But first, RWE’s demonstration project at the edge of the Garzweiler opencast mine in the Rhenish mining area in west Germany has been cultivating grain and raspberries alongside the production of green electricity from around 6,100 solar modules since early 2024. Three different agrivoltaic solutions are being tested under different seasonal weather conditions on the approximately seven-hectare recultivation site. ‘The aim is to develop suitable management methods and economic operating concepts for agrivoltaic systems on the basis of the knowledge gained over the next few years,’ says the company.

The first variant uses a vertical design with the solar modules installed rigidly on the substructure, similar to a fence. In the second variant, known as a tracker system, the modules are mounted on a movable axis, enabling them to follow the course of the sun from east to west. Agricultural crops are being grown between the rows of solar modules under both methods, including spring barley and spring and winter wheat.

The company reports that initial measurements for both systems – tracker and vertical – show soil humidity to be homogeneous, including below the PV modules, since they allow rainwater to pass through, and the shadow cast by the modules reduces evaporation. ‘This has a positive effect on plant growth. The first year of the trial showed that the crop yield for both agrivoltaics systems was comparable to that of the reference area, and was even of somewhat better quality, especially in terms of protein content,’ it says.

In the third method under test, the PV modules are elevated on a pergola-like substructure, which is suitable for fruit growing and viticulture (growing grapes) in particular. Below the solar modules in Bedburg, raspberries are being grown in pots. Initial results show that cultivation in pots and below the modules ‘enables healthy plant growth with high-quality yields and also allows for better planning of harvesting times’, says RWE. It also notes that the solar modules protect the raspberry plants against storms and extreme direct sunlight. Another advantage is that farmers can use the solar plant substructure simultaneously as a cultivation frame for the plants and to attach a watering system.

‘The need for large areas of land to further expand solar electricity generation makes the symbiosis of agriculture and photovoltaics a particularly valuable proposition,’ comments Katja Wünschel, CEO RWE Renewables Europe & Australia. ‘It is encouraging to see that we are achieving a good-quality harvest and high yields comparable to those from conventionally managed locations. I am already looking forward to what else we will learn in the coming years.’

Vattenfall commissions Germany’s largest agrivoltaics park

Meanwhile, Vattenfall has commissioned Germany’s largest agrivoltaics project to date, in Tützpatz, in the north-east of the country.

The 93-hectare site will have a nominal capacity of 76 MWp. All the electricity produced is to be supplied to Power and Air Condition Solution Management (PASM), a subsidiary of Deutsche Telekom, under a 10-year power purchase agreement (PPA).

‘The power supply agreement with the Tützpatz solar park combines ecological responsibility with clear economic rationality. It is a sustainable model that ensures cost stability for energy, increases space efficiency and makes a significant contribution to achieving climate neutrality within the Deutsche Telekom AG Group,’ comments Bernd Schulte-Sprenger, Managing Director, PASM.

The Tützpatz agrivoltaics park consists of three sub-areas, which will house both livestock and arable farming.  

In the first sub-area, solar modules are mounted on conventional rack systems with various inclination angles. A total of six mobile chicken coops are to be installed, each with up to 2,500 birds.

The second and third sub-areas feature tracker systems and will be used for arable farming with various crop rotations. A larger spacing between the tilted module rows will allow agricultural machinery to access the fields.