Meet the clean energy that never makes it home
Every day, solar farms and wind turbines produce electricity that never makes it to a single home or business. It's called curtailment — and most people have never heard of it.
Explore the Numbers
Total Curtailment (California) • 2023-2025
9,848,530,250,000 Wh
California alone has wasted 9.8 trillion watt-hours of clean energy since 2023
Select different items above to see how much could be powered with the wasted energy
When renewable energy is generated but can't reach the grid, it's "curtailed" (wasted).
Not stored. Not redirected. Just gone.
In this simplified example, a solar farm is ready to send 50 MW of clean energy, but the transmission line is already at 70% capacity with 70 MW from a gas plant. The result? Solar energy is curtailed (wasted) while fossil fuels continue to flow.
Curtailment happens everywhere, and California is just one example. Explore California’s data from 2023-2025 to get a taste of how much clean energy was generated but never used.
Data sourced from CAISO (California Independent System Operator).
Play our interactive challenge and see just how much clean energy is wasted in a single day — in terms you can feel.
Many renewable plants are generating clean energy but lack battery storage to save it for later. See where battery storage is needed most in California.
As you can see, California generates a lot of electricity from solar and wind, but many sites have no battery storage. That means when those plants generate more than the grid can immediately absorb and there's no battery to catch it, that electricity gets thrown away.
California is the only state with transparent reporting of curtailment, but this is a national problem. All across the United States, renewable energy generation is growing faster than the grid can handle. And where clean energy gets cut, fossil fuels fill the gap.
With old transmission lines and no storage,
clean energy waste isn't just possible — it's inevitable.
Curtailment persists for a few interconnected reasons — here's a simplified look at the key ones:
In many regions, fossil fuel plants have long-term contracts that guarantee grid priority. Even when solar or wind is cheaper and readily available, existing agreements and dispatch rules — such as must-run agreements — can force grid operators to dispatch gas ahead of renewables. Some plants also have technical minimums, limiting their flexibility to reduce output without tripping offline entirely and requiring hours to restart.
The power lines are old and weren't built for all the new solar and wind energy we have now. Long-distance, high-capacity transmission lines — the kind needed to move renewable energy from where it's generated to where it's consumed — are expensive and difficult to build.
Occasionally, clean energy generation simply exceeds demand, and we don't have enough battery storage to save that energy for later.
The bottom line? Curtailment is a symptom of a grid that hasn't kept pace with the clean energy transition. It will keep happening until policy, investment, and infrastructure catch up.
Join the movement to fix our grid infrastructure and ensure that no renewable energy is wasted in favor of fossil fuels.