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Overcoming Research Challenges for Geothermal Energy

Energy Research Knowledge Centre

E n e r g y R e s e a r c h K n o w l e d g e C e n t r e

This publication was produced by the Energy Research Knowledge Centre (ERKC), funded by the European Commission to support its Strategic Energy Technologies Information System (SETIS). It represents the consortium’s views on the subject matter. These views have not been adopted or approved by the European Commission and should not be taken as a statement of the views of the European Commission.

The manuscript was produced by Massimo Angelone and Stefano Sylos Labini from the Italian National Agency for New Technologies, Energy and Sustainable Economic Development (ENEA).

The purpose of this brochure is to summarise comments and rec-ommendations reported in previous documents from national and international organisations working on renewable energy or involved in geothermal activities.

While the information presented in this brochure is correct to the best of our knowledge, neither the consortium nor the European Commission can be held responsible for any inaccuracy, or accept responsibility for any use made thereof.

Additional information on energy research programmes and related projects, as well as on other technical and policy publications is available on the Energy Research Knowledge Centre (ERKC) portal at:

setis.ec.europa.eu/energy-research

Manuscript completed in September 2014

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Reproduction is authorised provided the source is acknowledged.

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Photo credits: Istockphoto, ECN, Shutterstock

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O v e r c o m i n g R e s e a r c h C h a l l e n g e s f o r G e o t h e r m a l E n e r g y1

Contents Key messages 2

Current status of geothermal energy 3

Challenges and potential of geothermal 5

Figuring out the future for geothermal 6 - Geothermal energy in EU Member States 11 - Geothermal strategies in non-EU countries 14

Research and opportunities 17 - Exploring and drilling technologies 17 - Electricity production 17 - Heating and cooling 20

- Desalination 21 - Environmental impact mitigation and public acceptance 22

Looking to the future 23

Policy implications and recommendations 26

References 28

Selected websites on geothermal energy 31

List of Acronyms 32

E n e r g y R e s e a r c h K n o w l e d g e C e n t r e2

Key messages• Emerging technologies for electricity production are at early-commercialstage and technological innovation for cost reduction is required as wellas deployment of large-scale Enhanced Geothermal System plants

• RD&D financial support and a new regulation frameworkare necessary for electricity exploitation

• Demand pull in the exploitation of heating and cooling is crucial

• Pilot projects for volcanic islands are advisable in orderto achieve a higher energy independence

• Need for environmental and socio-economic assessment andinformationinformationinf to population involved in deep geothermal exploitation

Natural geothermal

energy plant in Pisa, Italy.

© iStockphoto


Current status of geothermal energyThis Geothermal Energy Policy Brochure summarises the current status of develop-ments in geothermal energy. Emphasis is placed on the results of geothermal energy research programmes and their implications on future policy decisions and technological challenges.

• There is a mismatch between research, development and demonstration (RD&D) and industrial applications: the current large research programmes are not con-nected to immediate industrial applica-tions, but look towards future develop-ments, while current applications, such as heating and cooling (HC), are not associ-ated with large RD&D projects because they are related to consolidated technolo-gies that require incremental innovations.

• In 2013, shallow geothermal was the larg-est sector in terms of installed capacity with 63 % of total capacity, followed by direct use with 30 % and electricity with 7 %. In 2012, about 100 000 geother-mal heat pumps (GHP) were installed in the European market and total number of GHP in operation within the European Union (EU) is about 1 million units. The number of operational geothermal power plants is 68, providing an installed capac-ity of 935 MWe (megawatt electric) and producing 5 820 GWe (gigawatt electric). The direct and indirect jobs provided num-ber about 11 000 units in the geothermal electric sector and about 100 000 units in the GHP sector.

• These data show that the exploitation of deep geothermal energy for electricity production, in particular Enhanced Geo-thermal Systems (EGS), has a low impact on the economy, notwithstanding the fact that major research projects are focusing on this field. On the contrary, geothermal applications that are economically impor-tant, mostly heating and cooling, are not linked to major research projects, but mainly depend on the new construction market trend and on investments in reno-vating old buildings.

• For these reasons, a relevant increase in RD&D investment for exploiting electricity production requires effective policies to stimulate innovation and experimentation by launching new demonstration projects in order to move to large-scale EGS plants (the so-called “technology push” strategy). This approach implies a qualitative leap by governments and banking systems as well as in the involvement of large corpo-rations which should play an active role in the network of universities and public research centres.

• In the HC sector it is important to set up financial incentives and legislative rules in the new construction market to stimu-late the use of geothermal technolo-gies (“demand pull” policies) and thereby growth in production and innovation pro-cesses in the heat pump sector. Further-more, it is essential to reduce permissions and authorisations in order to liberalise installations of heat pumps.


• Last but not least, gas emissions and micro-seismicity are factors that reduce public confidence in EGS development. For this reason, it is still worthwhile fully assessing the social and environmental impact of the activities by developing new tools for analysis and involving the popula-tion in the geothermal projects in order to achieve wide public acceptance.

Geothermal power plant

production line.© iStockphoto


Challenges and potential of geothermal The importance of geothermal energy origi-nates from the availability and continuity of the source for heat exploitation, and the fact that it is clean energy which produces low harmful emissions and ensures cost stabil-ity for end-users. Furthermore, geothermal energy presents no geopolitical risk and can be used with the current industrial technol-ogy for HC, which has a significant impact on EU employment and gross domestic product (GDP). HC technologies are competitive, are characterised by a good level of diffusion, and are more dynamic than those in the electricity sector.

Conversely, geothermal energy has some limitations and barriers to overcome: high temperatures are concentrated in specific areas, geothermal energy has a lower capac-ity factor compared to fossil fuel and nuclear energy, and there are frequent mismatches between optimal energy site locations and district requirements. Furthermore, electric-ity grids need to be upgraded. The negative impacts are mainly related to hot water and gases released into the environment and to the occurrence of induced earthquakes triggered by rock fracturing, as has been observed at some experimental EGS plants.

Technological barriers lie mainly in high exploration and high investment costs for electricity production, long-term investment return, and the risk of failure during the exploration and drilling/stimulation phase

of a geothermal project, while technologies for offshore and magmatic exploitation are still at the experimental stage. In addition, regulations and administrative procedures represent obstacles that do not encourage the application and diffusion of this renew-able energy.

