A valuable contribution to making the most of intermittent renewable energy resources is likely to come, according to the Financial Times, from “storing energy in batteries when supply is plentiful — when the sun is shining and wind is blowing — and releasing it when needed.
Installing a domestic battery storage system to make best use of solar PV generated and cheap off-peak electricity has been big news recently with the launch by Tesla of their Powerwall system. However initial findings from a research project with 50 homes at Rose Hill in Oxfordshire suggests that savings from systems used this way only average £10 a month. Additional revenue streams could come from the householder making some of the battery’s capacity available “for a range of network demand and balancing service revenues”. A recent report from the Carbon Trust and Imperial College London concluded that “distributed storage at the household level with no interaction with the network is neither the most economically attractive solution for end users, nor most beneficial to the network.”
We are talking to companies who are planning to launch a ‘free to install’ domestic solar PV and battery system paid for by monthly payments charged to householders electricity bills. The initial proposed charges seem too high at the moment to be cost effective. However costs of both solar PV and batteries are falling rapidly, while electricity prices continue to rise, so we don’t think it will be long before domestic battery storage becomes cost effective.