarified: The amount of the contribution. According to the consultation draft, it is 50 Swiss francs per kW of newly installed generation capacity.
So far, distribution network operators have shown limited interest in long-term solar supply contracts. This could change from next year.
New: Minimum share of electricity from domestic and renewable sources At least 20% of the electricity required for the basic supply and at least 75% of the guarantees of origin in the standard electricity product of the network operators must come from domestic (domestic) and renewable sources.
The advantages in brief: Demand for solar energy is set to increase, at least among distribution network operators that do not operate large hydroelectric plants.
There are already auctions for a one-off remuneration for plants without their own consumption with a capacity of 150 kW or more. What is new is that such plants can instead participate in an auction for a floating market premium.
The advantages in brief: Instead of a one-off investment contribution, there is a minimum guaranteed remuneration for 20 years for the electricity produced.
Facade photovoltaic systems are becoming increasingly popular, but still account for less than half a percentage point of new photovoltaic systems. Facade systems have the advantage of generating more than 40% of their production in the winter months.
What's new: more incentives, simpler approvals From 1 January 2025, the bonus for systems with a tilt angle of at least 75 degrees will be significantly increased. For integrated systems, it will increase from 250 to 400 francs per kW of installed power, and from 100 to 200 francs for attached or free-standing systems. This will incentivise the construction of systems on façades. The revision of the Spatial Planning Act will also come into force in mid-2025: In principle, a building permit procedure will no longer be required for façade systems. Instead, the notification procedure that has already proven its worth for rooftop photovoltaic systems will apply.
The advantages at a glance: The installation of solar systems on façades will become more economically attractive and much simpler.
Aspects still to be clarified: The consultation procedure for the revision of the Spatial Planning Ordinance is still ongoing. The exact structure of the approval procedure for façade systems is therefore not yet known.
When launching the web platform www.sonnendach.ch, the SFOE estimated the exploitable solar energy potential of Swiss buildings at around 67 terawatt hours (TWh) per year (50 TWh on roofs, 17 TWh on facades). A more detailed analysis by the ZHAW in 2022 revealed a exploitable potential of 54 TWh on roofs.
An analysis of the potential outside buildings by Meteotest (2019) on behalf of Swissolar revealed an additional potential of 10.5 TWh on car parks and motorway embankments and 16.4 TWh on pre-exposed Alpine areas outside the protection zones.
The total exploitable potential for annual solar electricity production in Switzerland is therefore almost 100 TWh.
Large-scale photovoltaic systems like those in Germany, which produce at less than 5 euro cents per kilowatt hour, cannot be built in Switzerland. Large-scale photovoltaic systems on buildings in Switzerland produce at 6-8 cents, those on single-family homes at around 15 cents/kWh. In addition, the off-take remuneration of distribution network operators usually does not cover the production costs of the solar electricity sold. Therefore, additional incentives for investors are needed.
The one-off remuneration is a proven incentive for photovoltaic systems with own consumption. Since 2023, it has been supplemented by the high one-off remuneration (up to 60% of the investment costs) for systems without own consumption, which is paid out via an auction starting from a system size of 150 kW. This finally makes the construction of systems on noise barriers, warehouses, stable roofs, car park roofs or reservoirs economically attractive. In addition, large-scale Alpine systems can be subsidised up to 60% of the investment costs.
A newly installed solar system in Switzerland currently causes 43 grams of CO2 equivalent per kilowatt hour (CO 2eq/kWh), which is three times lower than the greenhouse effect of the electricity consumption mix in Switzerland. The energy payback period of a solar system in Switzerland is around 15 months. During this time, the energy required for production is compensated by the plant's own production (comparison at primary energy level). Source: Treeze 2020, Factsheet on photovoltaic electricity. With a lifespan of around 30 years, a photovoltaic system therefore produces around 20 times more energy than is needed for its production.
The 50 gigawatts (GW) of installed photovoltaic capacity that we propose correspond to around five times the current peak production of the Swiss electricity grid. Even if photovoltaic systems never reach their maximum production at the same time, there will be surplus production that can be temporarily stored. A distinction must be made between different storage periods:
with regard to seasonal storage, hydrogen is produced through electrolysis. This can be stored directly or after further conversion steps as methane or liquid fuel. This is called "Power to X" and gas or synthetic fuels. These can be used in winter, for example, to operate cogeneration plants or to power heavy vehicles such as trucks or construction machinery. The operation of reservoir hydropower plants (including raising dams and building new reservoirs) also contributes significantly to seasonal storage. While solar energy covers a large part of the summer demand, water reserves in reservoirs can be conserved.
