Power from the past – mine energy in the North East

Mine energy is the use of the geothermally heated water in abandoned coal mines in order to provide power to modern-day homes and commercial buildings.

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What is mine energy?

A quarter of the UK’s homes and businesses are sited on former coalfields. The Coal Authority, which manages the effects of past coal mining on behalf of the Government, estimates that there is an estimated 2.2 gigawatt hours (GWh) of heat available in these areas. This is enough to heat all of the homes and businesses in these areas and help to drive economic growth.

What benefits can mine energy bring?

In addition to providing heat, harnessing the energy found in geothermally heated water can create jobs and help to cut carbon emissions.

It is estimated that delivering 42 mine energy projects currently being examined by The Coal Authority will create almost 4,500 jobs as well as a further 9,000 to 11,000 jobs in the supply chain. It would also save some 90,000 tonnes of carbon emissions.

Recent advances in thinking and practice also suggest that the benefits associated with mine energy schemes can be enhanced by using mines to store surplus (waste) or seasonally available (solar thermal) heat sources.

How does mine energy work?

The Coal Authority estimates that there are 23,000 abandoned deep coal mines around the UK. Following abandonment, the void spaces created by mining fill with water which has been naturally warmed to a temperature of between 12 and 20°C by sub-surface geological processes.

Through the use of heat pumps, some of this heat can be extracted and used to heat fresh water, which can then be used to provide low carbon heating and hot water for use in domestic and commercial buildings via heat networks.

A number of mine energy schemes have been running successfully in locations in Europe and the US for a number of years with the first such scheme now 35-years-old.

Why is mine energy important for the North East?

As an industrial powerhouse during the 19th and 20th centuries, North East England is home to some of the largest and most numerous former coalfield areas. At the industry’s height in the 1920s, more than 220,000 men worked in mines across the North East with over 130 collieries in County Durham alone.

Harnessing this dormant energy source beneath the region’s surface using some of the renewable energy know-how which the North East boasts offers a real opportunity to create lasting regeneration. This is particularly the case in areas of the region which have been the most directly affected by the closure of the mines and the struggle to fill the gaps in employment and investment which that left behind.

A recent White Paper on mine energy noted how: “The development of mine water heat networks would bring immediate and direct economic benefits to coalfield communities and businesses.”

Why is mine energy important for the North East?

Are there any mine energy schemes in the North East at the moment?

Enabled by the Renewable Heat Incentive (RHI), County Durham-based wine importer and wholesaler Lanchester Wines has installed 2.4MW and 1.6 MW mine water-based heating systems. These are currently the largest schemes in the UK, but will shortly be eclipsed by a 6MW scheme led by Gateshead Council and a proposed garden village scheme at Seaham, both supported by funding from the Heat Networks Investment Programme (HNIP).

Multiple other UK schemes have been subject to some level of investigation and the Coal Authority has suggested that there is currently a potential pipeline of 42 mine energy projects.

If all these projects proceeded, the Coal Authority says this would create an estimated 4,227 jobs and £293 million gross value added (GVA). An additional 9–11,000 jobs and £400–500 million could be created through indirect and induced economic effects.

Are there any mine energy schemes in the North East at the moment?

What are the barriers to developing more mine energy schemes?

Before 2021, the relatively low cost of gas as an energy source had restricted the development of more mine energy schemes but the soaring cost of gas, exacerbated by the effects of the war in Ukraine, means that this is now much less of a blocking factor.

However, there are other issues associated with the expansion of mine energy.

These include:

uncertainty surrounding the future of support schemes for low carbon heat
concerns about whether the Coal Authority will start charging for access to mining infrastructure

Other issues include:

perceptions of risk deterring potential developers and investors, such as borehole-based schemes failing to locate a viable and sustainable resource
a potential decline in the projected heat yield over time or of access to heat stopped by the collapse of underground workings
a lack of expertise, specifically technical consultants, scheme design engineers (borehole and pump system) and drilling contractors.

What are the barriers to developing more mine energy schemes?

What’s next for the mine energy sector?

In 2021, a white paper on mine energy was developed by the North East Local Enterprise Partnership (North East LEP) and funded by Department for Business, Energy and Industrial Strategy (BEIS), the North East, Yorkshire and Humber, and Midlands Energy Hubs, and the MCS Charitable Foundation.

As well as outlining the case for expanding the number of mine energy schemes across the country, the white paper also produced a number
of recommendations including:

developing a subsidy regime which helps support development of the mine energy sector
facilitating and supporting greater co-operation across the sector particularly between mine energy scheme designers, developers, regulators and the research community
closer dialogue between mine energy stakeholders and the Coal Authority to ensure that mine energy tools and research programmes are geared towards the emerging market
greater clarity around charging for heat access and the Coal Authority’s preferred role in new project development

The substantial increase in the price of fossil fuel sources of energy, particularly since the outbreak of the war in Ukraine in February 2022, has meant that mine energy schemes have come under renewed focus.

While it remains to be seen how the sector develops in the years to come, it is clear that mine energy represents a way in which the North East can benefit in the future from its proud industrial past.