This paper examines five different low and no-carbon electricity technologies and presents the net benefits of each under a range of assumptions. It estimates the costs per megawatt per year for wind, solar, hydroelectric, nuclear, and gas combined cycle electricity plants. To calculate these estimates, the paper uses a methodology based on avoided emissions and avoided costs, rather than comparing the more prevalent “levelized” costs.
Three key findings result:
First—assuming reductions in carbon emissions are valued at $50 per metric ton and the price of natural gas is $16 per million Btu or less—nuclear, hydro, and natural gas combined cycle have far more net benefits than either wind or solar. This is the case because solar and wind facilities suffer from a very high capacity cost per megawatt, very low capacity factors and low reliability, which result in low avoided emissions and low avoided energy cost per dollar invested.
Second, low and no-carbon energy projects are most effective in avoiding emissions if a price for carbon is levied on fossil fuel energy suppliers. In the absence of an appropriate price for carbon, new no-carbon plants will tend to displace low-carbon gas combined cycle plants rather than high-carbon coal plants and achieve only a fraction of the potential reduction in carbon emissions. The price of carbon should be high enough to make production from gas-fired plants preferable to production from coal-fired plants, both in the short term, based on relative short-term energy costs, and the longer term, based on relative energy and capacity costs combined.
Third, direct regulation of carbon dioxide emissions of new and existing coal-fired plants, as proposed by the U.S. Environmental Protection Agency, can have some of the same effects as a carbon price in reducing coal plant emissions both in the short term and in the longer term as old, inefficient coal plants are retired. However, a price levied on carbon dioxide emissions is likely to be a less costly way to achieve a reduction in carbon dioxide emissions.