In “The 100 Percent Clean Energy Act of 2018” the California legislature set a target of 100\% of California’s electricity generated from renewable and zero-carbon sources by 2045.

The California Public Utility Commission (CPUC) and other state entities now have the task of planning to meet that target.

The California Energy Commission (CEC) has sponsored multiple studies and sought public input on the pathways that they are exploring.

A key result of that planning process is a Reference System Portfolio (RSP) based on existing and planned electricity generating capabilities, and modeled grid build out to meet the planned targets by 2045 at the lowest cost.

Although this RSP has been discussed by the CEC in a public forum, to our knowledge, it has not been presented to the photovoltaic community.

Here we document the CEC’s current RSP, with emphasis on understanding their expectations for build out of solar as well as the associated need for storage and curtailment.