The decision to locate a fossil-fueled electrical power plant on a particular site involves trade-offs among the costs of: (1) land acquisition, (2) plant construction, operation, and maintenance, (3) power transmission, and (4) air pollution damage to humans, animals, plants and materials. The fourth of these, pollution costs, has been of great concern in recent years. But seldom, if ever, are the specific dollar trade-offs between the environmental and the other costs associated with site selection taken into account. The sum of the costs of power generation (land, construction, operation, maintenance), power transmission, and air pollution damages (from sulfur dioxide, nitrogen oxides, and particulates) is the total social cost of a fossil-fuel plant; this total cost will generally vary by site. This paper presents an analysis of the total social cost, and the trade-offs between generation/transmission and air pollution costs, for various types of fossil plants at different sites in northern Illinois. The analysis identifies the combinations of site, fossil fuel, and sulfur dioxide (SO2) control technology that minimize total social costs.