By Kari Williamson
The research project, which looks into the use of lithium batteries as energy storage for solar photovoltaics (PV), was sponsored by REAPsystems and was led by MSc Sustainable Energy Technologies student, Yue Wu and his supervisors Dr Carlos Ponce de Leon, Professor Tom Markvart and Dr John Low.
Wu says: “Lead acid batteries are traditionally the energy storage device used for most photovoltaic systems. However, as an energy storage device, lithium batteries, especially the LiFePO4 batteries we used, have more favourable characteristics.”
Data was collected by connecting a lithium iron phosphate battery to a solar PV system attached to one of the University’s buildings, using a specifically designed battery management system supplied by REAPsystems.
Wu adds: “The research showed that the lithium battery has an energy efficiency of 95% whereas the lead-acid batteries commonly used today only have around 80%. The weight of the lithium batteries is lower and they have a longer life span than the lead-acid batteries reaching up to 1600 charge/discharge cycles, meaning they would need to be replaced less frequently.”
Although the battery will require further testing before being put into commercial solar PV systems the research has shown that the LiFePO4 battery has the potential to improve the efficiency of solar power systems and help to reduce the costs of both their installation and upkeep.
Dr Carlos Ponce de Leon and Dr. John Low now plan to take this project further with a new cohort of Masters students.