This brochure aims to provide suggestions for promoting awareness of geothermal technol-ogies and their real potential. It highlights the current status of the different applications for geothermal energy development. The main issues to be tackled are:

• improvements needed for resource assess-ment and forecasting;

• improvements in modelling and drilling technologies;

• fracturing techniques, water supply, and seismic 3D reservoir assessment;

• transmission and system integration; • environmental impact mitigation.

The Geothermal Energy PB also focuses on the current status of energy research regard-ing different technologies, based on the main European and international programmes, in order to show where the research should be focused to facilitate the spread of geother-mal technologies.Finally, suggestions are made for the devel-opment and diffusion of innovative geother-mal applications in different sectors (residen-tial, industrial, water desalination).


Figuring out the future for geothermal Geothermal energy is a dynamic and flexible source of renewable energy which is recog-nised as making a significant contribution to Europe’s energy mix since it could provide continuous heat production almost every-where.

First, the European strategy for geothermal energy development is related to the Direc-tive on the promotion of the use of energy from renewable sources, adopted on 23 April 2009 (Directive 2009/28/EC). According to Article 4 of this Directive, Member States must adopt a National Renewable Energy Action Plan (NREAP) setting out national tar-gets for the share of energy from renewable resources in electricity, heating and cooling, and transport, and the measures to be taken to achieve those targets. The following tables show the NREAP energy production targets from geothermal resources for each Member State for the years 2015 and 2020.

Most electrical applications should dou-ble their output in 2020 (10.9 TWh with 1 613 MW of installed capacity). Among the EU countries, France, Germany, Italy and Portugal should expand their existing installed capacity, while Greece, Hungary and Spain should develop their own sectors, in particular by operating binary cycle plants. (EurObserv’ER, 2013).

The energy output from geothermal instal-lations should increase significantly by 2020 to reach 2551 ktoe (thousand tonnes of oil

equivalent), with an interim target of 1296 ktoe by 2015 (ECN, 2011).

In the Working Document SEC(2011) 131 ‘Review of European and national financing of renewable energy in accordance with Article 23(7) of Directive 2009/28/EC’, the European Commission pointed out that the feed-in tariff is the main instrument in the EU for supporting geothermal electricity. The costs of capital for renewable energy system (RES) investments observed in countries with established tariff systems have proven to be significantly lower than in countries using other instruments that involve higher risks for future return on invest-ments (ECOFYS et al., 2010).

Austria, Czech Republic, France, Germany, Greece, Hungary, Portugal (Azores only), Slovakia, Slovenia, Spain and Switzerland have dedicated feed-in tariffs for geother-mal energy. The most attractive schemes are found in Switzerland (max. ct€ 33/kWh), Germany (ct€ 25/kWh for all projects and an additional ct€5 for EGS) and France (ct€ 20/kWh with an energy efficiency bonus of up to ct€ 8/kWh).

Estonia, Italy, the Netherlands and Slovenia promote geothermal electricity generation by means of feed-in premiums (a bonus paid on top of the electricity market price) as an alternative to feed-in tariffs. Currently, Bel-gium (Flanders), Romania and the UK have a quota system in place based on green cer-tificates (EGEC, 2013).


Table 1: Projected geothermal electricity generation for the period 2015-2020, GWh

Table 2: Projected total geothermal heat energy for the period 2015-2020, ktoe

2015 2020Belgium 0 29Czech Republic 18 18Germany 377 1654Greece 123 736Spain 0 300France 314 475Italy 6 191 6 750Hungary 29 410Austria 2 2Portugal 260 488Slovakia 28 30TOTAL 7342 10 892

Source: NREAPs, ECN (2011)

2015 2020Belgium 4 6Bulgaria 3 9Czech Republic 15 15Denmark 0 0Germany 234 686Greece 23 51Spain 5 10France 310 500Italy 260 300Lithuania 4 5Hungary 147 357Netherlands 130 259Austria 27 40Poland 57 178Portugal 18 25Slovenia 19 20Slovakia 40 90TOTAL 1 296 2 551

Source: NREAPs, ECN (2011)


In the HC sector, given the existence of con-solidated technologies, it seems more effec-tive to use a “demand pull” mechanism that works by incentives granted to geothermal technology applications in order to stimulate the growth of production and innovation pro-cesses. Operational aid similar to a feed-in tariff system is now beginning to be explored in some Member States, partly because of the inclusion of the sector in the European regulatory framework.

The Communications ‘Energy Roadmap 2050’ (COM(2011) 885) and ‘Renewable energy: A major player in the European energy market’ (COM(2012) 271) point out how crucial it is to invest in new renewable technologies and to improve existing ones through RD&D.

The Implementing Agreement for the Co-operative Programme on Geothermal Energy Research and Technology provides a frame-work for international co-operation on RD&D. Activities include information sharing; devel-oping best practice in the use of technologies and techniques; exploration, development and utilisation of geothermal; and producing and disseminating authoritative analysis and databases. There are currently 15 contracting parties, including Iceland and Mexico, as well as five sponsors.

Strategic research priorities in terms of scientific research and development in the geothermal sector were also identified in two noteworthy documents: ‘Strategic Research Priorities for Geothermal Technol-

Production line in thermal

power plant. © iStockphoto


ogy’ (European Technology Platform on Renewable Heating and Cooling – TP RHC 2012) and ‘Strategic Research Priorities for Geothermal Electricity’ (European Technol-ogy Platform on Geothermal electricity - TP Geoelec 2012). The aim of these Platforms is devoted to reducing Europe’s dependency on imported fossil fuels, stabilising energy prices, and achieving climate change miti-gation goals.

The Geothermal Technology Roadmap of the European Technology Platform on Renew-able Heating and Cooling (March 2014) highlights the technological challenges for an accelerated deployment of geothermal heating & cooling across Europe. These are to develop innovative solutions especially

Figure 1: RD&D expenditure on geothermal energy in 2011 in some European countries (EUR million - 2012 prices and exchange rates)

for refurbishing existing buildings, but also for zero and plus energy buildings and to develop geothermal District Heating (DH) systems in dense urban areas at low tem-perature with emphasis in the deployment of Enhanced Geothermal Systems. Finally, the third goal is to contribute to the decarboni-sation of the industry by providing competi-tive solutions for heating & cooling.

