China’s renewable curtailment worsens amid grid delays

China’s solar and wind curtailment rates rose sharply in the first half of 2025, highlighting growing grid constraints amid record renewable additions.

Solar curtailment reached 5.7 per cent, up from 3 per cent a year earlier. Wind rose to 6.6 per cent from 3.9 per cent, according to the National Energy Administration. Curtailment occurs when generated power cannot be delivered due to oversupply or transmission bottlenecks.

Remote western provinces like Xinjiang and Qinghai, where generation far exceeds local demand, saw the highest curtailment. Existing ultra-high voltage (UHV) lines are insufficient, and new ones take years to build.

Analysts point to the mismatch between renewable growth and grid readiness. Fitch Ratings said capacity expansion is outpacing transmission and storage. China raised its curtailment tolerance to 10 per cent, but some regions already exceed this.

Despite the challenges, China added 277 GW of solar in 2024 and broke monthly records in 2025. State Grid plans to spend over 650 billion yuan this year, mainly on UHV lines. But improvements may not ease curtailment before 2027.

The NEA aims to add over 200 GW of renewables annually through 2027. Experts warn that without faster grid upgrades and power market reforms, returns on new projects could decline, slowing future investment.

Source: Bloomberg