UK plans to use old coal mines to heat houses

Experts in the UK consider an innovative idea that involves heating houses via abandoned coal mines.

The impact of climate change and the depletion of fossil fuels have made people turn to alternatives to generate energy. Geothermal energy is a renewable power source that originates from the Earth's high internal temperature. Currently, scientists in the UK examine how some abandoned coal mines can been used to extract geothermal energy and produce heat for residences.

The idea is based on the fact that about 25% of the UK's houses are founded on top of old coal mines that played an important role in the industrial revolution but are currently inactive. Those mines are naturally filled with water which can be pumped and used to heat infrastructure. The flooded mines are reportedly filled with 2.2 GWh of heat with the capacity to store mode. Researchers suggest that this is one of the most unused sources of power that the UK possesses.

The scheme works as follows: The high-temperature water stored underground is pumped and utilized to heat buildings above the ground. Once its heat has been absorbed, it returns to the mine and is heated again. The initial temperature of the water is hot enough to warm houses in the winter and cold enough to cool them during summer. The total carbon emissions are reduced by 75% and the process is more efficient in financial terms by 10%. "Heat from abandoned coal mines is an innovative and practical solution to one of the big challenges facing the economy – decarbonising heat supplies," Jeremy Crooks, Head of Innovation at the UK's Coal Authority, stated.

In terms of energy consumption, heating accounts for around 50% of the UK's total power need, but about 70% of the heat is generated by natural gas. Reducing the dependence on gas will be very helpful for UK to reach its net-zero greenhouse emissions by 2050. Mine water is currently one of the best options in the effort to decarbonize the heating industry. The resource is reliable and exists in abundance (at least in the UK).

Various attempts to manipulate geothermal power and heat houses have been made in many places across the world. The most advanced mine water manipulation project is located in Heerlen, Netherlands. The system provides geothermal power to 500 residences and facilities reducing the total carbon footprint by about 67%. Additional attempts to decarbonize the region are made through the utilization of solar and wind power. 

Nevertheless, there are some drawbacks associated with the manipulation of the coal mine geothermal power. Firstly, treatment plants will be needed to pump the underground water and deliver it to the houses, therefore, significant funds have to be dedicated towards that direction. Afterwards, the old coal mines could be at risk of collapse, hence, the intervention may need additional resources to support the underground cavities. Therefore, there are also financial issues that need to be resolved. Experts believe that technological advances will persistently reduce the funds needed to extract the tapped power source, thus, at some point, it will be exploited.

Sources: BBC Renewables-networking Groundstability