RD&D support from Member States must be coordinated at European and national level. Initiatives like Geothermal ERA NET, a con-sortium of funding agencies working together to coordinate geothermal RD&D support pro-grammes, and supported by the EU’s Seventh Framework Programme (FP7), should enable this coordination to be set up.

Source: IEA, RD&D Statistics Database

2018.2

9.8

8.1

5.74.7

0.8 0.6 0.1 0.030

2

4

6

8

10

12

14

16

18

Germany

Switzerland

ItalySpain

France

NetherlandsBelgium

Austria

Ireland


Geothermal RD&D spending shows major variations among the Member States, although some research priorities are com-mon in some technologies among groups of countries. Synergies should be exploited in these areas, which are particularly important for capital-intensive RD&D activities.

In 2011, overall public RD&D expenditure on geothermal energy amounted to EUR 48 million, representing about 6.2 % of the total public budget for RD&D activities in the RES sectors for those countries analysed (Fig. 1). Germany represents the country with the highest public expenditure for RD&D activi-ties in the geothermal sector by far, spend-ing more than EUR 18 million in 2011, which corresponds to 38 % of the total geothermal budget for the countries under consideration. Switzerland follows with EUR 9.8 million, then Italy with EUR 8.1 million, Spain with EUR 5.7 million and France with EUR 4.7 million.

Until 2012, the EU RD&D funding allocated to geothermal energy during FP6 and FP7 amounted to EUR 29.4 million which was as much as 10 times lower than the funding for photovoltaic (The Geothermal Technol-ogy Roadmap of the European Technology Platform on Renewable Heating and Cooling - March 2014). Moreover, to date the geo-thermal sector, together with biomass, has experienced a proportional reduction in FP7 funding (from EUR 17.3 million in FP6 to EUR 12.1 million) (Pezzuto et al., 2012).

The NER300 programme is another financing instrument which exists at the EU level. In the first call, a Hungarian EGS project near Fer-encszállás received EUR40 million. In the 2nd round of the European NER300 programme two geothermal projects were selected for support. The first project in Croatia concerns

the production of electricity and heat from a geothermal aquifer and its associated natural gas. The project, located in Drasko-vec, close to the city of Prelog in Croatia, will generate 3.1 MWe from geothermal hot brine using an Organic Rankine Cycle (ORC).

The second project is GEOSTRAS, a French-German cross-border project that aims to pro-duce electricity and heat from a high tempera-ture geothermal resource near Strasbourg. It involves creating a circulation loop several kilometres long at a depth of between 4 km and 5 km that will function as a semi-open underground heat exchanger. The proposed geothermal plant is expected to produce 6.7 MWe electricity and 34.7 MWth heat.

In the context of the European Energy Research Alliance (EERA), a main Joint Programme on Geothermal Energy (JPGE)1 has been defined involving a total of 420 people who have been assigned different roles and responsibilities. The research infrastructures are shared among the participants and the comprehensive budget is about EUR 30 million per year.

The main objectives of the EERA concern increasing the contribution by geothermal energy to global power production. The research programme aims to:

• prepare EGS for large-scale deployment;• enhance the production from current oper-

ational plants;• explore on a large scale new, untapped

deep-seated (up to 6 km) hydrothermal systems;

• access ‘high potential’ resources such as supercritical fluids and magmatic systems.

Beside the technological challenges, other relevant aspects for the further development

1 For further information see: http://www.eera-set.eu/index.php?index=22


of geothermal energy need to be addressed with innovative approaches and tools to:• improve risk assessment and manage-

ment for a reliable evaluation of the tech-nical, environmental and economic sus-tainability of the projects;

• secure the social acceptance of geother-mal projects by ensuring that potential site and technology-specific side effects are typically relatively minor compared to the benefits;

• provide guidelines for the regulatory author-ities and policy-makers for the sustainable development of geothermal initiatives.

The JPGE will be developed over 10 years and is divided into five sub-programmes:

• Resource assessment• Exploration• Accessing and engineering of the reservoir• Process engineering and design of power

systems• Sustainability, environment and regulatory

framework

Geothermal energy in the EU Member States

National strategies for geothermal energy in the EU Member States have a significant impact on geothermal technology devel-opment because critical issues for techno-logical improvement and applications are being addressed. The cases of France, Ger-many, Italy and Spain have been highlighted because these countries are very active in this field, as shown in Fig. 1 above.

FranceThe National Committee for geothermal energy was established in 2010 with the task of promoting the development of this impor-tant renewable energy source, upon which the country has been focusing in recent years. The committee in question is composed of 35 experts who have already started work-ing on three guidelines: the simplification of bureaucracy and regulations regarding the facilities, staff training, and information for the general public.

Geothermal plant in Tuscany. © iStockphoto


So many projects have already been com-pleted in the country over the last 40 years and the French objectives for geothermal energy development in the medium term appear to be even more ambitious: by 2020, the production of geothermal energy will have increased sixfold. Substantial invest-ment has also been made available for the creation of a network of geothermal power plants of the last generation, amounting to EUR 20 billion.

To date, France represents the third coun-try per total capacity installed in the EU, both for electricity generation (17 MW) and direct heat use (365 GWth) from geothermal sources. The country has two high-tempera-ture geothermal plants, both in the overseas territories where the highest geothermal energy potential is to be found. In the com-ing years, the total capacity at the Bouillante and Guadalupe plants is expected to reach 20 MW. In the low-and medium-energy sec-tors, there are about 50 plants in France which are mainly used for district heating. In particular, in the Paris area there are 36 geo-thermal doublets that are directly connected to heating networks (IEA-GIA, 2012).

