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Utilities Vote To Close Largest Coal Plant In Western US (arstechnica.com)
An anonymous reader quotes a report from Ars Technica: At 2.25 gigawatts, Arizona's Navajo Generating Station is the biggest coal-burning power plant in the Western U.S. The plant, and the nearby Kayenta coal mine that feeds it, are located on the Navajo Indian Reservation, and the Navajo and Hopi peoples have had a conflicted relationship with coal since the plant opened in the 1970s. Almost all the 900-plus jobs at the mine and plant are held by Native Americans, and the tribes receive royalties to account for large portions of their budget. Negotiations were underway to improve the tribes' lease terms, which expire in 2019. But on Monday, the four utilities that own most of the plant voted to close it at the end of 2019. They decided that the plant's coal-powered electricity just can't compete with plants burning natural gas. A press release from Salt River Projects, which runs the plant, explained, "The decision by the utility owners of [Navajo Generating Station] is based on the rapidly changing economics of the energy industry, which has seen natural gas prices sink to record lows and become a viable long-term and economical alternative to coal power."
Hope so - that'd provide a bunch of jobs quickly, and the transmission infrastructure is already there...
It's true, natural gas combined cycles are far more efficient, produce much less CO2, require fewer operators and maintenance techs, and can be dispatched more easily with faster ramp rates. Design and construction times are much shorter, and the equipment is very robust after decades of optimization. They also require much less land and water (but that depends on whether they are air cooled or not). Modern control systems can be programmed to start up the plant at the push of a button with little operator interaction, or even operated remotely for some natural gas simple cycle plants.
There are drawbacks - modern heavy industrial gas turbines do have unique problems requiring extensive outages during major inspections (and often more unplanned outages depending on the design of the unit and age). Natural gas is more variable in price than coal, but operating companies and owners have gotten better at dispatching combined cycle plants to coincide with demand (some plants start up twice a day). Flexibility is important where natural gas power plants operate.
There will always be some fossil fuel plants in operation for the next century, if at a minimum to maintain voltage and VAR support. But coal has definitely seen its last decades. Few engineers I work with have done design work on a coal plant now, and those that have are all in their 50s or older. At some point that knowledge is going to be lost.