Harnessing the Power of Geothermal Energy

HARNESSING THE POWER OF GEC THERMAL ENERGY Geothermal energy, which is heat from the earth itself that is converted into power, is an exceptionally clean and efficient alternative energy source. The heat that produces the steam and water that power geothermal systems is eternally renewable and sustainable. And, because it doesn't need to be mined, refined, or transported over long distances, it's far less expensive and destructive than energy sources such as oil and coal. and heat pumps used Geothermal electricity is currently produced in for climate control are in use in 24 70 COUNTRIES COUNTRIES WORLDWIDE Geothermal energy is drawn from beneath the earth in a number of different ways. It is currently used both to generate electricity and as a natural means of heating and cooling homes and buildings. GEOTHERMAL ENERGY Geothermal energy is produced from heat pulled from the melted mantle, or magma, beneath earth's crust. CRUST MANTLE OUTER CORE INNER CORE Heat is formed from: O Naturally radioactive materials such as potassium and uranium Volcanic activity and solar absorption The heat produced within 33,000 square feet of magma is equal to: 50,000 x more energy than all the natural gas and oil resources in the world combined. The heat can be accessed either by: O Tapping directly into the ground HOT SPRING GEYSER beneath earth's crust O Installing wells and POROUS ROCK LAYER pumps into the steam and water of нот UNDERGROUND geysers and hot springs WATER POROUS ROCK LAYER MAGMA - GEOTHERMAL The technologies used to produce electricity include: Dry steam power plants, flash steam power plants, and binary cycle power plants. ELECTRICITY All three of these pull hot water and steam from the ground. DRY STEAM POWER PLANT Turbine Generator Load Dry steam power plants are the simplest design. They draw the steam directly through a turbine. It then goes into a condenser where the steam becomes water. Production Injection Well Rock Well Layers FLASH STEAM POWER PLANT IIIOIIOI IOIOIIOIOIIOIC Turbine Generator Load In flash steam power plants: Extremely hot water is rapidly depressurized or "flashed" into steam. It is then used to drive Injection Well Production Rock the turbine Well Layers BINARY CYCLE POWER PLANT Turbine Generator Load In a binary system: Hot water is passed through a heat exchanger. It heats a second liquid, isobutane, in a closed loop. The isobutane boils at a Injection Well Rock Layers Production Well lower temperature, and its steam runs the turbine. Combined, these plants currently have a worldwide capacity of 10,751 megawatts. The average emission intensity of these plants is approximately 122 kg of CO2 per megawatt-hour, about one-eighth of a conventional coal-fired plant. GEOTHERMAL Geothermal energy can also be directly tapped into to provide climate control in homes and buildings. HEATING Also called direct heating, this process involves installing heat pumps: Hot Spring Generating unit either into natural Drilling Rig hot springs Injection I Well Well Impermeable Caprock Cap Rock or into wells that tap into heat from the earth's mantle. Permeable The heat pumps use the steady temperatures underground to heat and cool buildings year-round, cleanly and inexpensively. Water Flow Rock Impermeable Rock Magma (Heat Source) These heat pumps can save a Hot Water Cylinder typical home hundreds of dollars in energy costs per year. They pay for themselves within 8-12 years. Heat Pump Under Floor Geothermal heat can also Heating be used to: O heat greenhouses O de-ice roads O improve oil recovery processes O in spas and health clinics Heat pumps for home heating are the fastest-growing means of exploiting geothermal energy. O Industry growth rate of 30% per year THE DANGERS While geothermal energy is undoubtedly cleaner and more efficient than any traditional coal, oil, or gas power, it does have a number of inherent costs, safety, and environmental issues. AND CHALLENGES Open geothermal systems, such as geysers and hot springs, emit air pollutants. H,S As These include hydrogen sulfide, arsenic, and some toxic minerals. These are rarely harmful, but mineral build-ups are frequently deposited in landfills. Closed systems like binary cycles avoid this problem with a closed loop. Everything brought up by the water is returned back into the ground. O Despite their long-term cost savings, geothermal heat pumps have very high up-front costs. O The equipment and installation are both very expensive. O Comparatively there are few professionals who know how to handle the process. O Installation can also be fairly destructive. O It requires a lot of digging around and beneath a building's structure. ПL THE CURRENT STATE OF GEOTHERMAL ENERGY As a free, clean, and ultimately cost-saving source of electricity and heat, geothermal energy is being widely adopted all over the world. These plants produce enough electricity to Geothermal plants in 24 countries currently have combined capacity supply power to nearly 12 million homes. 1m T Im T 1m T Im T 1m T Im of some 8,900 megawatts. 1m T Im T Im TIm T Im T 1m T Breakdown of Geothermal Electricity Production Kenya 1.44% El Salvador 1.69% - Others 3.17% I Others Costa Rica 1.82% - Iceland 2.26% I Kenya - United States 28.70% New Zealand 4.87% I El Salvador I Costa Rica Japan 5.99% Iceland I New Zealand I Japan I Italy Italy 8.85% - Indonesia I Mexico I Philippines Indonesia 8.92% IUnited States - Philippines 21.6% Mexico10.67% Unsurprisingly, areas with the highest underground temperatures are more likely to tap into geothermal energy, both for electricity and with heat pumps for home climate control. This includes regions near Iceland, and places where the earth's crust is thin, like Nevada and parts of California. active volcanoes, Other geothermal "hot spots" are tectonic plate boundaries, where underground and undersea volcanoes abound. The Pacific Rim, also called the Ring of Fire, has many such hot spots. The largest geothermal system in operation is the Geysers, north of San Francisco. Geothermal energy production is expected to triple in the next 5 years. The hot spot is home to 22 O The Geothermal Energy power plants, drawing Association estimates that 132 steam from over 350 wells. projects now underway will provide as much as 6,400 megawatts of additional capacity in the O The Geysers has 1,517 megawatts of active installed capacity. United States alone. Sources http://www.renewableenergyworld.com http://www.ucsusa.org http://www.renewableenergyworld.com http://www.smartplanet.com http://geothermal.marin.org http://www.eia.doe.gov Well Home. Impeove the weather insi