With regard to daily and weekly storage, the focus is on stationary battery storage (preferably as a second life for electric cars), as well as optimized self-consumption of electric cars and heat pumps. The greatest benefits are provided by the latter in the form of neighborhood storage systems, which at the same time help to relieve the load on electricity grids. Thanks to bidirectional charging, electric car batteries will quickly gain in importance. Pumped storage plants can also be used to make use of excess production (e.g. at midday).
In the event of a lack of line capacity, the dynamic regulation of PV production peaks at the household connection point is the last resort.
PV systems only deliver their nominal power for a few hours a year. Especially in rural areas, adjusting line capacities to this production peak would have high cost consequences. Efforts must therefore be stepped up to use excess electricity as decentrally as possible, both for charging batteries (in electric vehicles or stationary solutions) and for the production of gas and synthetic fuels (power-to-X).
For compensation purposes, it should be possible to regulate power peaks at the grid connection point. This means that more PV can be installed on the existing grid than currently if local consumption is too low. The focus is on dynamic power regulation: here, the plant operator himself ensures that the agreed maximum feed-in power at the grid connection point is not exceeded by controlling the loads. Local energy communities have dynamic power control with the inclusion of entire neighborhoods. However, it is also conceivable that in areas with low grid capacity, the maximum feed-in power at the grid connection point (where there is no corresponding control or battery on the inverter) is set at 70% of the nominal power. The resulting loss of production is only 1-3%, depending on the orientation of the plant, and does not need to be compensated. It is important to note that flexibility depends on the producer and must be compensated. Despite all these measures, selective network expansions will still be necessary, especially in the agricultural sector. The conditions must be put in place for this to happen quickly.
Stationary battery storage systems can make a significant contribution to the efficient use of existing networks, especially if they are operated in a grid-service manner and serve not just individual buildings, but entire neighborhoods at suitable points in the network. Today, network operators have virtually no incentive to build neighborhood storage systems or gas-fired power plants, since these - unlike pumped storage - are not exempt from the grid usage tariff. However, network operators could already pay private owners of battery storage systems a fee for operating their systems in a grid-serviceable manner.
The electrification of passenger transport is progressing rapidly. This means that more and more mobile battery storage systems are becoming available. Today, they are mostly unidirectional, i.e. they can only use the peak output of solar systems. Soon, however, bidirectional charging is likely to become the standard, which means that these systems1 can also make a significant contribution to securing supply (day-night balancing). However, a much larger charging infrastructure is needed than currently available so that this decentralized storage capacity can be used to exploit surplus solar energy production.
---
1 Swiss eMobility estimate: 2 million electric cars by 2035, which roughly corresponds to a storage capacity of 14.5 TWh, 22 GW
1. Morning time slot (6:00 - 10:00): In this time slot, energy demand increases and prices tend to rise. Variation of the “Variable transport tariff” component between 10.83 and 15.83 cts/kWh.
2. Solar time slot (10:00 - 17:00): This time slot takes into account energy production from solar sources and usually offers more competitive prices due to the abundant availability of renewable energy. Variation of the “Variable transport tariff” component between 5.83 and 10.83 cts/kWh.
3. Evening band (17:00 - 22:00): During these hours, prices can be higher due to the increase in energy demand. Variation of the “Variable transport tariff” component between 10.83 and 15.83 cts/kWh. With storage, this tariff is limited to 10.83 cts/kWh because the excess of solar band 2 supports the peak consumption that occurs between 17:00 and 22:00.
4. Night band (22:00 - 6:00): During these hours, prices are generally lower, as energy demand is lower. Variation of the “Variable transport tariff” component between 5.83 and 10.83 cts/kWh. On June 9, 2024, Swiss voters clearly approved the new Electricity Act with a vote share of 68% – a clear signal for the acceleration of the development of renewable energies. When the legislative changes come into force, the framework conditions will improve significantly, especially for photovoltaic installations. The problem, however, is that the ordinances, i.e. the implementing provisions, have not yet been decided. The following deadlines are planned for the entry into force of the provisions (from July 2024, subject to a decision by the Federal Council): amendments to the Energy Act (without feed-in tariffs) on 1 January 2025, adoption of ordinances in November 2024; amendments to the Electricity Supply Act (as well as restart tariffs) on 1 January 2026, adoption of ordinances in the first quarter of 2025; amendments to the Spatial Planning Act on 1 July 2025.
