The solar obligation (Art. 45a of the Energy Act) requires a photovoltaic or solar thermal system on new buildings with more than 300 m² of chargeable building area. It has applied since 1 October 2022 to building applications from 2023. From 1 January 2026, grid operators must purchase fed-in solar electricity at the quarterly reference market price, 3.9-10.3 Rp./kWh for solar electricity in 2026; plants below 150 kW receive a minimum remuneration. Economically, self-consumption remains superior: self-produced electricity costs 8-12 Rp./kWh, grid electricity 20-30 Rp./kWh.
Key Takeaways
7 min read
Key Takeaways
7 min read- Since 1 October 2022, for building applications from 2023: new buildings with more than 300 m² of chargeable building area need a photovoltaic or solar thermal system on the roof or facade.
- The grid operators' purchase obligation applies from 1 January 2026. Remuneration is the reference market price, 3.9-10.3 Rp./kWh per quarter for solar electricity in 2026, with a minimum below 150 kW.
- Self-consumption pays off far better: self-produced electricity costs 8-12 Rp./kWh, grid electricity 20-30 Rp./kWh.
Swiss commercial businesses face a twofold change, regulatory and economic. The solar obligation for new buildings over 300 m² has applied since 1 October 2022. The Mantelerlass package, which voters approved on 9 June 2024 with 68.7% in favour, gave it a new wording from 1 January 2025 and brings the grid operators’ purchase obligation from 1 January 2026, combined with a legally guaranteed minimum tariff for fed-in electricity. This article explains what both mean for your business in concrete terms and which economic strategy follows from them.
What does the solar obligation say for commercial buildings?
Art. 45a of the Energy Act (EnG) has applied since 1 October 2022 and covers building applications from 1 January 2023. It applies to commercial and residential buildings alike, but not in the same way in every canton.
Parliament adopted the obligation in autumn 2022 as an urgent measure for winter electricity supply; since 1 January 2025 it has stood in the law in the wording of the Mantelerlass. Cantons that had introduced their own requirements for electricity generation in new buildings under the cantonal model provisions (MuKEn 2014, Part E) by 1 January 2023 are exempt from the federal rule and apply their own provisions.
The solar obligation affects you if your business or a property development meets the following criteria:
- New build: the obligation applies to new buildings, not to existing ones. Renovations and conversions are not directly affected but may qualify for cantonal subsidies.
- Chargeable building area above 300 m²: what counts is the chargeable building area of the new building, not the roof area. The cantons can extend the obligation to smaller buildings and set the exemptions, for example where a system is technically impossible or economically disproportionate.
- Flexibility in technology: the law permits PV or solar thermal, that is, thermal solar systems for heat. In industrial practice photovoltaics is the more economical choice, because it produces electricity and has broader uses.
For commercial businesses that build, or plan extensive new-build projects, the solar obligation is a compliance requirement to be taken into account in project planning from the start. Not an option, but a precondition for the building permit.
The economic logic behind the feed-in rule
The solar obligation stipulates that a system must be installed. It does not stipulate how the electricity produced is used. That is where the economic decision begins: maximise self-consumption or feed into the grid?
The answer follows from a simple price comparison.
Every kilowatt-hour you consume yourself saves the difference between the grid price and your own production cost: typically 10-20 Rp./kWh. Every kilowatt-hour you feed in earns you only 3.9-10.3 Rp./kWh in 2026. That is a considerable difference.
Purchase obligation from 2026: grid operators must take your electricity
New from 1 January 2026: all Swiss grid operators are legally obliged to purchase your solar electricity. They pay the quarterly averaged BFE reference market price, for solar electricity 10.3 Rp./kWh in the first and 3.9 Rp./kWh in the second quarter of 2026. Plants below 150 kW receive a minimum remuneration that depends on system size (Art. 12 para. 1bis EnV):
- Systems below 30 kW: 6 Rp./kWh; depending on its tariff, the grid operator pays for guarantees of origin on top
- Systems of 30 kW to just under 150 kW with self-consumption: 6 Rp./kWh only on the first 30 kW, 0 Rp./kWh above, around 1.2 Rp./kWh averaged at just under 150 kW
- Systems of 30 kW to under 150 kW without self-consumption: 6.2 Rp./kWh
- From 150 kW: no minimum remuneration, the reference market price applies
The purchase obligation creates planning certainty: your fed-in electricity always finds a buyer. But it does not make self-consumption any less attractive. On the contrary: the guaranteed minimum tariffs are well below what you can save through self-consumption.
The economic consequence: whoever builds a system under the solar obligation should manage the business’s load profile so that as much electricity as possible is consumed directly. Manufacturing businesses with a day shift often manage this without additional measures at a 60-70% self-consumption ratio. Battery storage and self-consumption communities (ZEV) can raise the ratio to 70-90%.
More on self-consumption optimisation with ZEV and storage on our photovoltaics solution page.
Deadlines and compliance roadmap
The relevant dates at a glance:
Regulatory roadmap 2022-2026
1 October 2022: solar obligation comes into force
Art. 45a EnG applies as an urgent measure for winter supply. New buildings with more than 300 m² of chargeable building area need a PV or solar thermal system, covering building applications from 1 January 2023.
9 June 2024: referendum on the Mantelerlass
68.7% of Swiss voters approve the Electricity Act (Mantelerlass). It lays the basis for the new feed-in rules and takes over the solar obligation in a new wording.
1 January 2025: Electricity Act comes into force
Art. 45a EnG applies in the wording of the Mantelerlass. At the same time, the tilt angle bonus for system parts tilted at 75 degrees or more is introduced: +CHF 400/kW integrated or +CHF 200/kW attached.
1 January 2026: purchase obligation and new energy communities
Grid operators must purchase solar electricity at the reference market price, with a minimum remuneration for plants below 150 kW. Local electricity communities (LEG) become possible. The Winterstrombonus for large systems (100+ kWp) comes into force.
Next step: request a feasibility study
The solar obligation creates a situation in which you have to act anyway. The real question is: how do you size the system so that it meets the regulatory requirements and is economically optimal at the same time?
Ampere Dynamic accompanies commercial businesses from the first potential analysis to turnkey commissioning. Since its founding in 2020 the team has delivered 201 large-scale systems with a total capacity of 53.7 MWp (as of 2026-10), all of them with complete subsidy handling via Pronovo.
The first step is a feasibility study: roof area analysis, load profile evaluation, economic calculation and subsidy application. Result in 4 to 6 weeks.