Solar panels have been dropping in price for years. Couple that fact with Federal tax breaks for taxpayers who install solar panels on their roofs, and it adds up to a strong future for solar.

Maybe too strong. At least, that's the fear of electric utilities who haven't figured out how to manage the problem that rooftop power production poses for their existing business model. According to a report in the Washington Post, electric power utilities are mobilizing to put the brakes on the booming solar electric power industry (see: "Utilities wage campaign against rooftop solar," by Joby Warrick).

"Three years ago, the nation's top utility executives gathered at a Colorado resort to hear warnings about a grave new threat to operators of America's electric grid: not superstorms or cyberattacks, but rooftop solar panels," reports the Post. "The warning, delivered to a private meeting of the utility industry's main trade association, became a call to arms for electricity providers in nearly every corner of the nation. Three years later, the industry and its fossil-fuel supporters are waging a determined campaign to stop a home-solar insurgency that is rattling the boardrooms of the country's government-regulated electric monopolies."

A state-by-state effort to put a damper on solar in state legislatures flopped, the Post reports — because support for households generating their own electricity can be found across the political spectrum. But the Post says a second political strategy is finding more traction for the utilities: they're lobbying utility regulators at the state level, who are not elected and whose actions don't attract much public attention, to tack an extra fee onto the bills of customers who add solar to their rooftops. The rationale is that a portion of every rate-payer's bill goes to help pay for the infrastructure of the grid — the transformers, transmission lines, and switches that distribute power around the country from producers to consumers. Customers with solar panels on their roofs don't buy as much power from the utility, but they still need the grid at night, on cloudy days, and in winter. So the utilities reason that in exchange for hooking up to the grid, those customers should pay something to make up for the power they're not purchasing on sunny days.

The strategy's working, at least in some states. But in the long run, slapping fees on customers with solar panels may come back to bite the utilities. That's because solar panels are not the only technology getting cheaper: batteries are getting cheaper too. And if power companies keep making it more expensive to hook up to the pole on the street, customers might eventually start to cut the cord altogether and rely on their own battery banks for night-time and winter backup. And the faster the utilities increase the cost of hooking to the grid, the sooner homeowners may choose to opt out of the system. That could create a vicious cycle for utilities, as they have to charge their dwindling pool of ratepayer customers more and more to plug in — thus creating a stronger and stronger incentive for ratepayers to unplug altogether.

But the utilities have a point. Keeping solar panels tied to the grid does bring efficiency and cost benefit to electricity users. And as the total rooftop generating capacity grows, the problem of managing solar's effect on the grid is everybody's problem. In Europe, where public policy and private choices have helped solar power grow to a significant fraction of the total power supply, that fact will be driven home in dramatic fashion this summer by an astronomical event that's almost as old as Planet Earth itself: a solar eclipse that will completely mask the sun for a few minutes on March 20. This time around, the eclipse will darken enough solar panels to make a noticeable dent in the continent's power supply. The Huffington Post has that story (see: "The Total Solar Eclipse May Do More Than Just Darken Europe's Skies," by Jacqueline Howard).

""Within 30 minutes the solar power production would decrease from 17.5 gigawatts to 6.2GW and then increase again up to 24.6GW. This means that within 30 minutes the system will have to adapt to a load change of -10GW to +15GW," said analyst Patrick Graichen.

European utilities are concerned, but not alarmed, according to CNBC (see: "Solar eclipse threatens European power supplies," by Kalyeena Makortoff). The European Network of System Operators for Electricity (ENTSOE) said in a press release, "Despite preparations and coordination, the risk of incident cannot be completely ruled out."