Below is an overview of the current state of knowledge on provisions that have a significant impact on photovoltaics (PV):
When possible, it is advisable to consume solar energy where it is produced, also to avoid overloading the electricity grids. In this regard, there are two important innovations:
New: Virtual RCPs (from 2025) With virtual self-consumption groups (RCPs), the use of distribution grid connection lines is also permitted for self-consumption. In addition, the measurement data of different meters can be virtually summarized. This means that shared self-consumption can be easily implemented - especially in existing buildings - without replacing existing electricity meters and without replacing grid connections.
Self-consumption basins (RCP) are one of the tools promoted by the Confederation's Energy Strategy 2050 with the aim of increasing the share of renewable energy produced and consumed in Switzerland.
With an RCP, multiple tenants or owners of a property or adjacent buildings can come together in a single consumption community, powered by energy produced by a shared photovoltaic system and supplied via a single point connected to the local distribution company.
An RCP may consist of contiguous vertical supply points within a building and/or horizontal supply points within a district), provided that the production power of the shared installation is equal to at least 10% of the power of the “connection to the community network”¹ (above 30 kWc).
An RCP with an electricity consumption of more than 100 MWh/year (around 30 apartments) has the possibility of accessing the free electricity market, like any large Swiss consumer.
The landowner is the only contractual partner towards the distribution network manager.
1Energy Ordinance (OEn), art. 15, CPV. 1
New: CELs (from 2026)Thanks to the revision of the Electricity Supply Act, local electricity community (CEL) stakeholders can now use the public electricity grid at a reduced rate to supply each other with self-produced electricity from renewable energies. CEL participants must be located in the same municipality, in the same sector and network level, and must be equipped with a smart meter. They remain customers of the distribution network operator (DNO).
The benefits at a glance: – Larger installations improve their economic efficiency thanks to greater self-consumption. – More families and businesses can benefit from low-cost solar energy. – Public participation in projects is facilitated.
Aspects still to be clarified: – Amount of the reduction on the network usage tax. According to the draft ordinance, it amounts to 30% (or 15% in the case of use of several network layers). – Minimum load connected to the production facility(ies): according to the draft ordinance, the minimum level of photovoltaic electricity production in relation to the connected load is 20%.
The remuneration paid by the distribution network operator (DNO) for electricity fed into the network is called the purchase tariff (also called the "return tariff"). Currently, the level of this tariff varies considerably among the more than 600 DNOs in Switzerland (see www.pvtarif.ch).
New: Minimum unit feed-in tariffs From 2026, the remuneration of electricity from renewable sources will be based on the average quarterly market price at the time of injection into the grid. In addition, minimum tariffs are planned for systems with a capacity of up to 150 kW, in order to protect against very low market prices. These minimum rates are based on the depreciation of the reference systems over their useful life.
The advantages at a glance: – Uniform framework conditions for all photovoltaic systems in Switzerland. – Protection against strong fluctuations in the electricity market.
Some aspects remain to be clarified: – Can a DSO pass on to its customers the additional costs of a tariff higher than the average quarterly market price? – Amount of the minimum remuneration.
For every kilowatt hour taken off the grid, a tax must be paid for grid usage - the current median price for households is 12.71 ct/kWh. Until now, only pumped-storage turbine installations were exempt from this tariff.
New: Reimbursement of the grid fee for batteries From 2025, the grid fee will be reimbursed for electricity fed into the grid by a battery. In the case of stationary storage systems, only the quantity previously withdrawn from the grid will be reimbursed. For mobile storage systems (electric vehicles with bidirectional charging), the entire amount of energy is taken into account. It is planned that the exemption from payment of the grid fee will apply from 2025, while the reimbursement for accumulators with own consumption will only apply from 2026.
The advantages at a glance: – The use of battery storage systems to reduce the load on the power grids becomes much more attractive. – Bidirectional charging of electric vehicles can be ideally combined with a photovoltaic system.
Aspects still to be clarified: – Some details of the implementation of the new rules must be defined by the electricity sector and are not yet known. – Use of accumulators inside a CEL
To avoid bottlenecks in distribution networks, it is increasingly important that distribution network operators can use the flexibility of producers and storage system operators.
New: clear rules on the use of flexibility Distribution network operators must conclude agreements with owners willing to guarantee a certain flexibility. It must be compensated as soon as it represents more than 3% of the energy produced annually by the plant.
Large-scale photovoltaic systems in rural areas often cannot be connected to the power grid because the grid connection cables are too weak. The costs associated with the necessary extension of the connection lines have so far been borne entirely by the system operators, which can lead to prohibitive costs.