In 2011, a strategic geothermal roadmap was published by the ADEME (the French Agency for Environment and Energy). It describes the challenges and issues in the geothermal sec-tor, gives a vision for 2020, and identifies the technical and scientific barriers to defining R&D priorities and the need for demonstra-tion operations. Progress varies considerably among the various geothermal uses:

• Electricity: many projects are emerging on the mainland (combined heat and power), but fewer are planned for the overseas regions, due to a less-favourable frame-work (notably, the feed-in tariff);

• Direct use: a few installations are built

each year in the Paris Basin, which is encouraging but not sufficient. To reach the objective, the number of installations in the Paris Basin must be increased and other projects must be launched in a vari-ety of aquifers and geological contexts;

• Ground-source heat pumps: the installed capacity is growing very slowly, so the pace must increase to reach the target.

Germany In Germany, according to AGEE-Stat (the Min-istry of Environment working group on renew-able statistics), net installed geothermal capacity increased by 4 MW in 2012 via the new Insheim plant. The country now has seven geothermal cogeneration plants and the geo-thermal electric output is reaching 35 GWh (Agemar et al., 2014). Two more plants were commissioned in 2013 at Durrnhaar (5.5 MW) and Kirchstockach (5.5 MW), both in Bavaria.

Germany intends to significantly increase its geothermal electrical capacity by an attrac-tive feed-in tariff of €0.25/kWh over 20 years. The country plans to develop geother-mal resources of about 280 MW by 2020, compared to 12 MW currently installed. To date, there are about ten projects under con-struction in Germany with a capacity of more than 36 MW, and even more at the develop-ment stage.

From 2003 to 2013, the annual produc-tion of geothermal district heating stations increased from 60 GWh to 530 GWh. During the same time, the annual power production increased from 0 GWh to 36 GWh. Currently, almost 200 geothermal facilities are either in operation or under construction in Germany.

ItalyIt is well known that Italy is rich in geothermal energy, and since the beginning of the last century it has exploited this source to produce


electricity using large plants. In addition, Italy is one of the countries with great technologi-cal know-how in this field. The historical and important applications of geothermal energy are located in Tuscany. Over 30 manufactur-ing plants, with an installed capacity of 875 MW, an output energy of more than 5 600 GWh per year, and about 5 500 of direct and indirect jobs, represent about a quarter of the electricity consumed in the region itself, and nearly 2 % of the national supply. All activi-ties aimed at growing geothermal electricity production are made by the national electric company Enel. Geothermal energy has great potential for development and may allow the country to reach the target of 25 % of energy produced from clean sources more easily. At present, geothermal energy supplies 10 % of electrical energy from renewable sources and with the new legislative tools is expected to double within a short time (UGI, 2011).

In the Italian legal system, geothermal energy does not belong to the landowner but is the exclusive heritage of the state, like mineral resources. Consequently, geothermal exploi-tation requires a public concession. With the launch of the legislative Decree No. 22 of 11 February 2010, the rules for obtaining the necessary permits for the implementation of geothermal resources development projects for energy purposes, in particular, have been simplified. In this legislative decree, particu-lar emphasis was placed on the production of geothermal energy for non-electric uses and introduced a special and innovative dis-cipline related to geothermal heat pumps. Such technology, with or without the extrac-tion of water from the shallow subsoil, can be exploited in areas not characterised by high geothermal gradients.

Spain Cercs thermal plant chimney.© iStockphoto


The applications of geothermal energy used by private citizens – heating and cooling of buildings, greenhouses and sports facili-ties – are regulated by simplified forms of authorisation comprising incentives provided for renewable energy and energy efficiency. In this way, it should be possible to stimu-late the use of geothermal technologies and, thus, development of the geothermal industry.

As far as RD&D is concerned, an important project for geothermal energy exploitation – the Campi Flegrei Deep Drilling Project – has been launched in the suburban area close to Naples. This area is characterised by tem-peratures of about 150 °C at some hundred metres and has huge potential for heat sup-ply and electricity production.

SpainThe estimated geothermal potential for electricity production (conventional and new EGS) is close to 3 000 MWe. There has been an increasing trend in renewable energies in Spain over the last decade. In 2013, primary energy consumption of renewable energy reached 17 million toe (14.2 % of the total energy mix) and 7.5 % higher than the previ-ous year (IDAE, 2013). This trend has been seen as an example of successful policies to promote renewables energies. In 2013, the electricity generated from renewable sources accounted for 33.5 % of gross electricity con-sumption in Spain (Eurostat database). Despite the importance of Spanish geother-mal resources, the importance of geother-mal energy is low, notwithstanding the very large number of studies and investigations conducted up until the end of the 1980s. However, recently, there has been renewed interest in geothermal exploitation. Cur-rently in Spain there are no high-enthalpy geothermal plants for electricity generation,

although there is a large and growing inter-est in developing such projects in the short to medium term.

Therefore, for deep geothermal energy the technological challenge is to find ways of using existing geothermal resources in a technically and economically viable manner, which is only possible via the technological development of new drilling methods for reducing costs and stimulating wells.

At the end of 2012, the installed capacity of shallow geothermal energy was 50 MWth (EGEC, 2013). Spain’s target for geothermal heat use, in the decade from 2011-2020, has been fixed at 50 ktoes, to be achieved by using direct thermal applications and heat pumps. Studies on geothermal district heating development are ready to begin, and there are several projects for district heating networks in Madrid, Burgos and Barcelona, for example. However, some of these pro-jects are at the initial geothermal explora-tion phase.

Geothermal strategies in non-EU countries

Over the next few years, global growth is expected in geothermal energy, according to the most recent report by the Geothermal Energy Association (GEA) on the global geo-thermal market, which estimates the current installed geothermal capacity worldwide at 11 772 MW. According to the Renewable Energy Policy Network’s Renewables 2013 Global Status Report, the United States is leading the installed generating capacity in the world with 3 400 MW, followed by the Philippines (1 900 MW), Indonesia (1 300 MW), Mexico (1 000 MW), Italy (900 MW), New Zealand (800 MW), Iceland (700 MW) and Japan (500 MW).


It is important to point out the increase from 30 to 64 in the number of countries which are showing an interest in the development and applications of geothermal energy. This increase depends on several factors which are mainly related to the discovery of new resources, technological improvements in exploration and the ability to exploit resources in the medium- and low-enthalpy range at greater depths, together with the opening up of new prospects and markets besides the traditional ones.

