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European vision for geothermal electricity

By Brian Roberts,2014-08-13 10:23
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European vision for geothermal electricity ...

    European vision for geothermal electricity

Introduction

    This document is a draft document for the development of a vision of the European geothermal electricity industry.

    Starting with the present situation, the Vision sets out in global terms how geothermal stakeholders see the future development of their industry. It reflects on the basic features of geothermal electricity production, on the way the systems are expected to evolve and how the industry and associated stakeholders should evolve to make it happen.

    Challenged by climate changes, the need to secure sustainable economic growth and social cohesion, Europe must achieve a genuine energy revolution to reverse today unsustainable trends and live up to the ambitious policy expectations. A rational, consistent and far sighted approach to electricity supply is critical for ensuring such transformation.

    Geothermal is the sole source of renewable capable of supplying a consistent and reliable (24h per day, 365 days per year) source of electricity production. Geothermal energy utilization is based on harvesting the continuous heat flux coming from the center of the earth which represents 25 billion

    1times the world annual energy consumption, therefore representing an almost unlimited and renewable source of energy. The heat flux from the center of the earth to the atmosphere if not harvested is otherwise lost.

    It is available everywhere, local electricity production will stop the reliance on imports from unpredictable suppliers which could lead to wars for energy.

    Lack of a reliable and affordable source of energy is always highlighted as a reason for under-development, by removing dependence on fossil fuel imports geothermal energy removes a big burden in developing countries budget. In addition the cascade use of heat after electricity production has shown to have an even bigger effect of job creation (green houses, fisheries, food processing, refrigeration, etc).

    This document aims to draw a realistic picture of how a European Geothermal Electricity production industry can be built, in the mean time develop reliable, sustainable sources of energy and numerous jobs for all kind of qualifications everywhere.

     12421 The total heat content of the Earth stands in the order of 12.6 x 10 MJ, and that of the crust of 5.4 x 10 MJ, 14indeed a huge figure when compared to the total world energy demand which amounts to ca 5.0 x 10 MJ/yr

    i.e. the earth contains enough heat to cover the needs of humanity for 25 billion years with present energy consumption rate, not counting its replenishment by radioactive decay of natural isotopes, which has been 3estimated as 30 x 10 GW or approximately 2 times present worldwide energy consumption..

    thDraft Geoelec 2050 Vision 12 February 2010

    By 2020: laying the base of a European geothermal industry

    - Develop the hydrothermal resources in Europe from the known high enthalpy resources

    (Italy and ultra peripheral regions), and from Medium enthalpy resources (e.g.

    Pannonian basin), but also in other countries thanks to export capacity of European

    companies (Turkey and the Caspian area, African rift, South America, etc) - Expand the EGS concept in the different regions and geological conditions of Europe

    through the construction of power plants, thus keeping the leadership in this new

    technology development. This includes the development of efficient binary cycle for low

    temperature resources.

    - Lay the basis of a European model of geothermal power plants well integrated into the

    environment: medium size plants with fluid re-injection for minimum impact of

    landscape, environment, grid and maximum benefit to the communities through

    cascade use of heat.

    - Launch wide exploration programs to allow optimum allocation between the different

    underground potential uses (including gas storage, O&G exploration and production,

    mining nuclear waste repository and carbon storage)

    - Europe has pioneered geothermal 100 years ago in Larderello and still has a leading

    expertise thanks to the development of EGS in Soultz-Sous-Forêts, all efforts need to be

    put to keep this leadership in developing the geothermal industry of the future.

    By 2030: toward a competitive source of electricity

    - Bring down the cost of EGS plants thanks to technical developments to become

    competitive with other sources of energy.

    - Start implementation of massive construction programs to replace ageing and

    increasingly costly fossil fuel based power plants, starting with the most promising areas - Transfer EGS technology outside Europe in areas lacking hydrothermal resources thanks

    to the technical expertise developed and the capability of the European industry to

    develop large engineering projects around the world.

    - Develop mature technologies for exploitation of supercritical fluids and temperatures,

    and start exploitation of large off-shore geothermal reservoirs.

    By 2050: a substantial part of the base-load electricity supply

    - By that time technology will allow EGS to be developed everywhere at a competitive

    cost, the challenge will then be to implement it widely and quickly enough to capture a

    large market share from other type of base-load power plants (Coal , nuclear, fuel, etc)

    in Europe and outside Europe.

    Today

    What is geothermal electricity production?

    thDraft Geoelec 2050 Vision 12 February 2010

    The systems for geothermal electricity production can be subdivided in three large categories, which are also linked to the temperature ranges:

    1) 80?C

    with binary plants (Rankine or Kalina cycle), with typical power in the range 0.1-10 MWe.

