Shell gets into hot rock
11 Sep 2001
'Hot rocks' buried thousands of metres beneath the Earth's surface are going to be 'tapped' to produce energy by a joint venture between Shell El Salvador and Geotermica Salvadorena SA de CV (GESAL).
The project will apply advanced geothermal technology to produce electricity from one of GESAL's existing geothermal fields in El Salvador.
This is Shell's first geothermal project. Earlier this year, the company unveiled plans to invest between $0.5 billion to $1 billion in continuing to develop a range of new energy businesses, including solar, wind, geothermal and hydrogen.
The project in El Salvador will create a 'Hot Fractured Rock' (HFR) reservoir by engineering an extensive network of cracks or fractures around an existing hot but non-productive well. A second well will then be drilled into the fracture network. Water circulated through the fractures via the wells will pick up heat and be converted to steam.
This steam will be used to generate electricity for supply to the El Salvador electricity grid and will generate between two and five MegaWatts of power.
Conventional geothermal energy, in which naturally occurring steam is used, generates about 0.3% of the world's total power. Hot rock, exploitable by HFR technology, is abundant worldwide, and could develop into a major energy source.
No greenhouse gas emissions will be produced, so the project could earn carbon credits under the Clean Development Mechanism, which is part of the Kyoto Protocol.
'There is still a great deal of work to be done in developing hot fractured rock technology as a commercially viable energy source, but we believe it has real potential to be a significant renewable energy for the future,' said John Darley, Director of Technology for Shell's Global Exploration & Production business, which is using its oil and gas-production expertise to tap this energy source.
The technical viability of Hot Fractured Rock geothermal developments has been demonstrated in a number of government-sponsored research projects in the USA, Japan and the European Union.
However, there are some challenges to achieving large-scale commercial HFR power generation. Shell and GESAL believe that, by pooling their strengths, they can demonstrate for the first time that the technology can be a reliable, commercially viable source of power.
