In recent years, Sainsbury’s has invested in more than 100 biomass boilers, 40MW of solar PV, introduced LED lighting, 27 Ground Source Heat Pumps and Green Gas CHP. As a result our absolute energy consumption today is lower than it was in 2005-06, despite opening 52% more space in that period.As part of Sainsbury’s 20×20 Sustainability Plan, demand response technology also has a part to play.
The opportunity for demand response is huge because the business accounts for something like 0.6% of all UK electricity consumption. It is already trialling battery storage in at its Melton Mowbray branch - which aims to store up off peak electricity to be released on demand - and is working with Open Energi, using their expertise in frequency response to adjust the electricity consumption of immersion heaters, air handling units and fridges at over 200 stores, to help the National Grid balance electricity supply and demand in real-time. Sainsbury’s has identitfied 130MW of capacity in its back-up generators that could be put to use providing demand response.
In the event of a power cut, each of its sites has a back-up generator that starts up if the site comes off the grid for any reason. These generators produce enough power to enable each facility to function for a period of time and to get people out of the building safely. So far, a 150kW generator in its Dewsbury store in West Yorkshire and a 1.2MW generator at a depot in Tamworth, Staffordshire are participating in demand response when not in use by Sainsbury’s, but there is potential for 400 sites to do this. The generator sets are used as back-up so they are not connected directly to the grid and the process of connecting them is complex and time-consuming.
Each site needs to be separately assessed by one of the 14 Distribution Network Operators (DNOs) to be sure that any connection won’t cause a problem on the local grid. It estimates that the cost of completing applications for all sites could run into millions of pounds. It thinks businesses could be encouraged to connect their standby generators if it were possible to validate potential connections en masse.
Sainsbury’s has reached an exciting point in the development of its demand response capability and is working with the energy industry to make it happen.