RELIABLY REACHING CALIFORNIA’S CLEAN ELECTRICITY TARGETS

The study finds that California can reliably meet an 85% clean electricity target by 2030 using portfolios primarily composed of wind, solar, and battery storage. Through 264 PLEXOS simulations, the authors tested three portfolios—Base Case, Diverse Clean Resources, and High Electrification—against stressors including gas and coal retirements, low hydro availability, and extreme weather. Results indicate the system remains robust even under simultaneous stressors, though it remains dependent on a strategic amount of in-state natural gas and economic imports. The report emphasizes that diversifying resources with offshore wind and geothermal reduces the need for solar and storage and improves grid stability by lowering instantaneous inverter-based generation. While demand flexibility can offset some storage needs, the study concludes that further nodal transmission and grid stability analyses are required for a complete reliability assessment.

• California can reliably achieve an 85% clean electricity standard and a 75% renewable portfolio standard (RPS) by 2030 across multiple resource pathways, primarily utilizing wind, solar, and battery storage.
• Integrating diverse clean resources, such as 4 GW of offshore wind and 2 GW of geothermal, reduces the required new utility-scale solar capacity from 27 GW to 15 GW in the base load case and from 40 GW to 30 GW in the high-electrification case.
• The power system remains reliable even if all 14.3 GW of remaining coal capacity across the Western Interconnect is replaced by a portfolio of wind, solar, and storage, although this increases reliance on in-state natural gas by approximately 10% annually.
• California can target the early retirement of natural gas units sensitive to environmental justice concerns—approximately 11.5 GW of capacity—and still serve load, as these losses are largely offset by economic imports.
• The system is robust against extreme weather, including multi-day low wind and solar events (defined as three consecutive days below 30% of daily load) and heatwaves similar to the August 2020 rolling outages.
• When tested against simultaneous stressors—including gas and coal retirements, import constraints, low hydro, and extreme weather—the system remains generally reliable, with only 5 days of capacity shortfalls out of 3,680 evaluated days.
• Battery energy storage is the primary enabler for reliability, reducing the evening net load ramp by an average of 42% (from 26.8 GW to 15.5 GW over three hours).
• Demand flexibility and load shifting can act as a hedge against uncertainty and a partial substitute for battery storage, particularly in winter as electrification increases reliability risks.
• Diverse clean resources reduce the number of hours where instantaneous inverter-based generation exceeds 75% by approximately 40% compared to the Base Case, potentially improving grid stability.
• Current planning processes rely too heavily on capacity expansion modeling with limited sample days; the authors advocate for an iterative approach combining probabilistic resource adequacy and specific stress testing.

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} }