In the near future, the United States will be the country making the greatest effort in this field, followed by certain countries in the Pacific area, such as Indonesia which, considering its huge theoretical geothermal potential of 28 000 MW, aims to produce more than 9 000 MW of geothermal power by 2025, thereby becoming the world’s lead-ing geothermal energy producer.

Recently, China has expressed a great inter-est in geothermal energy with the aim of using this resource to cover 1.7 % of primary

energy demand by 2015, as reported by the Ministry of Land and Resources. The goal is to replace the use of 68.8 million tonnes of coal and reduce 180 million tonnes of carbon dioxide emissions. In the field of spa tour-ism, this resource is already widely used in some regions, especially in the province of Chongqing (south-west China), where there are 107 thermal sites. Currently in China, geothermal explorations are under way in 29 provinces, with public funding for research activities alone in 2011 reaching 164 million yuan (EUR 17 million). The objective is to pro-vide systems for the production of electricity across the country

In Canada, the largest conventional resources for geothermal power are located in British Columbia, Yukon and Alberta, regions which also have the potential for EGS exploitation. In 2007, it was estimated that geothermal energy could meet half of British Columbia’s electricity needs. Canada officially reports about 30 000 earth-heat installations pro-viding space heating to residential and com-mercial buildings. The most advanced project

Cogeneration in China.© iStockphoto


exists as a test geothermal electrical site in the Meager Mountain-Pebble Creek area of British Columbia, where a 100-300 MW facil-ity could be developed.

An important contribution could also come from South American countries, where there is large geothermal potential along the Andean Ridge and on the Central Pacific side. Ecuador has announced feasibility studies to analyse the country’s geothermal potential. The government has announced five projects that will exploit geothermal energy – the total potential has been estimated at > 500MW – the aim being to increase the percentage of energy from alternative sources. Pre-feasibil-ity studies to the value of 1.1 million dollars have been planned in Carchi province where the potential has been estimated at between 60-130 MW. However, the number of pro-jects remains limited and those that could be accomplished relate mainly to the policies of foreign companies that have been awarded concessions for exploitation.

In Switzerland, 22 deep geothermal projects are currently at the planning stage, their main objective being to produce electricity. Nevertheless, in July of 2013, earthquakes of magnitude 3.5 in Basel and St Gallen, produced by an unexpected encounter of gas at a depth of 4450 m, have significantly reduced the population’s confidence in EGS geothermal plant development.

Africa has huge geothermal potential, mostly unexplored, that has attracted the interest of many countries in geothermal resources development. Potential areas are: the Republic of Congo, Eritrea, Ethiopia, Kenya, Madagascar, Malawi, Mozambique, Rwanda, Tanzania, Uganda and Zambia with an esti-mated potential greater than 15 GW. In Ethi-opia, where it is up to 5 GW, the government is aiming to increase the power developed with the help of foreign sponsors such as the World Bank. However, the most promising geothermal area in Africa is in the Rift Valley where Kenya is planning the construction of a number of plants although it is not known when they will become fully operational.

In Australia, the government has provided research funding for the development of EGS technology. One of the most important projects in the world is being developed in Australia’s Cooper Basin by Geodynamics. The Cooper Basin project has the potential to develop 5 000-10 000 MW. Australia now has 33 firms involved in exploration, drilling and EGS project development. The country’s industry has been helped significantly by a national Renewable Portfolio Standard of 25 %, renewable by 2025, a Green Energy Credit market, and supportive collaboration between government, academia and industry.

Geothermal plant in California.

© iStockphoto


Research areas and opportunitiesThe main research areas and applications contributing to geothermal energy develop-ment and deployment are:

• exploring and drilling technologies• electricity production• heating and cooling • desalination• environmental impact mitigation and pub-

lic acceptance.

Exploring and drilling technologies

The main goal is to greatly improve model-ling techniques for assessing the geother-mal potential, to reduce drilling costs and the number of boreholes that are very cost-effective.

For the same reason, in the assessment of geothermal resources, research and explora-tion synergies with the oil and gas industries should be considered.

New drilling technologies should be devel-oped to reduce costs and drilling times. In this context, it is also necessary to improve and develop new 3D models of geothermal reser-voirs to reduce drilling and exploitation risks.

Drilling typically accounts for 30-50 % of the total development cost of electricity genera-tion. For example, two boreholes to a depth of 3 000 m. can cost up to EUR 14 million,

while piping costs vary from EUR 200 to EUR 6 000 million in urban areas.

Improving drilling technologies and model-ling accuracy to better estimate geothermal potential are crucial steps for assessing the cost and investment time return. Experi-ence suggests that this is the way to greatly improve geothermal energy development.

Electricity production

Nowadays, there are about 12 000 MW of geothermal power plant installed capacity in the world and 1 700 MW of geothermal power under construction. However, these data rep-resent a small fraction when compared to the data for wind energy (320 000 MW) and pho-tovoltaic (140 000 MW). The average annual growth rate for electricity produced from geo-thermal heat is 5 %, which is much lower than wind and solar electricity (20-30 %).

The electricity produced by geothermal heat using new technological approaches such as EGS does not attract significant investments in RD&D from large energy companies in relation to actual electricity surplus in indus-trialised countries. This overproduction is the consequence of both the economic crisis and the concomitant expansion of solar and wind energy, which are the most convenient clean energies requiring only a short time for imple-mentation. In addition, EGS power plant is still in the prototype stage and a further step


towards large-scale demonstration plant is crucial, as is the reduction of costs and time for geothermal power plant construction. Compared to other technologies in Europe, asset financing for geothermal energy is quite low: EUR 124 million for a new capacity of 34 MW. Furthermore, scaling and corrosion represent one of the most important chal-

lenges facing deep geothermal exploitation. RD&D activities are required in new materials and operational methods, bearing in mind the significant impact of scaling and corrosion on the cost and efficiency of geothermal tech-nology. The development of new components from polymers or plastics, optimised coating, the use of aluminium, and new materials to tackle deterioration resulting from UV expo-sure should all be taken into account.

