Agri-PV

Sonntag Energy Puts Solar Trackers Over Strawberries at Lake Constance

co-produced by AI21. Oktober 2026, 10:39

Four men with spades in front of a Sonntag Energy banner at the groundbreaking — Groundbreaking for the tracker agri-PV system above strawberries in Überlingen. © Sonntag Energy

Electricity on top, strawberries below: The Lindau-based start-up Sonntag Energy is building an agri-PV system with moving solar panels over a strawberry field at Lake Constance, according to the company the first of its kind in Europe. Ground was broken on Hubert Büchele’s farm in Überlingen, Germany. The first phase includes a solar installation with one megawatt peak (MWp) of capacity and a battery storage system with five megawatt-hours (MWh) of capacity.

Shade for the Berries, Power for the Farm

The panels serve a dual purpose. They generate electricity and give the strawberries below them shade, while also protecting the plants from the weather and excessive sunlight. With summers at Lake Constance getting hotter, that is becoming increasingly important for berry growers. “We want to keep growing our strawberries successfully even under changing climatic conditions,” said Mr. Büchele, the farmer. Generating electricity also gives the farm an additional source of income, he said.

Unlike fixed systems, the so-called trackers turn with the position of the sun, which increases electricity output. The battery can take in both solar power from the system and electricity from the grid and sell it later. That makes the project’s economics less dependent on electricity prices during sunny hours, which often plunge on sunny days. “We plan these three building blocks together from the start,” said Mark Kugel, a co-founder of Sonntag Energy.

Paid Off in Under Ten Years

The investment is in the low single-digit millions of euros, Sonntag Energy told Trending Topics. The system is expected to pay for itself in well under ten years, driven mainly by electricity generation. The strawberry business continues in parallel and, according to the company, benefits slightly from the protection the panels provide.

Much of the technology comes from the region: The mounting structure is supplied by Zimmermann from Oberessendorf, the medium-voltage components also come from German partners, and the battery storage system comes from a partner in the Allgäu region. The solar panels and battery cells, however, come from China. The system is being installed by Maschinenring Tettnang, a regional farmers’ cooperative. Leander Hengge, its managing director, stressed that the farmer will own the system himself, so the value stays on the farm.

Expansion is already planned. A permit has been granted for 2.4 megawatts on 2.5 hectares, more than double the first phase.

Ownership Instead of Leasing

That is Sonntag Energy’s business model. Instead of leasing land from farmers, as many solar park operators do, the start-up builds turnkey systems close to the farm that farmers own and operate themselves. Typical systems combine one to two megawatts peak of solar capacity with one to two megawatts of storage capacity, sharing a transformer station and grid connection. In addition to trackers for grassland and arable land, Sonntag also offers semitransparent protective roofs for specialty crops.

Aerial view of agri-PV systems above fruit orchards with Lake Constance in the background — Agri-PV systems above orchards at Lake Constance. © Sonntag Energy

Just in September, Sonntag Energy took over the agri-PV business of the insolvent GridParity AG (in German), an early German pioneer in the dual use of farmland. GridParity failed in part because a bonus for agri-PV systems adopted in Germany’s solar package did not receive state aid approval from the E.U., after which banks withdrew financing. That shows how heavily the business depends on the political framework.

Berries Under Solar Panels

Combining berries and solar power is not entirely new. The Munich-based energy company BayWa r.e. built a 2.7 MWp agri-PV park over raspberries (in German) in the Netherlands back in 2020 and also tested strawberries, blueberries and currants there, though with fixed, semitransparent panels. According to monitoring, the climate under the panels was more stable than under conventional plastic tunnels. Sonntag Energy, by contrast, is betting on moving panels, which are meant to generate more electricity.