Tesco refrigeration project hits the mainstream media
Posted on 17/06/2019
A project where KTN was instrumental in introducing the University of Lincoln to key project partners which enabled them to apply for and achieve Innovate UK grant funding has seen impressive outcomes. Featured in The Guardian, the article suggests supermarket freezer aisles could soon help power the National Grid after trials found that hundreds of thousands of fridges could provide a nationwide “virtual battery”.
KTN produced a case study on the project last year and the results of the trials, as well as being featured in the national medial, are now the subject of an academic paper from the University of Lincoln published in the Journal of Applied Energy.
The paper, ‘Facilitating static firm frequency response with aggregated networks of commercial food refrigeration systems’, which can be accessed here has studied how aggregated electrical loads from massive numbers of distributed retail refrigeration systems could have a significant role in frequency balancing services.
The paper’s authors have been able to conduct the study because the project, which resulted from the Innovate UK investment, developed an innovative technique involving the large-scale machine control of retail refrigerators.
The study was a 24-month full-scale collaborative research and development project looking at ways of stabilising the demand placed on the National Grid by large-scale refrigeration operations. Supermarkets operate hundreds of thousands of refrigeration units across the country and the refrigeration of food accounts for more than 14% of the UK’s electricity demands at any one time, representing one-third of a typical retailer’s energy cost.
The project team was brokered by KTN and was a combination of academia and industry: it was made up of the University of Lincoln (UK), Tesco Stores Ltd, The Grimsby Institute and IMS Evolve, which controls Tesco’s 112,000 refrigeration systems across 2,600 stores in the UK.
Lincoln University has shown a validated model that simulates the operation of retail refrigerators comprising centralised compressor packs feeding multiple in-store display cases. The model was used to determine an optimal control strategy that both minimized the engineering risk to the pack during shut down and potential impacts to food safety.
The authors show that following a load shedding frequency response trigger the pack should be allowed to maintain operation but with increased suction pressure set-point. This reduces compressor load whilst enabling a continuous flow of refrigerant to food cases.
Essentially, the project has shown that refrigeration temperatures can be dynamically controlled without compromising controlling food quality which has resulted in reduced energy consumption and reduced costs.
This presents intriguing possibilities for big retailers such as Tesco, enabling them to control a large-scale refrigeration operation safely and more cost-effectively. The results of the project are also good news for the National Grid and future adoption by other large-scale operators could see increased stability in demand side response to the National Grid resulting in reduced energy consumption.
You can view the original case study for this project here.