Heat from sub-station transformers exploited by Dimplex heat pumps
The expertise of Dimplex’s renewable-heating design team came to the fore in the application of two ground-source heat pumps to use waste heat from transformers at a major National Grid sub-station to provide space heating and water heating for two adjacent buildings. The heat pumps heat the main sub-station building and a neighbouring environmental education centre.
This innovative solution has been designed and patented by Rook Services and installed at Bishops Wood Centre near Stourport. The two heat pumps are connected via a header pipe to a series of four dry-air coolers. Each air cooler is connected to an individual brick enclosure that houses a 275/132 kV step-change transformer.
The brick enclosures are designed to reduce noise for surrounding properties, and the air in them is warmer than the ambient air. Water circulates through the header pipe to provide the heat source for the heat pumps in their own plant room.
The education centre dates from the late 1990s, and has a space-heating requirement of 27 kW, served via new wet radiator systems.
The sub-station has a total requirement of 73 kW for heating and hot water.
Hot water for the education centre is provided by a solar-thermal system.
The payback period is expected to be 8.7 years, which will be confirmed by a programme of monitoring.
