The northeast of England is famous for its industrial past, livelihoods built on powering the country using coal. But having been closed for decades, mines similar to this one in Beamish could have a role in powering the future.

The potential is phenomenal. We've got 23,000 disused deep coal mines across Britain.

It's something the Coal Authority is very excited about.

This infrastructure that we're sat in now was created heated by the miners centuries ago, but since it's no longer used, it's filled up with water that's heated by naturally occurring geothermal processes. We can use the heat in that water as an energy supply for the future.

There are over 6 million homes above abandoned coal mines. And while they can't say exactly how many could benefit, it's something local authorities across the country are looking at as an option. Further along the Seam in Gateshead, they've already put warm mine water to good use. By drilling down 150 meters, they've tapped into the tepid minewater. It's then pumped back above ground, where heat pumps, partly powered by an onsite solar farm, raise the temperature further. The warm minewater in the district heating system has been heated by the minewater. It goes out from here through a large, in effect, local plumbing system to then heat homes and businesses. The council here believes it. They're now at the forefront of a green revolution, one that can make a real difference to people's lives.

It's great for the environment, but also it's very economical as well. It's good for the customer. How does it feel?

It's almost a renaissance here from what was a dirty energy source to a cleaner one.

Well, actually, personally, I feel great because my father was a miner. He actually did some of these main workings in the past. Of course, I think he realized that it was a dirty, dangerous occupation. Actually, because of that work which is done, which is dirty, that carbon-based economy is now benefiting us in a green-based economy.

Tenants in these blocks of social housing are the first in the UK to benefit from this lower carbon form of district heating, meaning they can be weaned off gas without cost to them or any disturbance to their homes. Closer to the River Tyne itself is the Glasshouse International Center for Music, a charity and home to the Royal Northern Sinfonia. For them, the savings they made using the minewater has been a lifeline.

We feel really lucky to be part of the district Energy Network. There's two reasons. There's cost savings for us. It can be up to 5% cheaper than if we were getting it from the grid. And there's also carbon emissions savings. We've got a 2030 net zero target, and thanks to the solar power and the minewater heat pump, that really helps us achieve our target.

Back at Beamish, Charlotte Adams thinks the time has come for her favorite idea.

I do feel it's a vast resource. I've believed in it for a long time. A lot of my early work was looking at water in mines and treating them, and through that, I noticed how warm they are. So it's something I've been wanting to do for ages.

So you were a bit of a lost profit Now you've been listened to at last?

I am because the drivers have changed now. Back then, 20 years ago, when I started looking at this, we had our own suppliers of cheap gas. Now we're a net importer. Now we've got a lot of climate targets as well that we want to meet. So the game's changed considerably over the last few years.

Gateshead may be the first, but there's a good chance they won't be the last to feel the heat from coal mines once again.