European Geothermal Congress 2019 Den Haag, The Netherlands, 11-14 June 2019

Geothermal Energy Use, Country Update for

Robin Curtis1, Jonathan Busby2, Ryan Law3, Charlotte Adams4 1GeoScience Ltd, Falmouth Business Park, Falmouth, , TR11 4SZ, UK. 2British Geological Survey, Environmental Science Centre, Nicker Hill, Keyworth, Nottingham, NG12 5GG, UK

3Geothermal Engineering Ltd, 82 Lupus St, London, SW1V 3EL, UK 4Dept of Geography, Durham University, Lower Mountjoy, South Road, Durham, DH1 3LE, UK [email protected]

Keywords: Country update, United Kingdom, low granitic intrusions, particularly in southwest . enthalpy, direct use, GSHP, mine workings, EGS, HDR These granites were previously the site of the UK Hot Dry Rock programme in Cornwall and are now where ABSTRACT the United Downs Deep Geothermal Project is The exploitation of geothermal resources in the UK currently underway. continues to be slow. There are no proven high The work at the Eastgate and Newcastle boreholes in temperature resources and limited development of low northeast England also suggested higher than and medium enthalpy resources. However, in the anticipated temperature gradients and hence increased reporting period 2016-2019, there has been a focus on the possible application of geothermal heat in continuing resurgence of interest in all aspects of that region. geothermal energy in the UK. The comprehensive work by the British Geological The most significant development has been the start of Survey, (reported by Downing and Gray, 1986) is still the United Downs Deep Geothermal Project in the definitive reference to the geothermal prospects of Cornwall. Borehole UD-1 has recently been completed the UK. For a background to material provided here, to a depth of 5.2 km MD. readers are referred to earlier UK Country Updates Several deep aquifer projects, minewater projects, deep provided for the GRC International Symposia on co-axial projects and another EGS/HDR project are at Geothermal Energy (Garnish 1985, Batchelor 1990) the various preliminary stages. IGA World Geothermal Congresses (Batchelor 1995, Batchelor et al 2005, 2010, 2015) and EGC 2013, 2016 In terms of real activity "in the ground" in this reporting (Curtis et al 2013,2016). period, other than United Downs, a new borehole research facility has been started, a minewater project 2. POLICY / INSTITUTIONAL has begun, and the Renewable Heat Incentive has Two major legislative drivers continue to assist in finally led to a revival in growth of ground source heat driving forward interest in geothermal activity in the pump installations. "Geothermal" seminars and UK. The first is the European Union’s RES Directive conferences have been held. or 20/20/20 campaign. The UK has agreed a 15/20/20 commitment, which translates into 30% renewable With the growing interest in the need for large scale electricity and 12% renewable heat by 2020. While the utilization of low carbon heat, a recent announcement UK is on target to deliver on renewable electricity, it by the UK Climate Change Committee should lead to has fallen far behind on the renewable heat and significant expansion in the application of GSHPs and transport targets. The second legislative driver is the direct use geothermal heat. 2008 UK Climate Change Bill – the first in the world, that commits current and future UK governments to 1. INTRODUCTION publicly declared CO2 reduction targets. While the In a worldwide context, the exploitation of geothermal early targets were met, the UK is currently not on a energy in the UK remains small. The geological and trajectory to meet forthcoming targets. The Climate tectonic setting precludes the evolution of high Change Committee is currently addressing this, and a enthalpy resources close to the surface and only low to revised CO2 reduction plan is to be announced moderate temperature fluids have been accessed by imminently. Part of this will see a requirement for all drilling in sedimentary basins in the south and northeast new build housing after 2025 to be fitted with low of England. Elevated temperature gradients and high carbon heating systems. This is expected to become a heat flows have been measured in and above some significant driver for GSHPs. 1 Curtis et al

