# US renewable curtailment shatters records in 2026 as transmission fails to keep up
> CAISO and other ISOs throw away record solar and wind and hit deepening negative prices, with bottlenecks, not oversupply, the culprit

**Meta:** type: story · date: 2026-06-24 · heads: Qué se rompió, El cambio silencioso · 9 takes · 3 lenses · 4 regions

## Summary

US [Renewables](/es/entity/renewables) curtailment is breaking records again in 2026. Four of seven US ISOs set annual
curtailment records in 2024; 2025 broke them and the trend is accelerating, with [CAISO](/es/entity/united-states)
solar and wind curtailment spiking to record levels across April 2026. CAISO threw away 3.4 million
MWh in 2024 (+29% YoY). Negative-price hours are surging as utility-scale and behind-the-meter solar
flood midday while load is weak, prices often go negative around noon as [batteries](/es/entity/battery-storage)
charge. Analysts pin the cause on [Transmission](/es/entity/transmission) bottlenecks, not generation oversupply: congestion
drives curtailment and negative prices simultaneously. The same dynamic appears across Europe.

## By the numbers

- 4 of 7, US ISOs that set curtailment records in 2024 (broken again since).
- 3.4 million MWh, CAISO solar+wind curtailed in 2024 (+29% YoY).
- April 2026, record-level curtailment spike across CAISO.
- Surging, count of negative-price hours coinciding with peak solar.

## Why it matters

Curtailment and negative prices erode the value of new renewables and the returns that finance them
, a self-limiting drag unless storage and [transmission](/es/n/hvdc-transmission-buildout-2026) catch up.
It is the clearest market signal that the US grid's bottleneck is wires, not panels.

## What to watch

- Whether 2026 sets fresh annual curtailment records across ISOs.
- How fast storage absorbs midday surplus and lifts midday prices.
- Transmission and interconnection reform pace.

## Regional takes (batched by bias / lens)

### unlabelled
- **California ISO (CAISO)** (United States, en) — Grid-operator curtailment data series, CAISO and other ISO curtailment volumes and negative-price hours used as the underlying record.
  Source: https://www.gridstatus.io/insights/topics/curtailment
- **LBNL Energy Markets & Policy** (United States, en) — 
  Source: https://emp.lbl.gov/news/declining-cost-wind-and-solar-power
- **Solar Data Atlas** (Europe, en) — 
  Source: https://www.solardataatlas.com/en/data-solar-curtailment
- **IEA (Renewables 2025)** (France, en) — 
  Source: https://www.iea.org/reports/renewables-2025/executive-summary
- **Yes Energy** (United States, en) — 
  Source: https://www.yesenergy.com/blog/the-duck-curve-explained-impacts-renewable-energy-curtailments
- **Energy Central** (United States, en) — 
  Source: https://www.energycentral.com/renewables/post/tackling-renewable-energy-curtailment-causes-impacts-and-jmfnYmEouW8YwEB
- **Spectra (MHI)** (Japan, en) — 
  Source: https://spectra.mhi.com/energy-explained-what-is-curtailment-and-how-do-we-address-it

### power-forecasting analytics
- **Amperon** (United States, en) — Documents four of seven US ISOs setting curtailment records in 2024, with 2025 breaking them again and 2026 accelerating, pinning the cause on transmission congestion, not generation excess.
  > "In 2024, four of the seven US ISOs set annual records for curtailed renewable energy, and the trend is accelerating."
  Source: https://www.amperon.co/blog/us-solar-and-wind-curtailment-is-exploding

### grid-data analysis
- **Grid Status** (United States, en) — Shows CAISO solar increasingly curtailed and midday prices cratering as batteries charge, with weak load and behind-the-meter solar driving negative prices around noon.
  > "Battery charging peaks around noon, when energy prices crater and often go negative."
  Source: https://blog.gridstatus.io/batteries-boom-but-solar-slides-in-caiso/

## Across the graph
- Related: [[hvdc-transmission-buildout-2026]], [[china-battery-storage-surge-2026]], [[solar-tariff-shift-2026]], [[iberian-blackout-final-report-2026]]
- Entities: Renewables, Electricity, United States, Battery Storage

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Canonical: https://rbtfl.xyz/es/n/renewables-curtailment-record-2026