In a profile of the nation's largest urban solar panel farm, a 40-acre Exelon development housed in Chicago's West Pullman neighborhood, the Tribune's Gerry Smith writes that the solar power industry is ready to blossom in Illinois. Although the state currently has virtually no solar power capacity, the intensity of the sun here is equal to that of industry leaders like Germany and Japan. Because the cost of the technology is declining and unions are beginning to train electricians to install and operate the machinery, the future is looking bright.

Still, government support is needed to get solar really pumping. The General Assembly took another small step in the right direction this spring, passing legislation speeding up the date by which utilities will have to procure solar power under the state's Renewable Energy Standard. The Sierra Club's Jack Darin, minutes after the vote was cast, called it a "huge victory" that could create 5,000 new jobs in the state.

But experts tell the Trib that strengthening the state's net metering rules -- which determine how much solar producers are paid to sell energy to the electricity grid -- could really speed things along.

Net metering is a pretty simple concept. When a person uses electricity at their home, the utility meter runs. But say that same person sets up a solar panel on their roof. When the sun beats down on the panel, it generates new energy that can be sent back into the strained electrical grid. Net metering rules provide customers with retail credits on their electric bills for the clean electricity they generate themselves. In other words, they are only asked to pay the utility company for their "net" energy consumption. From the perspective of the utility, this is exactly the same result as if a home installed a more efficient refrigerator or turned off their lights more frequently.

Illinois passed a bill in 2007 offering customers of three major utilities (Exelon-owned ComEd, Ameren, and MidAmerican Energy Company) a one-to-one retail credit for electricity produced by renewable energy systems such as solar panels. The law included some of the best available practices in the nation; in 2009, the Network For New Energy Choices awarded Illinois' statute with a "B" grade. A residential solar panel system serviced by ComEd can offset an estimated 32 percent of annual energy consumption.

The problem with Illinois' statute is that larger customers -- think business parks, big box commercial stores, or industrial warehouses -- aren't given the full retail price for the energy they direct back to the grid, which discourages some of the state's most prolific energy users from setting up solar systems. From the Attorney General's net metering description:

Customers with eligible generators between 40 kW and 2 MW will receive credits equal to the utility’s avoided cost for their excess generation. The utility’s “avoided cost” is the cost the utility would have paid to purchase the electricity from another source if the customer hadn’t provided it.

In his article yesterday, Smith writes that a bill to address this problem by expanding eligibility for the one-to-one retail credit "did not pass" in Springfield this session. To be more specific, the bill never came up for a vote after State Sens. James Clayborne Jr. (D-East St. Louis) and Mike Jacobs (D-Moline) disregarded it in the Senate Energy Committee. Why? It could be that the two members are powerful allies of Exelon, which (like other utility companies) is worried that their profits will decrease if large retailers and manufacturers slap solar panels onto their buildings and start receiving larger credits.

Exelon may have built an innovative project on Chicago's South Side. But the publicly-financed development will boost the profit margins of a firm that's not always a friend of alternative energy producers. Keep that in mind when you read the glowing praise.