Even on bustling rail networks, the space between tracks often sits idle, facing the sky. Why not put that unused area to work? Swiss startup Sun-Ways is doing just that by installing solar panels between railway tracks, turning overlooked gaps into sources of renewable energy.
While many households and businesses have embraced rooftop solar panels, and solar farms are increasingly common, there’s still vast untapped potential for solar energy generation.
Sun-Ways aims to harness this potential by utilizing the estimated 1 terawatt-hour (TWh) of annual energy that could be generated from Switzerland’s 5,000 kilometers of railroad tracks.
The company believes this could meet nearly one-third of the electricity needs of the country’s public transport sector while reducing annual CO2 emissions by over 200,000 tons.
How It Works
Sun-Ways’ solar panels are designed to fit between railway tracks. Each panel measures 1 x 1.7 meters (3.3 x 5.5 feet) and features an anti-reflective filter to prevent glare. These panels are mounted in multi-array frames, with all components and wiring housed within. The system is currently designed for standard track gauges of 1.43 meters (4.6 feet), but it can be adapted for non-standard installations.
The panels can be installed and connected manually by engineers, but Sun-Ways has partnered with railway maintenance company Scheuchzer SA, which has developed a specialized machine capable of installing up to 1,000 square meters of solar panels per day.
The system is designed to be removable, allowing railway engineers to temporarily lift the panels for track maintenance and reinstall them afterward.
The setup has been rigorously tested to ensure stability, withstanding trains passing overhead at speeds of up to 150 km/h (93 mph) and wind speeds of 240 km/h (150 mph). While snowfall in winter months could reduce efficiency, Sun-Ways suggests that cylindrical brushes attached to trains could clear snow and dirt, similar to existing systems used for track maintenance.
Energy Applications
The electricity generated by these solar panels could power nearby railway infrastructure, such as switches, points, or even stations. Alternatively, the energy could be fed into the local grid or directly into the traction energy network that powers locomotives, eliminating the need for ground-based inverters.
Overcoming Challenges
Sun-Ways faced initial hurdles when its application to the Federal Office of Transport (FOT) was rejected last year. Undeterred, the company collaborated with academics from HEIG-VD (Haute Ecole d’Ingénierie et de Gestion du Canton de Vaud) to conduct independent assessments of custom-built panel prototypes. These findings, along with technical and safety documentation from Geste Engineering, were resubmitted for approval.
After 10 months of deliberation, the FOT granted approval for a pilot project set to launch in 2025. The pilot will cover a 100-meter (330-foot) stretch of the TransN line 221 near Buttes railway station in the Swiss canton of Neuchâtel.
The installation will include 48 panels with a total capacity of 18 kWp, connected to the local grid by electricity distributor Viteus and railway infrastructure company DG Rail. Trains on this pilot route will operate at 70 km/h, and the project will include tests for installation, removal, and performance monitoring to ensure no damage to railway infrastructure.
Expanding Horizons
In addition to the Swiss pilot, Sun-Ways is conducting a feasibility study for a 1,500-meter (4,921-foot) section of private track in the municipality of Aigle, with an installed capacity of 288 kWp. The company is also in early discussions for pilot projects in France (with SNCF), Spain, Romania, and South Korea. Exploratory talks with operators in China, Thailand, Australia, and the United States are also underway.
A Bright Future for Solar Rail
Sun-Ways’ innovative approach to solar energy generation demonstrates how underutilized spaces can be transformed into powerful sources of renewable energy. By integrating solar panels into railway infrastructure, the company is paving the way for a more sustainable future, reducing carbon emissions, and enhancing energy efficiency in public transport systems. As pilot projects roll out across the globe, this groundbreaking technology could revolutionize how we think about renewable energy and transportation.
