Battery Energy Storage: Functions and Technologies

Why Storage Exists

Solar generation does not necessarily occur when electricity demand is highest. Battery storage allows generated energy to be stored and used later: shifting energy across time, smoothing solar variability and improving resilience.

What Battery Systems Provide

Energy shifting, backup power, peak shaving, load shifting, frequency support, voltage support, solar smoothing, renewable-energy integration, grid services and black-start support in certain configurations.

Chemistries

Common technologies include lithium-ion, lithium iron phosphate (LFP), NMC, lead-acid and flow batteries. For modern stationary solar applications, LFP batteries are particularly important because of their safety characteristics, cycle life and suitability for stationary storage.

BMS and EMS

A battery management system (BMS) monitors cell voltage, current, temperature, state of charge and state of health, and provides cell balancing plus over-voltage, under-voltage, over-current and thermal protection.

An energy management system (EMS) decides how the sources and loads interact: solar to loads and battery by day, battery to loads at night, grid or generator support when solar is low.