Calgary, Alberta-based TransAlta will shut down its 1,340-MW coal plant in Centralia, Wash., and build a $1-billion combined-cycle natural-gas replacement plant as the result of an agreement with the state that is pending in the Legislature. Photo: Courtesy of Transalta The last remaining coal-burning powerplant in Washington state is scheduled to be replaced by a natural-gas plant by 2025. The agreement, in the works for almost two years, will result in one of the two Centralia units being shut down by Dec. 31, 2020, and the second unit to follow by Dec. 31, 2025. TransAlta will install additional selective non-catalytic-reduction
Arch dams, classically curved monoliths situated in narrow valleys, are not as common as other types of dams, such as embankment dams and gravity dams. ENR takes a look at some of the biggest arch dams in the world, both completed and under construction.