Screen capture from CaISO/Flickr/Creative Commons License

California seems to have beaten another record for solar power flowing into the grid Friday, and if so it's a big one. According to preliminary data provided by the California Independent System Operator (CaISO) in graph form, shown above, the state passed the 2,000 megawatts of solar mark for the first time on June 7, 2013, with the day's peak at or a hair below 2,100 megawatts.

and then there was one: California's last nuke standing at Diablo Canyon | Photo: Nick Kocharhook/Flickr/Creative Commons License

Environmental and citizens' groups and a U.S. Senator are applauding an announcement early Friday that Southern California Edison's San Onofre nuclear power plant will be staying closed permanently. And as the California Energy Commission (CEC) starts work on planning for a future without San Onofre, antinuclear groups are now setting their sights on the state's last remaining nuclear power plant at Diablo Canyon.

San Onofre Nuclear Generating Station | Photo: Timothy Tolle/Flickr/Creative Commons License

Southern California Edison (SCE) will permanently close its ailing San Onofre Nuclear Generating Station (SONGS) in San Diego County, the utility announced Friday. The company cited mounting costs and regulatory uncertainty as the main reasons for its decision.

The plant's two remaining units have been offline since January 2012, when radioactive steam was found to be leaking from tubes in Unit 3.

John Woolard, left, speaks at the 2009 National Clean Energy Summit | Photo: Center for American Progress Action Fund/Flickr/Creative Commons License

BrightSource Energy's CEO John Woolard is leaving the company after several months of discussion, according to a report Thursday in the San Jose Mercury News. The Oakland-based concentrating solar firm is building the Ivanpah Solar Electric Generating Station a few miles from the Mojave National Preserve, and hopes to have its Palen Solar project approved by the California Energy Commission sometime this year.

Now that's a cool roof. Green roof at the California Academy of Sciences' in San Francisco | Photo: Michael Fraley/Flickr/Creative Commons License

Quick, answer this question without getting on a ladder: what color is your roof? If you're like 90 percent of Californians, your answer will be "dark." The most common color for roofing materials in the U.S. is black. And that's a problem. Summer sunshine can raise the roof's temperature by a startling amount, and that heats the interior of the building, leading to more energy use for climate control.

Fortunately there's a relatively straightforward fix, and it's called a "Cool Roof."

Quartzsite Solar's cousin in Tonopah | Photo: Don Brrrr/Flickr/Creative Commons License

Big news from the Interior Department this week as it gave final approval to three new renewable energy projects on public lands in Arizona and Nevada. But among all the self-congratulatory statements, one fact went almost unmentioned: one of those plants probably won't be built until the developer finds a California utility to buy the power, and that might not be easy.