With a total installed capacity of 3,152.72 megawatts (MW), the country's geothermal output mainly comes from eight states: Alaska, California, Hawaii, Idaho, New Mexico, Nevada, Utah, and Wyoming.
California leads the pack with about 83% of the combined capacity. Geothermal energy caters to 4.5% of California's energy requirements and accounts for about 20% of Hawaii's electricity consumption.
The sector has seen a marginal growth during the past three years, with installed capacity rising from slightly more than 2,800 MW in 2006 from facilities in California, Nevada, Utah and Hawaii, to 3,153 MW in eight states. The number of facilities has grown from 34 to 132 since 2006.
While the U.S. leads the world as a nation in terms of geothermal energy production, the whole of North America reportedly commands a 42.3% share of the world's geothermal market, trailing behind the Asia Pacific region, which has a share of 47.6% of the market. Europe, with a 10% share, follows North America. The geothermal energy segment is forecast to see a steady growth of about 3% during the next few years, given the fact the costs associated with the sector are still quite high, and there is no universally proven technology to be adopted. With a carbon cap and trade policy edging into the U.S. Power Industry, the U.S. Energy Information Administration predicts a 6% growth in the sector between 2010 and 2030.
Geothermal energy offers a clean source of power with minimum impact to the environment. Carbon dioxide and other greenhouse gas emissions are nil, except in cases where the heat-transfer fluid contains some impurities. The power source is completely independent of climatic impact and is active throughout the year. Despite these favorable aspects, the cost of exploration and production is still quite high, varying from $1,600 to more than $5,000 per kilowatt of capacity, depending on various factors.
Geothermal energy exploration is a risky venture with a success rate of only 25%. Uncertainties regarding the availability of subsidies, the absence of strong guidelines and policies, newly evolving technologies, the distance of production areas from the region of use, and the lack of adequate transmission facilities are problems that the sector faces.
Several countries are slowly making headway in the geothermal energy sector. Mexico plans to generate 1,481 MW by 2015, while the Philippines is targeting 3,246 MW of capacity, and Indonesia is looking to add 3,200 MW within the same timeframe. Geothermal energy production in Germany is forecast to reach about 6,000 MW through 2020, with 150 sites earmarked for exploration. Iceland sources about 25% of its electrical power and 87% of building heating and hot water requirements from geothermal sources.
Australia, which generates 77% of its power from coal, has vast geothermal sources. According to an earlier report of the Australian Geothermal Energy Association, the country has resources to generate a base load of 2,200 MW of geothermal power by 2020, which forms 40% of Australia's renewable energy target for the same period.
The latest GEA report reveals that the U.S. plans to incorporate additional geothermal energy ventures in the states of Oregon, Mississippi, Florida, Louisiana and Colorado. In 14 states, 144 greenfield projects with a combined capacity of 6442.9 MW have been planned. Several potential unconfirmed projects are likely to increase the capacity to about 7,109.9 MW in the coming years. Projects in various development phases are under way in different states.
New technologies such as enhanced geothermal systems are in nascent stages, with pilot experiments being carried out to evaluate the outcome. Hydrocarbon coproduction, using exhausted mine shafts for geothermal energy production, and exploring geo-pressurized geothermal resources are a few other emerging trends being explored. A recently announced $35 million research grant, as well as the extension of production tax credits through 2013 that allow 30% cost recovery, are expected to boost further efforts in the sector.