Efficient power coupling in directly connected PV-battery module
Coupling of photovoltaic (PV) devices with energy storage such as batteries is essential to stabilize PV electricity supply. In this work usability of simple direct PV-battery coupling is investigated under realistically varied irradiance, temperature, battery state of charge (SoC), and applied load. A stable power coupling factor above 90% is demonstrated between a silicon heterojunction (SHJ) solar module and Li-ion battery in the wide range of SoC and load power. In the region of highest power generation, the directly coupled PV-battery module provides coupling efficiencies above 95%, reaching 100%, in realistic conditions. We demonstrate that direct PV-to-battery coupling is feasible for a variety of practical applications and scales.
The leading global solar PV trade magazine “PV Magazine” published an article "Replacing MPPT with direct PV-battery coupling" reviewing our research paper on "Efficient power coupling in directly connected PV-battery module" saying that ‘The researchers at IEK-5 Photovoltaics have assessed direct coupling and integration between PV and batteries at the scale of a single PV module. The directly coupled PV-battery solution could be cheaper and provide superior performance than maximum power point tracking (MPPT) in optimizing PV system performance’.