Thomas Donlan‘s latest editorial commentary for Barron’s offers little comfort to those who tout the benefits of solar and wind power.

… [W]e have just heard again, for the umpteenth time in 45 years of Earth Days, that the U.S. and the world are on the verge of a “great transition,” as the eminent Lester Brown titled his latest book on the bright future of solar and wind energy. He still believes that these are renewable energy sources great enough to replace most fossil fuels real soon now.

Unfortunately, Brown’s record as a prognosticator doesn’t match his record as a fund-raiser, a prize winner, and a Cassandra. We think of just two of his 50 books: Running on Empty: The Future of the Automobile in an Oil-Short World, published in 1979, and Who Will Feed China? Wake-Up Call for a Small Planet, published in 1995.

Neither oil nor food is yet in short supply, but Brown continues to be cited as one of the world’s most influential thinkers. He does deserve one prize (which we have just made up): the Paul Ehrlich prize for exceptional pessimism.

Solar and wind do have a future if the world adds one other source of energy—money supplied by governmental taxes and borrowing converted to subsidies for politically privileged technologies.

In the natural state, solar cells and windmills are still much more expensive than turbines powered by steam. With government intervention, solar cells and windmills will continue to spring up like green shoots, limited only by the imagination of presidents and lawmakers.

Whether the fuel is coal, oil, natural gas, or enriched uranium, the capital cost per kilowatt-hour of building central-station power plants in which steam is applied to turbines is still much less than the necessary cost of putting solar cells on millions of roofs.

Solar cells generate no kilowatts during the hours of darkness. Wind is less predictable. And engineers have not yet invented batteries able to store enough electricity cheaply enough to provide continuously reliable power, whether for a home or a city or a factory. Thus, solar and wind energy require backup production by fossil or nuclear fuel. That drives up the capital cost of supposedly clean power and adds the cost of fuel, as well. For the whole community of power consumers, it would be cheaper and more reliable not to build the solar and wind capacity at all.