Geothermal has the potential to provide the most economical and cleanest form of energy with the smallest environmental impact. It is worthy of much more attention and government support since it is the only renewable resource that can be used for 24/7 base load production. Geothermal needs to come to the forefront. Government policy should encourage its use wherever possible.
The U.S. is a world leader in geothermal electricity. We currently produce 2,800 MW and there are additional 2,900 MW under some form of development. The Geothermal Task Force of the Western Governors identified 5,600 MW of geothermal power that could be developed with existing incentives, and another 13,000 MW that could be tapped with additional time, higher prices, or both. Of course, these estimates assume today’s level of technology (for building power plants, resource characterization and identification methods). With better exploration technologies in these areas the potential is much higher.
The 2008 U.S. Geological Survey report estimates a hydrothermal resource base of 39,000 MW, of which 9,000 MW is a likely estimate of known resources. Most of the resources identified in the WGA study were included in the USGS estimates. In 1978 we lacked the technology to find and characterize lower temperature resources. The 2008 report is more inclusive of lower temperature resources, but still lacks depth.
Geothermal heat is co-produced with oil and gas wells in central and western U.S. and the Gulf Coast. Mature oil and gas fields in many areas in the U.S. produce large amounts of hot water along with oil and gas. NREL estimates the additional potential from 5,000 MW in 2015 to as much as 40,000 MW by 2050. This amount is not included in the USGS 2008 report and represents an additional source.
Engineering Geothermal System (EGS) – the upcoming new technology involves using hot rocks deeper under the surface. Water will be injected to the ground, the hot rocks will warm them and the temperature difference will be used to create electrical energy. For further details see MIT report “The Future of Geothermal Energy”. If the EGS technology is successful and economical, it could supply the entire energy growth requirements of the U.S. It would be reliable and with the smallest environmental footprint.
The USGS estimates that EGS has potential for 517,800 MW. The MIT report estimates the EGS potential at 100,000 MW. USGS notes: “with EGS technology at an early stage of development, the assessment results should be considered provisional”.
The DOE recently awarded $43 million to further EGS technologies and for four well system demonstration projects. If the experiment is successful, Federal allocations should be given to building five pilot EGS power stations in the western U.S. on federal lands in the fastest way possible. This experiment needs higher priority and higher budget.
If the operational results from the pilots are satisfactory, it should become a national priority. On its face it could be more economical than nuclear, solar and wind. It is impossible to set the policy before experimental results are known, but if they are viable, the policy should be geared for mass implementation.
An extension of the (section 45) Production Tax Credit and the Clean Renewable Energy Bonds is critical. It should be for 15 years to provide stability and encourage investment. Future projects are already being undercut because it takes 4-5 years to bring geothermal projects online.
The permitting of geothermal wells has to be streamlined, allowing for more rapid development. It takes more than a year to permit a geothermal well (it takes much less time to permit an oil well).
Bureau of Land Management (BLM) must release more land for geothermal projects and speed up the approval process. We may need a “positive default” legislation that does not require permits for geothermal projects unless it is in national parks or urban areas. The environmental footprint of geothermal power stations is very small. We should not burden it with the same regulations as fossil fuel based power plants.
The last major assessment of the U.S. geothermal potential was released in 1978. The USGS 2008 report is not nearly as comprehensive. We need a comprehensive U.S. geothermal survey. It should be well funded and use the latest technologies.
It will face the same power transmission problems as all new energy locations that must be solved. Solving the transmission bottleneck is critical for renewable technologies.
One of the bottlenecks to the development of geothermal energy is the shortage in drills due to stiff competition from the oil industry. If EGS is viable, we can tie licenses to drill for oil offshore to supply of drills to the geothermal industry. This is a stop-gap measure. In 10 years there will probably be a surplus of drills in the market. It may encourage oil companies to invest in EGS.