We assess several of the important health and environmental risks associated with a reference geothermal industry that produces 21,000 MWe for 30 y (equivalent to 20 x 10{sup 18} J). The analyses of health effects focus on the risks associated with exposure to hydrogen sulfide, particulate sulfate, benzene, mercury, and radon in air and arsenic in food. Results indicate that emissions of hydrogen sulfide are likely to cause odor-related problems in 29 of 51 geothermal resources areas, assuming that no pollution controls are employed. Our best estimates and ranges of uncertainty for the health risks of chronic population exposures to atmospheric pollutants are as follows (risks expressed per 10{sup 18} J of electricity): particulate sulfate, 44 premature deaths (uncertainty range of 0 to 360); benzene, 0.15 leukemias (range of 0 to 0.51); elemental mercury, 14 muscle tremors (range of 0 to 39); and radon, 0.68 lung cancers (range of 0 to 1.8). The ultimate risk of fatal skin cancers as the result of the transfer of waste arsenic to the general population over geologic time ({approx} 100,000 y) was calculated as 41 per 10{sup 18} J. We based our estimates of occupational health effects on rates of accidental deaths together …

A study of advancements in power plant designs for use at geothermal resources in the low to moderate (300 to 400F) temperature range is reported. In 3 case studies, the benefits of R and D to achieve these advancements are evaluated in terms of expected increases in installed geothermal generating capacity over the next 2 decades. A parametric sensitivity study is discussed which analyzes differential power development for combinations of power plant efficiency and capitol cost. Affordable tradeoffs between plant performance and capital costs are illustrated. The independent review and analysis of the expected costs of construction, operation and maintenance of the Heber Binary Cycle Geothermal Power Demonstration Plant are described. Included in this assessment is an analysis of each of the major cost components of the project, including (1) construction cost, (2) well field development costs, (3) fluid purchase costs, and (4) well field and power plant operation and maintenance costs. The total cost of power generated from the Heber Plant (in terms of mills per kWh) is then compared to the cost of power from alternative fossil-fueled base load units. Also evaluated are the provisions of both: (a) the Cooperative Agreement between the federal government and San Diego …