It is also important to remember that start-up costs are relatively high: an average geo-thermal plant costs EUR 3 500 per kilowatt (kW) installed versus EUR 1 200 per kW installed for a natural gas plant. A conven-tional 20 MWe high-temperature plant costs EUR 80-120 million and a 5 MW EGS plant costs EUR 35-65 million.

The most important RD&D project on EGS to be launched by the EU was carried out at Soultz-Sous-Forêts in France where it has recently connected its 1.5 MW demonstra-tion plant to the grid. The surface geothermal

Table 3: Main EGS research projects in the world

Project Country MW Plant Type Depth (km)

Soultz France 1.5 ORC 5.0

Landau Germany 3.0 ORC 3.0

Insheim Germany 4.8 ORC 3.6

Unterhaching Germany 3.0 Kalina 3.5

Desert Peak U.S.A 1.7 Binary 4.0

Paralana Australia 3.8 Binary 4.0

Cooper Basin Australia 25.0 Kalina 4.0

Hijiori Japan 0.13 Binary 1.1

Redruth U. K. 10.0 Binary 4.5

Eden U.K. 4.0 Binary 3/4Source: Data collected from the Geothermal Energy Journal and other sources


energy installations in this pilot scientific pro-ject, which started 20 years ago, have been supplying power to the grid continuously for a year, following the introduction of the new feed-in tariff in July 2010.

The Soultz project has explored the con-nection of multiple stimulated zones and the performance of triplet-well configura-tions (one injector/two producers). This pilot project, which draws on heat sources (up to 200 ºC) from 4 500 to 5 000 m deep, oper-ates on a binary cycle principle ORC (Organic Rankine Cycle). The hot fluid arriving at the wellhead circulates in a closed loop and passes through a heat exchanger which transfers heat to an organic fluid with a lower boiling point which allows it to drive a tur-bine. Having contributed to scientific work on well stimulation with a view to developing the site, in parallel with its operations related to the European Economic Interest Group (EEIG) on Heat Mining, the BRGM (Bureau de Recherches Géologiques et Minières), financed by ADEME, is now working on the

sustainability of the operation. The aim is to identify the circulation routes between the wells (by improving tracer tests and circula-tion modelling) and to understand how they evolve during operations.

Recently, in the field of low and mid-dle enthalpy, a new application called the ‘Green Machine’ has been developed to produce electricity. This machine exploits the ORC technology and is able to produce energy by heat sources at low temperatures, mainly between 77 °C and 116 °C. The mini and micro sizes in which ORC technology is provided by the Green Machine allow flow rates to be converted at low temperatures in renewable electricity with zero CO2 emissions in a range of nominal electric power from 20 to 110 kWe. It requires little space, thanks to its very compact dimensions and differ-ent options for installation. To summarise, the Green Machine is an apparatus with a versatile technology which is mainly devoted to the exploitation of low-temperature geo-thermal systems2.

Geothermal power station in Iceland.© iStockphoto

2 See http://electratherm.com/case_studies/


Heating and cooling

In Europe, the geothermal heating sector is led by Germany and Sweden, although in Austria, Finland and France the installed capacity of geothermal heat pumps is con-siderable.

Residential and commercial heating may be a more profitable option both in timing and costs with respect to the generation of electricity because these technologies are already competitive from the commercial standpoint. Within this sector there are no large research projects but mainly a minor upgrading of current technologies. According to the industry association (European Heat Pump Association – EHPA), the total num-ber of geothermal heat pumps installed in Europe from 1998 to 2012 was about 1 mil-lion units.

There are two options in the heating sector: heating through deep wells with a distribu-tion network for neighbourhoods (centralised heating with direct uses, also known as dis-trict heating), and heating/cooling through geothermal heat pumps for single buildings or residential centres.

Centralised heating exploits the deep wells to extract hot water which is then distributed to the neighbourhoods via a district heating network. The most interesting examples are found in Ferrara, Oradea (Romania), Paris and Reykjavík. This type of geothermal applica-tion presents some technical and social prob-lems because it requires the involvement of local authorities which should provide the necessary authorisation. Delays may be caused because the building of the district heating network and infrastructure is a com-plex task that can create considerable incon-venience for the resident population.

District heating in Vienna.© iStockphoto


Residential heating may be more easily achieved by small enterprises, especially when new buildings are planned and geo-thermal probes can be associated with the foundations. The best technologies are those that exchange the heat through a liquid in a closed circuit. This approach avoids direct liq-uid interaction with the groundwater, thereby greatly reducing the environmental impact. It can also be applied to old buildings which have to be restructured. In this case, fan coil heat pumps could be more convenient.

To promote the development of residential geothermal heating without water exchange, it is essential that the geothermal installations do not require any permission. In fact, restric-tions like those required for well drillings could be an obstacle to the growth of this technol-ogy which works as a closed loop system and does not involve water exchange. Financial incentives should be considered for new build-ings to improve the use of this technology.

Financial incentives to improve geothermal technology applications for the residential sector could drive demand and thus growth of the production sector related to these tech-nologies. To date, it could be possible to set in motion an innovative mechanism that would push producers to achieve increasingly effi-cient technologies at a lower cost to meet the growing demand. To support such a mecha-nism it might be very useful to implement a special industrial incentive law which allows the buyer to pay for the new technologies in instalments at a subsidised interest rate and enables the seller to receive all the payments immediately from the authorised bank. In other words, it is crucial to establish a connec-tion among producers, buyers, government and banks with the aim of setting in motion a virtuous interaction that can stimulate a large diffusion and innovation processes in residential geothermal technologies.

Desalination

Seawater desalination by geothermal heat plants represents a new and interesting perspective to enable volcanic islands to achieve greater energy independence. In Europe, most of the Mediterranean islands can be identified as volcanic islands with high geothermal gradient

A successful demonstration of the application of geothermal to desalination was provided by the European Commission research project THERMIE.GE.438.94.HE, known as the Kimolos project. The pilot project (1994-1999) used a low-enthalpy geothermal energy source with the aim of verifying the technical feasibility of seawater desalination.