    These systems are also suitable for heat & power co-generation, typically for single edifice

    to small towns heating.

    2) 180?C-390?C (High Enthalpy resources): temperatures in this range can be exploited with

    dry steam, flash and hybrid plants, with typical power in the range 10-100 MWe. These

    systems, characterised by high efficiency up to more than 40%, also allow heat co-

    generation for large towns district heating. Above 200?C, these resources are generally

    limited to volcanic areas.

    3) 390?C-600?C (Supercritical unconventional resources): temperatures in this range, limited

    to volcanic areas, generally involve superheated dry steam plants, with power per unit

    volume of fluid up to one order of magnitude larger than conventional resources.

    Besides the temperature range, the methods of exploitation of geothermal energy can be further subdivided in two large categories:

    a) conventional hydrological systems, which use the natural aquifers

    b) EGS (‘Enhanced’ or ‘Engineered’ Geothermal Systems), which use the high temperature of

    rocks with artificial water injection and, generally, with enhancement of permeability of the

    hot reservoir.

    A total of ca 500 geothermal units all over the world were reported online in 2008. The maximum addresses about 250 binary plants, totalling a 800 MWe installed capacity (i.e. a unit 3.3 MWe plant load). The sizes of flash and dry steam plants average 31 MWe and 44 MWe respectively. In the EU, the total installed capacity is ca. 850 MWe, generating about 7 TWh in 2010. Main production comes from conventional geothermal systems in Italy. Recently, binary power has been produced in Austria and Germany from low temperature geothermal sources and in France and Germany from Enhanced geothermal Systems (EGS).

    At present, projects representing a total of 400 MWe are ongoing in the EU (EGS and low temperature power plants).

    Hydrothermal

    As far as conventional geothermal electricity is concerned, the vast majority of eligible resources, in Continental Europe at large, is concentrated in Italy, Iceland and Turkey.

    There are two major geothermal areas in Italy, Larderello-Travale/Radicondoli and Monte Amiata respectively, achieving a 843 MWe installed capacity in 2010. Projects, adding a further 100 MWe capacity, have been commissioned and will be completed in the near future.

    Iceland is increasing its electricity production, which reached a 575 MWe installed capacity in 2010. Although significant, this capacity ought to be compared to the huge potential of the island, estimated at ca 4000 MWe. This country has recently started pioneering researches about the exploitation of supercritical fluids, able to increase of one order of magnitude the power output of geothermal wells.

    thDraft Geoelec 2050 Vision 12 February 2010

    Turkey’s geothermal resources are mainly located in Western Anatolia on the Aegean sea façade. Some geothermal power plants have been recently installed. The national geothermal electricity potential has been (conservatively) estimated at 200-300 MWe.

    In Greece, proven shallow high temperature geothermal resources are located in the Aegean volcanic island arc, in the Milos (Cyclades) and Nisyros (Dodecanese) islands. Recent volcanism and abundance of hot springs indicate the presence of high enthalpy resources at 2-4 km depth in many other places.

    A similar situation exists in the small fields of the Guadeloupe and Azores volcanic islands. At Bouillante (Guadeloupe, France), a small, 4.7 MWe rated, plant was built in 1984. Its capacity has recently been increased to 15 MWe.

    In the Sao Miguel Island (Azores, Portugal), 43% of the electrical production is supplied, from a high temperature (230?C @ 1200 m) saline brine, by three flashed steam plants (23 MWe total installed capacity) online since 1980. An additional 12 MWe capacity is scheduled in the near future. Binary plants

    Recently, binary power has been produced in Austria, Turkey and Germany from low temperature geothermal sources. The conversion process ; which consists of vaporising a low boiling point working fluid, either a hydrocarbon -Organic Rankine Cycle (ORC)- or an ammonia/water mixture- Kalina cycle-raises considerable interest as it makes it possible to produce electricity from cooler geothermal sources (typically within the 100-120?C temperature range, exceptionally down to 70-75?C depending upon the availability of a cold water source for re-condensation of working fluid). However, no high plant ratings can be expected for obvious thermodynamic reasons. Hence, improvements should concentrate on cycle and plant efficiencies along side cogeneration production. As a result, two development routes are contemplated

    (i) small plant designs targeted at 1MWe/2MWth CHP capacities, close actually to those implemented already in the EU [(0.5 - 3 MWe) / (1-6Mth)], and

    (ii) a microgeneration standard for small scale ORC modules.

