Capitol Power Plant Becoming Cogeneration Plant, Quitting Coal

Last week, the Capitol Power Plant in Washington, DC quietly secured the final permits needed to transform it into an efficient cogeneration plant. Once constructed, the new cogeneration system will use 100 percent natural gas to power the buildings in the Capitol complex, including the Capitol Building, the House and Senate office buildings, the Supreme Court, the U.S. Botanic Garden and the Library of Congress buildings, among others.

Located in southeast DC, the Capitol Power Plant (CPP) was built in 1910 under the terms of an act of Congress passed on April 28, 1904. Originally intended to supply steam for heating and electricity to the U.S. Capitol, the CPP added a refrigeration plant to provide chilled water for air conditioning in the 1930s and stopped producing electricity altogether in 1951.

Today, the CPP produces steam and chilled water to heat and cool the 17 million square feet of building space of the 23 facilities in the Capitol complex using seven boilers capable of burning three types of fuel for steam generation: coal, natural gas, and oil. Fortunately, coal use has been steadily declining at the plant — going from 56 percent of CPP’s fuel mix in 2007 to 5 percent in 2011. Coal is mostly used as an emergency backup fuel source.

The effort to reduce the use of coal at the CPP goes back to 2000 when the office of the Architect of the Capitol, the administrator of the plant, tried to eliminate coal from the fuel mix. Senator Mitch McConnell (R-KY) and former Senator Robert Byrd (D-WV), both representatives of coal-producing states and recipients of campaign money from the coal companies that supplied the CPP, effectively shut down the attempt to switch to natural gas — a cleaner-burning fuel source.


But momentum for the switch to natural gas began to slowly build and in 2007 Speaker of the House Nancy Pelosi launched the Green the Capitol Initiative (defunded in 2011 by the GOP) and though it did not include a plan to reduce the CPP’s emissions, it did address the emissions controversially through a policy to purchase carbon offsets. More importantly, it called attention to the fact that the Capitol really wouldn’t be “green” until its main plant was no longer relying on one of the dirtiest, most air-polluting fuel sources.

The breaking point came in December 2008 when environmental activists Wendell Berry and Bill McKibben wrote an open letter to all Americans calling for civil disobedience that would take place in front of the CPP on March 2, 2009. This call to action seemingly prompted Speaker Pelosi and Senate Majority Leader Harry Reid to pen their own letter in February 2009, but this one went directly to Acting Architect of the Capitol Stephen T. Ayers, saying:

… there is a shadow that hangs over the success of your and our efforts to improve the environmental performance of the Capitol and the entire Legislative Branch. The Capitol Power Plant (CPP) continues to be the number one source of air pollution and carbon emissions in the District of Columbia and the focal point for criticism from local community and national environmental and public health groups.

Pelosi and Reid went on to say that they were “interested in identifying and supporting funding to retrofit CPP if necessary so that it can operate on 100 percent natural gas,” adding that the switch to natural gas would “allow the CPP to dramatically reduce carbon and criteria pollutant emissions, eliminating more than 95 percent of sulfur oxides and at least 50 percent of carbon monoxide.”

The office of the Architect of the Capitol responded quickly and on May 1, 2009, Speaker Pelosi and Senate Majority Leader Reid announced that the Capitol Power Plant would no longer burn coal, unless it was needed for backup capacity. This was a big step but there was still the issue of electricity. The CPP currently uses purchased electricity for some of its operations, such as the production of chilled water, so a heavier reliance on natural gas at the plant still doesn’t address an electricity mix that includes coal-fired power.


This is where the advantages of cogeneration come in. A cogeneration system allows the CPP to reduce its use of purchased electricity by over 93 percent by producing its own electricity. The electricity, steam and chilled water generated through cogeneration can achieve total efficiency levels of 60–80 percent, compared to the 33 percent efficiency level of conventional coal power plants.

In order to make the change to cogeneration at CPP, the Architect of the Capitol had to get funding from Congress (included in fiscal 2012 omnibus spending deal) and air quality permits from the Environmental Protection Agency (issued January 23, 2013) and air quality and construction permits from the District Department of the Environment (issued June 5, 2013). Though concerning to some activists and environmental groups because a ban on coal use was not included, the air quality permits do significantly lower the emission limits at the plant, limiting the use of coal.

Less coal use means cleaner air in the DC region, which is great for people who live or work in the area. A 2010 Clean Air Task Force study found that fine particle pollution from coal plants was expected to cause an estimated 13,200 deaths, 9,700 hospitalizations and more than 20,000 heart attacks per year.

The move to gas-fired cogeneration at the Capitol Power Plant signals a greater commitment to cleaner air, fewer emissions and energy efficiency in the District of Columbia, but there is more work to do. An even greater commitment would be a transition to clean, renewable energy using free fuel and producing no carbon pollution.