Controlling acid deposition by seasonal gas substitution in coal- and oil-fired power plants

Abstract

Acid deposition, primarily the result of sulfur emissions due to fossil fuel combustion, is a serious environmental problem. Resolving the problem will impose costs measuring in the billions of dollars. Based on evidence that the rate of vet sulfate deposition in eastern North America is higher in the summer half of the year than in the vinter half of the year, seasonal control of emissions is proposed as a means of minimizing acid deposition control costs. This paper evaluates the proposal that natural gas be substituted for coal and oil in electric pover plants during April through September. A model is presented that simulates the substitution of natural gs for coal and oil in pover plants in the eastern 31 state region so as to minimize total costs with respect to deposition reductions at an Adirondack receptor. The results of the model show: 1) changes in fuel coansumption as a result of substitution, 2) the increased effectiveness of seasonal versus year-round controls. and 3) the costs of achieving various levels of deposition reductioan at an Adirondack receptor. The costs of seasonal gas substitution. in terms of emission and deposition reductions, are compared to cost estimates for other proposed control methods and strategies. An example is given that calculates the cost with respect to deposition of a source-oriented control strategy, so that the cost of seasonal gas substitution can be fairly compared with it. The conclusion of these cost comparisons is that seasonal gas substitution is cost-competitive vith some other control methods. at least in some states.