Tuesday, an alarm in John Berton's kitchen beeped twice, and from that moment until the sun went down on the longest day of the year, Commonwealth Edison would be paying him for electricity.
They are hooked up to panels on his roof that provide all of the power his home needs, even on the darkest days of winter.
He is one of 53 homeowners in the city who collect enough solar power to sell some of the resulting electricity back to ComEd.
Along with solar power devotees scattered through the suburbs, they are trying to prove that Chicago--which is not in anybody's sun belt--has plenty of sunshine to provide for household needs.
"I don't have central air--my system wouldn't support it," Berton said.
He believes he has invested about $30,000 in his home's elaborate renewable energy system and another $20,000 in his truck, which he converted to electricity himself.
Berton's version of energy conservation is extreme, but across Illinois more people are taking the first steps toward alternative energy systems that used to draw little interest here.
Led by commercial and public buildings, Chicago has become a leader among cloud-belt cities in generating solar electricity, industry officials say.
"We're light years behind California, of course," said Ted Lowe, an Illinois Solar Energy Association board member, who installed panels at his Wheaton home five years ago.
"But we're up-and-coming with both wind and solar power."
Some people installed solar panels in Illinois during the oil embargo of the 1970s, but interest in renewable energy stalled in the 1980s as energy prices stabilized, he said.
Year-round, people in Illinois can produce only about 80 percent of what people in Arizona can produce.