UK: An ammonia heat pump from German manufacturer GEA is being used in a project using the water in an abandoned coal mine to supply a 6MW district heating network.
The project in Gateshead is the largest mine water heat scheme of its kind in the UK. Until now mine water has only been used to heat smaller-scale buildings or warehouses.
Gateshead has operated its own district energy network since 2018 through its wholly-owned Gateshead Energy Company, but until now the water in the network has been heated solely by gas-powered CHP engines.
Now mine water will provide up to half the heat required by buildings connected to the network.
The mine water, at 15ºC, is taken from 150m deep boreholes and passed through a heat exchanger which transfers heat, via the heat pump, into a network of underground pipes that supply hot water at 80ºC to homes and buildings.
The scheme will provide 3MW of low carbon heat to 1,250 new private homes, Gateshead International Stadium and other council-owned buildings.
Alongside the mine water scheme are two brand new £4m urban solar parks, some of the UK’s largest, which will be capable of providing 4MW of electricity to run the mine water heating system, as well as other council buildings.
The Gateshead Energy Company has worked with contractors Balfour Beatty and Drilcorp and suppliers GEA Refrigeration and SAS Energy to bring the projects forward.
“Where we were a leader in the industrial revolution 200 years ago, we are now a leader in the green energy revolution of today,” commented Gateshead Council leader Martin Gannon.
The mine water scheme forms part of the council’s zero carbon heat strategy, which aims to provide low carbon heating for everyone in the borough whilst reducing greenhouse gases in the environment. In addition, the council is guaranteeing customers’ bills to be at least 5% below the market rate.
The Gateshead District Energy Network supplies heat and power to homes, businesses and public buildings over a 5km private network across Gateshead town centre. It already has the capacity to supply the energy needs of the equivalent of 5,000 homes, and GEC is currently expanding the network further to reach Gateshead Stadium and a new housing development.
The project is currently in its testing phase, awaiting final permits from authorities and will soon be switched on for consumers to start benefitting ahead of the autumn.
Geothermal energy from mines is seen as a low carbon, sustainable source of energy that could be of great importance to coalfield areas and the UK in years to come. Across the UK, The Coal Authority estimates that there is enough heat stored within the coalfield areas to meet the heat demands of all the buildings that are located over them.