New: remuneration for the reinforcement of connection lines Contributions are planned for the reinforcement of connection lines relating to production installations with a power greater than 50 kW.
The benefits in brief: Large installations with low production costs and low self-consumption will benefit, for example on agricultural roofs or on various types of infrastructure.
Aspects still to be clarified: The amount of the contribution. According to the consultation draft, this is 50 Swiss francs per kW of new installed production capacity.
So far, the interest of distribution system operators in long-term solar energy supply contracts has been limited. This situation could change from next year.
New: Minimum percentage of electricity from indigenous and renewable sources At least 20% of the electricity needed for basic supply and at least 75% of the guarantees of origin in the standard electricity product of the network operators must come from indigenous (national) and renewable sources.
The benefits at a glance: Demand for solar power is expected to increase, at least among distribution system operators that do not operate large hydroelectric plants.
Auctions already exist today for the single remuneration for plants without own consumption with a capacity equal to or greater than 150 kW. What is new is that these plants can participate in auctions for a floating market premium.
The advantages in brief: Instead of a one-off investment contribution, a guaranteed minimum remuneration for 20 years is provided for the electricity produced.
Facade PV systems are increasingly popular, but still account for less than half a percentage point of new PV installations. Facade systems have the advantage of generating more than 40% of their production during the winter months.
New: More incentives, simpler permits From 1 January 2025, the bonus for systems with a tilt angle of at least 75 degrees will be significantly increased. For integrated systems, it will range from 250 to 400 francs per kW of installed capacity, and from 100 to 200 francs for attached or isolated systems. In this way, the construction of systems on the façade is encouraged. The revision of the Spatial Planning Act will also come into force in mid-2025: in principle, a building permit procedure will no longer be required for façade systems. Instead, the notification procedure that has already proven itself for photovoltaic systems on roofs will apply.
The advantages at a glance: The installation of solar systems on facades will become more economically attractive and much simpler.
Remaining aspects to be clarified: The consultation procedure on the revision of the spatial planning ordinance is still ongoing. The exact structure of the permit procedure for façade systems is therefore not yet known.
When launching the web platform www.sonnendach.ch, the SFOE estimated the exploitable solar potential of Swiss buildings at around 67 terawatt hours (TWh) per year (50 TWh on roofs, 17 TWh on facades). A more in-depth analysis carried out by the ZHAW in 2022 revealed an exploitable potential of 54 TWh on roofs.
An analysis of potentials outside buildings carried out by Meteotest (2019) on behalf of Swissolar revealed an additional potential of 10.5 TWh on car parks and motorway embankments and 16.4 TWh on pre-exposed alpine areas outside protection zones.
The total exploitable potential for annual solar electricity production in Switzerland therefore amounts to almost 100 TWh.
In Switzerland, it is not possible to build large photovoltaic systems like those in Germany, which produce for less than 5 euro cents per kilowatt hour. In Switzerland, large photovoltaic systems for buildings produce between 6 and 8 euro cents, those for single-family homes around 15 euro cents/kWh. In addition, the offtake remuneration of distribution network operators generally does not cover the production costs of the solar electricity sold. Additional incentives are therefore necessary for investors.
The one-off remuneration is a proven incentive for photovoltaic systems with own consumption. Since 2023, it has been supplemented by the high one-off remuneration (up to a maximum of 60% of the investment costs) for systems without own consumption, which is paid via an auction from a system size of 150 kW. This ultimately makes the creation of systems on noise barriers, warehouses, stable roofs, car park roofs or water basins economically interesting. In addition, large alpine systems can be subsidised up to 60% of the investment costs.
A newly installed solar system in Switzerland today generates 43 grams of CO2 equivalent per kilowatt hour (CO 2eq/kWh), which is three times less than the greenhouse effect of the electricity consumption mix in Switzerland. The energy payback period for a solar system in Switzerland is around 15 months. During this time, the energy required for production is offset by the plant's output (comparison to primary energy level). Source: Treeze 2020, Fact sheet on photovoltaic electricity. With a lifespan of around 30 years, a photovoltaic system therefore produces around 20 times more energy than is required for its production.
The 50 gigawatts (GW) of installed photovoltaic capacity that we are proposing corresponds to approximately five times the current peak production of the Swiss electricity grid. Even if the photovoltaic systems never reach their maximum production at the same time, there will be surplus production that can be stored temporarily. A distinction must be made between different storage durations:
In seasonal storage, hydrogen is produced by electrolysis. This can be stored directly or after further conversion steps in the form of methane or liquid fuel. This is referred to as "Power to X" and synthetic gases or fuels. These can be used in winter, for example, to operate cogeneration plants or to operate heavy vehicles such as trucks or construction equipment. The management of reservoir hydroelectric power plants (including raising dams and building new reservoirs) also makes a significant contribution to seasonal storage. Even if solar energy covers a large part of the summer demand, the water reserves in the reservoirs can be conserved.
