Battery Energy Storage Systems

In the UK, demand for solar PV grew exponentially as a result of the FIT scheme around 12 years ago. The basic premise of this was that owners of PV systems on their homes or buildings would be paid for what they generate, regardless of whether the power generated was used ‘on-site’ or exported to the grid.  This served to address the inherent mismatch between peak power demand and peak generation within a typical home.  A PV array will be at its most productive on a summers day when the sun is high in the sky, i.e. late morning to mid-afternoon.  However, a typical home (and indeed the nation as a whole) draws maximum power in the evening when families are at home, the lights are on, along with kitchen appliances, washers, dryers, TVs and so on.

However, in recent years, battery technology has emerged that provides a new dimension, and addresses the mismatch of peak output and peak demand, simply by enabling excess power generated by a PV system to be stored for use when needed within the home or building it serves. 

By matching the capacity of the battery to that of the PV system and the demands of the home, a cost benefit analysis can establish the optimal system.