On the average sunny day, Germany’s huge energy grid gets 40 percent of its power from the sun. Guess what happened one recent morning when the sun went into eclipse. Nothing.

Or close to nothing. When the moon hid the sun for a few hours, the backup natural gas and coal plants switched on. The price of electricity rose briefly. That was it. Solar again showed itself to be a reliable energy source under a tough challenge.

Back in the United States, meanwhile, electric companies and various fossil fuel interests are fighting the American public’s growing passion for rooftop solar panels. They’re also doing battle with state laws requiring utilities to get a certain percentage of their power from renewable sources.

Oil, gas, and coal lobbyists, fed by Koch brother checks, are backing a campaign by utilities to slap fees on solar panels. Their target is net metering — the system whereby homes and businesses with solar panels sell their excess electricity back to the grid.

In Arizona, the big utility Salt River Project is adding a $50-a-month surcharge for customers with rooftop solar panels. SRP argues, as do other utilities, that solar customers rely on the grid for backup power when the sun doesn’t shine and should pay for it.

Studies out of Missouri, New York, Texas, Nevada, and Vermont counter that the alleged subsidies to those with solar panels are being offset. After all, solar consumers reduce the amount of power the utilities must provide — especially on hot sunny days, when demand is high. And a price can be put on greenhouse gases that were not emitted.

Big voices in the conservative movement are leading the charge for solar panel taxes. They also liken states’ green energy mandates to Obamacare. The conservative masses, however, don’t seem to be taking the bait. You don’t even have to ask about the liberals.

A power source that is domestic, is pollution-free and costs nothing (once the panels are paid off) — all courtesy of Mr. Sun — would seem to be in our national interests. Also, how interesting that SRP, in super-sunny Arizona, reportedly gets less than 2 percent of its power from solar and wind sources combined.

Huge numbers of Americans have been installing solar panels, thanks to better and cheaper technology. Businesses that stand to lose from this fact have set off clashes in nearly half the states — from Maine to California and Washington to South Carolina.

The utilities weren’t getting much traction in the legislatures — even in such Republican states as Indiana and Utah. So they turned to the public utilities commissions, where they can get a more private hearing.

Pro-solar conservatives hold that taxing solar panels stifles competition. A group called T.U.S.K. (Tell Utilities Solar won’t be Killed) is led by a former congressman named Barry Goldwater Jr. (the son).

Of a plan in Indiana to tax solar panels, one woman wrote, “Indiana’s utilities are interested in keeping us reliant on traditional fuel sources that hurt our national security and weaken our economy.” She would be Roberta Combs, president of the Christian Coalition of America.

So Senate Majority Leader Mitch McConnell can huff and puff about a “war on coal,” but to little avail. By the way, the domestic solar industry now employs more workers than does coal mining.

The utilities’ distress is understandable, but they can’t win this war. The means of generating energy are undergoing profound change worldwide. The utilities must change their business model or, if they can’t, concede the inevitable. You can’t stop the march of solar power any more than you can stop the sun from rising.

Follow Froma Harrop on Twitter @FromaHarrop. She can be reached at fharrop@gmail.com. To find out more about Froma Harrop and read features by other Creators writers and cartoonists, visit the Creators Web page at www.creators.com.

Photo: Solar panels at the Pittsfield Waste Water Treatment Facility (Massachusetts Department of Environmental Protection/Flickr)