It is a project that farmer Johann Deix planned carefully. He started producing raspberries and blackberries in 2018. However, the berries don't like it hot or wet. At the same time, he learned from a study by Wageningen University in the Netherlands that the fruit can tolerate up to 40 per cent shade without complaint.
The Dutch scientists also found that the fruit grows more slowly when there is more shade. This is an advantage for the farmer. He can extend his harvest by allowing some of the berries to grow in the sun and others in the shade.
Harvest season extended
These arguments persuaded Johann Deix to cover part of his plantation with semi-transparent solar modules with 35 per cent shading. The other parts have remained under the previous foil tunnels. This allows him to extend the harvest season and enjoy other benefits of the agri-PV system.
See also: Mobile agri-PV system protects young vines
The solar modules protect the berries from heavy rain, hail and overheating. The system also requires less work than the foil tunnels, which have to be replaced regularly. ‘It also gets really hot in the 1,800 metres of foil tunnel in summer,’ explains Johann Deix. This is not good for the raspberries, nor for the farmer and his employees.
Solar power for self-consumption
The solar system also supplies a lot of electricity, which the farmer can consume directly on site. This is because the farmer needs around 120,000 kilowatt hours of electricity every year to cool the harvested berries. The new solar system with its 499 kilowatts of power will supply around four and a half times as much electricity.
Dual use of land: Download our Special Edition on agri-PV
The farmer shares the rest of the electricity with his neighbours. Matthias Zawichowski, manager of the climate and energy model region (KEM) Elsbeere Wienerwald, supported Johann Deix with the project development and is organising a local renewable energy community around the plant.
New financing idea
The farmer also took an unusual approach to financing. He gave anyone who wanted to the opportunity to participate. The citizen participation runs via so-called ‘solar building blocks’. This means that for a one-off payment of 360 euros, supporters receive a total of 36 bottles of raspberry Prosecco and six kilograms of raspberries over three years. ‘As well as a clear conscience,’ emphasises Matthias Zawichowski. The system is also subsidised via a market premium in accordance with the Austrian Renewable Energy Expansion Act.
Also interesting: Let the show begin! Sonnenkraft installs PV on listed theatre in Austria
Solar openings at Energy Decentral
You will also find solutions like this at this year's Energy Decentral. Photovoltaics will take centre stage at the trade fair dedicated to the decentralised supply of renewable energy to farms. As part of the solar offensive spotlight, farmers and suppliers of solar systems and storage units will come into direct contact with each other. Find out more about the solar offensive here. (su/mfo)
