It is a way of heating a home by taking warmth directly from the ground without the need to rely on fossil fuels or even stump up the cost of connecting to the main gas lines.

But, so far, ground-source heat pumps have been a niche way of supplying household energy used only in isolated locations.

However, the technology could soon be part of the mainstream energy network in Scotland after a company pioneering the technology announced it is expanding operations north of the Border.

Kensa are providers of “shared ground loop arrays”, a form of heating that provides each home with its own ground source heat pump, which the firm claims will mean lower bills and low-carbon heating with no heat loss.

The company, based in Cornwall, said deployment of ground source heat pumps is particularly effective at alleviating fuel poverty in rural areas.

Ground-source heat pumps work by running water through energy-absorbing pipes that are fed back into a house and used to heat a secondary fluid which turns into gas in a condenser.

This gas is hot enough to provide heating and hot water from the taps without the need to connect to largescale infrastructure. The firm has enlisted the services of Matthew Black, previously a senior energy adviser at the Stirlingshire-based Fintry Development Trust, specialising in reducing carbon emissions and enhancing sustainability.

Mr Black said: “Shared ground loop arrays are the most effective solution for delivering Scotland’s ambitions for the decarbonisation of heat. Along with the right policy changes in Scotland, we can make significant progress towards Scotland’s 2045 net-zero carbon target and beyond.

“The race to decarbonise electricity in Scotland has made considerable progress. The race to decarbonise heat and transport is on.”

Currently celebrating its 20th anniversary, Kensa’s heat pumps already provide heating to a number of sites, notably Orkney Islands Council’s multipurpose facility Stromness Warehouse, which is heated using the sea, and the first and most northerly ground source installations in Unst, Shetlands.

The Warehouse Buildings house the town’s library and customer services team, and provide a work base for staff from a variety of Council services, and draw heat from coils of pipes fixed to 12 stainless steel platforms – known as “pond-mats” – sunk beneath a nearby pier to draw heat from the surrounding water.

This has allowed the local authority to make substantial savings, thanks to the £1,550 cost of the electricity used to run the 2x40kW heat pump over a 12-month period, compared to £2,420 for an oil-based system.

It also means the Warehouse Buildings now produce substantially less greenhouse gas emissions than if a more conventional source of heat was used.

The carbon emissions linked to keeping the Warehouse Buildings warm are calculated to be six tonnes of CO2 per year, compared to more than 15 tonnes if an oil boiler had been fitted.

James Stockan, who chairs the council’s Development and Infrastructure Committee, said at the time: “Across the country very few buildings currently use sea-source heating systems. “As the Warehouse Buildings stand close to the sea, it made sense to opt for this innovative approach to keeping them warm and I am very pleased the system is proving to be efficient and effective.

“As we’re using heat from the sea and electricity primarily from renewables, these buildings are an excellent example of how the council is making significant steps towards creating buildings that are virtually carbon neutral in terms of their energy consumption.

“This investment clearly demonstrates our commitment to making best use of one of Orkney’s greatest assets – the abundant renewable energy we can harness from the wind and seas around us.”