Alpine Solar Systems: Expansion Progresses, Overall Balance Lacking
Several major projects are now online or under construction. However, a current Switzerland-wide overview of realized systems and their actual power production is still unavailable.
Why Alpine Solar Energy is Interesting in Winter
Photovoltaic systems at higher altitudes can generate more electricity per installed capacity in winter than comparable systems in the lowlands. Reasons include thinner atmosphere, less fog, and sunlight reflection by snow. The Federal Office of Energy (BFE) points out that actual yield heavily depends on location and orientation.
This difference is relevant for Switzerland's electricity supply. Electricity demand is particularly high in winter, while production from many photovoltaic systems in the Swiss Plateau decreases significantly due to shorter days, lower sun angles, and frequent cloud cover.
Alpine systems therefore do not simply aim for maximum annual production. Their particular value lies in generating an above-average share of their energy when electricity is most in demand in Switzerland.
The Federal Government Introduces Additional Incentive from 2026
Since January 1, 2026, a new winter electricity bonus applies to large photovoltaic systems. A prerequisite is that a system produces more than 500 kilowatt-hours per kilowatt of installed capacity during the winter half-year.
The bonus replaces the previous altitude bonus. This means that an installation's altitude is no longer the sole consideration. Instead, the decisive factor is whether increased winter electricity production is actually achieved. The funding mechanism is thus intended to more specifically favour systems that contribute to winter electricity supply.
The regulation applies to systems commissioned from January 1, 2026. Other legal requirements also apply to large photovoltaic systems, particularly regarding location, permits, and winter production.
Madrisa Shows Projects Are Indeed Coming Online
A key reference point is Madrisa Solar above Klosters in Prättigau. The facility, located at about 2000 meters above sea level, began feeding electricity into the grid at the end of September 2025. It was the first alpine open-field system under the Solarexpress to produce power.
At full expansion, Madrisa Solar is expected to generate approximately 17 gigawatt-hours per year. More than 40 percent of this is anticipated during the winter half-year. The fully expanded system will feature around 3200 solar tables with a total of about 20,000 bifacial modules.
The first winter also provided a practical test. According to operators, Madrisa Solar produced more electricity than forecast during its first winter. At that time, approximately 3600 solar modules were in operation. Further expansion will be gradual, with full commissioning planned by the end of 2027.
Madrisa is therefore more than a model on paper. At the same time, the experiences from this single installation cannot be directly extrapolated to all alpine projects. Altitude, orientation, snow conditions, shading, and local weather conditions all influence the yield.
Other Systems Are Also Already Supplying Electricity
Madrisa is not the only alpine solar project that has started operation. At Sedrun Solar and the Sidenplangg facility, alpine solar power was also first fed into the grid at the end of 2025.
However, at the start of both projects, only about 13 percent of the planned capacity was operational. Therefore, the systems are not yet operating at their full future total production.
This highlights a fundamental problem with current accounting: “in operation” for a major project does not automatically mean that the planned capacity is already fully available. Many systems are built and connected in stages.
39 Alpine Projects in Current VSE Overview
The Association of Swiss Electricity Companies (VSE) provides a current overview of the project landscape. Its overview from June 26, 2026, lists 39 planned alpine open-field photovoltaic systems across Switzerland.
The VSE records a total of 153 larger expansion projects for renewable energies. If all listed major projects are realized, they could collectively achieve an annual production of approximately 5.2 terawatt-hours. The potential additional winter electricity is stated as at least 4.3 terawatt-hours.
However, these figures should not be equated with today's production. They represent the potential of the recorded projects, not electricity that is already actually flowing into the Swiss grid.
This distinction is crucial, especially for alpine photovoltaic systems: several years can pass between a project idea, a building permit, a system under construction, partial commissioning, and full operation.
