German science institution, Karlsruhe Institute of Technology (KIT), has joined hands with partners from science and industry to reduce the losses that shade, dirt and aging cause to the yield of large photovoltaic ground-mounted systems. Coordinated by KIT, this 3-year project is called Solarpark 2.0 and began in July 2022. The Federal Ministry of Economics and Climate Protection (BMWK) has granted € 2.5 million to this project.
To increase the yield and service life of systems and to reduce the operating costs, Solarpark 2.0 will use of innovative circuits, AI-supported optimization, and new types of power electronics. Researchers are also developing electronic components and methods for large open-space systems.
Using space efficiently
Speaking on this, Researcher at the Electrotechnical Institute (ETI) of KIT and initiator of Solarpark 2.0, Nina Munzke said, "Large solar parks are an important instrument to achieve climate neutrality. However, finding new and ever larger areas for such systems is a problem, especially in heavily populated regions of the world. In order for us to still achieve our climate goals, we have to use the available space much more efficiently."
Maximum Power Point & High Efficiency Low Effort MPPT
To use a photovoltaic module with maximum efficiency, photovoltaic modules must work close to its individual Maximum Power Point (MPP).
Dwelling more on this, Lukas Stefanski from the ETI said, "The output power of the module results from the product of current and voltage. This performance is highest with the MPP, so that the greatest possible yield is achieved. Hence, it is more advantageous to regulate individual modules and, depending on the specific wiring of the system, to optimize the voltage on the strings."
To achieve this, KIT is using the patented-HiLEM (High Efficiency Low Effort MPPT) circuit in Solarpark 2.0. The traditional combiner box used to connect strings in parallel is now replaced by this circuit, enabling an efficient MPPT at the string level. The HiLEM circuit with innovative power optimizers then enables simultaneous MPPT both at string and module level. This leads to photovoltaic system giving out higher yields, reduced operating costs and extended its service life.
Test facility at KIT Campus North
Evaluation of the new optimization components will be done through 2 PV test systems, each with 30 kW. While one system will map different test scenarios for the new performance optimizers, the second will serve as a reference without them. Both systems will operate side by side on an open space within the existing solar field of the Energy Lab 2.0 at KIT.
KIT is also active in solar module research – least year its scientists had made perovskite solar mini-modules almost without any loss of scaling, reaching 18% efficiency (see Scaled up with Almost No Losses)