“Green” energy sources such as solar and wind power are the answer to all our needs, ultra-liberals claim. If Americans would just use more of them, we could shut down all our coal-fired power plants, claim some opponents of fossil fuels.

Californians had an opportunity to demonstrate the wonders of solar power this year. In February, the largest solar power plant of its type in the world opened in their state. It includes solar arrays spread over nearly five square miles of land.

Proponents of the facility, the Ivanpah Solar Electric Generating System, claimed it would produce enough power to serve 140,000 homes.

But the bragging has died down. Since the power station began operating, it has generated only about half the promised electricity. The California Energy Commission explains that “factors such as clouds, jet contrails and weather have had a greater impact on the plant than the owners anticipated.”

As you may have expected, we taxpayers have a stake in the facility. The federal government provided $1.8 billion in loan guarantees for it.

Rational people understand energy sources such as solar and wind power can never be more than back-ups for dependable, low-cost electricity generated with coal. Instead of pouring money into “green” energy, Washington should be devoting more to technologies such as clean-coal power plants.