The lightweight structure protects the young vines and can be quickly moved to another location.
With an easy-to-install solar system, the developers at SPV Sonneburg aim to protect grapevines during their growth phase. The first test installation shows promising results.
A research project involving the engineering firm SPV Sonneburg, Geisenheim University, and the Fraunhofer Institute for Solar Energy Systems (ISE) is currently testing a mobile photovoltaic system specifically for viticulture. The goal is to better protect young vines in their first years from heat and drought stress—while simultaneously generating renewable energy. “We wanted to develop a flexible system that can be quickly assembled and dismantled and, after a few years, easily moved to another plot,” explains project manager Paul Weinbauer.
Lightweight modules span the vines
The solution is a structure that utilizes existing trellis posts. These are supported with steel cables to stabilize the entire construction. In Geisenheim, this is achieved using special anchors driven approximately 3.5 meters into the ground. Flexible photovoltaic modules from Mirai Solar are then stretched on steel cables between the posts.
The module manufacturer specializes in such solar shading solutions, where low weight is essential. To achieve this, the company laminates solar cells between special polymer sheets. As a result, the modules weigh only 2.5 kilograms per square meter.
The transparency is adjusted through the spacing of the individual solar cells. In Geisenheim, about 30% shading reduces stress on the plants, while 70% of the light remains available for growth. Depending on the degree of transparency, the modules deliver between 100 and 175 watts per square meter. The installation on the test field in Geisenheim provides about 40 kilowatts of power.
More information on photovoltaics in agriculture
- Further expert knowledge on the topic of agri-PV and solar technology in agriculture can be found in Photovoltaik magazine.
- Keep track of developments in photovoltaics for farmers with the joint special newsletter from DLG and photovoltaik.
- The feature series “Solar technology for farmers” combines additional articles under the theme “Paths to double harvests,” showing how dual use of agricultural land—for generating solar energy as well as field crops and specialty crops—can be successfully implemented.
Modules can be moved to storage in bad weather
The system is complemented by a battery storage unit that powers control systems, a weather station, and other devices. “This allows us not only to use the energy to operate the system but also, for example, to charge an electric car,” explains Paul Weinbauer.
In strong winds—when there is usually no sunshine anyway—the solar modules can be retracted into a storage unit mounted on an extension of the trellis posts. This provides additional stabilization for the slender structure.
Initial test results are promising
In addition to climate protection and electricity generation, Weinbauer highlights the targeted support for young plants as a key advantage for winegrowers: “The first few years determine whether a vineyard will be successful in the long term. Our system can significantly ease this start.”
The project is still in the testing phase, and minor technical challenges are being addressed. However, initial results give the developers reason for optimism. “We are seeing a clear improvement in soil moisture and a reduction in temperatures. That’s exactly what young vines need in times of climate change.”
Thanks to its simple design, the entire system can be quickly dismantled and reassembled elsewhere. Once the vines are mature enough to no longer require protection from the modules, the installation is simply relocated to another site, where new vines can then be planted and protected under the solar modules.
Text: Sven Ullrich, photovoltaik magazine
