What the last boiler actually is

If you drive Interstate 5 through Lewis County, the stacks at the TransAlta plant north of Centralia are hard to miss, and for a few more weeks they are still the only place in Washington where coal is burned to make electricity. The site has run two coal-fired boilers (large furnaces that boil water to spin a turbine), each on the order of 670 megawatts, for a combined nameplate of roughly 1,340 megawatts at last public report. The first boiler stopped burning coal at the end of 2020. Under the 2011 state agreement that set the schedule, the second and final boiler is due to stop by the end of 2025.

This is often confused with Colstrip, but the two are not the same thing. Colstrip sits in Montana, and the Washington story there is utilities selling or walking away from out-of-state shares. Centralia is in-state ground and in-state payroll, and the coal it burns has been railed in from the Powder River Basin since the adjacent local mine closed back in 2006. The timing is no accident: the state's 2019 Clean Energy Transformation Act (which bars utilities from using coal power to serve Washington customers after the end of 2025) lines up with the date the 2011 deal already set.

What leaves the grid, and what does not

Taking roughly 1,340 megawatts of coal capacity off the board sounds dramatic, and on paper it is a large number. In practice the plant has not run flat out for years, so the energy it actually delivered was well below that headline figure, and much of Washington's power already comes from Columbia River hydro, wind, and a growing slice of solar. The regional balance is managed in large part through the Bonneville Power Administration, the federal agency that markets most of the Northwest's hydropower and runs much of the high-voltage backbone.

The honest answer on reliability is that it depends on the weather and the season. Hydro is strong in a wet year and thinner in a dry one, and the hardest hours are winter cold snaps and the occasional late-summer heat event, when demand climbs and the region leans on imports. Losing a steady coal baseload does not, by itself, mean your lights flicker, but it does put more weight on hydro, storage, new wind and solar, and the regional market to cover those peaks. Expect BPA and state regulators to keep publishing adequacy assessments; read them as the real scorecard, not the retirement ceremony.

The transition funds, and who holds the receipts

The part of the 2011 deal that reaches a Lewis County reader's block is the money. In exchange for the phased shutdown, TransAlta agreed to pay into community funds over time, on the order of $55 million across three buckets at last public report: one for weatherization and energy efficiency, one for economic and community development, and one for energy technology. The point was to cushion a county that was about to lose a major employer and tax base, not to replace the plant with a single project.

The payments run on a long schedule stretching across the 2010s and into the 2020s, and they are tracked through the Washington State Department of Commerce and local boards set up to award the grants. If you want to see where a given dollar went, the board agendas and Commerce's grant pages are the accountable record, and they are more reliable than any round-number summary (including the one above, which is why we hedge it). Payouts have gone to home weatherization, local business and workforce projects, and energy-related pilots, though the exact totals by year are best read straight from the board minutes.

Worth watching this month

1. The scheduled end-of-2025 coal-off date for the final boiler, which is routine on paper but worth confirming against TransAlta's own filings rather than the calendar.

2. The next Centralia Coal Transition grant round and board meeting agenda, posted through the Washington State Department of Commerce, where disbursement figures are listed line by line.

3. Any TransAlta notice to state regulators or to its shareholders describing what continues on the site after the coal boiler stops, since some gas-fired and support operations may remain.

4. Bonneville Power Administration's winter and regional resource adequacy updates, which matter far more to your reliability than the closure headline does.

5. Lewis County economic development reporting on how the community development money has landed locally, a slower story that is easy to miss.

Questions from readers

Is Centralia the same as the Colstrip retirements?

No. Colstrip is a Montana plant where Washington utilities are shedding out-of-state shares. Centralia is the only coal plant physically in Washington, and its closure was set by a separate 2011 state deal.

Does the whole plant shut down at the end of 2025?

The coal boiler stops burning coal by the end of 2025. Other operations on the site, including gas-fired and support units, may continue, so it is not accurate to say the entire facility goes dark that day.

How much power does it remove from the grid?

Roughly 1,340 megawatts of nameplate coal capacity at last public report, split between two boilers. The energy it actually produced in recent years was lower, since the plant had not run at full output for some time.

Where did the community money come from, and who tracks it?

TransAlta agreed to pay into local funds under the 2011 agreement, on the order of $55 million across three buckets. The Washington State Department of Commerce and local grant boards hold the public records of how it was spent.

Will my bill or my reliability change because of this?

Not directly or overnight. Washington already runs mostly on hydro and growing wind and solar, so the main thing to watch is how the region covers winter and heat-event peaks, which regulators and BPA report on regularly.

Sources for this story

  1. Washington State Department of Commerce, Centralia Coal Transition Grants, State agency page (.gov) that administers the transition funds and posts grant awards and board information., www.commerce.wa.gov/growing-the-economy/energy/centralia-coal-transition-grants
  2. Washington State Legislature, 2011 TransAlta coal transition law, Primary bill record (.gov) for the 2011 agreement that set the boiler shutdown schedule and the funds., app.leg.wa.gov/billsummary?BillNumber=1825&Year=2011
  3. Bonneville Power Administration, Federal power marketer and grid operator (.gov) for the Northwest; publishes regional resource and adequacy information., www.bpa.gov
  4. Washington Utilities and Transportation Commission, State regulator (.gov) where utility filings touching Washington's coal transition and the Clean Energy Transformation Act appear., www.utc.wa.gov
  5. TransAlta, Centralia operations, Plant owner's own page describing the Centralia facility and its coal phase-out commitments., www.transalta.com/plants/centralia-thermal