Energy savings: Case study on a cool way to cut energy consumption in the UK food industry
A collaborative research and development project led by a mechanical engineering team from Brunel University, UK, found that supermarkets and food processing plants could cut their energy costs by over 30% and reduce greenhouse gas emissions by 25-50% using combined heat, refrigeration and power (CHRP). Refrigeration accounts for around half of the total energy consumption of supermarkets and potential savings could be significant to the economy, as retail food outlets account for 5% of total UK energy consumption and food processing plants for 10%. The project investigated the use of micro-turbines and studied how waste heat could be recovered from the exhaust and fed to an absorption chiller. The results showed that an absorption plant would be able to deliver all the refrigeration needed at a typical large supermarket, providing chilling in two temperature ranges: one for frozen products and one for chilled food. Three to five micro-turbines would be required at each store. The units capture heat generated in the production of electricity and are claimed to increase overall efficiency from 38-76%. According to the project team, the technology can be applied to all applications including supermarkets, cold stores, freeze-drying plants, etc. As many as 2500 supermarkets and 1000 refrigerated food process plants could benefit from the research if CHRP is used in the future, helping meet efficiency targets set in the Government's Energy White Paper in 2003. A second phase will focus on the design of a low-temperature absorption chiller and associated heat exchangers, also able to provide space and water heating for food processing plants. A mini-supermarket will also be built at Brunel University to test the complete system and an application to patent the technology, which could be launched commercially in 2007, will be filed.