DiSTf!!BUXON OF THlS 03CUhENT IS UNLIMITED v\ 1 * The use of residual geothermal heat instead of residual condenser heat is a significant distinction between geothermal power plant waste heat usage and t h a t from coal or nuclear plants. The geothermal heat a t 130" to 2 O O O F or above from the heat exchanger or flasher discharge represents an inexpensive form of thermal energy by as much as a factor of three compared t o gas-fired h i g h temperature steam. discharge from coal, nuclear, or geothermal plants have similar temperatures, i n the range of 1OOOF. practical use, except for nearby space heating.

The information contained in this report provided the background and source material used in preparing the chapter of the Geothermal This source book is being assembled and edited under the direction of Dr. J. Kesten of Brown University. and detailed information than could be included in the source book chapter and is being published for reference. examples o f instrumentation and control techniques currently being used in geothermal power plants. In addition, the basic guidelines and unique characteristics of instrumentation and control in geothermal systems, are presented. * Source Book on instrumentation, measurement, and control techniques. This report presents more complete Included are detailed This report addresses the instrumentation and control philosophy and the hardware involved in geothermal electric plants and their supply and injection systems. systems. Sources of information for standard I&C practice are listed in the The intent is to address €he unique 5 characteristics o f geothermal electric instrumentation and control (I&C) Standard I&C practice is available in the general 1 iterature.-Appendix. The information contained in this report presents (1) The philosophy o f I&C system design (2) The development of the system, from power grid considerations through subsystem operation to specific system details (3) Component selection and operating considerations.