In terms of daily and weekly storage, the focus is on stationary battery storage (preferably as a second life for electric cars), as well as on optimized self-consumption of electric cars and heat pumps. The greatest benefits are provided by the latter in the form of local storage systems, which at the same time help to reduce the load on the electricity grids. Thanks to bidirectional charging, electric car batteries will quickly become important. Pumping stations can also be used to exploit excess production (e.g. at midday).
In the event of a lack of line capacity, the last resort is dynamic regulation of photovoltaic production peaks at the connection point of the home.
Photovoltaic systems only provide their nominal power for a few hours per year. Especially in rural areas, adapting the capacities of the lines to this peak in production would have significant cost consequences. It is therefore necessary to intensify efforts to use excess electricity in the most decentralized way possible, both for recharging batteries (in electric vehicles or in stationary solutions) and for the production of gas and synthetic fuels (power-to-X).
For compensation purposes, it should be possible to regulate the peak power at the grid connection point. This means that it is possible to install more photovoltaic energy on the existing grid than is currently available if local consumption is too low. The focus is on dynamic power regulation: in this case, the grid operator itself ensures that the agreed maximum feed-in power at the grid connection point is not exceeded by controlling the loads. Local energy communities have dynamic power control with the inclusion of entire districts. However, it is also conceivable that in areas with low grid capacity, the maximum power absorbed at the grid connection point (where there is no corresponding control or battery on the inverter) is set at 70% of the nominal power. The resulting production loss is only 1 to 3%, depending on the orientation of the plant, and does not need to be compensated. It is important to note that flexibility depends on the manufacturer and must be compensated. Despite all these measures, selective network extensions will still be necessary, especially in the agricultural sector. The conditions must be prepared for this to happen quickly.
Stationary battery storage can make a significant contribution to the efficient use of existing grids, especially if they are operated in a way that serves the grid and serves not only individual buildings but also entire neighbourhoods at suitable points in the grid. Today, grid operators have virtually no incentive to build local storage or gas-fired power plants, because these, unlike pumped storage, are not exempt from the grid usage fee. However, grid operators can already pay private owners of battery storage a fee to operate their storage batteries in a way that makes them useful to the grid.
The electrification of passenger transport is progressing rapidly. This means that more and more mobile battery storage units are becoming available. Today, they are mostly monodirectional, i.e. they can only use the production peaks of solar systems. But bidirectional charging is soon to become the norm, which means that these accumulators1 will also be able to make a significant contribution to security of supply (day-night balancing). However, a much larger charging infrastructure than we currently have is needed so that this decentralized storage capacity can be used to take advantage of excess solar energy production.
---
1 Swiss eMobility estimate: 2 million electric cars by 2035, which corresponds approximately to a storage capacity of 14.5 TWh, 22 GW
1. Morning period (6:00 a.m. - 10:00 a.m.): During this period, energy demand increases and prices tend to rise. Variation of the “Variable transport tariff” component between 10.83 and 15.83 cts/kWh.
2. Solar band (10:00 - 17:00): This band takes into account energy production from solar sources and generally offers more competitive prices thanks to the abundant availability of renewable energy. Variation of the “Variable transport tariff” component between 5.83 and 10.83 cts/kWh.
3. Evening time (17:00 - 22:00): During these hours, prices may be higher due to the increase in energy demand. Variation of the "Variable transport tariff" component between 10.83 and 15.83 cts/kWh. With accumulation, this tariff is limited to 10.83 cts/kWh because the excess of solar band 2 provides support for the peak consumption that occurs from 17:00 to 22:00.
4. Night (22:00 - 06:00): During these hours, prices are generally lower, because the demand for energy is lower. Variation of the “Variable transport tariff” component between 5.83 and 10.83 cts/kWh.
On 9 June 2024, Swiss voters clearly approved the new Electricity Act with a vote share of 68% – a clear signal for the acceleration of the development of renewable energies. When the legislative amendments come into force, the framework conditions will improve considerably, particularly for photovoltaic systems. The problem, however, is that the ordinances, i.e. the implementing provisions, have not yet been decided. The following deadlines are planned for the entry into force of the provisions (from July 2024, subject to a decision by the Federal Council): Amendments to the Energy Act (without feed-in tariffs) on 1 January 2025, adoption of the ordinances in November 2024; Amendments to the Electricity Supply Act (including restart tariffs) on 1 January 2026, adoption of ordinances in the first quarter of 2025; Amendments to the Spatial Planning Act on 1 July 2025.