In October 2017 the UK government released its Clean downhole pump with a modern electro-submersible Growth Strategy, This sets out a comprehensive set of pump. policies and proposals that aim to accelerate the pace of “clean growth”. The hot springs at Bath have long been a tourist attraction among the Roman architecture of the ancient These overarching drivers translate into lower level city. After their extensive refurbishment they continue legislative drivers such as the energy/carbon to be popular ( http://www.thermaebathspa.com/ ). A components of the Building Regulations, and planning recent development is that the cascaded flow from the requirements for new buildings. To assist with the hot springs, as supplied to the baths, is to be used to achievement of these targets, a number of financial provide space heating for a new underfloor installation support schemes are in place. As well as ongoing in the nearby Bath Abbey. support for mainstream renewable electricity generation (through Renewable Obligation Certificates In 2018 work commenced on a geothermal borehole to (ROCs) and Contracts for Difference (CfDs)), enabling supply the newly refurbished seawater lido pool at legislation was passed in 2008 to allow for feed-in- in Cornwall. The intention was that a 1700m tariffs (FITs) for both small scale electricity generation deep borehole would supply direct use heat to a and for renewable heat. The latter is the Renewable partitioned sub-section of the larger seawater pool. In Heat Incentive (RHI) scheme which applies to biomass, the event, there were difficulties with the drilling. The solar thermal, and heat pump technologies. After four first borehole on the esplanade was abandoned at circa years of evolution and development, the RHI for 100m depth due to seawater ingress. A second hole was domestic and non-domestic installations has been then attempted which reached a depth of ~400m before operating in this reporting period. Unfortunately, the encountering difficult drilling conditions. However, tariffs for biomass and borehole based GSHPs initially significant water inflow was encountered at a o led to a disproportionate fraction of the non-domestic temperature of ~25 C. The project has been modified to RHI being taken by biomass installations (>90%). This be an open loop water source heat pump system. The tariff imbalance has been reviewed and addressed by contract for this has been let at the time of writing, and DECC / DBEIS resulting in a fall-off in the rate of the system is expected to be operational by late autumn biomass installs, and a significant increase in GSHP 2019. installs, particularly in larger installations in the non- domestic sector. It is hoped that this will continue until Other preliminary work on aquifer based geothermal heat schemes and deep coaxial projects was reported in the end of the RHI scheme in March 2021. the Country Update paper for the period 2013-16. Legislation for deep geothermal development has been (Curtis et al 2016). At the time of writing there are no slow to catch up with the renewed level of interest in further updates to report on these. the sector. There is still no official licensing scheme for deep geothermal development in the UK. 3.2 Deep Coaxial Projects Following the demonstration of a deep coaxial heat Because of the increasing interest in geothermal energy exchanger in borehole RH15 at Rosemanowes, in the UK, The British Geological Survey published a Cornwall in 2014, (Law et al 2016) a number of Briefing Paper in November 2018 on the topic of proposals have been developed developed for similar geothermal heat ownership. (Abesser et al, 2018) projects in England and Scotland. Currently these projects are on hold for a variety of reasons. 3. GEOTHERMAL UTILISATION 3.1 Medium / Low Enthalpy Aquifer Projects 3.3 EGS / HDR Projects The City of Southampton Energy Scheme (Smith 2000) In February 2016 the UK government issued a call on remains the only significant exploitation of low behalf of inviting bids for funds to be enthalpy geothermal energy in the UK. It is owned and used in the development of a deep geothermal system. operated by Cofely District Energy, now part of These funds have been secured via the European ENGIE. The scheme was started in the early 1980s Regional Development Fund from the European when an aquifer in the Triassic Sandstone containing Structural and Investment Funds (ESIF). Combined 76oC fluid was identified at approximately 1800m in with £2.4 million of matched funding from Cornwall the Wessex Basin. Construction of a district-heating Council, the total amount of public funding available is scheme commenced in 1987 and this has since evolved £13 million. Applicants were specifically invited to and expanded to become a combined heat and power make proposals that included the drilling of a scheme for 3,000 homes, 10 schools and numerous commercial scale demonstration well in Cornwall. The commercial buildings1. While gas fired CHP now call closed in June 2016. supplies the majority of the district energy scheme's low-carbon heat, money from DECC's Deep In previous UK Country Update papers (Curtis et al Geothermal Fund has been provided to allow for the 2013, Batchelor et al 2015) brief descriptions were replacement of the original hydraulically driven provided of the projects expected to bid for this

