Desperate Response For the Losing Transition - Part 3: California’s Solar and Import

California Solar, battery storage and imports

In a July 9, 2025, New Yorker article titled “4.6 Billion Years On, the Sun Is Having a Moment,” environmentalist Bill McKibben praises California’s solar and battery storage advancements as a model for renewable energy. He frames renewables as poised to dominate, even as Inflation Reduction Act (IRA) subsidies are set to expire on December 31, 2025, potentially increasing renewable energy costs by 30%. This blog, the third in a series, uses 2024-2025 energy data to challenge McKibben’s claims, arguing that California’s renewable energy strategy, while technically impressive, is an economic failure that burdens ratepayers.

Claim #1 - California’s Solar Peak on May 25, 2025

In California, at one point on May 25th, renewables were producing a record hundred and fifty-eight per cent of the state’s power demand. Over the course of the entire day, they produced eighty-two per cent of the power in California,…

I want to begin by reminding you what I touched on in Part 2 - he switched the discussion to electric power generation only which includes 25% of the US GHG and ignores the other 75%. McKibben highlights May 25, 2025, “when California’s renewables, primarily solar, produced 158% of the state’s electricity demand at peak (12:50–12:55 PM), and 82% over the entire day, according to California Independent System Operator (CAISO) data.” While this demonstrates solar’s technical potential, it obscures the economic and operational challenges of intermittent renewable energy.

• Intermittency and Grid Management:

Figure 1 (CAISO Renewables as % of Demand, May 25) shows renewables peaking at 153.5% of demand midday but dropping significantly at night. To manage this, California relies on two strategies: exporting excess power during peak solar hours and charging batteries. Figure 2 (CAISO Demand vs. Generation) illustrates the mismatch between solar generation and demand, requiring grid operators to balance supply dynamically.

Figure 1 - CAISO Renewables as a % of the Demand on May 25, Midnight to Midnight.

Figure 2 - CAISO Demand versus amount generated in State

• Imports and Exports:

Figure 3 (CAISO Imports and Exports, May 25) reveals California imported power from midnight to 7 AM, exported from 7 AM to 6:30 PM, and imported again after 6:30 PM. While net imports were 6,450 MWh, the gross figures are telling: California imported 57,287 MWh and exported 50,837 MWh. This reliance on neighboring states highlights the grid’s dependence on external balancing to handle solar’s peaks and valleys.

Figure 3 - CAISO Imports and Exports for May 25

• Economic Impact:

Figure 4 (CAISO Real-Time Pricing) shows electricity prices at ~$35/MWh during imports and ~ negative $18/MWh during exports, reflecting oversupply. Figure 5 (Approximate Costs of Imports) estimates California paid ~$2 million for imports (57,287 MWh × $35/MWh) and incurred a ~$0.9 million loss exporting at negative prices (50,837 MWh × -$18/MWh), totaling a ~$2.9 million cost for the day. Additionally, utilities paid solar-equipped homeowners ~15–30 cents/kWh for excess power under Net Energy Metering (NEM) agreements, far above the negative export price, further inflating costs.

From a Net Imports perspective, the reported 6,450 MWh for the day costs around $452 per MWh which converts to 45.2 cents per KWh. The average residential electric rate for California in 2024 was 31.86 cents per KWh.

Figure 4 - CAISO Real Time Pricing

Figure 5 - Approximate costs of imports for May 25,2025

This dynamic, where California buys high and sells low (or pays to offload), underscores the economic inefficiency of over-relying on solar without sufficient storage or demand alignment. A Los Angeles Times article, “Solar Power Glut Boosts California Electric Bills” (referenced in my earlier blog, California Dreaming), notes how neighboring states profit from this imbalance, as California effectively subsidizes their grids.

Claim #2. Batteries as California’s Nighttime Power Source

Meanwhile, battery-storage capability has increased seventy-six per cent, based on this year’s projected estimates; at night, those batteries are often the main supplier of California’s electricity.

McKibben claims batteries are “often the main supplier” of California’s electricity at night. This exaggerates their role. Figure 6 (Charging and Discharging of Batteries, May 25) shows battery discharge is a small fraction of total demand, typically providing short-duration support (up to four hours) to stabilize the grid. Batteries help with rapid load response but cannot sustain California’s nighttime demand, which relies heavily on imports and natural gas.

Figure 6 - Charging and Discharging of Batteries on May 25

Claim #3 - Claim 3: 40% Reduction in Natural Gas Use

As a result, California is so far using forty per cent less natural gas to generate electricity than it did in 2023, which is the single most hopeful statistic I’ve seen in four decades of writing about the climate crisis.

McKibben celebrates California’s 40% reduction in natural gas for electricity generation compared to 2023, calling it a hopeful climate statistic. This reduction shifts the burden to neighboring states. California’s imports, particularly from coal- and gas-heavy grids in the Northwest and Southwest, allow it to relabel fossil fuel consumption as “imports.” The large swings in imports and exports (Figure 3) show neighboring states act as California’s de facto battery, absorbing excess solar and supplying power when renewables falter. This undermines claims of emissions reductions, as California’s strategy externalizes fossil fuel use. Utilities like PacifiCorp, serving Northern California, supply a small portion of Northwest imports, estimated at 5–10% of the region’s contribution.

Figure 7 - Imports Plus Natural Gas versus Demand

Conclusion

On May 25, 2025, California’s solar output set a technical record, producing 158% of demand at peak. However, this required costly imports at $35/MWh during low solar periods and paying neighbors to take excess power at negative prices, costing ~$2.9 million in one day. Homeowners with solar panels, were paid ~ 15–30 cents/kWh under Net Energy Metering, further increase costs passed to ratepayers. McKibben’s narrative of a renewable triumph ignores these economic failures. California’s grid strategy—relying on neighbors as a virtual battery and paying for both imports and exports—raises bills and questions the sustainability of its renewable model. Technical success does not equate to economic viability, and California’s ratepayers bear the cost of this disconnect.