Below is an overview of the current state of knowledge on provisions that have a significant impact on photovoltaics (PV):
When possible, it is advisable to consume solar energy where it is produced, also to avoid overloading the electricity grids. In this regard, there are two important innovations:
New: Virtual RCPs (from 2025) With virtual self-consumption groups (RCPs), the use of distribution grid connection lines is also permitted for self-consumption. In addition, the measurement data of different meters can be virtually summarized. This means that shared self-consumption can be easily implemented - especially in existing buildings - without replacing existing electricity meters and without replacing grid connections.
Self-consumption basins (RCP) are one of the tools promoted by the Confederation's Energy Strategy 2050 with the aim of increasing the share of renewable energy produced and consumed in Switzerland.
With an RCP, multiple tenants or owners of a property or adjacent buildings can come together in a single consumption community, powered by energy produced by a shared photovoltaic system and supplied via a single point connected to the local distribution company.
An RCP may consist of contiguous vertical supply points within a building and/or horizontal supply points within a district), provided that the production power of the shared installation is equal to at least 10% of the power of the “connection to the community network”¹ (above 30 kWc).
An RCP with an electricity consumption of more than 100 MWh/year (around 30 apartments) has the possibility of accessing the free electricity market, like any large Swiss consumer.
The landowner is the only contractual partner towards the distribution network manager.
1Energy Ordinance (OEn), art. 15, CPV. 1
New: CELs (from 2026)Thanks to the revision of the Electricity Supply Act, local electricity community (CEL) stakeholders can now use the public electricity grid at a reduced rate to supply each other with self-produced electricity from renewable energies. CEL participants must be located in the same municipality, in the same sector and network level, and must be equipped with a smart meter. They remain customers of the distribution network operator (DNO).
The benefits at a glance: – Larger installations improve their economic efficiency thanks to greater self-consumption. – More families and businesses can benefit from low-cost solar energy. – Public participation in projects is facilitated.
Aspects still to be clarified: – Amount of the reduction on the network usage tax. According to the draft ordinance, it amounts to 30% (or 15% in the case of use of several network layers). – Minimum load connected to the production facility(ies): according to the draft ordinance, the minimum level of photovoltaic electricity production in relation to the connected load is 20%.
The remuneration paid by the distribution network operator (DNO) for electricity fed into the network is called the purchase tariff (also called the "return tariff"). Currently, the level of this tariff varies considerably among the more than 600 DNOs in Switzerland (see www.pvtarif.ch).
New: Minimum unit feed-in tariffs From 2026, the remuneration of electricity from renewable sources will be based on the average quarterly market price at the time of injection into the grid. In addition, minimum tariffs are planned for systems with a capacity of up to 150 kW, in order to protect against very low market prices. These minimum rates are based on the depreciation of the reference systems over their useful life.
The advantages at a glance: – Uniform framework conditions for all photovoltaic systems in Switzerland. – Protection against strong fluctuations in the electricity market.
Some aspects remain to be clarified: – Can a DSO pass on to its customers the additional costs of a tariff higher than the average quarterly market price? – Amount of the minimum remuneration.
For every kilowatt hour taken off the grid, a tax must be paid for grid usage - the current median price for households is 12.71 ct/kWh. Until now, only pumped-storage turbine installations were exempt from this tariff.
New: Reimbursement of the grid fee for batteries From 2025, the grid fee will be reimbursed for electricity fed into the grid by a battery. In the case of stationary storage systems, only the quantity previously withdrawn from the grid will be reimbursed. For mobile storage systems (electric vehicles with bidirectional charging), the entire amount of energy is taken into account. It is planned that the exemption from payment of the grid fee will apply from 2025, while the reimbursement for accumulators with own consumption will only apply from 2026.
The advantages at a glance: – The use of battery storage systems to reduce the load on the power grids becomes much more attractive. – Bidirectional charging of electric vehicles can be ideally combined with a photovoltaic system.
Aspects still to be clarified: – Some details of the implementation of the new rules must be defined by the electricity sector and are not yet known. – Use of accumulators inside a CEL
To avoid bottlenecks in distribution networks, it is increasingly important that distribution network operators can use the flexibility of producers and storage system operators.
