Encouraging news for anyone who believes our continued reliance on coal for electric generation is a risk to the future of the planet: Google will apply its money and brains to making renewable energy cheaper than coal. The Google search for new energy sources will focus especially on solar, wind and geothermal systems.

That’s particularly good news to Gretchen and me. We’ve been waiting for a quarter century to fill a space on our roof that we designed for solar panels. We first became interested in the 1970s when Barry Commoner, the ecologist who ran on a third-party ticket for president in 1980, was writing about the need to rethink our energy policy in America.

I remember one piece he wrote in the late ’70s saying that we would regret a decision by the federal government not to engage the military in solar panel development and use, thus bringing down the cost and efficiency of solar. One can think of a different path the world might have taken since then if we had followed his advice.

Our latest bid for enough solar panels to supply our needs is in the neighborhood of $18,000 — a cost too great for us to justify. But the Google news and other reports of promising research and applications in alternative energy keep hope alive that we will live long enough to participate in the new energy age.

For example, the November/ December issue of Orion magazine has an article by Bill McKibben about the potential for using waste heat from industrial production to generate electricity. The potential is said to be enormous — enough to provide 14 percent of the electric power the United States now uses just by recycling waste heat from factories, according to McKibben, who quoted Sean Casten, of Recycled Energy Development — a company that sells the waste-heat recovery boilers.

McKibben comments: “You’re talking about a recycling project infinitely more important than all that paper we’ve been bundling and glass we’ve been rinsing for the last two decades.”

Still, it’s the thought of Google throwing its wealth and reputation for innovation into the energy issue that gives me hope.

Sergey Brin, a co-founder of Google, said, “This isn’t just about solving a problem. It also creates a gigantic opportunity.”

Indeed, among all the gazillion of Google searches, this Google search for new renewable energy is the greatest.

Speaking of energy, as I write this, a dozen or so chickadees and juncos are skittering across the glittering surface of the frozen snow and ice below the bird feeder just outside the window. The downy woodpecker and tufted titmouse have scattered seeds from the feeder across the hard, slippery surface.

The juncos skid into a seed pickup like a tennis player sliding into a shot on clay. Then they hop on to the next seed, pausing for a moment to draw one foot into their soft belly feathers.

They’re burning energy from the sun, just like the rest of us in one way or another. Theirs is renewable. Ours should be, too.