Matt Cooper

Advisor:  Dr. Baldwin

FYP Tech to the Rescue

SLU Festival of Science 2001 Poster Presentation

HEAT FROM THE DEEP

Our earth's interior, like the sun, provides heat energy from nature. This heat, geothermal energy yields warmth and power that we can use without polluting the environment. Geothermal energy is renewable heat energy from deep in the earth. Heat is brought to the near-surface by thermal conduction and by intrusion into the earth's crust of molten magma originating from great depth. Ground water is heated to form hydrothermal resources, naturally occurring hot water and steam. Hydrothermal resources are tapped by existing well-drilling and energy-conversion technology to generate electricity or to produce hot water for direct use. For generation of electricity, hot water, at temperatures ranging from about 300deg.F to more than 700deg.F, is brought from the underground reservoir to the surface through production wells, and is flashed to steam in special vessels by release of pressure. The steam is separated from the liquid and fed to a turbine engine, which turns a generator.  Spent geothermal fluid is injected back into peripheral parts of the reservoir to help maintain reservoir pressure. If the reservoir is to be used for direct-heat application, the geothermal water is usually fed to a heat exchanger before being injected back into the earth. Heated domestic water from the output side of the heat exchanger is used for home heating, greenhouse heating, vegetable drying and a wide variety of other uses. In the United States, geothermal resources are concentrated in the West, although low-temperature resources can also be found in the rest of the country. Geothermal heat pumps can be used nearly anywhere.  Advanced technologies will help manage geothermal resources for maximum power production, improve plant operating efficiencies, and develop new resources such as hot dry rock, geopressured brines, and magma. Geothermal power can be used pretty much all over.  Soon it will be more widespread and cost efficient to use regularly.