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Coal mine flood water used in first heating scheme

Ben Price
BBC News
Mining Remediation Authority Water pours from a series of outlets in two rows into a stream of water in the middle. On the other side of the two rusty walls are two flat bodies of water. Mining Remediation Authority
Mine water treatment sites across Wales already process enough water to fill the Principality Stadium 10 times over each year

Flood water from a disused mine is being used as a renewable source of heating for the first time in Wales.

The business near Ammanford, Carmarthenshire, has started pumping water from a nearby mine water treatment site to heat its warehouse.

The Mining Remediation Authority, formerly the Coal Authority, said it continued to help develop similar projects across south and north-east Wales and hoped Wales could be at the "forefront" of the approach, but a similar heat scheme was scrapped by Bridgend council in 2021 due to the concern of rising costs.

The Welsh government said it recognised the "significant role mine water heat can play in our journey to net zero".

About 25 litres of water per second is pumped from the former Lindsay pit every day in order to be cleaned and released into natural waterways.

Flood water which has filled old mines can reach up 20C (68F), depending on the depth.

Business owner Nick Salini, who makes heat pumps, said he recognised the potential of the mine water a long time ago.

"We've installed a ground source heat pump that takes the water from the surface mine water treatment plant which runs at a constant 14C to 15C," he said.

"We take that warm water to a heat pump, compress it to a useable temperature for heating the building and this will heat the building all year around.

"This system is specifically designed for this building. It's a 35 kilowatt system which could heat up to 10 new-build properties and it is scalable so it could provide heating for hundreds of homes by absorbing the available energy from the ground."

Mining Remediation Authority A graphic showing a row of three homes, linked with red and blue bands, and connected to a heat pump and a heat exchanger with lines stretching to two layers of water beneath the ground. Above the homes the graphic says 'buildings are connected with a heat network'. It also says 'heat exchanger takes 5C from the mine water' and 'heat pump boosts the temperature'. The deeper body of water says 12-20C, and the body of water closer to the surface says 7-15C. Mining Remediation Authority
When done at scale, energy centres could be built within communities to boost the temperature of the water from underground

The Welsh government published a mine water heat opportunity map last year to highlight the parts of Wales' former coalfields where similar schemes might be viable.

Innovate UK, funded by the UK government to help businesses grow, provided the money for the project in Carmarthenshire but getting the right funding for larger projects remains a challenge.

There are a growing number of mine water heat projects in England. The first to be completed in Gateshead serves more than 600 homes, businesses and an arts centre.

Gareth Farr, head of heat and by-product innovation at the Mining Remediation Authority, said: "Everyone in Wales has been looking at what we've delivered in the north east of England but there's no reason why Wales can't be at the forefront of this as well.

"We've got a quarter of Wales' population living on the coalfield so the demand is there and we want to link our proud industrial heritage to this new green future."

Nick Salini with short hair and wearing a black shirt, standing right of frame. Behind him is a heating system with black pipework, a compressor and boiler system.
Mr Salini says water from old mines could be pumped hundreds of metres across communities but infrastructure and costs need to be considered

It took two weeks to lay the pipework for the small project near Ammanford but the developers said the long-term benefits outweigh the short-term disruption.

"Across Great Britain, we're already in the process of developing and delivering new schemes, so we really hope this scheme will be a springboard to encourage others and provide confidence so they can progress the ideas we've been working on with them," Mr Farr added.

The Welsh government said: "We do not have a dedicated heat network fund, however they could be in scope with local energy funding.

"Applicants would need to demonstrate how their idea fits with local area energy plans and that they are the optimum use of funds, returning the biggest impact for the investment both in terms of decarbonisation and wider benefit.

"Ynni Cymru has recently launched a £10m capital fund for smart local energy systems to help develop novel energy projects and maximise local benefits; we would encourage developers to explore this potential route."