The Stillwater geothermal plant in Nevada has added a solar array and now provides 59 MW of clean, steady power. Geothermal produces power 24/7 while the solar provides extra power during the day when it is most needed.
Traditional geothermal technology requires 360+ degrees Fahrenheit sources that are difficult to find, less abundant, and therefore costly to discover and develop. Low-temperature geothermal technology makes it possible to access resources as low as 165°F. According to the SMU Geothermal Laboratory, this innovative technology is a “game-changer” and widely opens doors for the geothermal industry.
This type of geothermal is used to create power not to heat and cool homes. Because this technology could be used in many new places, the possible power that could be generated is in terawatts.
The Geysers in northern California is planning a $700 million expansion, to add 98 new MW of geothermal power.
The Geysers is [already] the single largest geothermal operation in the world, producing up to 725 megawatts of green energy around the clock — enough electricity to power the entire city of San Francisco.
At night, geothermal production meets 50% of Reno’s needs. Geothermal is reliable and steady, producing power 24/7.
Pumps pull 6,000 gallons of water a minute out of reservoirs 3,000 feet below the surface. The water, naturally heated by geologic forces to approximately 300 degrees Fahrenheit (150 C), boils a chemical refrigerant contained in sealed loops. The refrigerant, now a gas, cranks a turbine.
If asked what type of renewable energy is most prevalent in California, most would choose solar or wind, but in reality, those two forms of renewable energy aren’t even close. Instead, the current California champion for renewable energy is geothermal, followed by small hydro. Say what?
As an example, on Wednesday May 4, 2011, geothermal energy production in California was 23,980 MWh, followed by small hydro with 13,210, then wind at 10,166. Solar power was last, with 3,094, behind biomass and biogas. Yes, that’s right, solar power produces the least amount of renewable energy, even as it (and wind) get most of the attention. Total renewables production for the day was 61,549 MWh against a total system demand of 670,435 MWh or about 9%. Clearly, California has a long way to go to meet its ambitious goal of 33% renewable energy by 2020.
These numbers are from California ISO, a non-profit that monitors and operates much of California’s high-voltage wholesale power grid. They post full details of renewable energy production each day at Renewables Watch and real time system demand overall at Today’s Outlook.
Several geothermal plants on the southeastern shore of the California’s inland and saline Salton Sea have reliably been producing power for 30 years. A new 50 MW plant should be online by next February.
A quake that caused cracks in buildings in August 2009 and six more perceptible temblors the next month probably came from an increase in hot-water pressure in the pores of the rock after water was forced down a bore to keep the supply of hot water going.
Geothermal can produce power on a steady basis, but clearly can be dangerous too.
CalEnergy Vice President Mark Gran introduces the company’s 340 megawatt geothermal plant on the southern shore of the Salton Sea. The plant produces enough energy to power around 300,000 homes. The Imperial Valley has the potential to produce a stunning 2300 megawatts of this renewable resource. Thats enough energy to power more than 2 million homes. One major challenge is building transmission lines to deliver that energy to the large, urban areas that need it.
As he points out in the video, geothermal produces power 24/7, so there are no fluctuations as with wind and solar.