The Union of Concerned Scientists (UCS) today released a new report that argues for closing more than 350 of the nation’s oldest — and dirtiest — coal-fired power plants. The plants are located in 31 different states, mostly east of the Mississippi River.
The UCS used economic criteria to identify up to 59,000 megawatts (about 6.3% of total U.S. production) of coal-fired generation that the group called “ripe for retirement.” The range is 153 to 353 power plants in addition to 288 already scheduled by the plants’ owners to be closed. The combined total generation of the “ripe for retirement” plants and the others already set to be closed totals about 100,000 megawatts, or just over 10% of total U.S. generation capability.
While acknowledging the pollution and health impacts of coal-fired generation, the UCS focused on economics in reaching its conclusions:
Less widely appreciated is that many of these coal plants have reached the end of their useful life—it simply makes no economic sense to keep them running when cheaper, cleaner alternatives are available. … The owners of these  soon-to-be-retired generators have concluded that paying for costly upgrades to keep their outdated coal plants running is a bad investment—particularly now that there are many cleaner, lower-cost alternatives that can
replace old coal units while maintaining the reliability of the electric system.
According to the UCS, natural gas-fired plants ran at an average of 39% of capacity in 2010. If that average were to be ratcheted up to 85%, no new power plants would have to be built. That’s just a raw number and the solution is probably not that simple. Another issue with this solution is that natural gas-fired plants are heavily used at peak demand periods and other spare capacity may need to be built.
A last significant issue is whether or not the antiquated U.S. electrical grid could move the electricity to where it is needed. The report just skates over this issue:
Investments in new transmission lines could be targeted to bring renewable energy to market. Investments in advanced energy technologies that better balance supply and demand, and integrate large amounts of variable resources into the electricity grid, could also help enable a smooth transition to a low-carbon energy future in the long run.
The “investments” needed to upgrade the U.S. electricity grid have been estimated as high as $1 trillion. That much may not be needed to accommodate the UCS plan, but a significant fraction would be required, and who pays for the upgrade is a non-trivial question.
The executive summary of the report is available here.