In the final hours of the legislative session, California lawmakers passed a landmark climate bill that will promote greater deployment of clean energy technologies over the next 15 years, but which some supporters say still fell short of expectations.

SB 350 will increase building energy efficiency in the state by 50 percent by 2030. It will also boost the amount of renewable energy utilities need to buy to 50 percent by 2030. California's three investor-owned utilities are already well on their way to meeting the state's 33 percent renewable energy goal by 2020, according to the California Public Utilities Commission's fourth-quarter 2014 RPS report.

The third major component of the bill -- a target to reduce oil use in cars and trucks by 50 percent over the next 15 years -- was struck down earlier in the week. The measure was strongly opposed by oil industry groups, including the Western States Petroleum Association, which insisted that the target would cripple California’s economy and even lead to bans on SUVs.

"We are disappointed that the legislature was unable to take action this session setting specific transportation goals for 2030, which would have sent a clear market signal for continued growth of electric vehicles and alternative fuels over the next decade," said Graham Richard, the CEO of Advanced Energy Economy.

Senate leader and bill author Kevin de León harshly criticized the oil industry’s scare tactics earlier this week. “Big Oil might be on the right side of their shareholder reports, but we’re on the right side of history,” he said.

SB 350 embodies the environmental goals Governor Jerry Brown laid out in his inaugural address earlier this year. Brown praised the passage of the bill on Friday, but insisted the battle to reduce oil use is far from over.

In addition, to the dismay of both solar companies and utilities, SB 350 does not specify that distributed solar arrays count toward the mandatory component of the renewable energy target.

SB 350 is one of 12 climate bills that have been working their way through the California state legislature.

A separate bill (SB 32) that would have required California to reduce emissions 80 percent below 1990 levels by 2050 failed to pass in the Assembly, despite strong support from the governor, as well as from U.S. Senators Barbara Boxer and Dianne Feinstein.

However, lawmakers did pass legislation (SB 185) mandating that the state's two largest pension funds divest from coal companies.

With the state's legislative session now over, clean energy advocates are focusing their attention on the California Public Utilities Commission.

California’s three investor-owed utilities have filed proposals to reduce compensation for net-metered solar customers, and add monthly charges for the electricity these customers consume. While the changes are expected to raise solar customers’ electricity bills (from an average of $65 per month to $135 per month in Southern California Edison territory), utilities claim solar customers will continue to see savings, especially as solar costs decrease.

In a recent blog post, Caroline Choi, SCE’s vice president for energy and environmental policy, wrote that solar customers can still expect to pay off their system in seven years under the utility's proposal.

Under a 2013 law (AB 327), the CPUC has until the end of the year to create a successor “NEM 2.0” tariff . Solar advocates, including the state’s leading cleantech investors, are pushing for regulators to keep solar incentives the same through 2020.

“If California intends to maintain its role as leader in renewable energy, it will have to reject these proposals,” said Bryan Miller, vice president of policy at Sunrun. “Net energy metering exists in 44 states; South Carolina recently became the 44th. If California wants to be more regressive than South Carolina on renewable energy policies, it would accept these utilities’ proposals. But I don’t think that’s where California’s values are.”

Miller pointed to Arizona, where Salt River Project recently approved solar demand charges, and consequently solar installations fell by 95 percent. “There is a dead body in Arizona, and utilities in California really like that result, and want to do the same thing,” said Miller.

This debate comes after the CPUC passed reforms to residential electricity rates in July, including a requirement for utilities to create time-of-use plans, a move to a two-tiered rate structure, and the rejection of fixed monthly charges in favor of a minimum bill approach.