Tesco is trialling using refrigeration units to provide frequency response in a partnership with the University of Lincoln, IoT firm IMS Evolve and The Grimsby Institute.
Mass refrigeration is responsible for around 12% of UK carbon emissions and, combined with heating, venting and air-conditioning, make up 14% of total UK electricity demand.
The aim of the trial is to determine how an aggregated collection of refrigeration units could participate in the frequency response market, alleviating strain on the national grid.
If the findings of the trials are rolled out across Tesco’s stores, its refrigeration units could provide the grid with 25 – 50MW of flexibility.
Control systems of refrigeration units currently use static control temperatures. However, algorithms to dynamically control temperatures have been developed as part of the project, with IMS Evolve’s IoT technology being used to optimise the IT architecture and data flows needed to handle the data scale.
When providing a frequency response, temperatures of the refrigeration units are regulated in line with demand from the grid, alongside food safety requirements. A food safe temperature is accomplished by exploiting thermal inertia, whereby cold temperatures are maintained in the short-term by the contents of the refrigeration units.
An imitation supermarket has been built for the trials, which are funded by Innovate UK as part of a Knowledge Transfer Network.
Simon Pearson, director of the Lincoln Institute for Agri-food Technology, said: “Successfully integrating food refrigeration systems into DSR mechanisms would have national and internationally relevant impact, and our research has shown that this can be done while controlling food quality and temperature control limits.”