BayWa r.e., a global renewable energy company, and Ampt, a DC optimizer company for large-scale photovoltaic (PV) systems, have deployed a combination of wind and solar generation together with battery storage within the microgrid at the Fraunhofer Institute for Chemical Technology (ICT) campus in Pfinztal, Germany.
The main campus of the Fraunhofer Institute ICT has over 100 laboratories with several pilot plants and three test centers on a 21-hectare site.
BayWa r.e. installed three rooftop arrays and one ground-mounted system to expand renewable energy utilization onsite. The PV systems, with a total capacity of 690 kWp, are connected to the power grid without their own inverters through an existing 2 MW wind turbine and a 10 MWh flow battery energy storage system.
Ampt’s string optimizers were utilized to integrate each of the different technologies through a shared DC bus called a DC-coupled architecture. Through this, the generation variability across the PV systems is managed, and the different systems are united at a high and fixed voltage to increase system efficiency.
“Combining both rooftop and ground-mounted solar in seven different orientations and two module sizes in one common microgrid with wind power and batteries is a significant challenge,” said Levent Gun, Ampt CEO. “This project is a testament to the capabilities of our industry-leading power conversion technology to simplify control of the diverse systems spread across a site.”
Ampt string optimizers are DC/DC converters performing maximum power point tracking (MPPT) and recovering energy losses due to voltage and technology differences.
They mitigate the energy losses caused by shade from surrounding buildings on the Fraunhofer ICT campus through individual string MPPT. The optimizers are programmable and provide string-level data to improve the visibility of the system functions as well as operation and maintenance capabilities.
“It was important for us to add solar to the microgrid that powers our campus, to bring additional flexibility and ensure higher utilization of our system,” said Dr. Frank Henning, Institute Director of Fraunhofer ICT. “Sustainability plays a crucial role for Fraunhofer ICT, and by combining the advantages of wind, solar and storage, we are ensured to meet our sustainability goals and operate in a responsible manner.”
