Geothermal Heat and Power

Baroness Henig Excerpts

Thursday 6th July 2023 Grand Committee

[Lord Cameron of Dillington]

To ask His Majesty’s Government what assessment they have made of the geothermal potential for heat and power in Great Britain; and what plans they have, if any, to make use of it.

[The Deputy Chairman of Committees (Baroness Henig) (Lab)]

My Lords, Members will notice that the clock is not working, but I am sure they will seek to respect the time limits.

[Lord Cameron of Dillington (CB)]

My Lords, first, I thank everyone, including the Minister, for taking part in this important debate. Apparently, I am not allowed to say anything at the end, so I thank noble Lords now.

The importance of what we have to say is evidenced by the fact that heating and hot water make up around 40% of the UK’s energy consumption and nearly one-third of our greenhouse gas emissions. That is quite a large proportion, so this area needs a lot of focus. However, so far, compared to our continental neighbours—who, like us, are blessed with geothermal potential—we have done little to harness the power lying waiting for us: the heat beneath our feet.

In Holland, they hope to meet 23% of their heat demand by 2050 using geothermal heat. I realise that we cannot hope to match that because of our more dispersed population and our dispersed geothermal resources—population centres and geothermal resources do not always occur in the same place—but, with the right policies, there is considerable potential, which I will come to in a moment.

Meanwhile, the deep aquifer under Paris is supplying geothermal heat to around 250,000 homes, while in Munich and its surrounding communities some 130,000 houses now have geothermal heating. France currently has 74 geothermal plants and aims to increase that by 40% by 2030. The Netherlands has 21 plants and major increases planned, and Germany has 190 plants. But in England, only a few buildings are currently heated geothermally, although a few schemes are currently being developed around the country. Given the heat resources beneath our feet, it is a pretty poor record so far.

The UK has good potential in terms of enhanced geothermal systems—that is, 5 kilometres down, or more. A mere 2% of this potential could cover the current UK energy demand for over 1,000 years. We have two pilot schemes in Cornwall: one near Eden and one near Redruth. This heat is very expensive and difficult to tap into—right now, a lot of drill bits are wearing themselves out on our Cornish granite—but both these projects should eventually provide large amounts of meaningful heat, not only for direct use in homes, businesses, biospheres and hospitals, but, I hope, with temperatures capable of driving a turbine to produce electricity. We shall see.

While some of our very deep rocks have potential, the greatest potential for heat lies in much shallower aquifers. The geothermal gradient in the UK averages—I stress that word—27 degrees per kilometre, so temperatures at 1,000 metres, 3,000 metres and 5,000 metres underground are usually 40, 90 and 150 degrees centigrade respectively.

Even a small amount of heat combined with a heat pump is worth harnessing. For instance, our family home in Scotland is heated with a water-based heat pump using an aquifer only some 20 metres down. It was cheaper to install than a flat surface loop in the field, and the aquifer water temperature is 9 degrees centigrade, compared to the normal flat ground loop temperature of 5 degrees centigrade, which therefore minimally reduces the cost of our hot water.

More to the point, many major population centres in the UK live above, or are adjacent to, hot sedimentary aquifers at, say, 500 to 2,000 metres’ depth, with temperatures usually in the range of 25 to 60 degrees centigrade. These, combined with an at-scale community heat pump, have huge potential to produce heat for hundreds of thousands of homes, plus factories, hospitals, greenhouses and so on.

A recent report by Dr Mullan MP identified the enormous benefits available from such heat sources and made the point that these resources are, luckily, predominately available in areas suffering from a lack of economic resilience—in other words, areas which would qualify for levelling up and where these geothermal projects would, therefore, do the most good. But at the moment we are doing little or nothing to tap into these resources: the heat beneath our feet.

Cutting to the chase, we need, first, a proper, detailed subsurface survey of all our geopotential. This geothermal atlas should identify all the opportunities in detail, and it then needs promoting so that businessmen, builders and local authorities are aware of the local potential. The recent fuel crisis must surely give properties with cheap heat potential an advantage in the marketplace, and the marketplace needs to be informed of that potential advantage.

Secondly, the Government must then set themselves targets for the development of geothermal wells—so many per year to be developed. That is what they have done in Holland. Then the Government must promote these opportunities and put in place a firm long-term plan of support. This sustained support is very important and could include some form of initial grants, subsidies—perhaps in the form of FiTs or CfDs—or investment assistance. For some reason, energy projects do not qualify for EIS relief, which seems to make a mockery of the Government’s ambitions to make the UK a green and renewable energy investment hothouse.

Drilling is the most expensive bit, and in that context, with the expertise available from our now hopefully fading oil and gas industries, we should have an advantage. France, the Netherlands and Germany have all used national risk insurance schemes to attract private capital. For instance, for every £1 paid by the French Government, £42 has been leveraged from private investors. The Mullan report indicated that our potential investors are not attracted by this route, and it is not for me to tell the Government and the industry how to achieve their target number of geothermal wells. Setting a target and delivering it are the important bits, along with some sort of stable but long-term support or derisking measures.

Thirdly, the UK must deregulate. It is absurd, for instance, that in England and Wales you still need both an abstraction licence and a discharge licence to take water out of an aquifer and put it straight back in again. In Scotland, under general binding rules, abstractions and discharges in an open loop system do not need any licence or permit, provided that the water is discharged back into the same geological formation from whence it came. Furthermore, the planning system in a heat network zone should encourage and facilitate the harnessing of our geothermal resources, rather than cause delays.

Fourthly, in order to build the supply chain, the Government should zone areas which have geothermal resources, and then put in place in those heat network zones effective legislation compulsorily to reduce the long-term carbon output from all new buildings and, where possible, older ones as well. This legislation should look to promote communal heating systems—I really do not know why we have so few such systems in this country—or it could promote the use of geothermally heated water with so-called shoebox heat pumps. I always prefer to encourage rather than compel people to do the right thing, but in the Netherlands, which is virtually one large geothermal zone, they have already prevented all new-build houses connecting to the gas grid. There must be a lesson there. In this country, we are too hooked on the gas grid.

Fifthly and finally, the UK Government must involve local communities and get people and planners involved in heat network zoning. This should be part of a drive to grow the demand and the supply chain. Tapping into geothermal heat should become part of national thinking in the architectural, planning and construction worlds. We have geothermal resources in the UK: we have the heat beneath our feet. We also have the drilling skills left over from our oil and gas exploration. The UK geothermal industry is poised to deliver growth, renewable heat and employment; it just needs a small amount of government focus and pump priming.