If there were any remaining doubts, the age of coal is over and the era of natural gas and renewables is officially here.

Luminant's decision last week to shut its Monticello Power Plant near Mount Pleasant, one of Texas' largest and dirtiest coal-fired electricity plants, is a prime example of this shift. The plant's pending closure in January is a win for clean air and the result of the new economics of energy that renders coal-fired power plants like the Monticello facility cost-prohibitive relics.

This is particularly true in Texas: Hydraulic fracturing has made natural gas production cleaner and cheaper than coal. Each year, electricity from the sun and wind contribute more megawatts to the state's power grid. The state's deregulated electricity market increases competition, which leaves costly, emissions belching coal-fired power plants like Monticello on the wrong side of a historic transformation.

We're pleased that Luminant took this step after a year-long review of its operations. A decade ago, this editorial board helped lead the charge against the former TXU Corp.'s plan to build about a dozen coal-fired power plants in the state.

Imagine how badly out of step Texas would have been had TXU succeeded. Texas and the energy company would have been saddled with 50-plus-year investments in facilities too expensive to operate. And what about air quality? In 2013, a report from Environment Texas found that Monticello emitted the 17th most carbon of any U.S. power plant.

Even with cleaner, state-of-the-art technology, the additional plants would have fouled the air we breathe at a historic rate.

All that stands in the way of Monticello's closure early next year is a sign-off from the Electric Reliability Council of Texas, which manages Texas' electric grid. Texas is so awash in power sources that the Council should be confident that the plant can be closed without endangering the reliability of power statewide.

The Monticello plant has a maximum operating capacity of 1,880 megawatts. That's enough to power about 940,000 homes in normal conditions and 376,000 homes in periods of peak demand. But in recent years, the plant, which comprises 20 percent of Luminant's coal fleet and 10 of the overall fleet, ran only for a few weeks in summer and winter. Plus, Luminant recently added nearly that much capacity with new natural gas and solar facilities.

About 200 plant employees will be without jobs when the plant closes. That's unfortunate; we urge the company and the community to do everything possible to help the workers transition to other positions.

Sadly, President Donald Trump doesn't seem to understand the economics of energy. His administration reiterated on Monday plans to restore coal-mining jobs and to repeal the Obama administration's Clean Power Plan. Trump seems oblivious to the fact that the power industry has already reduced its dependence on coal as a source of electricity.

The answer isn't to prop up a money-losing industry that harms public health.

We urge Luminant to phase out its four remaining coal-fired power facilities, which are operating on borrowed time, as well. Its decision to close an archaic coal-fired power plant is an important step in shaping a competitive energy future and one that we urge others to take as well.

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