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

Based on evidence that the rate of wet sulfate deposition in eastern North America is higher in the summer half of the year than in the winter half, 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 power plants during April through September. A model is presented that simulates the substitution of natural gas for coal and oil in power 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) the increased effectiveness of seasonal versus year‐round controls; 2) changes in fuel consumption levels as a result of substitution; and 3) the costs of achieving various levels of deposition reduction at an Adirondack receptor. The costs of seasonal gas substitution are compared to cost estimates for other proposed control methods. The conclusion is that seasonal gas substitution is cost‐competitive with other control methods, at least in some plants and states.