Centralia coal plant

Washington’s only coal-fired power plant generates enough electricity to light up more than a million homes. The Centralia plant in Lewis County also releases more planet-warming pollution than any other single source in the state, which is why Governor Gregoire is aiming to cut the plant’s greenhouse gas emissions in half by 2025. That one action would have roughly the same benefit as convincing 1 million commuters to go car-free.

For the last few months, state officials have been negotiating with TransAlta Corp., a Canadian energy company that owns Centralia, and looking for ways to replace its polluting coal with cleaner options. So far, though, no one seems to have answers to key questions, especially these two:

1. How much of Centralia’s power production do we need to replace?

2. Are there existing power plants or alternatives that could fill the gap left by Centralia’s ramp-down?

For this post, I’m going to focus on the first question. (I’ll save the second one for later). Figuring out how much coal power needs to be replaced is a hugely important question. One answer might reveal that the path to a coal-free state lies in encouraging conservation on cold winter mornings or summer afternoons—those times when energy demand is highest. And that kind of problem might be addressed by painless innovations in the way the electric grid works—such as automatically shutting off electric water heaters for a few minutes when no homeowner would notice. Or the data might suggest that all we need is a few relatively small biomass plants burning wood during peak energy-demand months. Or the answer might point to the need for big new natural gas plants in the vicinity.

(Sneak preview of my next post: the answer depends on what time of the year you’re talking about, and we may not need as much new power as you might think.)

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  • Keeping the Lights On

    So how much coal-fired energy flowing into Washington’s electric grid do we need to replace anyway? To answer that question, we would need to know three basic things about the Centralia plant: how much it power it produces, how it operates, and how it interacts with the rest of the electric grid.

    First, Centralia’s two coal-burning units have a capacity of roughly 1400 megawatts. But in reality, they don’t run all the time. In the last few years their annual output has ranged from 650 to just under 1200 average megawatts. So we probably don’t need to replace the plant’s full capacity, but likely some lower figure.

    Second, Centralia is a “merchant” plant. It’s not a utility that serves customers or has obligations to keep anyone’s lights on; rather, it’s a power producer that sells its electricity to utilities or power marketers. And because electric markets are so complex, it’s virtually impossible to trace where Centralia’s power is going. Some experts hypothesize that the bulk of it is being bought in California or other states. So it’s an open question whether replacing Centralia’s power is a concern for Washington’s electric consumers or for those elsewhere.

    Third, because Centralia is a massive energy generator on the west side of the Cascades, it does play a role in keeping the electrical grid stable and happy. So we’d definitely want to know how much of Centralia’s output is necessary for grid stability. Yet after asking officials from the Washington departments of Ecology and Commerce, the Bonneville Power Administration and regional power planners, I was unable to find any analysis that could answer that question (State negotiators say they are interested in figuring it out.) So, at present, it seems we don’t know how much of Centralia’s power is necessary to stabilize the west-side grid or how much of the year it’s essential.

    Working in the Dark

    So where are we headed? And who has a stake in the state’s deal with TransAlta?

    In initial negotiations with TransAlta, the state has proposed to replace all 1400 megawatts of Centralia’s coal capacity with renewable energy and natural gas, or some future technology, over the next 15 years. But it’s not clear that replacing all that energy is necessary, or even wise, particularly if it means building new energy generation that runs on natural gas, a fossil fuel that’s less dirty than coal but still pollutes the atmosphere with carbon. In early discussions, the state has considered helping TransAlta seek customers and financing to develop these new energy resources, including a gas plant. While state officials estimate this plan would dramatically reduce Centralia’s greenhouse gas emissions, that’s no reason to overlook alternatives that could move the state away from coal faster or be even more beneficial for the climate.

    The state’s proposal looks like a good deal for TransAlta and its shareholders, which must realize that once governments put a price on carbon and hold polluters accountable for greenhouse gas emissions, the economics of burning coal will go south in a hurry. Getting state help in replacing all of its coal power with greener options could give it a competitive advantage in making that necessary transition.

    If you’re one of Centralia’s several hundred workers—a steam plant mechanic or shift supervisor or electrical technician—the state’s plan might or might not benefit you. It would depend on what the sources of replacement energy are, when they’re coming online, what kind of skills those industries need and where the jobs are located.

    If you’re someone who lives in Washington whose utility isn’t buying electricity from Centralia anyway, you probably only care about replacing enough of the coal plant’s capacity to keep the grid humming along and your coffeemaker working. Is that 1000 MW? Is it 50 MW? Right now, the public simply has no idea.

    We also need to know who’s buying the plant’s power. If we only need a fraction of the plant’s output here in the Northwest, should the state be helping replace power that’s headed to California?

    Without these key pieces of information, it’ll be difficult to evaluate any deal that the state reaches with TransAlta. In the next post, I’ll take the next step toward answering these questions. In particular, we’ll look at some of the alternatives to replacing Centralia’s coal power.

    For other posts on this topic, see our special series The Dirt On Coal.

    Centralia photo courtesy of flickr user theslowlane via the Creative Commons license.