California will have to deploy renewable power at record-breaking speed over the next few decades to meet its target for carbon-free electricity by 2045, a transformation that state agencies say in a new report this week is technically achievable but immensely challenging.

The scale of deployment California alone will need to achieve underscores the hurdles facing President Biden and his team as he calls for eliminating carbon from the power sector by 2035, 10 years earlier than California’s target. The effort would require the biggest transformation of the electricity sector since it was built.