Geothermal Energy
Geothermal Background
In a sense geothermal energy is nuclear power since it uses the heat generated by the natural atomic fission that occurs in the Earth's core. So it is like a nuclear power plant, except without all the issues concerning radiative meltdown, waste storage, vulerabiltiy to terrorism, and billions of dollars in taxpayer subsidies. Radioactivity in the Earth's core generates 6,000 degrees of heat which is transported up near the surface by rising magma. Most area's on the Earth's surface have access to reliable sources of geothermal heat, but areas close to volcanic hot spots and crustal faults will have easier access.
Photovoltaics Twenty Times Cheaper?
"The new solar cells would even be able to compete with electricity generated by burning fossil fuels such as oil and gas, which costs about $0.40 per watt, said Salvo Coffa, who heads ST's research group that is developing the technology."...
"We believe we can demonstrate 10 percent efficiency by the end of 2004," Coffa said.
Following that, ST and others would need to develop production technologies to make solar cells and panels in large quantities to achieve the $0.20 per watt target, he said.
"Our target is fixed at $0.20," said Coffa, who expects no major technological difficulties in going from prototypes to mass-produced commercial products.
Free Solar Fuel
Since the energy source, sun light, is free and renewable, the solar cells are immune to fuel price fluctuations and availability. This must be factored into the over all operating cost of generation since often power plants which use renewable fuel cost more in the construction phase when compared to the installed capacity of fossil fuel plants. When the cost of the fuel is included over the life cycle of the photovoltaic cells (often lasting 20 years), solar power can be competitive with fossil fuel and nuclear power. The natural availability of sun light nicely matches the summer electricity demand curve as air conditioners kick in during afternoon hours when photovoltaic cells would be reaching their peak output. Solar power, then, could play an important role in supplying the electrical power grid in the western United States, along with existing hydroelectric and natural gas plants.
The Advantages of Distributed Power
Geothermal plants could be built throughout the U.S. and help decentralize the production of electricity. The more distributed power supplies are installed the interstate power grids will become more stable and reliable. For example, had there been more local, distributed power sources on the east coast, the electrical blackout of 2003 would have affected fewer people.
Where Do We Build the Geothermal Plants?
The MIT study concluded that geothermal energy is available throughout the entire United States, including the east coast. Most of the near-surface heat sources are in the west. The wells would have to be dug deeper in the eastern half of the country.
Geothermal Paves the Way to the Eventual Hydrogen Economy
One alternative to producing electricity for the Western States power grid would be to use solar electricity to produce hydrogen fuel from water. Electricity can be used to separate the hydrogen from oxygen in water. When hydrogen is burned as a fuel it then produces water again. Hydrogen fuel could also be used for fuel cells in buildings and cars to produce electricity and heat. As we transition from a fossil fuel economy to a renewable "hydrogen economy", hydrogen offers many advantages as a fuel since it is plentiful, renewable, and produces almost no air pollution and few greenhouse gases. Ultimately renewable sources of energy such as geothermal, solar, wind, and hydroelectric will be used to produce hydrogen fuel for storage and for fuel cells.
Related Links
- U.S. Department of Energy Geothermal facts
- Geothermal Education Office Energy Facts
- Wikipedia article on Geothermal Power Plants