The Multi-stage distillation process (MED) was selected for this project because it needs less energy compared to other technologies, requires working temperatures of <70 °C and low vessel pressure. In addition, the feed water forms a thin film layer that reduces the formation of scaling. The water produced is of good quality as testified by the result-

Desalination at Trapani in Sicily.© iStockphoto


ing salinity which is less than 10 ppm. This technology is also energy efficient because the heat released by condensing vapour is utilised to boil feed water, too. Compared to Multi-stage-flash distillation (MSF), it is a cost-saving technology which produces fresh water and requires fewer stages.

It would appear that the potential of low-enthalpy geothermal energy for desalination via MED is significant and many countries are now showing interest in this techno-logical option. Among others, Middle Eastern countries, Algeria, Australia and Mexico have considered the possibility of exploiting low-enthalpy geothermal energy for desalination even if this process has yet to be developed significantly on a commercial scale and tech-nical design problems and high investment costs have still to be overcome.

Environmental impact mitigation and public acceptance

Although geothermal energy is regarded as a source of energy with a low level of pollut-ing emissions compared to traditional energy sources, geothermal fluids, especially those at medium and high temperature, contain some potentially toxic elements such as mercury (Hg), arsenic (As) and gases such as hydrogen sulphide (H2S), which could prove

hazardous to the environment. For these rea-sons it is necessary to put greater effort into developing new technologies and systems to remove the solid residues and condensable gases associated with geothermal fluids.

In relation to EGS, it is also important to consider the seismic activity induced by this technology. The critical issue is to obtain the acceptance of the general public. Earth-quakes triggered by rocks fracturing should be reduced as much as possible, and experi-ence shows that public acceptance can only be achieved if the population is involved in all stages of the procedure. For example, in St Gallen, Switzerland, the government has given advanced warning and informed the public about the possible risks linked to the construction of an EGS plant. Following a low-intensity earthquake related to the application of EGS technology, the authori-ties compensated residents for any damage and, following a discussion with the public, secured the authorisation to proceed with geothermal exploitation.

To summarise, gas emissions and micro-seis-micity are factors that reduce public confi-dence towards geothermal development. So, it remains worthwhile to fully assess the social and environmental impact of the activ-ities, to develop new tools for analysis, and to inform the population in order to achieve greater public acceptance.


Looking to the future The most recent SET-Plan integrated road-map3 pays special attention to the Smart Cit-ies Initiative which aims to improve energy efficiency and to deploy renewable energy in large cities above and beyond the levels envisaged in the EU’s energy and climate change policy. This initiative will support cities and regions in taking ambitious and pioneering measures to progress by 2020 towards a 40 % reduction in greenhouse gas emissions through the sustainable use and production of energy. Geothermal heat exploitation may provide an important con-tribution to the Smart Cities Initiative.

In the geothermal heat-pump sector, the RD&D priorities are to maximise efficiency (coefficient of performance – COP, and sea-sonal performance factor – SPF) and reduce costs. The focus is on developing components that are easy to connect and disconnect from the surface, as well as advanced control systems, natural and more efficient working fluids, single-split and multi-split heat-pump solutions for moderate climate zones, and the increased efficiency of auxiliaries, such as pumps and fans. The key component areas are heat exchangers, compressors, fans and pumps, expansion valves, defrosting strate-

Iceland’s geothermal plant in the Krafla volcanic region.© iStockphoto

3 http://setis.ec.europa.eu/set-plan-implementation/technology-roadmaps/european-initiative-smart-cities


gies, and new materials. In order to reach maximum efficiency, these advanced compo-nents should be perfectly designed into one system and controlled and operated by smart systems, including automatic fault detection and diagnostic tools, too.

For relevant growth in RD&D investment for new geothermal technologies for electricity production (EGS) it will be essential to adopt effective policies to stimulate innovation and experimentation by launching new demon-stration projects. This implies a qualitative leap in government and banking systems as well as the involvement of large corpora-tions which should play an active role in the network of universities and public research centres. The main efforts should focus on lowering the cost of exploration and drilling, reducing the time and costs involved in power plant constructions, optimising efficiency, and increasing the longevity of installations.

Scaling and corrosion represent one of the most important challenges facing deep geo-thermal exploitation. RD&D activities are required for new materials and operational methods, bearing in mind the significant impact of scaling and corrosion on the cost and efficiency of geothermal technology. The development of new components from polymers or plastics, optimised coating, the utilisation of aluminium, and new materi-als to tackle deterioration resulting from UV exposure should all be taken into account.

Since deep geothermal fluids contain some potentially toxic elements, such as Hg, As and gases like H2S, which could damage the environment, it is necessary to carry out fur-ther and advanced research to develop new technologies and systems able to remove the

solid residues and condensable gases associ-ated with geothermal steam.

Future research programmes will increas-ingly focus on offshore and magmatic geo-thermal energy exploitation. In fact, most of the areas with the highest geothermal potential are located at sea where geologi-cal frameworks characterised by high geo-thermal gradients (> 100 °C/km) are diffused. In particular, supercritical fluids are present in the deep ocean surface in sub-marine volcanic areas. The main research chal-lenge in this field is to develop technologies to exploit these supercritical fluids at high temperatures in deep marine environments in order to exploit the enormous geothermal sub-marine reservoirs.

In this respect, the first offshore geothermal project has been proposed in Italy to exploit the heat produced by the sub-marine volcano Marsili, located in the southern Tyrrhenian Sea, close to the Aeolian Islands’ volcanic arc. The project has been developed by a private company, Eurobuilding, in collaboration with certain Italian public research centres and universities.

In 2009, the Marsili project received the approval of the Italian Ministry of Economic Development. The Marsili volcano is the larg-est volcanic structure in Europe and releases fluids at high temperatures, around 300 °C. When fully operational, the plant will produce 4.4 billion kWh per year4.

In Iceland – a country where approximately 87 % of the houses are heated using geo-thermal energy and 27 % of the electricity comes from this energy source – a project is being carried out which aims to produce

4 For further information see: http://www.senato.it/documenti/repository/commissioni/comm10/documenti_acquisiti/IC%20strategia%20energetica/2011_10_28-Eurobuilding.pdf


energy from magma rather than from solid rock: the ‘magma enhanced geothermal sys-tem’ (Elders et al., 2014). Scientists from the Iceland Deep Drilling Project (IDDP), which is owned by the National Energy Authority of Iceland (Orkustofnun), and other public and private companies are working on this project.

