When rooftop solar systems generate more power than can be used on site, the local utility typically ends up acquiring the excess – often for very little money or none at all.

Iowa state Rep. Mary Mascher, who has been investigating the best way to have solar panels installed at her Iowa City home, has come up with an alternative: why not donate that power to low-income customers in peril of having their electricity shut off?

She recently introduced a bill to do just that. House File 149 would require any utility that has to periodically file an efficiency plan to include within that plan a system for giving excess solar energy to people who’ve fallen behind in their utility payments.

Mascher sees it as a logical extension of utility benefits currently available to people with low incomes, such as LIHEAP, the federal Low Income Home Energy Assistance Program.

“Our LIHEAP monies run out every year before the end of the winter season,” Mascher said. “We have more need than money to go around. This is another way to generate more energy money – in terms of providing a safety net for those folks. For me, it’s a win-win because the energy company doesn’t have to turn off someone’s power. And the people who need it the most are able to continue to get the power they need.

“This would be a way to make a credit that would help those who can’t afford it. I have not heard of this. When I was talking to my solar energy guys this fall, I asked them if this had been done anywhere. They said this is a unique idea.”

Justin Foss, a spokesman for Alliant Energy, said that customers already have the option of making a donation that would go towards offsetting the bills of customers behind in their payments. Known as Hometown Care, the funds given by Iowa customers are distributed by local Community Action Agencies according to federal income thresholds.

A spokeswoman for MidAmerican, Roth Comer, said that 33,175 of the company’s Iowa customers, or about 4 percent of the total, qualify for that energy assistance — and would qualify for the excess solar energy, as outlined in Mascher’s bill.

However, she said in an e-mail, “The legislation doesn’t contain many specifics about how the program would work in practice. We will be talking to many of the stakeholders on this issue to understand how it would be implemented and the impact it might have on our customers.”

Steve Fugate, a onetime solar developer now serving more as a solar advocate in Iowa, helped Mascher develop her concept. He sees no reason why excess solar energy should ever revert to the local utility. Both of Iowa’s largest electric utilities, Alliant and MidAmerican, allow generating customers to continue to roll over excess production for future use, until an account is terminated. At that time, any excess production is wiped off the books.

Utility policies vary considerably as to how excess generation is treated. Some utilities purchase excess power, usually for a fairly low rate. Others wipe it off the books every year, or even every month.

In those cases, Fugate said, “It’s like telling the farmer he has to clean out his grain bin at a certain time every year. Why not be able to gift those kilowatt hours to people who need it?”

Whenever she gets solar panels installed on her roof, Rep. Mascher, said, “If I overproduce, I’d like it to go to the people I want it to. I want to have a say in that, and to be able to utilize that for the people who need it the most.”