Supermarket Fridges Are a Surprise Grid Power Battery Buffer

By Gary Cutlack on at

Tesco and a team of energy experts from the University of Lincoln have had an idea right out of the pages of a very boring straight-to-Kindle science fiction novel set about seven months into the future. They think supermarket fridges could be engineered to provide the equivalent functionality of a massive battery to smooth out fluctuations in demand across the energy grid.

They built a pretend supermarket for the trial, which used an algorithm to cut the electricity supply to fridges for short bursts. This doesn't have much of an impact of the temperature of the stored food, but it does – when multiplied by the number of chiller cabinets keeping our pork pies safe nationwide – free up a lot of power. This on-demand burst could then be used to help balance the grid's energy frequency, a job usually carried out by batteries owned by the utility firms.

Professor Simon Pearson from the University of Lincoln said: "Cold food is, in fact, the UK's largest battery. There is sufficient 'cold energy' in the food to keep a refrigerator cold if the system reduces power for short periods to help offset power shortages on the National Grid. Our work effectively replicates a defrost cycle but matches the timing of the cycle to the power availability on the National Grid." [Business Green]