An Economic Analysis of Selected Agricultural Uses of Warm Water in the Pacific Northwest Resulting from Electric Power Generation1,2

Between 1970 and 1990, 85% of all new electric power generating capacity is estimated to require water for cooling. This poses a question for research scientists from several disciplines of finding some productive use for the waste water required by steam generating plants. Since there is usually a finite amount of water available for cooling purposes adjacent to the plant sites, the problem becomes one of finding an economic use for a scarce resource. Several possibilities are discussed for making use of waste water: aquaculture, soil heating, and greenhouse heating. Two alternatives were considered for using cooling reservoirs (i) the production of carp for feed or fish meal, and (ii) catfish for the fresh market. Soil warming and greenhouse heating would involve locational problems relative to plant production, processing facilities, and transportation. None of the uses studied showed clear-cut advantages in terms of profits which would attract economic investment. The price of carp must be greater than $59.52/metric ton to pay for the rental costs; the current market price ranges from $55 to $60/metric ton. The market demand for catfish has been overestimated and prices have been declining for the past 5 years. Using a 607-ha (1,500-acre) cooling pond, the market price for catfish would have to be $.44/kg ($.20/lb) or the enterprise would not pay for the use of the facilities. Catfish prices for 1970–71 were $.57/kg ($.26/lb); further increases in production in the southern USA will likely cause even lower prices. Relocating greenhouses in order to use warm water for heating appears to be a marginal investment. The size of soil-warming systems is limited by the high initial investment, estimated yield response, and vegetable prices. A soil-warming technique costing only $4,942/ha ($2,000/acre) to install would be profitable for 20 or 29 vegetable crops considered; an investment cost of $12,355/ha ($5,000/acre) would be profitable for only 1 of the 29 crops considered.