Wednesday, October 03, 2007 Osmeña: Sitting on a gold mine By Antonio V. Osmeña Estatements
OUR country is sitting on a gold mine of geothermal energy. The decay of radioactive elements deep within the earth generates heat that slowly flows into buried rock formations.
Under intense pressure and lava flow from the molten interior of the earth, some of the earth’s geothermal energy escapes through hot springs, geysers and volcanoes, and some transfer over thousands to millions of years to normally nonrenewable deposits of dry steam, wet steam (a mixture of steam and water droplets), and hot water lying relatively close to the earth’s surface.
Geothermal wells can be drilled like oil and natural gas wells to bring the dry steam, wet steam or hot water to the earth’s surface. Today, over 40 countries are tapping deposits of geothermal energy to produce electricity, provide low to moderate temperate heat for some industrial processes, to heat water in homes and businesses, and to provide space heating.
Although such sources are nonrenewable, they are projected to last for 100 years to 200 years. Congress needs to legislate and prioritize the finding, extraction and processing of accessible geothermal deposits in the Philippines.
In the Visayan archipelago, we have the existing extraction of steam deposits in the islands of Leyte and Negros which is now producing electricity from geothermal sources and serving vital industries, such as real estate.
Dry steam deposits are the preferred geothermal resource, but they are also the rarest. Only dry steam wells can be tapped easily and economically at present. This is done by drilling a hole into the reservoir, releasing the superheated steam through a pipe, filtering out solid material and piping the steam directly to a turbine to generate electricity.
Underground wet steam deposits are more common but are harder and more expensive to convert to electricity. When a geothermal well is drilled to bring this superheated water to the surface, about 10 percent to 20 percent of the flow flashes into the steam because of the decrease in pressure.
A centrifugal separator is then used to separate the steam from this mixture of steam and water droplets, and the steam spins a turbine to produce electricity. The largest geothermal electric power plant in the world based on wet steam wells is in Wairakei, New Zealand.
Other wet steam power plants are in operation in Mexico, Japan and the Soviet Union. The third type of nonrenewable geothermal deposits contain hot water only, and these deposits are even more common than dry steam and wet steam deposits.
With oil and gas prices continuing to rise and with the increasing air pollution caused by coal-fired electric power plants, geothermal deposits could produce enough electrical energy to meet the needs of the Filipino people for at least 200 years. The area within the Negros-Canlaon volcano is a potential source of geothermal deposits.
Potentially harmful environmental effects from geothermal energy vary widely from site to site and with the type of geothermal resources being used. The advantages of nonrenewable geothermal energy, which is abundant in our country, is that the technology is well-developed and relatively simple, with moderate cost and moderate net useful energy yield for large and easily accessible deposits.
This energy resource also does not produce carbon dioxide or materials that can be used to produce nuclear weapons.
Its land disturbance is low to moderate and can generate supply for 100 to 200 years for areas near the deposits.
Affordable supplies of crude oil and, possibly, natural gas will begin running out between 2020 and 2060.
During this period, the world is expected to face massive economic disruption, unless it has significantly improved the efficiency of the use of primary energy resources and has shifted to a mix of affordable and environmentally acceptable energy resources to replace its dependence on crude oil.
An integrated set of short, intermediate and long-term geothermal development plans over the next 50 years to supply electricity all over the country is a must to save us from economic crisis.
