UK research shows batteries could boost solar PV efficiency

Using lithium batteries as energy storage alongside solar PV could make solar cheaper and more efficient, according to a joint research project carried out by the University of Southampton and UK lithium battery firm REAPSystems. Researchers found that a lithium battery has an energy efficiency of 95 per cent, compared to the 85 per cent efficiency of a traditional lead-acid battery, currently the most common energy storage used for solar PV.

The research team connected a lithium iron phosphate (LiFePO4) battery to a photovoltaic system attached to one of the university’s buildings, using a specifically designed battery management system.

Yue Wu, the MSc student leading the research, said: “As an energy storage device, lithium batteries, especially the LiFePO4 batteries we used, have more favourable characteristics [than lead-acid batteries]. The weight of the lithium batteries is lower and they have a longer life span than the lead-acid batteries, reaching up to 1,600 charge/discharge cycles, meaning they would need to be replaced less frequently.”

The team now plans to test the battery further, before it is applied to a commercial PV system to assess how it can improve efficiency and reduce costs and upkeep.