    EGS

    To the question of how could geothermal energy expand its power market penetration share, the EGS (Enhanced or Engineered Geothermal Systems) issue is the answer. The rationale behind the concept is the following: whereas drilling technology is in the mature stage and efforts dedicated clearly to reducing its costs, stimulation technologies of geothermal rock environments are still in the pilot stage. There exists many geothermal prospects enjoying high temperatures but lacking sufficient rock permeability to allow fluid circulation. Such tight rock, poorly conductive, systems could be turned into technically and commercially exploitable reservoirs, provided their permeability be enhanced by engineering adequate stimulation procedures, such as hydraulic fracturing and acidising. Development of these technologies will make it possible to access a huge geothermal potential.

    thDraft Geoelec 2050 Vision 12 February 2010

    An EGS plant today has a capacity of 3-10 MWe, but future commercial plants will have a capacity of 25-50 MWe ( producing from a cluster of 5 to 10 wells like in oil&gas industry). Among the ongoing EGS projects worldwide, the Soultz European pilot site is in the most advanced stage, providing already an invaluable data base. A critical aspect of the EGS technology addresses the seismic hazards induced by the hydraulic fracturing process. Commercial exploitation in Europe has already started in Germany and the UK but these are at 3-10MWe scale. Te driving force is the large potential for non hydrothermal countries and the financial tariff proposed by some Member States. EGS has large potential and much wider applications for many of the EU countries. EGS technology is also being applied to hydrothermal projects to maintain sustainability by reinjection and expansion of dry field on the periphery.

    EGS (Engineered Geothermal System) is the technology to move the industry from a resource base industry (targeting the most productive spots) to an engineering based industry (capable of reproducing installations reliably and consistently in all sort of environments). Cascade use benefits

    - District heating and cooling

    - Industrial processing

    - Green houses, fisheries

    - De-icing, tourism, spa bathes

    European Geothermal Industry stakeholders:

    Direct players

    - Municipalities: e.g. Unterhaching

    - Utilities: Major (ENEL, EnBW, RWE), regional (ES, Pfalswerke),

    - Private developers: e.g. GeoEnergie Bayern, Exorka, EGS Energy, Petratherm,

    Geothermal engineering ltd, Martifer...

    - Subsurface suppliers: consultants, drillers, services companies, suppliers

    - Surface suppliers: consultant, engineers, electricity suppliers, turbine manufacturers,

    contractors

    - Public institutes: Geological surveys, Universities, Research Institutes, policy makers and

    regulators

    - Financial services, lawyers, insurances

    Indirect geothermal electricity stakeholders

    - Cascade users of heat

    - Civil, works and electro-mechanical contractors for whom smaller plants (compared with

    fossil fuel or nuclear may mean easier access to the market).

    The missing players: oil and gas companies (Total, Shell, BP, Wintershall, Statoil), most utilities (EDF, GDF Suez, Dalkia, etc), large engineering firms (e.g. Technip, Dornier, etc). All of them have a role to play and effort should be made to involve them.

    thDraft Geoelec 2050 Vision 12 February 2010

    2010/2020: Laying the foundations of a European geothermal industry

    Hydrothermal (high enthalpy resources)

    - Development of Italy and ultra peripheral regions (Guadeloupe, Martinique, Azores, etc)

    to get the most of the existing exceptional resource (Iceland?) and be used as a show

    case and base for export in other hydrothermal regions.

    - Develop projects in & out of Europe to leverage industry capabilities in term of

    exploration, project management, financing capability, etc

    Binary plants:

    - On medium and low enthalpy resources (e.g. Pannonian basin)

    - Or in combination with steam or flash plants on high enthalpy resources. EGS

    - Continue development of commercial demonstration plants to validate the concept in all

    conditions thanks to governmental incentives (feed-in tariffs, green certificates) and risk

    mitigation schemes (insurances)

    - Increase plant size to optimize cost (exploration, drilling, site, etc)

    - Establish the base of a financial costing model

    - Establish the basis of a European model of EGS plant:

    o All wells starting from a single drilling pad to minimize surface impact during drilling

    and operations.

    o Minimal surface occupation (possibly water cooled rather that air), building

    integration

    o Maximize cascade use with innovative proposal for optimal economical and social

    benefits

    o Possible combined source of heat (biomass or gas) to optimize efficiency,

    repeatability and consistency and minimize uncertainty of well heat flux when

    ordering the surface equipment.

    o Possible use of CO2 as a geothermal fluid

    o Master induced seismicity

    - Experiments on supercritical EGS

    Exploration

    There are at some moment some competition between geothermal use and other use of subsurface resources like oil and gas exploration and production, gas storage, carbon sequestration, or mining activities as well as some concerns with environmental impacts and in particular micro-seismicity associated with all subsurface activities. Therefore authorities should launch or optimize regional subsurface exploration programs, going as deep as possible to clearly identify all possible usage of

    thDraft Geoelec 2050 Vision 12 February 2010

    the resources and allocate them in the best interest of the community. Resources allocation may be decided after debates and tendering with schedules and commitments. Such effort would further minimize the main investment risks and act as a strong incentive for private investors. These geothermal resources surveys (exploration plans) may be managed by national geological surveys (or Universities, Research Institutes etc.) when they have the capabilities, if not they could be outsourced to other GS or private companies. Financing by the authorities (regional, national or European) may be the only way to make sure data are evenly shared to guarantee a fair resource allocation.