Universities of Applied Sciences Saw Significant Potential in 2024
Four universities of applied sciences provided an earlier interim status. Bern University of Applied Sciences, Eastern Switzerland University of Applied Sciences, SUPSI, and ZHAW launched the platform alpine-pv.ch in July 2024. The survey then recorded planned, rejected, and already realized alpine photovoltaic projects.
The surveyed projects collectively amounted to a potential annual production volume of approximately 939 gigawatt-hours. Of this, 563 gigawatt-hours were attributed to projects in active planning. For withdrawn or rejected projects, 373 gigawatt-hours were reported.
Compared to Switzerland's expansion target of 18.7 terawatt-hours of photovoltaic power per year, the potential at that time corresponded to about five percent. Alpine photovoltaics are therefore not a quantitative replacement for total solar expansion. Their significance lies rather in the additional winter production.
Albigna Provides Important Reference Values
Even before the Solarexpress brought forth a larger number of new projects, the photovoltaic system on the Albigna dam wall in Graubünden's Bergell region provided important experience. The system has been operational since September 2020.
Accompanying research determined a specific yield of 1269 kilowatt-hours per kilowatt of installed capacity for the first three years of operation. The average share of the winter half-year in total production was 47.8 percent.
These values show the production profile possible at a suitable alpine location. However, they are not automatically transferable to other projects. A system at a different location can achieve significantly different results due to orientation, altitude, shading, or local weather conditions.
What is Known in 2026 – and What is Not
The data situation has improved since 2024. The Federal Office of Energy (BFE) now provides a dataset on reported large photovoltaic systems. This includes information on planned and realized systems.
Project overviews from the VSE and information from individual operators also provide a current view of the expansion. From this, it is clear: Alpine photovoltaics are no longer just a planning project in 2026. First systems are already producing electricity, and more are under construction.
What is still missing is an easily understandable, Switzerland-wide consolidated balance that simultaneously shows for all alpine systems which projects are fully or partially operational and how much electricity they actually produce.
Precisely this distinction is crucial for political assessment. A list of planned projects shows the possible potential. A list of approved projects shows legal progress. A list of commissioned systems shows expansion. However, only the actually measured production shows the contribution alpine solar energy already makes to Switzerland's electricity supply.
The Expansion Is Real – Its Contribution Remains Limited
The available data suggests neither a failure nor a completed expansion. Alpine solar systems are indeed being built and are now supplying electricity. At the same time, a large portion of the potential is still in various stages of planning or realization.
Quantitatively, alpine photovoltaics should not be overestimated. The 39 projects recorded by the VSE are part of a much larger Swiss expansion of renewable energies. They can make an additional contribution to winter electricity but will not secure Switzerland's electricity supply alone.
The crucial factor is therefore less the number of announced projects than the question of how many of them are actually built, when they are fully connected to the grid, and how much electricity they produce in winter.
The Decisive Balance Will Come Only with Production
Alpine solar expansion has taken a significant step in 2026: the first major systems are online, more are being built, and the federal government has more strongly aligned funding with actual winter electricity.
However, a final balance cannot yet be drawn. The potential is now clearly visible, but the actually realized capacity and the effective electricity production of all projects are less so.
For the assessment of the Solarexpress, the number of announced projects will ultimately not be decisive. What will be decisive is how many systems are actually fully built and how much additional electricity they supply in winter.
Alpine solar energy has thus become a real component of Switzerland's energy transition – but not yet a measurably large part of its electricity supply.
Sources
- Federal Office of Energy (BFE): Information and dataset on large photovoltaic systems.
- Association of Swiss Electricity Companies (VSE): Overview of expansion projects, as of June 26, 2026.
- EKZ / Madrisa Solar: Information on partial commissioning, production, and further expansion.
- Energie Wasser Bern (ewb): Project status Sedrun Solar and Sidenplangg.
- Bern University of Applied Sciences, Eastern Switzerland University of Applied Sciences, SUPSI, and ZHAW: Survey on alpine photovoltaic systems, July 2024.
- BFE: Explanatory report on the revision of the Energy Promotion Ordinance and the winter electricity bonus.
