China stops publishing data highlighting solar power constraints

BEIJING – China appears to have stopped publishing data that highlights the extent to which power generated by solar and wind plants is being wasted, as rapid renewable energy expansion runs up against constrained grids.

The National Energy Administration (NEA) typically publishes a monthly power report that includes a section detailing average utilisation for each generating source, including hydro, thermal, nuclear, wind and solar generation. For much of 2024, the figures had pointed to reduced solar panel usage, as overloaded networks forced them to shut down during peak generating hours.

Yet the most recent edition, published on June 28 for the period through to May, included only average utilisation for all sources. The NEA did not respond to faxed questions about the missing data.

Usage rates for wind and solar had been expected to drop further after the government

relaxed rules on renewable power utilisation in May.

China has a track record of quietly ceasing to disclose numbers that shine a light on trouble spots in its economy, such as when it temporarily stopped releasing its youth jobless rate in 2023 after soaring numbers made international headlines.

When it comes to clean energy, Beijing usually has nothing to hide. China leads the world in the deployment of renewable power, and has built supply chains for solar panels, batteries and electric vehicles that have lowered the price of the key transition technologies globally.

But as that success has tangled these industries in international trade disputes, Chinese leaders have stepped in to protect what they see as vital economic growth engines. That includes by creating strong demand for panels and turbines – even after record installations in 2023 left power grids in certain areas struggling with too much generation during peak daytime hours that then disappears at night.

The NEA usage data so far in 2024 had highlighted those struggles.

In the first four months of 2024, the average operating hours of wind and solar power plants dropped by 77 hours and 42 hours to 789 and 373 hours, respectively. Hydro plant operating hours rose by 48 hours to 783 hours on average and thermal power plants rose by 23 hours to 1,448 hours, respectively.

The reduction in wind and solar is a sign that

overloaded networks are forcing some green power projects to unplug

in peak daytime hours. This process is called curtailment, when grid managers stop a certain amount of supply coming onto the grid to maintain balances with demand.

Soaring curtailment rates during an earlier, more modest solar boom in the mid-2010s led to restrictions on new builds that caused installations to crash after 2017. The government is trying to allay fears of a repeat, vowing continued support of both rooftop and large-scale projects and promising to construct more power lines and energy storage plants. 

Beijing has already changed its rules to allow renewable plants to have as much as 10 per cent of their generation curtailed, compared with a previous cap of 5 per cent, meaning more wind and solar can still be deployed even in places where the grid would normally have been deemed overcrowded. BLOOMBERG, REUTERS