The following are some key facts on how geothermal energy works. Geothermal energy is one kind of renewable energy.
March 24 (Reuters) - The crisis at Japan's quake-battered Fukushima nuclear power complex raises questions about the costs and risks associated with nuclear power, and has rekindled interest in safer and cleaner renewable energy sources such as geothermal.
Countries from the United States and the Philippines to Iceland and Indonesia use geothermal energy to generate electricity, helping reduce their reliance on fossil fuels.
Geothermal can be a viable alternative to nuclear power, industry experts say.
Following are some key facts about geothermal energy:
* The amount of heat within 10,000 meters (about 33,000 feet) below the earth's surface contains 50,000 times more energy than all the oil and natural gas resources in the world.
* Naturally occurring geothermal resources are found in regions with active or geologically young volcanoes. One study puts the world's geothermal potential at 2,841 gigawatts (GW), more than half the world's current power demand.
* However, many geothermal-rich sites are in national parks and forests where development is prohibited, limiting the use of the resource to bathing in hot springs and heating homes and buildings.
* The most common way to capture the energy from geothermal sources is to tap into naturally occurring hydrothermal convection systems -- where cooler water seeps into the earth's crust, is heated up and then rises to the surface.
* When this heated water is forced to the surface, it is relatively simple to capture that steam and use it to drive electric generators. Geothermal power plants drill holes into the rock to more effectively capture the steam.
* The leading companies in this sector are in North America, led by Ormat Technologies and Magma Energy Corp . Both have invested in projects in Asia and will benefit from growth in the region. Ormat is involved in all aspects of the geothermal business.
* In Asia, companies with investments in geothermal include Philippines' Energy Development Corp , Panax Geothermal , Origin Energy , Tata Power and Idemitsu Kosan .
* Japan's Mitsubishi Corp , Toshiba and Fuji Electric supply 70 percent of the steam turbines and equipment used at geothermal stations worldwide.
* Geothermal heat occurs everywhere under the earth's surface, but the conditions that make water circulate to the surface are found only in less than 10 percent of the earth's land area.
* To tap the earth's full potential, companies such as Google are investing in a technology that will capture heat in dry areas, known as enhanced geothermal systems (EGS) or "hot dry rock."
* The hot rock reservoirs, typically much deeper below the earth's surface, are first broken up by pumping in high-pressure water. More water is then pumped through the broken hot rocks, where it heats up, returns to the surface as steam and powers turbines to generate electricity.
* Australia's Geodynamics is a leader in this market in Asia.
Source: af.reuters.com
No comments:
Post a Comment