For years, critics pointed at the "duck curve" as proof that solar would eventually defeat itself. Midday solar is so abundant it pushes net load — demand minus renewables — into a deep belly; then the sun sets, demand peaks, and the grid has to find tens of gigawatts in a few hours. Adding more solar, the argument went, only makes the evening ramp steeper. For a while, that was true.
It isn't anymore. On a typical California evening, grid-scale batteries now export more than 8 GW at their peak — roughly 65% of the fleet's nameplate capacity, and about 26% of net load at that hour. Across an evening, California's batteries deliver on the order of 33 GWh to the grid, and they have flattened the steep 4–9 PM ramp by close to half. The duck curve didn't beat solar. Storage answered it.
The milestone moment came in April 2024, when batteries became California's single largest source of evening-peak supply for the first time ever.
The mechanics are simple
A battery charges in the middle of the day, when solar is abundant and power is cheap — often near zero. It discharges into the evening peak, when the sun is gone, demand is highest, and the marginal megawatt would otherwise come from an expensive gas "peaker." Because most California batteries are four-hour systems, the fleet can hold that output across the entire evening window. The result is a smoother net-load curve and a direct displacement of the dirtiest, priciest hours on the grid.
Why this is the whole game
The grid's scarcest, most valuable product isn't energy in the abstract — it's dispatchable capacity from 4 to 9 PM. That window is where prices spike, where reliability is won or lost, and where firm capacity earns its keep. Solar alone can't serve it. Solar paired with storage can — and increasingly does.
What it means for Solyx
This is precisely what our San Diego County project is built to sell. We bank cheap midday solar in long-duration storage and deliver it into the 4–9 PM peak — in-basin, inside the San Diego Local Capacity Area, displacing imported power and the gas peakers that set the region's prices. The market has already proven the thesis; we're building to it.