Geothermal energy potential for district and process heating applications in the U. S. : an economic analysis

Abstract

Geothermal energy is competitive for space and process heating applications over significant distances when employed on a large scale to serve concentrated markets. Under these conditions geothermal energy from 90 to 150/sup 0/C hydrothermal resources should be economically competitive for high-density urban district heating out to distances of 50 miles from the wellhead. Supply curves (price-quantity relationships) were developed for both process heating and district heating applications for distances out to 50 miles. The 90 to 150/sup 0/C hydrothermal resources, which were identified in the assessment of geothermal resources by the U.S. Geological Survey, contain usable energy for space and process heat equivalent to 50 billion barrels of oil. The potential demand for space and process heat near these hydrothermal resources is large; over 10% of the U.S. population resides within 40 miles of the resources. The sensitivity of production costs to the important factors of production was determined. The most important factors are well costs, well flow rate, resource temperature, distance separating demand and supply, population density, size of demand, and the system load factor. Technological advances are needed to reduce costs and increase the distances over which geothermal energy can be competitive. Institutional deterrents to widespread nonelectric applicationsmore » of geothermal energy will probably be significant. Among these will be the acquisition of rights-of-way, the need to organize concentrated markets, and price competition from the conventional fuels based on average cost rather than marginal cost.« less