Plans to develop the country’s largest mine water source heat network are moving forward in Sunderland, with the green light set to be given to appoint contractors to undertake viability studies.

The former Wearmouth Colliery workings – once mined for coal that powered homes and industry across the city – could soon provide a low carbon heat source if borehole drilling, set to be commissioned by Sunderland City Council, confirms it is able to support the energy needs of properties in the area.

It is understood that the former colliery began filling with water when operation ceased in 1993, which could see it deliver a new heat source for hundreds of commercial properties and homes in the city.

Now the council’s cabinet is set to green light a £1.6m project – subject to Government funding from the Green Heat Networks Fund Transition Scheme – that will see a specialist contractor engaged to drill pilot boreholes some 600m below ground.

The drilling – which will see the council, supported by the Coal Authority, engage a specialist contractor due to the pinpoint accuracy required – will ascertain whether the former colliery has the ability to be used in this way.

Once the initial drilling work is carried out, it is expected that further studies will be undertaken to understand whether heat extracted from the former mine workings could support the new homes that are being developed on Riverside Sunderland as well as other buildings across the city.

If the exercise confirms viability, Sunderland could become home to the UK’s largest geothermal mine water source district heat network, which would be a major milestone in achieving the council’s ambition to be carbon neutral by 2030 and the city’s target of being carbon neutral by 2040.

It is thought that the scheme could save upwards of 4,100t of CO2e per annum, representing a 70per cent carbon saving against mains gas, and that it will create jobs and opportunities for the city too.

Councillor Graeme Miller, leader of Sunderland City Council, said: “We have a vision to create a greener Sunderland, and our level of ambition in terms of the many ways we deliver this is high.

“We know that the city has assets that we can explore to deliver more sustainable energy, and we’re very interested in how geothermal energy from the mineworks might play a role in meeting the needs of the city in the future.

“It’s a ground-breaking project, but one that – with partner support – could deliver huge advantages for the city.”

The council is exploring how it could use the sustainable energy source to power everything from homes to commercial buildings, and it is understood that a range of city partners, including South Tyneside and Sunderland NHS Foundation Trust and the University, could tap into the heat source to deliver more sustainable power supply year-round.

Richard Bond, innovation and engagement director for the Coal Authority, said: “The Coal Authority is committed to providing its knowledge and experience to help local authorities explore the opportunity mine water heat could bring.

“This is a low carbon, sustainable option which could heat hundreds of homes and several community buildings in Sunderland.

“There are several projects in Britain now progressing and each one has the potential to offer significant benefits to communities living on the coalfields and help achieve Net Zero targets.

“We are delighted Sunderland is seizing this opportunity to help improve the lives of people living in the area and contribute to their wider mission to be carbon neutral by 2040.”

Early modelling shows plans to put in place 8.1km of insulated pipe, which will extend as far east as the University of Sunderland’s St Peter’s campus and westwards to Sunderland Royal Hospital.

Projections suggest that the colliery could have the capacity to support with the energy needs of hundreds of buildings.

Councillor Miller added: “Local Authorities have a key role to play in making heat networks succeed and we’re keen to play our part in creating a more sustainable Sunderland.

“Given our focus is on what is best for the city – not just short-term commercial returns – we can ensure that carbon reduction and alleviation of fuel poverty are key drivers in our application of this network, should viability studies show it is an option.”