Huxley College Graduate and Undergraduate Publications

College Affiliation

Huxley College of the Environment

Department or Program Affiliation

Department of Environmental Studies

Abstract

Geothermal reserves represent a source of energy production with a remarkably low impact on the environment. Geothermal power plants do not rely on fossil fuels, so they avoid the associated emissions associated with combustion reactions and fuel transport. Because water can be pumped through the system continuously, geothermal power is more reliable than other forms of clean energy such as wind and solar power. The relatively low temperature of the geothermal resources at Mt. Baker makes the lease site suited for the construction of a binary geothermal power plant, which is the newest and most technologically-advanced system for geothermal power production. The binary system is the cleanest and "greenest" of the three types of geothermal power plants. In all geothermal plant systems, deep wells must be dug in order to pump hot waters out of the ground. Dry steam power plants involve the turning of turbines directly using the hot steam, and this represents the simplest method of energy harvest. Flash steam power plants update the previous method by pumping the waters into a low-pressure tank and using the resultant flash steam to turn the turbines. Both of these plant types emit steam and geothermal vapors to the atmosphere, resulting in emissions of steam and geothermal dissolved gases. Another issue with many older geothermal plants is that they do not re-inject spent fluids into the reservoir. Such emptying of geothermal aquifers can pose a threat of edifice collapse due to the resulting reduced stability of the rock. In contrast, the binary system alleviates these impacts by enclosing the extracted hot water in a "closed-loop" pipeline, and injecting the spent, cool water back into the ground for reheating. Because the fluid is never exposed to the air, dissolved gases cannot be emitted. Thus, geothermal power plants have operating emissions approaching zero. Injecting the water back into the ground greatly reduces the impacts on stability that occur when underground aquifers are emptied.

Document Type

Environmental Impact Assessment

Subject – LCSH (for OAI)

Geothermal power plants--Environmental aspects--Washington (State)--Baker, Mount; Environmental impact analysis--Washington (State)--Baker, Mount

Geographic Coverage

Baker, Mount (Wash.)

Genre/Form

Environmental impact statement

Publisher

Western Washington University

Date

Winter 2013

First Advisor

Bodensteiner, Leo R.,

OCLC Number

841588879

Rights

Copying of this document in whole or in part is allowable only for scholarly purposes. It is understood, however, that any copying or publication of this document for commercial purposes, or for financial gain, shall not be allowed without the author's written permission.

Date Permissions signed

3-15-2013

Type

Text

Format

application/pdf

Language

English

Department

Environmental Studies

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