Feasibility of a geothermal direct use enterprise park in Puna, Hawaii

Abstract

"After a public information process which included surveying community members regarding the acceptability of 21 different geothermal direct use applications, four agriculture-related businesses were selected as candidates for a hypothetical 15-acre (6 ha) geothermal enterprise park in the Kapoho/Pohoki area of the island of Hawaii. The applications included greenhouse bottom heating, pasteurization of potting media, biodiesel production, and lumber drying. There was significant community support for the chosen applications, and minimal opposition expressed. An engineering analysis concluded that a direct use enterprise park is technically feasible. Such a park could require up to 11 million Btu/hr (770 kcal/sec) of heat which might be supplied from a high-temperature resource, such as waste heat from a power plant, causing less than a 10° F (5.6° C) decrease in injectate temperature. The analysis was based on this hypothetical scenario, since waste heat is not currently available for direct use. The direct use enterprise park would cost an estimated $12.5 million to develop and construct, and$738,000 per year to operate and maintain. The hypothetical park would only be marginally economically viable, even with significant financial subsidies. Annual revenues are expected to be $1.21 million, based on a$200/acre annual lease rate and a geothermal heat rate priced at $1.32/therm, or half of the prevailing average cost of diesel and propane. Annual revenues could be as high as$2.42 million if the geothermal heat was priced the same as conventional fuels. The geothermal applications in the park could be expected to replace the use of 6,500-9,700 barrels of crude oil each year. In addition, 130 new jobs could be created.