APV-RESOLA Agrophotovoltaics resource-efficient land use

APV Research Plant

Location of the APV research plant

A biodynamic (Demeter) farm in Heggelbach in the region Lake Constance-Upper Swabia (Bodensee-Oberschwaben) was selected to be the site of the research facility. In the district of Lake Constance, which is one of three districts in the region, the share of renewable energies is below average. The district is facing the challenge to increase the share of renewable energies from 10 % (as in 2013) to 26 % in 2022. With 15 %, PV is supposed to be the main renewable energy source in the region. Rooftop installations alone are not sufficient to realize the objective of 15 %, the available agricultural land and conversion sites are limited. Innovative approaches like APV are necessary and their success can be accelerated by including citizens at an early project stage. The potential capacity for wind power is limited: Currently, only one percent of the local demand for electricity can be covered by wind power. This is due to a low acceptance of wind power plants in the local society and their attempt to protect the characteristic landscape and the panoramic view of the Alps. The share of wind power in the region can only be increased to 6 % by 2022. Also, energy production from biomass use is limited by a low acceptance of the local society. The share of bioenergy on renewable energy production in the Lake Constance-Upper Swabia region is expected to be around to 2 % in 2022.

The research site has a total size of 2.4 hectares. The APV-plant covers only one third of a hectare and the rest of the field serves as reference area to compare biomass yield. The APV-plant has an installed capacity of 194 kWp.

Technical Details

First prototype

In March 2016 a prototype was installed. The practical knowledge of this installation is used for the final construction and design of the APV research plant.

Prototyp Agropv-Anlage
Prototyp Agropv-Anlage

Source: Fraunhofer ISE

APV mounting system

Within the research project Fraunhofer ISE and Hilber Solar, an experienced solar engineering company, developed a mounting system which on one hand is adjusted specifically to the local conditions (wind load, slope, direction of processing with agricultural engines) and on the other hand can be adapted flexibly to other sites with minimal effort because of its modular construction. Watch the construction of the research plant here.


Photovoltaic-system

For solar power generation, we installed bifacial solar cells of a German provider. Row distances and orientation of PV-modules are optimized with respect to plant growth and electrical yields.


Monitoring and lightning protection concept

In addition to electric performance parameters of the APV, the light conditions beneath the APV-plant are being monitored. Therefore, several photosensors are being installed on the level of the PV-modules as well as on ground level. The photosensors will collect data during the whole research period. A lightning protection concept is common for larger PV-plants and will be developed for the APV-plant.