Swiss Family's Solar Tractor Wins National Award

A Swiss family turned a simple observation into an award-winning invention that's changing how small farms operate across Europe.

The Knüsel family of Schwyz, Switzerland noticed something clever. Farmers had solar panels on their barns, but their tractors just sat underneath them, unused. What if the tractor itself could soak up that sunshine?

Sepp Knüsel had been building tractors for over 20 years when his four daughters joined him in 2019 to develop the continent's first all-electric tractor with solar assistance. Daughter Theres Beutler-Knüsel, now the company's managing director, started working on the prototype while still at the University of Dresden in 2018.

The journey wasn't smooth. "Many of the necessary individual parts were not yet on the market," Beutler-Knüsel explained. The family worked directly with suppliers to develop custom components from scratch.

Six years later, their patience paid off. In 2025, the Swiss Federal Office of Energy awarded the Knüsel family the prestigious Watt d'Or, or Golden Watt, recognizing innovations in future energy technologies.

The Rigitrac SKE 40 packs four electric motors generating 84 kilowatts of power. One motor drives the front wheels, another the rear, and a third handles starting. While it's not built for heavy plowing, it excels at vegetable farming and snow removal.

The Ripple Effect

Today, all six family members work for Rigitrac AG. Sepp's wife Marlis and daughters Edith, Doris, and Ruth handle advertising, HR, sales, and supply chain. The tractor now sells in Austria, Norway, Denmark, Germany, and Switzerland.

The invention even caught the attention of game developers. The SKE 40 now appears in Farming Simulator, introducing the concept of electric farming to millions of players worldwide.

The Golden Watt award brought something more valuable than prize money: recognition that electric farming equipment has moved from concept to reality. "It shows us that we are on the right path," Beutler-Knüsel said.

One family's observation about unused solar power is now helping farms across Europe reduce emissions while they work.