It’s a no-brainer: Capture the sunlight that pours down most days on Los Angeles rooftops and convert it to electricity. If solar panels can generate enough power to run even a few of the air conditioners that Southern Californians use to weather our scorching late-summer days, it will be worthwhile. The Department of Water and Power estimates that the city can do that and more -- it expects 400 megawatts from rooftop panels that pump energy right into the local distribution system without new transmission lines running across sensitive ecosystems. The program could make L.A. the nation’s leader in nonpolluting solar technology. No arguments here.

But City Hall has wrapped up solar energy into a no-brainer of another kind, with a measure the City Council rushed to the March 3 ballot promising to answer, on some later day, numerous questions about the cost and feasibility of the plan. The inevitable result of the vote-now, ask-questions-later tactic is the queasy feeling that Los Angeles voters and ratepayers are about to be snookered. David Zahniser’s article in Friday’s Times, on a study that claims the DWP can’t implement the plan and that predicts rate increases far in excess of those discussed on the council floor, is only the latest evidence of a bungled process.

The report by P.A. Consulting Group, as summarized in an e-mail to council President Eric Garcetti from the council’s chief legislative analyst, Gerry Miller, calls the proposal “extremely risky” and “extremely aggressive” and questions whether there is even enough roof space to get the job done. In defending the ballot measure, one advocate told this page that the report is out of date and was just one of many solicited by council members to make sure the proposal was workable and not just another Million Trees. The reference to Mayor Antonio Villaraigosa’s widely promoted but narrowly successful tree-planting effort is kind of funny. What’s not funny is that the solar program would be more expensive and have far longer-lasting implications.

Los Angeles should have an ambitious solar energy plan, and the DWP is right to pursue it, as are the council and the mayor. But because of the slapdash and suspicious way the program has been rolled out, voters need to be on alert. The city muffed a solar program a decade ago, and the resulting bad will delayed, until now, a serious second attempt. Voters deserve to know whether they are being asked to sign on to a well-thought-out plan, or just another idea only half-baked by the L.A. sunshine.