The breadth and coverage of analytical expertise in the IEA Technology Collaboration Programmes (TCPs) are unique assets that underpin IEA efforts to support innovation for energy security, economic growth and environmental protection. The 38 TCPs operating today involve about 6 000 experts from government, industry and research organisations in more than 50 countries1.
Geothermal Energy (Geothermal TCP)
Reducing costs by combining geothermal sources
The Geothermal TCP provides a flexible and effective framework for international collaboration on R&D concerning the sustainable use of geothermal energy. Recent studies found that combining high-temperature geothermal for electricity generation with direct use of low-temperature geothermal heat (space and water applications) can greatly improve the overall economics of the system and reduce payback time.
Geothermal resources (water or steam) may be used directly for applications such as space heating or swimming pools. Higher temperature resources enable heat as well as electricity generation. Because geothermal energy has definite base-load characteristics and relatively high annual full-load hours, the return on investment for geothermal installations can be attractive. In 2014, some 80 countries used geothermal energy for heat generation and 25 for electricity production.**
In order to maximise the benefits from geothermal it is beneficial to take full advantage of the “cascading” uses of hot water or steam from geothermal sources such as wastewater from a geothermal electricity plant. These multiple uses offer several advantages, including better resource efficiency and higher rate of return on the initial investment when waste heat or wastewater can be used in an industrial process or agriculture application located at relevant distance.
To date geothermal cascading has been successfully implemented throughout the world. Applications include greenhouses that are heated with wastewater from an electricity plant; reusing wastewater from a pavement snow melting system to heat water in spas; and cascading uses of geothermal steam and hot water for residential space heating and swimming pools. The Geothermal TCP identified over 50 known applications of geothermal heat. As such there is considerable further potential for expansion of geothermal projects, particularly in those countries where there is an abundance of high temperature ground water close to the surface.
The Geothermal TCP set out to assess the current status of technologies for direct use of geothermal heat, to establish guidelines for project development and design, to identify barriers to commercial development and possible responses, and to examine further potentials. A recent report focused on Canada, a country with more than 150 hot springs though with a relatively limited number of geothermal installations. Low-temperature geothermal resources are currently used directly for heating buildings, swimming pools or therapeutic spas (a capacity of 8.8 MWth). Yet there remains considerable further geothermal resources estimated at 12 000 MWth. Through cascading, these resources could be used for greenhouses, agricultural processes or industrial applications.
Despite high potential, a number of barriers hamper further development of geothermal sources in Canada. First, there is no complete or current survey of geothermal resources (the 1986 Geological Survey of Canada shows only 40% of land mass as surveyed). Second, the economics of the geothermal systems are affected by the high initial investment cost of the technology and the relatively low market price of energy due to Canada’s abundant natural gas reserves. These and other findings are the focus of the publication Direct Utilization of Geothermal Energy: Suitable Applications and Opportunities for Canada.
- Advanced drilling and logging technologies
- Data collection and information
- Deep roots of volcanic geothermal systems
- Direct use of geothermal energy
- Enhanced geothermal systems
- Environmental impacts
- Induced seismicity
For more information: www.iea-gia.org
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