    Exploration should include the development of a network of dense seismic monitoring networks, to get a better understanding and mastery of possibly induced seismic phenomenon as well as identify and avoid high risk areas.

    2020/2030: Making EGS a competitive source of Electricity Hydrothermal

    In 2020, it is very likely that most hydrothermal resources in Europe will be exploited, then potential should be in other countries blessed with such resources but with less technical and financial capabilities to develop projects by themselves. This will be the continuation of the move already started in the previous period, and experience gained in the early days will certainly be very valuable (e.g. ENEL or Icelandic companies). Binary plants, possibly in combination with traditional steam or flash plants shall be the standard for optimal use of heat.

    EGS

    EGS plants should be present all over Europe and in various places in the world thanks to governmental incentives to compensate for the higher drilling cost and lower heat flux, the challenge is now to bring the cost down to be competitive with other comparable sources of energy. Technology development in exploration, drilling and well optimization should improve ability to detect from surface the most promising zones (naturally open fractures), predict and optimize fracture propagation, locate the next wells and eventually get the necessary high flow and temperature to make projects viable. Technology should also allow to possibly targeting deeper zones at higher temperature (higher heat flux as well as increased conversion ratio). Note: Add a few sketches showing cost decrease with flux and temperature.

    Progress in the engineering, design and number of well per project also has dramatic effect of drilling costs (in the oil and gas drilling there is commonly a 40% reduction in drilling cost between

    thththe first and the 5 or 6 well for a project done by the same team in the same location). This will be an immediate benefit of the size increase of projects, in the mean time novel technologies (spaliation, laser, etc) may also bring additional benefit as well as research made by the oil and gas industry for the drilling in hard rocks.

    thDraft Geoelec 2050 Vision 12 February 2010

    In the mean time it is expected that fossil fuel electricity production cost to increase both from the effect of fuel price and from the obligation to avoid carbon emissions (CCS is expected to increase electricity price by 25 to 30% compared with present situation, due to a combination of higher fuel demand and higher plant cost).

    In terms of cost, the estimated current cost of EGS electricity generation from the first-generation prototype plants is of the order of ? cent 20-30/kWh. A continued reduction in cost through

    innovative developments, learning curve effects and co-generation of heat and power should lead to an electricity cost of around or 5 euro cents /kWh. A dry steam power plant today produces electricity at ca. 5 eurocent / kWh, a flash power plant at 8 euro cents / kWh and a Binary-ORC systems at 10 euro cents / kWh. Industry believes that this cost can be reduced by more than 25% in improving drilling technologies and with better resource identification.

    2030/2050: Powering Europe and the world from geothermal Hydrothermal

    In 2030, most hydrothermal resources shall sustainably exploited in Europe and in most countries, the market will be mainly related to the maintenance of existing capacities: work-over and replacement of existing wells, improved surface equipment with higher efficiency. However by 2030 the geothermal market for geothermal production should be EGS.

    EGS

    By 2030, EGS should be a mature technology capable of providing a reliable, sustainable and competitive source of energy in all area. The challenge will be the implementation all over Europe to replace the ageing existing power production infrastructures.

    At present one of the bottleneck for geothermal development is the lack availability of drilling rigs and subsequently the cost of drilling. To reach an objective of 20% of Europe primary energy supply by 2050, an average of 15 drilling rigs dedicated to geothermal should be brought to the European market every year between now and 2050. This is a very large number when compared with the 5 to 10 rigs currently involved in geothermal activity in Europe today, but nothing when you compare with the 3500 rigs operating worldwide for the oil and gas industry.

    This means the manufacturing of the rigs but also the development of all associated services representing a big challenge for recruitment and training but also a major opportunity for job creation.

    The Geothermal have the resources to supply at least 20% of Europe Global Energy consumption in 2050. The technology is available, should be proven all over Europe in various geological conditions by 2020 and become competitive with other sources by 2030. For large scale development there may be need of some kind guidance / direction with objectives put in place by the authorities to make things happen at this scale.

    thDraft Geoelec 2050 Vision 12 February 2010

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