Dow Chemical USA Report - Appendix B

The geopressured zone, assuming the presence of natural gas and high water productivity, may be used to produce economical electric power only if the water is at least 375 F or a means of conversion more efficient than flashing is found. The design and costing of a double-flash 25-megawatt plant using water at 325 F gave a capital cost of $678/kwh, a fuel cost of 63?/M Btu and a unit power cost of 46 mills/kwh. The conversion efficiency of the plant, including hydraulic turbine energy from the well head overpressure, was 10.3%. This low efficiency accounts for the high unit power cost. A one-well, 1.5-megawatt test facility will require a total capital cost of $6,661,000. Expansion of this site to a four-well, 10-megawatt pilot plant will require an additional capital expenditure of $27,843,000. The total capital cost for an independent 10-megawatt pilot plant was estimated at $31,777,000. It should be noted that the economics calculated in this report is based on industrial power plant experience. Maintenance, operating costs, and rate of return for industrial investment, as used in the calculations, do not reflect utility plant practices. The cost of power producing may compare more favorably with that of utility plants. Future power costs are projected to at least equal the costs expressed here