Estimated cost saving is based on hot water heated with electricity not gas, using an electricity price of 0.144p/kWh, with the heata unit supplying 80% of a 200W average hourly hot water demand (the immersion heater would be used to top-up the remaining 20%). Average daily UK domestic hot water energy use: 4.67kWh[4] - therefore average hourly hot water power consumption = 195W. We’ve rounded up to 200W for simplicity of calculations.
CO₂ saving is based on electricity generating 0.307kg/kWh {0.283 kg/kWh (generation)[5] + 0.024kg/kWh (distribution)[5]}. Typical Data Centre + domestic hot water: 680W/hour (300W compute + 180W air conditioning[6] + 200W hot water). Heata: 300W/hour (300W compute, including 200W harnessed from waste heat). Average UK domestic hot water energy use: 4.67kWh[4]. Therefore average hourly hot water power consumption = 195W. We’ve rounded up to 200W for simplicity of calculations.
Ni, Jiacheng & Bai, Xuelian. (2017). A review of air conditioning energy performance in data centers. Renewable and Sustainable Energy Reviews. 67. 10.1016/j.rser.2016.09.050.
