The rhythmic clatter of train wheels on steel rails has been the soundtrack of rail travel for two centuries. Now, a Swiss startup is adding a new element to that familiar sound: the silent, invisible hum of solar energy generation. Sun-Ways, a spin-off from the Swiss Federal Institute of Technology in Lausanne (EPFL), has successfully installed and operated photovoltaic panels between active railway tracks in Neuchâtel, western Switzerland, throughout the first half of 2026 — proving that the space between rails can become a viable power plant without consuming a single square meter of additional land.
How the solar carpet withstands 150 km/h train traffic
The core innovation of the Sun-Ways system lies in its mechanical design. Rather than mounting rigid solar panels on fixed structures, the company developed a flexible 'solar carpet' that conforms to the railway bed. Each panel is encased in a shock-absorbing frame that distributes the mechanical stress caused by passing trains. The system has been tested under trains traveling at speeds of up to 150 kilometers per hour, with sensors recording vibration, air pressure fluctuations, and structural integrity in real time. Data from the 2026 pilot phase, reviewed by the Swiss Federal Office of Transport (FOT), confirmed zero incidents of panel displacement, cracking, or electrical failure during six months of continuous operation.
Robotic installation solves the maintenance puzzle
One of the earliest objections to the concept was practical: how do you maintain railway tracks if they are covered with solar panels? Sun-Ways answered this question by partnering with Scheuchzer, a Swiss railway maintenance equipment manufacturer, to build a custom train wagon equipped with robotic arms. This machine can lay up to 1,000 square meters of panels per day, rolling them out like a carpet between the rails. When track maintenance is required, the same machine reverses the process, lifting the panels in minutes to give crews full access to the rails and ballast. In 2026, the company began testing a second-generation robotic wagon that doubles installation speed and includes an integrated cleaning system to remove brake dust and debris — a key factor in maintaining panel efficiency over time.
Europe's 260,000-kilometer rail grid as the next solar frontier
Sun-Ways is not thinking small. In mid-2026, the company signed a pilot agreement with SNCF, France's national railway operator, to test the system on a segment of the Paris-Lyon high-speed line. France alone has approximately 15,000 kilometers of non-electrified railway tracks, representing a massive potential installation area. Across the European Union, the total railway network spans roughly 260,000 kilometers, of which about 40 percent remains non-electrified. 'We are not just generating electricity — we are turning existing infrastructure into power plants,' said Baptiste Danichert, CEO of Sun-Ways, in a June 2026 interview. The company has also received expressions of interest from rail operators in Spain, Italy, Germany, and Romania, positioning the technology as a scalable solution for Europe's ambitious decarbonization targets.
Switzerland's unique energy landscape drives innovation
Switzerland's topography — dominated by the Alps, deep valleys, and limited flat terrain — makes large-scale solar farms difficult to deploy. The country's 2050 net-zero strategy therefore places a premium on creative, space-efficient renewable energy solutions. According to the Swiss Federal Office of Energy's 2026 assessment, covering the nation's entire 5,300-kilometer railway network with Sun-Ways panels could yield approximately 1 terawatt-hour of electricity annually, equivalent to the consumption of 300,000 households or roughly 2 percent of Switzerland's total electricity demand. While this may seem modest, it represents generation that requires no new land, no visual impact on landscapes, and no competition with agriculture — a trifecta that is rare in the renewable energy sector.
Economic viability and grid integration in a volatile energy market
The economics of railway solar are becoming increasingly compelling against the backdrop of 2026's volatile global energy prices. Sun-Ways estimates that the levelized cost of electricity (LCOE) from its system is competitive with rooftop solar in Central Europe, falling between €0.04 and €0.06 per kilowatt-hour depending on solar irradiation levels. Crucially, the electricity can be fed directly into the railway's own power supply — powering trains, station lighting, and signaling systems — or injected into the local grid. This dual-use capability provides rail operators with a hedge against electricity price fluctuations. The European Union's revised Renewable Energy Directive, which took effect in early 2026, includes specific provisions for 'infrastructure-integrated renewables,' unlocking subsidy mechanisms that could accelerate deployment across the continent.
Addressing the skeptics: dirt, safety, and reliability
When Sun-Ways first proposed the idea in 2023, it faced considerable skepticism. Critics pointed to three main concerns: panel soiling from train brake dust and lubricants, safety risks for passengers and maintenance crews, and the sheer mechanical punishment of daily rail traffic. The company has systematically addressed each issue. A proprietary nano-coating repels dirt and reduces adhesion of metal particles, while the robotic wagon's integrated brush system performs periodic cleaning runs. Safety testing conducted in collaboration with the Swiss Federal Railways (SBB) demonstrated that the panels can support the weight of a person without shattering, thanks to a specialized anti-slip lamination layer. The FOT's comprehensive safety report, published in March 2026, certified the system for operational use on active lines, removing the final regulatory barrier to commercial deployment.
Beyond Europe: global applications and the limits of railway solar
While the European rail network offers an obvious first market, the technology has potential applications worldwide. Countries with extensive rail infrastructure and high solar irradiation — India, Australia, parts of the United States, and China — could theoretically generate significant electricity from their rail corridors. However, the system is not universally applicable. Tracks with tight curves, frequent switches, or heavy freight traffic that requires regular ballast maintenance may pose challenges. Additionally, the economic case weakens in regions with low electricity prices or limited grid connectivity. Sun-Ways acknowledges these limitations and is focusing its near-term efforts on Western and Central Europe, where regulatory support, high electricity costs, and dense rail networks create an ideal launch environment. Pilot discussions are also underway with Japan's JR East, where land scarcity makes space-efficient solar solutions particularly attractive.
The broader lesson for infrastructure innovation
The Sun-Ways story illustrates a broader shift in how societies think about renewable energy deployment. Rather than treating energy generation as a separate land use — requiring dedicated solar farms or wind parks — the approach integrates generation into existing infrastructure corridors. Highways, canals, airport perimeters, and now railways are all being reimagined as potential energy assets. This paradigm shift is particularly relevant for densely populated regions where land-use conflicts often stall renewable energy projects. As of 2026, Sun-Ways has raised CHF 12 million in Series A funding and plans to expand its team from 15 to 40 employees by year-end, signaling that investors see railway solar as more than a niche experiment. The company's trajectory suggests that the humble space between two steel rails may yet play a meaningful role in the clean energy transition.
