The bill still needs a final approval from the state senate house, before the legislative session ends on Friday 31 August, and for it to be signed of by governor Jerry Brown.
State senator Kevin de Leon authored the bill. He said: "When it comes to fighting climate change and reducing our reliance on fossil fuels, California won't back down."
It follows a similar law passed in Hawaii in June 2015, which legislated for 100% renewable electricity useage by 2045.
California’s bill calls for electricity utitliies to source 60% of power from renewable sources by 2030, up from the already mandated 50% target, agreed in 2015.
Then the state has until 2045 to source the remaining 40% from carbon-free sources — not necessarily renewables.
It already has over 5.5GW of installed wind capacity, with the state legislators pushing for more.
California is taking the lead on climate issues in the US — flying in the face of the federal administration — even indicating it would stick to the 2015 Paris Climate Accord targets despite the president’s decision to leave the UN agreement.
Earlier this year, the state legislated for newly built homes to require solar panels.