1 see: http://www.energiecites.org/db/southampton_140_en.pdf 2 Curtis et al funding. Two projects had already identified and of GSHPs in the UK, due to the rapid reduction in the secured potential sites in Cornwall. In this reporting carbon intensity of the UK grid, the GSHPA released period, it was announced that the project at United an online app that provides realtime CO2 emissions for Downs, headed by Geothermal Engineering Ltd (GEL) various heating systems: had received approval to proceed. The delivery partners https://planetcooler.pythonanywhere.com/static/CO2.html in this project are GEL, GeoScience Ltd, British Geological Survey (BGS) and Plymouth University. During this reporting period, the Renewable Heat The drilling contract has been awarded to a joint Incentive (RHI) for both domestic and non-domestic venture formed between Marriott Drilling of the UK, heating installations (solar, biomass and heat pumps) and Angers-Soehne of Germany, who supplied the finally began to have significant (positive) impact on HAS Innova drilling rig (Figure 1). Site preparation the rate of GSHP installations, following a decline since began in early 2018, and the drilling of the first 2010. A review by DECC / DBEIS of the relative RHI (production) borehole, UD1 commenced in November tariffs for heat pumps compared to other technologies following installation of the shallow conductor casing. led to revised tariffs and a subsequent acceleration in TD was reached in April 2019 at a measured depth of GSHP installations since spring of 2017. The RHI 5275 metres, (5075m TVD) with a down-hole scheme will continue up to March 2021. o temperature of approximately 180 - 185 C (awaiting In April 2019 the Climate Change Committee full recovery before final temperature is known). announced that they are recommending to UK Following logging and preliminary hydro-testing, the Government that in 2025, all new housing will have to rig will be slid on the drill pad to commence the drilling be fitted with low / zero carbon heating systems. At a of the shallower injection well, UD2 in early May. local level, the Greater London Authority (GLA) has More project information is available at also recently announced revised carbon performance https://www.uniteddownsgeothermal.co.uk requirements for new and redeveloped buildings that In addition, funding has been secured for initial fall within its region. development of the other deep EGS project in Cornwall The challenge for the UK GSHP industry will be to at the Eden Project. Final negotiations on the drilling of manage the four year gap between the end of the RHI the first well are currently underway. in 2021 and the requirement for low carbon heating A new assessment of the resource base for EGS systems systems in 2025. in the UK was published in 2017 (Busby, Terrington A comprehensive review of the evolution of GSHPs in 2017). The potential for further suitable EGS sites in the UK domestic sector is summarized in a review Cornwall is already underway. paper by Rees / Curtis (2014), and the initial impact of the RHI scheme was reported at EGC 2016 (Curtis, Pine 2016).

The latest update (Dec 2018) from OFGEM on the RHI installation statistics for Domestic systems is published here: https://www.ofgem.gov.uk/publications-and- updates/domestic-renewable-heat-incentive-quarterly- report-issue-18

and for Non-Domestic systems: https://www.ofgem.gov.uk/publications-and- updates/non-domestic-renewable-heat-incentive-rhi- Figure 1: HAS Innova drilling rig on Borehole UD1 quarterly-report-october-december-2018 at United Downs Cornwall. February 2019

3.4 GSHP Activity 4. MINEWATER. The background to GSHP activity in the UK up to 2013 The EGC 2016 UK Country Update reported on a and 2015 respectively is provided in two earlier significant awakening of interest in the possible use of Country Update papers (viz for EGC 2013 (Curtis et al flooded abandoned coal and metal mines in different 2013) and for WGC 2015 (Batchelor et al 2015). regions of the UK, viz Scotland, England, Wales and Cornwall. A number of potential schemes were Along with installation activity, a number of parallel described, and are not repeated here. In the interim supporting activities have continued. The UK Ground there have been ongoing investigations. It is reported Source Heat Pump Association (www.gshpa.org.uk) that the Coal Authority, who manage abandoned mines has held technical seminars and has continued to in the UK, are developing the heat resource from 16 develop technical standards. In this reporting period a existing minewater treatment schemes. In South Wales, new standard for Thermal Pile installations has been following feasibility studies and reports, Bridgend published, and all of the UK GSHPA standards are now Council have started drilling into old coal mines in the available via the CIBSE website. To promote Llynfi Valley with the intention of heating 200+ homes. awareness of the significant carbon reduction potential 3 Curtis et al

