Proposition 7 would require all California utilities to get at least half their electricity from clean, renewable sources such as wind, solar and geothermal by 2025. It tilts toward solar power as a solution to global warming.

WHAT IT DOES

• Brings public utilities such as the Sacramento Municipal Utility District under the same law that requires private utilities to generate 20 percent of their electricity from renewable sources by 2010.

• Requires utilities to double the pace of acquiring renewable energy sources to 2 percent a year, so that by 2020 they account for at least 40 percent of utilities' electricity and by 2025, at least 50 percent.

• Shortens the approval process for building large renewable generators and lengthens the minimum contract term for renewable power supplies from 10 years to 20 years.

HISTORY

California strengthened its renewable energy standards for power plants in 2006 to help cut exhausts linked to global warming. Natural gas-burning generators emit about 25 percent of the state's climate-altering gases.

The standards require the state's three investor-owned utilities ­Pacific Gas and Electric, Southern California Edison and San Diego Gas & Electric ­- to ratchet up use of renewable sources by at least 1 percent each year.

These companies, however, are not expected to meet the mandated target of 20 percent renewables by 2010.

The portion of renewable power all California utilities consume actually has declined in the past five years, from 14 percent to 12.7 percent, according to the California Public Utilities Commission.

WHAT IT COSTS

The Legislative Analyst's Office says it's unclear how much Proposition 7's higher goals would cost consumers because of unpredictability in energy prices. But state regulatory costs could increase by up to $3.4 million annually, which would be paid by utility fees.

MONEY WATCH

• Proposition 7 is financed almost entirely by Arizona billionaire Peter Sperling, whose wealth comes from the for-profit University of Phoenix colleges. He and former San Francisco Supervisor Jim Gonzalez, a political consultant, have contributed about $7.4 million.

• Opponents have raised $27.8 million so far, all from the state's three largest investor-owned utilities or their parent companies: Pacific Gas and Electric, $14 million; Edison International (Southern California Edison), $13.7 million; Sempra Energy (San Diego Gas & Electric), $104,000.

MULTIMEDIA

Supporters' Web site, video ads: http://www.yeson7.net

Opponents' Web site, video ads: http://www.noprop7.com

Read previous installments in 2008 Ballot Watch: http://www.sacbee.com/ballotwatch

SUPPORTERS

• Peter Sperling, vice chairman of Apollo Group Inc., which runs the large for-profit University of Phoenix.

• Jim Gonzalez, former San Francisco supervisor and political consultant.

• S. David Freeman, former general manager of SMUD, Los Angeles Department of Water & Power and other major public utilities.

WHAT THEY SAY:

• Proposition 7 would launch the bold steps needed for California to reach its targeted cuts in global warming emissions.

• Doubling the rate at which the state shifts from fossil fuels to solar, wind and geothermal power would create hundreds of thousands of new high-wage construction and engineering jobs.

• Consumers would see no more than a 3 percent increase in their electricity rates. Utilities that fail to meet the increased renewable energy requirements would be subject to tougher penalties, but prohibited from passing fines to consumers.

OPPONENTS

• Pacific Gas and Electric, Southern California Edison, San Diego Gas & Electric

• California Solar Energy Industries Association

• Natural Resources Defense Council and other leading environmental groups.

WHAT THEY SAY:

• Proposition 7 is well intentioned but poorly drafted. The measure could actually decrease use of renewable power by shutting out small generators, which currently provide about 60 percent of California's renewable energy supplies.

• The proposal would result in higher electricity bills for consumers by allowing power companies to charge 10 percent above the market price, while providing no mechanism for limiting cost increases to the promised 3 percent a year.

• The measure's flaws would be difficult to rectify. Changes would require a two-thirds vote of approval by the Legislature.

Sources: California secretary of state, California Energy Commission, Legislative Analyst's Office