Since 1 January 2025 the solar obligation requires a photovoltaic or solar thermal system on new buildings with more than 300 m² of usable roof or facade area (Art. 45a of the Energy Act). From 1 January 2026, grid operators must purchase fed-in solar electricity at minimum tariffs of around 6-9 Rp./kWh. 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 January 2025: new buildings with more than 300 m² of usable roof or facade area must install a photovoltaic or solar thermal system.
- The grid operators' purchase obligation applies from 1 January 2026. Minimum tariff for feed-in: around 6-9 Rp./kWh, depending on system size.
- 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 Mantelerlass package, which voters approved on 9 June 2024 with 68.7% in favour, brought two major changes. First, the nationwide solar obligation for new buildings from 300 m², in force since 1 January 2025. Second, 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?
The Mantelerlass (in force from 1 January 2025) introduced Art. 45a of the Energy Act (EnG). The rule applies nationwide to commercial and residential buildings alike.
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.
- Usable area above 300 m²: what counts is the usable roof or facade area. Heavily shaded or structurally unsuitable areas can be deducted.
- 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 6-9 Rp./kWh. 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. The minimum tariff they must pay depends on system size:
- Systems up to 30 kW with self-consumption: around 9 Rp./kWh (including guarantees of origin)
- Systems of 30-150 kW with self-consumption (first 30 kW tranche): 6 Rp./kWh
- Reference value: quarterly averaged market price (BFE definition)
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 2024-2026
9 June 2024: referendum on the Mantelerlass
68.7% of Swiss voters approve the Electricity Act (Mantelerlass). The basis for the solar obligation and the new feed-in rules is in place.
1 January 2025: solar obligation comes into force
Art. 45a EnG applies. All new buildings with more than 300 m² of usable roof or facade area need a PV or solar thermal system. At the same time: the KLEIV bonuses (integration bonus CHF 400/kW, mounting bonus CHF 200/kW) are introduced.
1 January 2026: purchase obligation and new energy communities
Grid operators must purchase solar electricity at minimum tariffs. 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 196 large-scale systems with a total capacity of 53.3 MWp (as of 2026-09), 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 2-4 weeks.