The British Geological Survey are also developing a The various deep geothermal heat projects that were new geothermal research facility over former coal reported in for EGC 2016 are still taking considerable workings in Glasgow time and effort to bring to fruition. Hopefully the Bridgend minewater project should be realised and There are few technical barriers to putting the old mine encourage the utilisation of other UK minewater workings back to work in sustainable developments to resources at last. provide heating, hot water and cooling. However, the issues of surface and subsurface ownership, licences for REFERENCES abstraction and discharge, the control of pollution and Abesser, C., Schofield, D., Busby, J., Bonsor, H.: Who the potential claims of mineral owners all need Owns (Geothermal) Heat? British Geological resolution for any particular project. Survey http://geoatlantic.eu/portfolio/wp- 5. MEETINGS AND PUBLICATIONS. content/uploads/2019/01/whoOwnsGeothermalHe The level of interest in all things geothermal in the UK at.pdf (Nov 2018) is reflected in recent symposia/meetings held on the subject and a number of generic papers on the subject. Batchelor, A.S.: Geothermal Resources of the UK - Country Update Report 1985-1990, International The principal UK geothermal energy conference was Symposium on Geothermal Energy, GRC the 6th London Geothermal Symposium held on 16th International Volume, Hawaii, USA, (1990). October 2017 at the Geological Society. Batchelor, A.S.: Geothermal Developments in the UK- The UK GSHPA continues to hold its Annual AGM Country Update Report 1990-1995, IGA WGC and Seminar/Exhibition and has also held two technical Proceedings, Florence Italy, (1995). seminars in this reporting period, the last one in 2018 Batchelor, A.S, Curtis, R.H, Ledingham, P.: Country being hosted at the University of Leeds. Update for the United Kingdom, IGA WGC Proceedings, Antalya, Turkey, (2005). 6. RESEARCH Batchelor, A.S, Curtis, R.H, Ledingham, P.: Country UK geothermal research is largely concentrated on Update for the United Kingdom, IGA WGC developing the potential of less conventional resources Proceedings, Bali Indonesia, (2010). as deep hot sedimentary aquifers are only found in a few regions and often not in regions of high heat Batchelor, A.S, Curtis, R, Ledingham, P, Law, R.: demand. Much research is undertaken within the Country Update for the United Kingdom, Proc Higher Education sector, usually as part of PhD World Geothermal Congress, Melbourne, programmes, as follows: Australia, (April 2015). - Exploiting the permeability of deep fracture Busby J., Terrington, R.: Assessment of the Resource systems as viable geothermal resources (Glasgow Base for Engineered Geothermal Systems in Great University). Britain. Geothermal Energy, pp18, DOI 10.1186 - Exploring the extent of palaeokarst within the /s40517-017-0066-z. (2017) buried Carboniferous Limestone and its geothermal Curtis, R., Ledingham, P, Law, R, Bennett, T: potential (Durham University). Geothermal Energy Use, Country Update for - Quantifying the potential of the thermal resource United Kingdom. European Geothermal Congress within disused mine systems in the UK (Newcastle 2013, Pisa, Italy, (June 2013). University, Glasgow University, British Geological Survey). Curtis, R., Law, R., Adams, C.: Geothermal Energy Use, Country Update for the United Kingdom. 7. CONCLUSIONS European Geothermal Congress 2016, Strasbourg, France (Sept 2016). With the increasing pressure to develop secure, low carbon, sustainable energy sources for the delivery of Curtis, R., Pine, T.: RHI – Incentive or Inhibitor to UK both electricity and heating, there has been a revival of GSHP Growth? European Geothermal Congress interest in geothermal energy in the UK. After a wait of 2016, Strasbourg, France (Sept 2016). over 30 years, real activity has restarted in Cornwall, Downing, R.A. and Gray, D.A.: Geothermal Energy with the United Downs Deep Geothermal Project now The Potential in the United Kingdom, HMSO, fully underway. The outcome of this significant project ISBN 0 11 884366 4, (1986). will be closely followed, with interest already developing in future systems in . Garnish, J.D.: Geothermal Resources of the UK - Country Update Report, International Symposium GSHP activity is at last back on an upward curve after on Geothermal Energy, Geothermal Resources a decline triggered by a combination of factors in 2010. Council, International Volume, ISBN 0-934412- The requirement for low carbon domestic heating 88-X, Hawaii USA, (1985). systems from 2025 should mean that there is a prospect of rapid growth in this sector. Law, R., Chendorain, M., Free, M., Collins, M.: Development and Deployment of Deep