New: clear rules on the use of flexibility Distribution network operators must conclude agreements with owners willing to guarantee a certain flexibility. It must be compensated as soon as it represents more than 3% of the energy produced annually by the plant.
Large-scale photovoltaic systems in rural areas often cannot be connected to the power grid because the grid connection cables are too weak. The costs associated with the necessary extension of the connection lines have so far been borne entirely by the system operators, which can lead to prohibitive costs.
New: remuneration for the reinforcement of connection lines Contributions are planned for the reinforcement of connection lines relating to production installations with a power greater than 50 kW.
The benefits in brief: Large installations with low production costs and low self-consumption will benefit, for example on agricultural roofs or on various types of infrastructure.
Aspects still to be clarified: The amount of the contribution. According to the consultation draft, this is 50 Swiss francs per kW of new installed production capacity.
So far, the interest of distribution system operators in long-term solar energy supply contracts has been limited. This situation could change from next year.
New: Minimum percentage of electricity from indigenous and renewable sources At least 20% of the electricity needed for basic supply and at least 75% of the guarantees of origin in the standard electricity product of the network operators must come from indigenous (national) and renewable sources.
The benefits at a glance: Demand for solar power is expected to increase, at least among distribution system operators that do not operate large hydroelectric plants.
Auctions already exist today for the single remuneration for plants without own consumption with a capacity equal to or greater than 150 kW. What is new is that these plants can participate in auctions for a floating market premium.
The advantages in brief: Instead of a one-off investment contribution, a guaranteed minimum remuneration for 20 years is provided for the electricity produced.
Facade PV systems are increasingly popular, but still account for less than half a percentage point of new PV installations. Facade systems have the advantage of generating more than 40% of their production during the winter months.
New: More incentives, simpler permits From 1 January 2025, the bonus for systems with a tilt angle of at least 75 degrees will be significantly increased. For integrated systems, it will range from 250 to 400 francs per kW of installed capacity, and from 100 to 200 francs for attached or isolated systems. In this way, the construction of systems on the façade is encouraged. The revision of the Spatial Planning Act will also come into force in mid-2025: in principle, a building permit procedure will no longer be required for façade systems. Instead, the notification procedure that has already proven itself for photovoltaic systems on roofs will apply.
The advantages at a glance: The installation of solar systems on facades will become more economically attractive and much simpler.
Remaining aspects to be clarified: The consultation procedure on the revision of the spatial planning ordinance is still ongoing. The exact structure of the permit procedure for façade systems is therefore not yet known.
When launching the web platform www.sonnendach.ch, the SFOE estimated the exploitable solar potential of Swiss buildings at around 67 terawatt hours (TWh) per year (50 TWh on roofs, 17 TWh on facades). A more in-depth analysis carried out by the ZHAW in 2022 revealed an exploitable potential of 54 TWh on roofs.
An analysis of potentials outside buildings carried out by Meteotest (2019) on behalf of Swissolar revealed an additional potential of 10.5 TWh on car parks and motorway embankments and 16.4 TWh on pre-exposed alpine areas outside protection zones.
The total exploitable potential for annual solar electricity production in Switzerland therefore amounts to almost 100 TWh.
In Switzerland, it is not possible to build large photovoltaic systems like those in Germany, which produce for less than 5 euro cents per kilowatt hour. In Switzerland, large photovoltaic systems for buildings produce between 6 and 8 euro cents, those for single-family homes around 15 euro cents/kWh. In addition, the offtake remuneration of distribution network operators generally does not cover the production costs of the solar electricity sold. Additional incentives are therefore necessary for investors.
The one-off remuneration is a proven incentive for photovoltaic systems with own consumption. Since 2023, it has been supplemented by the high one-off remuneration (up to a maximum of 60% of the investment costs) for systems without own consumption, which is paid via an auction from a system size of 150 kW. This ultimately makes the creation of systems on noise barriers, warehouses, stable roofs, car park roofs or water basins economically interesting. In addition, large alpine systems can be subsidised up to 60% of the investment costs.
A newly installed solar system in Switzerland today generates 43 grams of CO2 equivalent per kilowatt hour (CO 2eq/kWh), which is three times less than the greenhouse effect of the electricity consumption mix in Switzerland. The energy payback period for a solar system in Switzerland is around 15 months. During this time, the energy required for production is offset by the plant's output (comparison to primary energy level). Source: Treeze 2020, Fact sheet on photovoltaic electricity. With a lifespan of around 30 years, a photovoltaic system therefore produces around 20 times more energy than is required for its production.
