Ques No: 1-7
Read the passage carefully and answer the questions that follow. Some words may be highlighted. Pay attention.
Coal mines were the beating heart of Britain's industrial revolution. Their sooty, energy-dense output gave life to new-fangled factories and shipyards, fuelling the nation's march towards modernity. They helped shape a carbon-intensive economy and paved the way for a global dependence on fossil fuels, and in doing so, fired the starting pistol on the climate crisis that today confronts us all.
But what if, in a serendipitous circle of history, our extractive past could be repurposed for a greener, cleaner future? What if the vast maze of coal mines beneath our feet, now filled with naturally warm water, could help decarbonise the UK's – and the world's – herculean heating needs?
That was the question Adam Black, a renewable energy enthusiast employed by one of Britain's largest bottling firms, Lanchester Wines, asked himself a decade ago. "I had about 400,000 sq ft of warehouse that needed heating and it was right over four layers of mine workings, which had naturally flooded over time. I felt we could use this mine water for heating", he recollects.
With the help of a few geothermal experts from Iceland, Black sunk a borehole into the murky depths of the old High Main coal seam in Gateshead, Tyne and Wear, England. Warmed by natural geological processes, the water they pumped to the surface was a pleasant 15C (59F). With a little supplemental warmth from an electric heat pump – "a bit like a fridge in reverse" – it was perfect for keeping the company's warehouse, and the millions of wine bottles within, at the right temperature. "Nowadays we're heating a couple of warehouses, a distribution depot, a local bakery, and soon a nearby car showroom too!", says Black.
He's not the only one excited by the energy potential of mine water. The UK Coal Authority, which is responsible for the country's disused pits, has big plans for the coming decade. Its geologists believe one-quarter of British homes currently sit on a coalfield, stretching across Wales, central Scotland, northern England, and the Midlands. An estimated 2 billion cubic metres of warm water occupy the old mine shafts and these flooded shafts contain around 2.2 million GWh of heat, with the potential to store more. Researchers suggest that this makes mine water one of the UK's largest underused clean energy sources. Accordingly, to help meet the country's sweeping carbon-reduction target, the Coal Authority is exploring the feasibility of some 70 mine water heating projects across the country.
Yet, while there's mounting evidence of mine water's energy potential, the idea isn't without issue. Retrofitting houses with the means to tap into a geothermal district heating network isn't cheap and new builds aren't often sited next to derelict collieries. Further, there are technical hurdles like stability concerns around abandoned mine shafts which were simply left to collapse. The capital costs are much higher with mine water geothermal, though under the right conditions the energy generated can be cheaper than that from conventional sources.
Adam Black at Lanchester Wines hopes that the costs will fall as the technology develops and uptake increases, "and if the energy authorities do their bit with regulation".
Beyond doubt is that the resource is there and waiting: A labyrinth of warrens once laden with men and machinery, now flooded with naturally warm water, ready to be tapped.