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Geothermal Single Wells in the UK.European Smith, M.: Southampton Energy Scheme. World Geothermal Congress 2016, Strasbourg, France Geothermal Congress, IGA, Kyushu - Tokyo (Sept 2016). Japan, (2000) Rees, S., Curtis, R.: National Deployment of Domestic Geothermal Heat Pump Technology: Observations Acknowledgements of the UK Experience 1995 – 2013. The views expressed in this paper are those of the Energies 2014, 7(8), 5460-5499; authors alone. https://doi.org/10.3390/en7085460

Sinclair Knight Merz (SKM): Geothermal Energy Potential: Great Britain and Northern Ireland, (May 2012).

Tables A-G

Table A: Present and planned geothermal power plants, total numbers

Total Electric Power Share of geothermal in total Geothermal Power Plants in the country electric power generation

Capacity Production Capacity Production Capacity Production (MWe) (GWhe/yr) (MWe) (GWhe/yr) (%) (%)

In operation 0 0 81,300 * 339,000 * 0 0 end of 2018 *

Under construction 0 0 2500 18,750 0 0 end of 2018

Total projected 1 - 3 ~ 15 80,000 340,000 0.0025 0.0044 by 2020

Total expected 3 ~22.5 82,000 350,000 0.0036 0.0064 by 2025

Under development In case information on geothermal licenses is available in your country, please specify here the number of licenses in force in 2018 (indicate exploration/exploitation if applicable): Under investigation

* If 2017 numbers need to be used, please identify such numbers using an asterisk

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Table C: Present and planned deep geothermal district heating (DH) plants and other uses for heating and cooling, total numbers

Geothermal heat in Geothermal heat for Geothermal heat in Geothermal DH plants agriculture and industry buildings balneology and other

Capacity Production Capacity Production Capacity Production Capacity Production

(MWth) (GWhth/yr) (MWth) (GWhth/yr) (MWth) (GWhth/yr) (MWth) (GWhth/yr)

In operation 3 14.8 0.55 ~3.0 end of 2018

Under constru-

ction end 2018

Total projected

by 2020

Total expected 12 90.0 2 14 0.55 ~3.0 by 2025

Table D1: Existing geothermal district heating (DH) plants, individual sites

Geoth. Total 2018 Geoth. Year capacity capacity produc- share in Locality Plant Name commis- CHP Cooling installed installed tion * total prod. sioned (MWth) (MWth) (GWth/y) (%)

Southampton 1987 YES ~2.0 9.7 14.8* ?

total

* If 2017 numbers need to be used, please identify such numbers using an asterisk

Table E: Shallow geothermal energy, ground source heat pumps (GSHP)

Geothermal Heat Pumps (GSHP), total New (additional) GSHP in 2018 *

Number Capacity Production Number Capacity Share in new (MWth) (GWhth/yr) (MWth) constr. (%)

In operation 28,800 520 936 3000 ~50 <0.5 end of 2018 *

Projected total 37,800 680 1,224 by 2020 * If 2017 numbers need to be used, please identify such numbers using an asterisk

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Table F: Investment and Employment in geothermal energy

in 2018 Expected in 2020

Expenditures Personnel Expenditures Personnel (million €) (number) (million €) (number)

Geothermal electric power 20.0 ~15 2.0 5

Geothermal direct uses 0.1 ~5 1.0 10

Shallow geothermal 75 ~150 80 180

total 95.1 170 83 195

Table G: Incentives, Information, Education

Geothermal electricity Deep Geothermal for Shallow geothermal heating and cooling

Financial Incentives No No No – R&D

Financial Incentives ROC / CFD (A) RHI (=FIT) RHI (=FIT) – Investment

Financial Incentives – Operation/Production

Information activities Community engagement No No – promotion for the public for United Downs Project

Information activities – geological information

Education/Training Components of MSc / BSc Components of MSc / BSc – Academic courses courses

Education/Training No No Technician level training – Vocational for GSHP installers

Key for financial incentives:

DIS Direct investment support FIT Feed-in tariff -A Add to FIT or FIP on case the amount is determined LIL Low-interest loans FIP Feed-in premium by auctioning RC Risk coverage REQ Renewable Energy Quota O Other (please explain)

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