Since 1 January 2026 the Winterstrombonus supports PV systems from 100 kWp that produce more than 500 kWh per kW during the winter half-year (1 October to 31 March). Per kW it pays CHF 2.50 with or CHF 3.50 without self-consumption for each kWh/kW above this threshold, once, after three winters. It supersedes the altitude bonus and is an alternative to the tilt angle bonus: on facades in the Swiss Plateau the tilt angle bonus usually pays more, at alpine and snowy sites the Winterstrombonus.
Key Takeaways
5 min read
Key Takeaways
5 min read- Winterstrombonus active since 1 January 2026The new federal programme applies to PV systems commissioned from 1 January 2026. Existing systems are not covered retroactively.
- System size from 100 kWp requiredThe bonus is available exclusively to commercial and industrial systems from 100 kWp, the typical scale for industrial, commercial and logistics buildings.
- Vertical PV as the technical answerFacade-integrated and vertical bifacial modules capture the low winter sun optimally and use snow albedo for up to +25% additional yield.
- Federal and cantonal funding combineThe federal government pays one bonus, the tilt angle bonus or the Winterstrombonus, not both. Cantonal facade programmes (e.g. GR: CHF 300/kWp) come on top.
Flat-roof PV produces over 70% of its annual energy in the summer months. That is not a technical problem but a structural challenge for the grid: demand peaks and supply shortfalls occur in winter, not in summer. The Winterstrombonus, in force since 1 January 2026, addresses exactly this point. It creates a financial incentive for systems that produce electricity when the grid actually needs it.
What is the Winterstrombonus?
The Winterstrombonus is a new element of the Einmalvergütung (EIV). The Federal Council introduced it with the amendment to the Energy Promotion Ordinance of 26 November 2025 (AS 2025 830); it supersedes the altitude bonus in force since 2023. It targets PV systems whose design delivers an above-average share of their annual production in the winter half-year.
Key facts of the programme:
- Valid for commissioning from 1 January 2026
- Systems from 100 kWp
- Production threshold: more than 500 kWh per kW of installed capacity during the winter half-year (1 October to 31 March)
- Target group: alpine sites, facade systems facing south-west or south-east, steeply tilted systems
- Subsidy amount: per kW CHF 2.50 (with self-consumption) or CHF 3.50 (without self-consumption), multiplied by the average winter yield above 500 kWh/kW in the first three full winter half-years (EnFV, Annex 2.1 No. 2.7.3)
- Payout: once, after the third full winter half-year, provided a detailed statement of construction costs was submitted after the first full year of operation (Art. 45 para. 5 and Art. 46a EnFV)
- Not cumulative: a system that receives the Winterstrombonus has no claim to the tilt angle bonus (Art. 38 para. 1quater EnFV)
Worked example for 100 kW. If a system with self-consumption delivers 550 kWh/kW in the winter half-year, the bonus is CHF 12’500, or CHF 17’500 without self-consumption. At 600 kWh/kW it is CHF 25’000 and CHF 35’000 respectively, at 700 kWh/kW CHF 50’000 and CHF 70’000. The tilt angle bonus would pay the same system CHF 40’000 for integrated and CHF 20’000 for attached mounting. With self-consumption the Winterstrombonus therefore only pays more from around 660 kWh/kW (integrated) or 580 kWh/kW (attached), without self-consumption from around 614 and 557 kWh/kW.
The threshold of 500 kWh/kW in the winter half-year corresponds to a share that conventional flat-roof systems as a rule do not reach. This is where vertical PV comes in.
Vertical PV as the technical answer
Why do vertical and steeply tilted facade systems reach the winter production threshold while flat-roof PV falls short? The answer lies in the geometry of the sun’s path and in the bifaciality of modern modules.
Optimal angle of incidence in winter. In December and January the sun in Switzerland sits low on the horizon, typically 15 to 25 degrees above it. For a vertical or steeply tilted surface this light strikes the module almost perpendicularly. A flat-roof system (10-15 degrees) receives the same light at an unfavourable grazing angle.
Snow albedo with bifacial modules. Bifacial modules generate electricity on both sides. In winter, snow on the ground, the road or the roof surface below reflects sunlight onto the rear of the modules. Depending on site and snow cover, this albedo effect delivers up to +25% additional yield compared with single-sided modules, a figure well documented by Fraunhofer ISE studies on bifacial gains as a function of ground albedo.
Combined subsidy logic. From the federal government, a vertically integrated PV system (BIPV) receives either the tilt angle bonus for integrated systems (CHF 400/kW) or, with sufficient winter production, the Winterstrombonus, not both. The Winterstrombonus is only set after three full winter half-years; the operator then receives the higher of the two bonuses. On facades in the Swiss Plateau with self-consumption that is usually the tilt angle bonus, at alpine and snowy sites more often the Winterstrombonus. We calculate both variants, and applying for the Winterstrombonus carries no risk: if the system misses the threshold or the operator waives the bonus within one month of the decision, the tilt angle bonus applies instead (Art. 38 para. 1quinquies EnFV). Two cantonal programmes reinforce this framework particularly strongly:
- Canton of Graubünden: CHF 300/kWp for vertical and facade-integrated systems, one of the most generous cantonal schemes in Switzerland.
- Canton of Lucerne: CHF 100/m² for systems with a tilt of 75 degrees or more.
Real project in Landquart GR: A 23 kWp bifacial system on a 50 m long partition wall delivered 11’332 kWh of annual production and received total subsidies of CHF 10’730. The project shows that even smaller facade areas can secure significant subsidy contributions when site, orientation and subsidy logic fit together.
For the system solution, design variants and technical details, see our solution page on vertical PV.
Checking eligibility, step by step
Clarifying Winterstrombonus eligibility
Check the system size (>= 100 kWp)
The Winterstrombonus is available exclusively to systems from 100 kWp. Smaller systems are not eligible but can be supported through KLEIV and cantonal programmes.
Calculate the winter production potential
Site, orientation (south-west or south-east is optimal), tilt angle and any albedo surfaces below determine whether the threshold of 500 kWh/kW in the winter half-year is achievable. This calculation belongs in a preliminary study.
Calculate both bonus variants
With the technical parameters of the planned system, you weigh the tilt angle bonus against the Winterstrombonus; the Pronovo tariff calculator supplies the base payment. You apply for the Winterstrombonus in the application for the one-off remuneration, together with a yield simulation.
Start planning with winter optimisation built in
Changes to capacity or category must be reported to Pronovo. The Winterstrombonus requires a yield simulation in the application and cannot be claimed afterwards. That is why winter optimisation belongs in the first design.
For a complete overview of all federal subsidy programmes (GREIV, KLEIV, HEIV and the bonus structure), see our Subsidy Guide 2026. It covers every programme and explains the full application process.