Geothermal 101
Geothermal power is a form of renewable energy using heat from deep inside the earth. In geothermal power plants, steam, heat or hot water from geothermal sources provide the energy that spins the turbine generators and produces electricity. The used geothermal water is then returned down an injection well into the reservoir to be reheated, to maintain pressure, and to sustain the reservoir.
There are many geothermal technologies. Hydrothermal is the most common today, and accounts for 90% of the electrical production from geothermal. Hot dry rock is another geothermal technology, as are enhanced geothermal systems. These geothermal technologies offer enormous potential for electricity production nationwide. In this process, energy is extracted by circulating water through man-made fractures in the hot rock. Heat can then be extracted from the water at the surface for power generation, and the cooled water can be recycled through the fractures to pick up more heat, creating a closed-looped system. The capital cost of geothermal development is expensive, and drilling accounts for two-thirds of those costs. Yet, as we overcome some of these technology challenges and make the process more standardized, it is believed that geothermal can supply up to 20% of the United States electricity needs by 2050. It’s important that innovation and investment in initial steps happen now.The current production of geothermal energy from all uses places it third among renewables, following hydroelectricity and biomass, and ahead of solar and wind. Despite these impressive statistics, the current level of geothermal use pales in comparison to its potential. The key to wider geothermal use is greater public awareness and technical support.Geothermal in Washington StateThe Geothermal Energy Association estimates the near-term power production potential of Washington at 50 MWe (megawatts electric), with a longer-term, higher-cost projection of 600 MWe for sites at Mount Baker and Wind River in the Cascades.In 2006, the net generation of electricity in Washington was 108 million megawatt hours annually. At 600 MW Washington could generate 5.2 million megawatt hours annually through geothermal – nearly 5% of the annual total. At 50 MW Washington could generate 438,000 megawatt hours annually.The typical geothermal power plant operates at full capacity about 95% of the time. This means that 300 MW of developed geothermal in Washington could produce about 2.5 million megawatt hours of electricity – enough to provide about 265,000 average homes with electricity.Geothermal – BenefitsClean. Geothermal power plants, like wind and solar power plants, do not have to burn fuels to manufacture steam to turn the turbines. Generating electricity with geothermal energy helps to conserve non-renewable fossil fuels, and thus reduces emissions that harm our atmosphere. There is no smoky air around geothermal power plants — in fact, some are built in the middle of farm crops and forests, and share land with cattle and local wildlife.For ten years, Lake County, California, home to five geothermal electric power plants, has been the first and only county to meet the most stringent governmental air quality standards in the U.S.Easy on the land. The land area required for geothermal power plants is smaller per megawatt than for almost every other type of power plant. Geothermal installations don’t require damming of rivers or harvesting of forests — and there are no mine shafts, tunnels, open pits, waste heaps or oil spills.Reliable. Geothermal power plants are designed to run 24 hours a day, all year. A geothermal power plant sits right on top of its fuel source. It is resistant to interruptions of power generation due to weather, natural disasters or political rifts that can interrupt transportation of fuels.Flexible. Geothermal power plants can have modular designs, with additional units installed in increments, when needed to fit growing demand for electricity.Keeps Dollars at Home. Money does not have to be exported to import fuel for geothermal power plants. Geothermal “fuel’” – like the sun and the wind – is always where the power plant is; economic benefits remain in the region and there are no fuel price shocks.Helps Developing Countries Grow. Geothermal projects can offer all of the above benefits to help developing countries grow without pollution. And installations in remote locations can raise the standard of living and quality of life by bringing electricity to people far from “electrified” population centers.For more details, view some of the websites on our links page (LINK TO THIS)