German engineering firm BEC Energie Consult has developed a substructure for low-mounted agrivoltaic systems, designed to provide a cost-efficient installation while supporting crop growth and livestock management, with the potential to increase economic viability.
A recent study by Germany’s Thünen Institute has raised questions about the economic viability and wider societal benefits of agrivoltaic systems, particularly those built with elevated mounting structures. High upfront costs combined with relatively low land use efficiency often make it difficult to operate such systems profitably without subsidies.
“While this criticism is justified in many respects, an important segment of agricultural voltaics has so far received little attention in both study and public discourse: systems mounted relatively low above crops or agricultural land, allowing agricultural activities beneath the panels,” says Peter-Ludwig Gutberlet, project manager at German engineering firm BEC Energie Consult GmbH. pv magazine. “These systems differ fundamentally in design, cost structure and integration into agricultural operations, and may provide a path to economically viable agricultural voltaic systems without financial support.”
BEC Energie Consult has developed a mounting structure for agrivoltaic installations at ground level with heights varying from 1.1 to 1.5 meters. The PV modules are supported by Magnelis-coated reinforcing steel bars with a diameter of 16 mm. “Instead of conventional row layouts, the modules are arranged in flexible block units,” says Gutberlet. “This design significantly reduces material consumption while enabling high installed capacity per hectare. At the same time, it creates favorable conditions for plant growth under the system.”
The company cites structure costs ranging from €0.03 ($0.035)/W to €0.04/W, with an installed capacity of 1.3–1.6 MW per hectare. “For a 5 MW project, this translates into substructure costs of approximately €200,000, compared to €600,000 for a 2.1 meter high system and €900,000 for a 4 meter design,” Gutberlet explains. “Land use efficiency further strengthens the business case: assuming a lease rate of €3,000 per hectare per year over twenty years, the land cost per megawatt is approximately €40,000 for the BECU system, compared to €60,000 and €75,000 for the higher-mounted alternatives.”
An important feature of the system is the distance between the modules: 15 centimeters horizontally and 10 centimeters vertically. These gaps ensure that each module has its own drip edge, so that sloping rainfall is evenly distributed under the installation. Diffuse light also penetrates, improving conditions for the underlying vegetation. Minimal soil coverage and the stable microclimate created by the low installation height further support plant growth, the company said.
“The benefits are particularly evident in livestock applications, especially free-range poultry farming,” says Gutberlet, noting that chickens in conventional systems tend to remain close to the house due to predation risk, leading to uneven land use, loss of vegetation and increased disease pressure. “The low-mounted agrivoltaic structure provides protection from birds of prey and at the same time creates shaded areas with improved microclimatic conditions. Animals make greater use of the available space, vegetation can recover and the overall management of the farm improves. The dense arrangement of reinforcing bars further limits the access of predators, enhancing the protective effect.”
Economically, the system can benefit farmers in several ways. “Additional revenue streams from land leasing or participation models, reduced livestock losses and potentially improved product quality,” said Gutberlet. “As animals gain access to a more varied diet, including grasses, herbs and insects, early field experience suggests that product quality can improve. The flexible design of the system also allows adaptation to operational requirements, for example by leaving paths open for mobile poultry houses.”
A recent project illustrates the proposed approach. The installation was designed according to German agricultural voltaic regulations, has a capacity of 3.5 MW and covers 2.5 hectares of PV modules, of which 1.35 hectares are directly in the shade. The total plan area covers 4.33 hectares and is intended for housing agricultural activities. The costs of the substructure amounted to a total of € 140,000. According to the developer, the project could be competitive under the current tender conditions without additional subsidies.
“While elevated systems often receive justified criticism, low-mounted concepts such as the BECU substructure show that economically viable solutions may already exist,” Gutberlet concluded. “They combine cost-efficient electricity generation with continued agricultural use, while delivering benefits for animal welfare and land management. The key question is therefore not whether agrivoltaics makes sense, but which system design can best meet both economic and agricultural needs.”
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