The 50 gigawatts (GW) of installed photovoltaic capacity that we are proposing corresponds to approximately five times the current peak production of the Swiss electricity grid. Even if the photovoltaic systems never reach their maximum production at the same time, there will be surplus production that can be stored temporarily. A distinction must be made between different storage durations:
In seasonal storage, hydrogen is produced by electrolysis. This can be stored directly or after further conversion steps in the form of methane or liquid fuel. This is referred to as "Power to X" and synthetic gases or fuels. These can be used in winter, for example, to operate cogeneration plants or to operate heavy vehicles such as trucks or construction equipment. The management of reservoir hydroelectric power plants (including raising dams and building new reservoirs) also makes a significant contribution to seasonal storage. Even if solar energy covers a large part of the summer demand, the water reserves in the reservoirs can be conserved.
In terms of daily and weekly storage, the focus is on stationary battery storage (preferably as a second life for electric cars), as well as on optimized self-consumption of electric cars and heat pumps. The greatest benefits are provided by the latter in the form of local storage systems, which at the same time help to reduce the load on the electricity grids. Thanks to bidirectional charging, electric car batteries will quickly become important. Pumping stations can also be used to exploit excess production (e.g. at midday).
In the event of a lack of line capacity, the last resort is dynamic regulation of photovoltaic production peaks at the connection point of the home.
Photovoltaic systems only provide their nominal power for a few hours per year. Especially in rural areas, adapting the capacities of the lines to this peak in production would have significant cost consequences. It is therefore necessary to intensify efforts to use excess electricity in the most decentralized way possible, both for recharging batteries (in electric vehicles or in stationary solutions) and for the production of gas and synthetic fuels (power-to-X).
For compensation purposes, it should be possible to regulate the peak power at the grid connection point. This means that it is possible to install more photovoltaic energy on the existing grid than is currently available if local consumption is too low. The focus is on dynamic power regulation: in this case, the grid operator itself ensures that the agreed maximum feed-in power at the grid connection point is not exceeded by controlling the loads. Local energy communities have dynamic power control with the inclusion of entire districts. However, it is also conceivable that in areas with low grid capacity, the maximum power absorbed at the grid connection point (where there is no corresponding control or battery on the inverter) is set at 70% of the nominal power. The resulting production loss is only 1 to 3%, depending on the orientation of the plant, and does not need to be compensated. It is important to note that flexibility depends on the manufacturer and must be compensated. Despite all these measures, selective network extensions will still be necessary, especially in the agricultural sector. The conditions must be prepared for this to happen quickly.
Stationary battery storage can make a significant contribution to the efficient use of existing grids, especially if they are operated in a way that serves the grid and serves not only individual buildings but also entire neighbourhoods at suitable points in the grid. Today, grid operators have virtually no incentive to build local storage or gas-fired power plants, because these, unlike pumped storage, are not exempt from the grid usage fee. However, grid operators can already pay private owners of battery storage a fee to operate their storage batteries in a way that makes them useful to the grid.
The electrification of passenger transport is progressing rapidly. This means that more and more mobile battery storage units are becoming available. Today, they are mostly monodirectional, i.e. they can only use the production peaks of solar systems. But bidirectional charging is soon to become the norm, which means that these accumulators1 will also be able to make a significant contribution to security of supply (day-night balancing). However, a much larger charging infrastructure than we currently have is needed so that this decentralized storage capacity can be used to take advantage of excess solar energy production.
---
1 Swiss eMobility estimate: 2 million electric cars by 2035, which corresponds approximately to a storage capacity of 14.5 TWh, 22 GW
1. Morning period (6:00 a.m. - 10:00 a.m.): During this period, energy demand increases and prices tend to rise. Variation of the “Variable transport tariff” component between 10.83 and 15.83 cts/kWh.
2. Solar band (10:00 - 17:00): This band takes into account energy production from solar sources and generally offers more competitive prices thanks to the abundant availability of renewable energy. Variation of the “Variable transport tariff” component between 5.83 and 10.83 cts/kWh.
3. Evening time (17:00 - 22:00): During these hours, prices may be higher due to the increase in energy demand. Variation of the "Variable transport tariff" component between 10.83 and 15.83 cts/kWh. With accumulation, this tariff is limited to 10.83 cts/kWh because the excess of solar band 2 provides support for the peak consumption that occurs from 17:00 to 22:00.
4. Night (22:00 - 06:00): During these hours, prices are generally lower, because the demand for energy is lower. Variation of the “Variable transport tariff” component between 5.83 and 10.83 cts/kWh.
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