RELIABLY REACHING CALIFORNIA’S CLEAN ELECTRICITY TARGETS

This report evaluates the operational feasibility and reliability of California achieving an accelerated interim target of 85% clean electricity by 2030. Using production cost modeling (PLEXOS) and capacity expansion modeling (RESOLVE), the study stress-tests three resource portfolios—Base Case, Diverse Clean Resources, and High Electrification—against various stressors including extreme weather, gas and coal retirements, and import constraints. The findings indicate that an 85% clean target is reliably achievable, provided there is sufficient battery storage and a strategic retention of some natural gas capacity or access to regional imports.

• California can reliably achieve an 85% clean electricity standard by 2030 using multiple resource pathways primarily composed of wind, solar, and battery storage. Modeling across various portfolios and sensitivities shows the system is able to serve load, with most sensitivities maintaining a positive natural gas margin.
• Integrating diverse clean resources, such as offshore wind and geothermal, improves reliability and reduces the amount of new solar and storage capacity required. For example, under base load growth, diverse resources reduce estimated new solar build from 27 GW to 15 GW, which may mitigate land-use and transmission challenges.
• While natural gas generation will be used sparingly, California must retain a significant portion of its existing gas fleet for reliability. However, the state can prioritize the early retirement of units sensitive to environmental justice concerns without compromising the ability to serve load.
• The California power system remains reliable even if all coal plants across the Western Interconnect are retired and replaced with a clean energy portfolio of solar, wind, and storage. However, this scenario increases reliance on in-state natural gas, particularly during the summer.
• The system is robust against extreme weather, including multi-day low wind and solar events (Dunkelflaute) and heatwaves similar to the August 2020 rolling outages. In a proxy 2030 simulation of the August 2020 event, the system served load even with a 0 MW import limit by dispatching up to 22,500 MW of in-state gas.
• The power system remains reliable when subjected to simultaneous stressors, including in-state gas retirements, WECC-wide coal retirements, import constraints, low hydro availability, and extreme weather. In a 20-year summer sample, only 5 days experienced capacity shortfalls.
• Demand flexibility and load shifting can serve as a hedge against uncertainty and reduce the need for battery storage, particularly for newly electrified loads in winter. However, its impact was relatively small in this study due to the high levels of assumed battery storage capacity.
• Battery energy storage is the primary enabler for the 85% clean portfolio, reducing evening net peak demand and the 'duck curve' ramping requirements by an average of 42%.
• Current modeling and planning tools must evolve to better account for geographic resource diversity, inter-regional coordination, and multi-year chronological weather data to accurately assess the risks of a decarbonized grid.

APA

Stenclik, D., Welch, M., & Sreedharan, P. (2022). RELIABLY REACHING CALIFORNIA’S CLEAN ELECTRICITY TARGETS. Energy Innovation. https://energyinnovation.org/wp-content/uploads/GridLab_California-2030-Study-Technical-Report-5-9-22-Update1.pdf

Chicago

Stenclik, Derek, Michael Welch, and Priya Sreedharan. RELIABLY REACHING CALIFORNIA’S CLEAN ELECTRICITY TARGETS. Energy Innovation, 2022. https://energyinnovation.org/wp-content/uploads/GridLab_California-2030-Study-Technical-Report-5-9-22-Update1.pdf.

Wikipedia

{{cite report |last1=Stenclik |first1=Derek |last2=Welch |first2=Michael |last3=Sreedharan |first3=Priya |title=RELIABLY REACHING CALIFORNIA’S CLEAN ELECTRICITY TARGETS |publisher=Energy Innovation |date=May 2022 |url=https://energyinnovation.org/wp-content/uploads/GridLab_California-2030-Study-Technical-Report-5-9-22-Update1.pdf |access-date=17 August 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{stenclik2022reliably, author = {Stenclik, Derek and Welch, Michael and Sreedharan, Priya}, title = {{RELIABLY REACHING CALIFORNIA’S CLEAN ELECTRICITY TARGETS}}, institution = {Energy Innovation}, year = {2022}, month = may, url = {https://energyinnovation.org/wp-content/uploads/GridLab_California-2030-Study-Technical-Report-5-9-22-Update1.pdf}, urldate = {2026-08-17}, note = {Indexed by Climate Insights Directory} }