Magma exploitation started a few years ago during the drilling of the Krafla caldera by IDDP in the north-east of Iceland. The sensors evidenced an area had been struck which had a temperature of 1000 °C, producing huge steam vents with temperatures around

450 °C. The team was astonished to discover that a magma chamber 5 km below the Earth surface was drilled through. Therefore, it was possible to use the heat to generate 36 MW of power, giving rise to the first geothermal energy system based on magma as direct source. The well, about 2 km deep, is known today as IDDP-1 and is located near the Kra-fla caldera. By this chance of direct magma exploitation, Iceland hopes to improve the geothermal energy production. This project would be an important step towards the development of high-temperature geother-mal resources.


Policy implications and recommendationsConsidering the low financial interest shown by large electricity companies in the exploi-tation of deep geothermal energy for elec-tricity production in Europe, it is crucial that governments aggregate consortia of large corporations, small and medium-sized enter-prises and universities around large research projects and provide public funds to promote electricity production by means of deep large-scale demonstration projects. (Accord-ing to the 13th EurObserv’ER Report in 2012, there was a drop in both total asset financ-ing and the number of projects: investments fell by almost 34 % from EUR 190 million in 2011 to EUR 124 million in 2012.)

In Europe, the most suitable areas for geo-thermal energy for electricity production are in Greece, Hungary, Italy and Romania: since high geothermal anomalies are located in these countries EGS research projects should be focused on these high-geothermal gradi-ent areas.

The Mediterranean volcanic islands represent special consideration because they could achieve greater energy independence by implementing geothermal technologies for desalination, heating and cooling and, where possible, for electricity production. A pilot pro-ject for a selected island could be launched in order to assess the possibility of repeating it in other EU islands.

Heating and cooling for residential buildings is the most interesting geothermal applica-

tion from a commercial standpoint because competitive technologies are already avail-able and there are no significant barriers to implementing such technologies. As regards heating and cooling, it is important to create financial incentives and legislative rules in the new construction market for the use of geo-thermal technologies (“demand pull” policies) in order to stimulate the applications and dif-fusion mechanism and subsequently growth in production and innovation processes by those industrial firms producing geothermal heat pumps. Furthermore, it is essential to reduce permissions and authorisations so as to liberalise heat pump installations.

In conclusion, the key barriers to larger geo-thermal energy exploitation for electricity production are the high costs of drilling and power plant construction, the long period for developing deep geothermal projects to commercial deployment, and the risk that electricity production will not reach the pro-jected objectives. Success ratios for both exploration and production wells remain low. Future research activities should address reducing risks by improving approaches to exploration and better mapping and model-ling. Furthermore, fragmentation of existing knowledge is limiting progress in the sec-tor while technological and environmental knowledge gaps increase the financial risk. Actions to share existing knowledge, also with other sectors (for instance, oil and gas exploration) are crucial for the future devel-opment of geothermal energy exploitation.


For all these reasons it is essential to move to a full-scale demonstration level of EGS plants.

Last but not least, gas emissions and micro-seismicity are factors that reduce public

confidence in EGS development. Therefore, it is worthwhile to fully assess the social and environmental impact of such activities by developing new tools for analysis and involv-ing the population in geothermal projects in an effort to achieve wide public acceptance.

Interior chimney looking skywards. © iStockphoto


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www.unionegeotermica.it/

www.egec.org/

www.vigor-geotermia.it/

www.gshp.org.uk/gshp.htm

www.thermogis.nl/worldviewer/ThermoGISWorldEdition.html

www.eera-set.eu/index.php?index=22

mitei.mit.edu/publications/reports-studies/future-geothermal-energy

www.heatflow.und.edu/index2.html

www.geo-energy.org/

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www.iea.org/files/ann_rep_sec/geo2010.pdf

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www.eurobuilding.it/index.php?option=com_content&view=article&id=61&Itemid=93

www.rhc-platform.org/fileadmin/Publications/Geothermal_Roadmap-WEB.pdf

Selected websites on geothermal energy


ADEME French Agency for Environment and Energy ManagementAGEE-Stat Germany Ministry of Environment Working Group on Renewable

Energy StatisticsAs ArsenicBRGM Bureau de Recherches Géologiques et MinièresCOP Coefficient of PerformanceECN European Competition NetworkEEIG European Economic Interest Group EERA European Energy Research AllianceEGS Enhanced Geothermal SystemEHPA European Heat Pump AssociationEnel Ente Nazionale per l’energia ELettrica ERKC Energy Research Knowledge CentreEU European UnionFP Framework Programme for Research and Technological DevelopmentGDP Gross domestic productGEA Geothermal Energy Association GHP Geothermal Heat PumpsGWe Gigawatt (electric)HC Heating and cooling

List of Acronyms


H2S Hydrogen sulphideHg MercuryIDDP Iceland Deep Drilling ProjectIEA International Energy Agency JPGE Joint Programme on Geothermal EnergykW kiloWattktoe thousand tonnes of oil equivalentMED Multi-effect distillation MSF Multi-stage-flash distillationMWe Megawatt (electric)NREAP National Renewable Energy Action PlanORC Organic Rankine CycleR&D Research and developmentRD&D Research, development and demonstrationSET-Plan European Strategic Energy Technology PlanSETIS Strategic Energy Technologies Information System SPF Seasonal performance factorTP Geoelec European Technology Platform on Geothermal electricity TP HC European Technology Platform on Heating and Cooling TWh TeraWatt hours

Residential and commercial heating may be a more profitable option, both in timing and costs, for elec-tricity generation because these technologies are already competitive from the commercial standpoint.

Financial incentives to improve geothermal technol-ogy applications for the residential sector could drive demand and therefore growth of the production sector. In addition, it is essential that geothermal installations do not require permission.

For the relevant growth in RD&D investment in new geothermal technologies for electricity production it will be essential to adopt effective policies to stimulate new demonstration projects and large-scale deployment.

Documents

Energy Research Knowledge Centre Overcoming ... - · PDF fileavailable on the Energy Research Knowledge Centre (ERKC) ... number of operational geothermal power ... production requires