California Air Resources Board

Charles Davidson
Sunflower Alliance, Researcher

Subject: A Hybrid Renewable Energy Project using Solar PV + Ramping Natural Gas Combined Cycle (NGCC) Electrical Power Plant + Batteries.

Potential Alternative CEQA Project to Carbon Capture and Sequestration (CCS), requiring knowledge of grid modeling and renewable energy integration

The following is a grid-integrated low-carbon and cost-effective renewable energy alternative to the Montezuma Carbon Capture and Sequestration (CCS) Project and other CCS projects—one that would potentially deliver better climate benefits while avoiding serious risks to nearby communities. (1,2)

The Problem with Montezuma CCS
The concern about global warming centers about the methods and the motivation by which society has as its disposal to reduce global CO2 greenhouse gas emissions. There are multiple choices of methods for reducing GHG reductions. The following discussion is two alternative examples of the choices presented in the San Francisco Bay Area. and it includes rough cost-benefit analyses and risk reduction scenarios.

The difference between the two choices is clear:
• CCS utilizes the (maximum) daily full-capacity CO2 emissions produced by the natural gas power plant. And
• The hybrid renewable energy scenario uses local grid-integrated solar PV electricity and battery storage with partial down-ramped natural gas power plant usage during daytime peak solar. (3-6)

The Montezuma project plans to capture CO₂ from three natural gas power plants in Pittsburg and Antioch, then transport it by pipeline (and initially barge it) to Solano County for underground injection beneath the Montezuma injection site. The projects second phase would include capturing emissions from Bay Area refineries.

The CCS approach carries significant dangers:
• Pipeline safety risks: heavier-than-air, ground-hugging CO₂ leaks can cause asphyxiation to individuals in nearby communities and also environmental damage
• Seismic concerns: The injection site sits along the Pittsburg-Kirby Hills Fault that has had two >6.0 magnitude earthquakes in the 1890s.
• Corrosion problems: Impurities from refineries (like H₂S and N₂O) will accelerate pipeline deterioration, in and act synergistically with carbonic acid from H2O intrusion.
• Long-term liability: Taxpayers bear the cost of maintaining fossil fuel infrastructure disguised as climate action and high log-term sunk costs at end of powerplants’ lifetime.

The Superior Alternative: Solar + Flexible Gas Plants + Batteries
Instead of expensive, risky CCS technology, we can achieve deeper emissions cuts through a smarter cost-effective and reduced greenhouse gas production approach:

Deploy large-scale solar and wind power across the Bay Area on abundant brownfields (for example) and along regional power corridors, paired with battery storage where needed.

Use existing natural gas combined cycle (NGCC) plants as flexible "backup" power that partially ramps up and down to follow the sun—running at low capacity during sunny hours and ramping up for evening peak demand. (4-6)

This approach would:
• Cut emissions immediately (not after years of construction)
• Save over a billion dollars in natural gas costs over 20 years
• Avoid pipeline and sequestration risks entirely
• Accelerate renewable energy deployment
• Phase out gas plant dependence as renewable energy and storage capacity expand
• Solar panels have been found to maintain almost all original generation capacity after 30 years

Technical Implementation
The system would work through:
• Automated, weather-adaptive controls to optimize efficiency
• Utility-scale batteries to smooth power plant ramp-up during peak demand
• Protective measures to prevent thermal stress on gas plant equipment
• Strategic renewable siting to improve regional grid stability and resilience and cost

Why This Collaboration Matters
The most valuable deliverable would compare both approaches on cost per ton of CO₂ avoided, engineering viability and reliability, public health benefits, community risk, and deployment timeline.

Subject-matter expertise in gas-fired power plant operations, grid modeling and renewable energy integration could be pivotal in shifting the conversation away from risky CCS schemes toward truly sustainable solutions.

The Urgency
Given the rushed timeline for the Montezuma and numerous other subsidized CCS projects, we need to act quickly to ensure decision-makers have a comprehensive cost-benefit analysis and risk analysis and consider the grid-integrated hybrid renewable energy alternative.

This "solar + flexible gas + batteries" approach represents a potential pragmatic bridge to a much cleaner energy future—one that protects frontline communities, keeps the lights on, and accelerates the integration of renewable energy supplies without locking in decades of unnecessary fossil fuel dependence.

This discussion outlined a cost-effective proposal for hybrid renewable electrical power plant operations using viable and safe daily plant ramping to accommodate high solar PV grid input. These hybrid renewable projects are alternative projects for Carbon Capture and Sequestration.
REFERENCES:
1) SECTION A.I. SITE CHARACTERIZATION 40 CFR 146.82(a)(2), (3), (5), and (6) MONTEZUMA NORCAL CARBON SEQUESTRATION HUB Facility Information Facility name: Montezuma NorCal Carbon Sequestration Hub IW-A1 Facility contact: Jim Levine, Managing Partner 2000 Powell Street, Suite 920 Emeryville, CA 94608 Phone: (510) 409-1765 Email: jim.levine@upstream.us.com Well location: Collinsville, Solano County, California. Collinsville, Solano County, California Lat: 38o 5’ 7.334” N Long: -121o 51’ 30.914” W NAVD 88 Sec 28 T 3 N R 1 E. Application Materials: Montezuma NorCal Carbon Hub (zip). (Class VI Application Materials/Project Narrative.)
2) EPA Region 9. “The United States Environmental Protection Agency, Region 9 (EPA) has identified information or clarification needed for continued evaluation of the site characterization and area of review (AoR) delineation modeling for the Montezuma NorCal Carbon Sequestration Hub Project.” (Letter to Jim Levine. April 3, 2024). “EPA has determined that your response to the RAI does not contain sufficient information to move forward with our technical review of the application. As such, we are temporarily pausing our review, while Montezuma works on updating these portions of the application with essential technical information. (Letter to Jim Levine. August 14, 2024) Application Materials: Montezuma NorCal Carbon Hub (zip). Technical Materials.
3) Interactions between hybrid power plant development and local transmission in congested regions. Lawrence Berkeley National Laboratory. Kemp, Julie Mulvaney, Dev Millstein, James Hyungkwan Kim, Ryan H Wiser (06/2023)
4) Fast-Start HRSG Life-Cycle Optimization. POWER (June 1, 2013) https://www.powermag.com/fast-start-hrsg-life-cycle-optimization/
5) Power Plant Cycling Costs. N. Kumar et al. Intertek APTECH Sunnyvale, CA. NREL (April 2012) https://www.researchgate.net/publication/241910062_Power_Plant_Cycling_…
6) Combined cycle power plants. Siemens Energy. Global (Oct. 2025) https://www.siemens-energy.com/global/en/home/products-services/product…