Scientists are finalising plans to exploit the vast reservoir of warm water that fills a labyrinth of disused mines and porous rock layers underneath Glasgow. They believe this subterranean store of naturally heated water could be used to warm homes in the city. If the system proves successful, such water could then be exploited in other cities and towns across Britain, they say. The £9m project will initially involve drilling narrow boreholes filled with instruments to survey temperature, seismic activity, water flow, acidity and other variables to establish the state of the water in the rocks below the city. The aim will be to establish whether this warm water can be extracted for long periods to heat Glaswegian homes. Drilling of the first test boreholes – at sites yet to be selected – is the first part of an initiative by the BGS: the creation of several UK geo-energy observatories. Where other observatories look up to the sky, these will monitor conditions underground, say scientists. One test system has been selected for Scotland: the Glasgow Geothermal Energy Research Field Site. A second has been proposed for Cheshire – where scientists want to study rock conditions to assess the possibility of using underground vaults as storage for heated water. Heating of homes is set to become a crucial issue, researchers have warned. The UK is on target to decarbonise electricity generation as a result of the growing numbers of renewable power plants. However, the nation is still heavily reliant on North Sea and imported natural gas to heat its homes. Combustion of these fossil fuels forms a substantial part of the carbon dioxide emissions which the UK has pledged to reduce to help limit glob al warming.