Performance of distributed energy resources in three low energy dwellings during the UK lock down period

Under the scope of UK’s net-zero emissions target by 2050, decarbonisation of the housing sector is necessary. With the need to move to a smarter energy system with flexible demand, there is a drive to install batteries in homes to maximise the utilisation of local renewables. This paper empirically examines the effectiveness of distributed energy resources (DERs) comprising smart home batteries coupled with rooftop solar on actual energy use and peak demand in three dwellings designed to high thermal standards in York, England. The paper also explores the change in daily energy use and performance of DERs during the Covid-19 lockdown period (23 March to 31 May 2020). All three dwellings are occupied continuously by families, have identical heating systems (district heating), rooftop solar PV (4kWp) and home batteries (14kWh). The energy use, generation and charge-discharge of the batteries are monitored every five minutes using remote sensors. Analysis shows that the solar PV and battery combination reduced average direct grid consumption during peak hours by over 95%. Since the PV system installed for each dwelling was large (4kWp), instantaneous self-consumption (SC) was low, ranging between 20 – 30%. The batteries helped to increase SC up to 50%, resulting in an 80% reduction in net total energy consumption over four months Though the occupants in two of the dwellings claimed to be ‘always at home’ even before the lockdown there was a slight increase in electricity consumption for these two dwellings, and a notable increase in the other. Space heating consumption did not reflect the same impact possibly because of the unseasonably warm weather during the Covid-19 lockdown period