SB 1, California’s Million Solar Roofs bill, was signed into law by Governor Schwarzenegger yesterday. For those new to the story, this bill — which some have called humankind’s last, best hope for surviving global warming — failed to pass out of the legislature three years running, until the California Public Utilities Commission enacted the meat of the measure — $3.2 billion in rebates for one million solar roofs — through a regulatory process last January. This bill codifies that funding into legislation, and fills in several very important missing pieces. Namely:

  1. Raises the cap on net metering from 0.5% to 2.5% of peak demand. Net metering is a policy that allows solar system owners to get credit for excess electricity fed back into the grid. This policy makes solar systems effectively about 25% cheaper, and by lowering system demand during peak load periods, reduces costs for all ratepayers. Without this expansion, the cap would have been exceeded in PG&E territory, severely impacting the largest solar market in the country. The new cap will allow for around 1,200 MW of net metered solar in California.
  2. Requires production home builders — that is, home developments over 50 units — to offer solar systems as a standard option. Done right, solar systems can potentially be installed more cheaply during construction than as a retrofit.
  3. Brings municipal utilities into the fold. Munis will have to develop their own solar rebate program, directing as much as $800 million in municipal ratepayer funds for solar.

There’s more. For the real policy wonk, check out the text of the bill here (PDF).