Researchers hail potential for HCS (that's heat capture and storage)

Waste heat from power plants could be stored deep underground for use months later by homes and offices, under ambitious new plans being researched by the Energy Technologies Institute (ETI).

The government and industry-backed body is preparing to announce a number of new research projects in the coming months designed to assess the viability of large-scale low carbon projects, including plans to reforest large areas of the UK to support domestic biomass power plants, improve the UK's nuclear industry supply chain, and develop new energy-storage technologies.

Dr David Clarke, chief executive of ETI, said that one area of focus would be research in support of an innovative proposal to capture waste heat from power plants and store it underground in geological formations.

He explained that the aim was to deliver "underground inter-seasonal storage of heat", which would allow for waste heat generated by power plants during the summer to be stored for use by district heating systems in the winter.

Smaller-scale gravel bed heat-storage projects have been successfully trialled in the past, while ground source heat pump technologies have become increasingly popular in recent years. However, Clarke admitted that underground heat storage had yet to be attempted on the scale being proposed by the ETI, and was at this stage only being pursued in the "academic realm".

Under the proposals, fossil fuel-fired power plants along the East coast could be fitted with heat as well as carbon-capture technologies, allowing heated water to be pumped into geological formations beneath the North Sea for use at a later date.

Clarke said the ETI's research would focus on the technical and economic viability of the scheme, noting that the cost of building district heat networks to carry the heated water for use in buildings could prove prohibitive.

However, he expressed confidence at the technical and environmental p otential for the project, arguing that the system would work like a giant ground-source heat pump and could deliver huge carbon savings for the UK. "At the moment the area where we waste the most energy is in heat," he said. "We waste more heat from power stations than we use in our buildings."

The ETI is also poised to announce a major mapping project designed to assess whether the 10 per cent of UK land that is classified as under-utilised could be productively employed to produce biomass crops for use in power plants or biofuels.

"The UK has 2.4m hectares of under-utilised land that is not being used for food production," he said. "The question is how much of that land can be sensibly used for bio-energy."

The wide-ranging project is expected to assess land ownership and suitability, which crops would prove most effective at curbing carbon emissions, and how planting trees or fast-growing grasses would impact soil chemistry.

Clarke said that it was too early to draw conclusions from the study, but predicted that with many British biomass power plants currently importing wood chips from overseas there could be strong demand for UK-grown biomass.

The two new research projects will join a raft of existing initiatives, including programmes to improve the supply chain for the UK's nuclear industry, reduce the cost of offshore wind turbines, and identify suitable waste streams for waste-to-energy plants.

Clarke said that having invested £54m across 17 projects last year, the organisation expected to invest £70m across a smaller number of select projects this year.

He added that the imminent election and prospect of public sector budget cuts was unlikely to have a major impact on the public-private body, which counts E.ON, EDF and Shell among its corporate backers. "The challenge presented by the need for affordable, sustainable and secure energy will not go away," he said. "And I do not see any of the political parties making wildly contrary statements to that effect."