Abstract: Several recent studies have used simulation models to quantify the potential effects of recent environmental regulations on power plants, including the Mercury and Air Toxics Standards (MATS), one of the US Environmental Protection Agency’s most expensive regulations. These studies have produced inconsistent results about the effects on the industry, making general conclusions difficult. We attempt to reconcile these differences by representing the variety of assumptions in these studies within a common modeling platform. We find that the assumptions, and their differences from the way MATS will be implemented, make a substantial impact on projected retirement of coal-fired capacity and generation, investments that are required, and emissions reductions. Almost uniformly, the actual regulation, when examined in its final form and in isolation, provides more flexibility than is represented in most models. We find this leads to a smaller impact on the composition of the electricity generating fleet than most studies have predicted.

Abstract: A variety of renewable electricity policies to promote investment in wind, solar, and other types of renewable generators exist across the United States. The federal renewable energy investment tax credit, the federal renewable energy production tax credit, and state renewable portfolio standards are among the most notable. Whether the benefits of promoting new technology and reducing pollution emissions from the power sector justify these policies’ costs has been the subject of considerable debate. We argue in this paper that the debate is misguided because it does not consider two important interactions between renewable electricity generators and the rest of the power system. First, the value of electricity from a renewable generators depends on the generation and investment it displaces. Second, a large increase in renewable generation can reduce electricity prices, increasing consumption and emissions from fossil generators, and offsetting some of the environmental benefits of the policies. Two policy conclusions follow. First, existing renewable electricity policies can be redesigned to promote investment in the highest-value generators, which can greatly reduce the cost of achieving a given emissions reduction. Second, subsidies financed out of general tax revenue reduce emissions less than subsidies financed by charges to electricity consumers.

Abstract: Residential buildings are responsible for approximately 20 percent of U.S. energy consumption, and single-family homes alone account for about 16 percent. Older homes are less energy efficient than newer ones, and although many experts have identified upgrades and improvements that can yield significant energy savings at relatively low, or even negative, cost, it has proved difficult to spur most homeowners to make these investments. In this study, I analyze the energy and carbon dioxide (CO2) impacts from three policies aimed at improving home energy efficiency: a subsidy for the purchase of efficient space heating, cooling, and water heating equipment; a loan for the same purchases; and efficiency standards for such equipment. I use a version of the U.S. Energy Information Administration’s National Energy Modeling System, NEMS-RFF, to compute the energy and CO2 effects and standard formulas in economics to calculate the welfare costs of the policies. I find that the loan is quite cost-effective but provides only a very small reduction in emissions and energy use. The subsidy and the standard are both more costly but generate emissions reductions seven times larger than the loan. The subsidy promotes consumer adoption of very high-efficiency equipment, whereas the standard leads to purchases of equipment that just reach the standard. The discount rate used to discount energy savings from the policies has a large effect on the welfare cost estimates.