1. Brief History The first known use of geothermal resources happened over 10,000 years ago. It was used by the Paleo-Indians as a source of warmth, cleansing, and the minerals were used as a source of healing (eere, 2007). Today geothermal resources are still used for those same reasons but you can now add to the list electricity and geothermal heat pumps. The first geothermal power plant was invented in 1904 by Prince Piero Ginori Conti at the Larderello dry steam field in Italy. Fifty six years later the first US plant was built in Sonoma County, California (REPP, 2007). Dry Steam power plant Oldest type of Geo power plant Steam needs to be at least 455F Flash Steam power plant Most common type of Geo power plant Fluid needs to be at least 360F Fluid vaporized into steam to turn the turbine Binary-Cycle power plant Future of Geo power plants Fluid needs to be at least 225F Heat exchanger passes heat from ground fluid second fluid Usually Iso-butane or Iso-pentane Vaporizes at a much lower temp Cost Near a geyser about $0.03 per KWh Anywhere else about $0.05 per KWh Direct Use Used in homes, greenhouse, gold mining, etc Costs 80% less than fossil fuels Economy 1996 created 30,00 jobs 1.5 billion dollar a yea industry Environmental CO2 emissions much lower than fossil fuels Power plants large and disturb landscapes Are very noisy Re-injection of fluid causes earthquakes Within 15 years, renewable energy could be generating enough electricity to power 40 million homes and offset 70 days of oil imports. On average, 16 million tons of carbon dioxide are emitted into the atmosphere every 24 hours by human use worldwide. (U.S. Department of Energy) World energy consumption is expected to increase 40% to 50% by the year 2010, and the global mix of fuels--renewables (18%), nuclear (4%), and fossil (78%)--is projected to remain substantially the same as today; thus global carbon dioxide emissions would also increase 50% to 60%. Germany generated 2,863 MW using solar PV power plant, which is almost half of the world total production.(Lothar Wissing, 2006) Government policy helped this result In 1999, 100,000 Rooftops Solar Electricity Programs started, and terminated in 2003. In 2000, Renewable Energy Sources Act was legislated. (International Energy Agency, 2002) These policies made economic incentive The house owners who generate electricity with their own solar panel scan sell electricity to the electric power companies at a high rate, currently about 0.45 EUR/kWh. As a result, this Feed-in Tariff system succeeded to build 65,700 systems and to generate 345.5 MW of capacity. (IEA, 2003) Source: IEA PV Power Systems Programme, 2003 Future of solar PV needs the positive government policies In African rural areas, electrification levels are lower than national averages, often at 1–2%. (Mathias Gustavsson et al, 2003) More solar panels should be donated by developed countries from the view of social justice Solar PV make their life better Only one solar panel is enough to electrify the rural freezers which are necessary to store the vaccine. Only one solar panel enables the children to study in their homes. (Jacobson, 2007) The problem is cost Most African people in rural area cannot afford to buy solar power system. (Otiti and Soboyejo, 2006) Source: Jacobson, 2007 Solar energy costs 18 to 23 cents per kilowatt-hour to produce. (LA Daily News, 2007) Natural gas in some states costs 5 cents per kilowatt-hour to produce. (LA Daily News, 2007) This cost gap is the barrier for the dissemination of solar PV Source: IEA PV Power Systems Programme, 2005 Current highest efficiency is 42.8 percent, which is almost the theoretical maximum efficiency. (Corcoran, 2007) All we have to do is to think the way of mass production which can produce solar cell Cheaply. Source: International Energy Agency, 2007 Bird strikes are very rare On average only one in 10,000 bird deaths are from turbines (Wind Power Outlook 2006) Turbine blades spin at low revolution Source: International Geothermal Association, 2007