Ripe for Retirement: The Case for Closing America's Costliest Coal Plants (2012)

December 2012
As many as 353 coal-fired power generators in 31 states — representing up to 59 GW of power capacity — are no longer economically viable compared with cleaner, more affordable energy sources.

UPDATE December 2013: Ripe for Retirement analysis updated with new 2011 power plant data. Learn more about the latest findings.

A significant number of U.S. coal-fired generators are old, inefficient, dirty, and no longer economically competitive. Simply stated, they are ripe for retirement and should be considered for closure.

America’s coal power fleet is facing an increasingly uncertain economic future. Growing competition from cheaper, cleaner alternatives — including natural gas and renewable energy sources such as wind and solar — is making it harder for these generators to produce energy economically.

With appropriate planning, these outdated coal generators can be closed down while still maintaining a reliable electricity system. By ramping up underutilized natural gas plants, increasing renewable energy through existing state policies, and reducing demand through improved energy efficiency, every region in the country could more than replace the electricity currently produced by ripe-for-retirement generators.

Shutting them down doesn't just make sense financially. Reducing America's reliance on coal would also improve public health, lower global warming emissions, and provide a historic opportunity to accelerate the transition to a cleaner, healthier energy future.

Report identifies U.S. coal generators that are old, inefficient, uncompetitive, and should be considered for closure

  • A coal-fired power generating unit, or generator (a power plant comprises one or more generators), is deemed ripe for retirement if it would cost more to operate — including the costs of installing any needed pollution controls — than a typical cleaner-burning and more efficient natural gas plant.
  • Up to 353 coal-fired generators in 31 states (out of a national total of 1,169) are ripe for retirement, equal to a total of 59 gigawatts of power generating capacity. Collectively they represent as much as 18 percent of the country’s coal-generating capacity and approximately six percent of the nation’s power.
  • Ripe-for-retirement generators are typically older, inefficient, and less utilized than the rest of the nation's coal fleet. They average 45 years in age, well beyond the 30-year expected life span for a typical coal generator, and operate at an average of just 47 percent of their power generation capacity, compared with 64 percent for the total U.S. coal fleet.
  • The states with the most ripe-for-retirement generating capacity are primarily in the Southeast and Midwest, with the top five (in order) being Georgia, Alabama, Tennessee, Florida, and Michigan.

These generators can be retired over the next several years while maintaining a reliable and affordable electricity system

  • Existing power plants have sufficient excess capacity to replace the electricity produced by the 353 ripe-for-retirement generators and reliably maintain electricity supplies at the regional power grid level.
  • The nation's current natural gas power plant fleet operated at only 39 percent of its design capacity in 2010. Running these plants at 85 percent capacity would generate more electricity than is currently being produced by all ripe-for-retirement coal generators, plus an additional 288 coal-fired generators that have already been scheduled for closure.
  • Some of the reduction in coal generation would not need to be replaced at all if states put in place measures that reduce electricity demand, such as investments in improved energy efficiency.

Ripe-for-retirement generators are dirty, release harmful pollution and global warming emissions, and damage public health

  • More than 70 percent of ripe-for-retirement generators lack adequate equipment to control the emissions of at least three of the four harmful pollutants examined in the report: sulfur dioxide, nitrogen dioxide, mercury, and soot.
  • The sulfur they emit causes acid rain. The mercury they release poisons waterways and causes neurological damage in children. The soot they emit creates smog that causes lung disease, premature death, and triggers asthma attacks.
  • Shutting down all ripe-for-retirement generators could avoid significant amounts of these dangerous pollutants every year, including approximately 1.3 million tons of sulfur dioxide, 300,000 tons of nitrous oxide emissions, as well as large amounts of mercury, particulates, and other toxic emissions.
  • Coal-fired power plants are the country's largest single source of carbon dioxide emissions, the primary contributor to global warming. Using cleaner alternatives to replace ripe-for-retirement generators and coal plants already scheduled for closure would reduce global warming emissions from the power sector by 9.8 to 16.4 percent, depending on which energy sources are used as a replacement.

Shutting down these coal generators provides a historic opportunity to accelerate the transition to a cleaner, healthier energy future

  • Achieving a smooth transition to a cleaner, sustainable, and more affordable electricity system will require utility regulators, power grid operators, utility companies, and power producers to rethink costly retrofits and make appropriate resource planning and policy choices.
  • A wholesale switch to natural gas is not a long-term solution to climate change. Though cleaner-burning than coal, natural gas still creates significant global warming emissions.
  • Replacing coal plants with renewable energy sources such as wind and solar — plus investments in energy efficiency that reduce overall electricity demand — offers the best, most effective strategy to reduce global warming emissions and move the country toward a clean, healthy, and sustainable energy future.

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