Limiting Envelope of Electrical Generation from Geothermal Sources

Abstract

The selection of the best power production cycle is dependent upon geothermal supply temperature and re-injection temperature. Ih,s work attempts to establish the economic envelopes of a Single Flash and an Organic Rankine Cycle with respect to these two variables.

The power cycles are analyzed by the methods of energy analysis and thermoeconomics. Distinctions made between the concepfs of power plant efficiency and power plant effectiveness in order to be able to incorporate
the well field cost into the analysis. The power cycle performance is presented by normalized estimated electricity cost, where the well field costs incorporated. The normalized specific investment cost for the power plant only is calculated as well, but this variable is not influenced by the well field investment.

Finally the limiting envelopes are shown on a supply re-injection temperature contour diagram for both normalized power plant specific investment cost as well as normalized estimated cosf of electricity.