California to source 50% of energy from renewables by 2050

California Governor Jerry Brown plans to use his fourth term to push through some of the most ambitious clean energy policies in the world.

Brown outlined targets for the state to source half its power from renewables by 2030.

Speaking in his address on Monday, the Governor promised action to promote renewable energy investment, double the energy efficiency of existing buildings, cut the use of road transport fuels by up to 50 per cent, and make heating fuels cleaner.

Brown said: "I envision a wide range of initiatives: more distributed power, expanded rooftop solar, micro-grids, an energy imbalance market, battery storage, the full integration of information technology and electrical distribution and millions of electric and low-carbon vehicles.”

The measures would boost California's position as one of the leading clean tech hubs around the world and will also provide further support to the network of clean tech start-ups and investors that has emerged in Silicon Valley in recent years.

It will add to the states existing policies, including the target to reduce carbon emissions to 1990 levels by 2020 and source a third of electricity from renewables by the same date.

The announcement comes as the state's emissions trading scheme is set for significant expansion, after the mandatory scheme was expanded this year to cover power plants and industrial facilities as well as distributors of transportation and heating fuels.

Brown’s comments came on the same day as former Treasury Secretary Larry Summers called for the U.S to take the opportunity presented by the recent fall in oil prices to introduce a nationwide carbon tax, arguing it could be the effective means of tackling climate change while enhancing competitiveness.