Washington Eyes a Future Free of Coal Power — Almost

Legislation signed last week in Washington State requires the closure of the state's only coal-burning power plant, which is owned and operated by TransAlta, by 2025. Credit: Robert Ashworth/flickr.

Within the next 15 years, Washington State is going to phase out its only remaining coal-burning power plant, thanks to new legislation signed by Gov. Chris Gregoire (D) late last week.

As reported by local news sources, the coal plant, owned by TransAlta and located in the town of Centralia, is currently the state’s largest greenhouse gas emitter — not to mention mercury polluter. Starting in 2020, the TransAlta plant will shut down one of their two boilers and then, within five years, will cease its operations at the coal-burning power plant entirely.

According to a press release from the governor's office on April 29, the plant’s shut down is part of the state’s commitment to focusing on more clean energy sources, like natural gas and wind power.  

“Coal power was a part of our past,” said Gov. Gregoire last week, after the bill signing. “Our prosperity now depends on our ability to move forward with a clean energy future.”

The closure of TransAlta’s Centralia plant will make Washington one of only three states without a coal-burning power plant — Rhode Island and Vermont are the other two. Eliminating the coal plant will also reduce the state’s total carbon dioxide (CO2) emissions by about 25 percent, reports say, assuming the facility is replaced by a natural gas-burning power plant, which TransAlta has announced may be a possibility.

It sounds like Washington is making a bold step towards a coal-free future, but closing the Centralia plant may not have as significant an impact on emissions as some in the press have made it sound.

Despite its substantial emissions contribution, electricity from the Centralia plant accounts for just 10 percent of the power generated within Washington (most of the state’s electricity — more than 65 percent — comes from low emissions hydroelectric dams). But, Washington also receives a good portion of its electricity from Montana-based power plants that burn, you guessed it, coal.

So even after the TransAlta plant is closed, some of the electricity consumed in Washington State is still going to come from coal-fired plants.

There is also some question about how much better natural gas really is when compared to coal. A recent study published by Cornell University scientist Robert Howarth casts doubt on the view that there are greenhouse gas emissions advantages to burning natural gas, specifically when the gas is mined from shale rock formations. The new findings suggest that more methane gas (aka, the natural gas) leaks into the atmosphere during the mining process, and that extra methane can have such a large warming impact that it cancels out any benefit from emitting less CO2 during fuel-burning at the power plant.

This result, however, is based on a single study (and a controversial one at that), so some scientists say there may still be sizable emissions benefits from burning natural gas instead of coal. According to Climate Central calculations, CO2 emissions from burning natural gas are about half that of coal-fired plants, and that takes into account all the energy needed to mine, transport and burn the fuel for traditional (non-shale) sources of natural gas.

Most of Washington’s natural gas, which is largely imported from British Columbia, Alberta, and Wyoming, isn’t currently mined from shale gas sources.

In addition to being a greenhouse gas contributor, the Sierra Club has identified the Centralia power plant as a toxic mercury polluter on a new interactive map illustrating what they claim are the country’s most polluting coal-burning power plants. Once the mercury enters the environment, it can, in large enough doses, cause neurological problems, particularly in young children. 

The Sierra Club recently released an interactive map illustrating the most toxic mercury polluting coal-fired power plants in the United States. Credit: Sierra Club. 

Washington’s move to eliminate coal-fired power plants may soon be mirrored south of the border in Oregon; in 2010, Portland General Electric announced it was interested in closing the state’s only coal-fired power plant by 2020, though no official plan to do so has yet been put in place. 

To Washington’s east, however, an opposite announcement was recently made, when Idaho lifted a five-year ban on the construction of new coal-burning power plants, although the state simultaneously announced it doesn’t have plans to build any new plants right now.