China marches on in deploying renewables.
More battery storage needed. No problem, China is the leading manufacturer of Batteries.
In addition, new transmission and transformer technology making renewables “more reliable and predictable at scale.”
China’s mostly coal-based thermal power generation fell in 2025 for the first time in 10 years, government data showed on Monday, as growing renewable generation met growth in electricity demand even as overall power usage hit a record.
The data is a positive signal for the decarbonisation of China’s power sector as the country sets a course for carbon emissions to peak by 2030. Still, coal output edged up to a record high last year.
Thermal electricity, generated mostly by coal-fired capacity with a small amount from natural gas, fell 1% in 2025 to 6.29 trillion kilowatt-hours (kWh), according to the National Bureau of Statistics (NBS).
It fell more sharply in December, down by 3.2%, from a year earlier, the data showed.
“The record-level buildout of renewables over recent years has cumulatively impacted the generation mix and squeezed more coal out, coupled with a milder power demand growth of 5% in 2025,” said Peng Chengyao, head of APAC power and renewables research at S&P Global Energy. Power demand had grown by 6.8% year-on-year in 2024, according to the China Electricity Council.
Still, 2025 growth was enough to tip China’s electricity consumption to a new record high, the National Energy Administration (NEA) announced on Saturday, surpassing 10 trillion kWh for the first time.
That was more than the combined consumption of the European Union, Russia, India and Japan in 2024, driven by rapid consumption growth in internet and related services and EV manufacturing.
Last year, China’s electricity network nearly faced a major disruption when fluctuating wind power in the northwest caused instability across the grid.
To prevent similar situations in the future, Chinese engineers have now developed a 750-megavolt-ampere (MVA) smart DC transformer, the largest of its type in the world.
Designed to handle grids with heavy wind and solar power, this transformer could redefine how electricity systems worldwide manage renewable energy.
It has “set the world record for the highest capacity of a single converter transformer in the field of flexible direct current transmission,” claims a report.
Electricity grids must constantly balance supply and demand. Even small imbalances can cause frequency changes, which, if unchecked, may spread and cause widespread outages.
Moreover, renewable energy, which depends on the weather, can change output faster than traditional power plants can adjust, creating periods of instability. Last August, this problem became critical in Xinjiang, where uncoordinated wind generation caused low-frequency oscillations that threatened the broader national network.
Current transmission systems have difficulty managing these fluctuations over long distances because the flow of power cannot be controlled precisely. To solve this problem, Changzhou Xidian Transformer, part of China XD Group, developed a large-capacity flexible DC transformer.
This smart machine converts the alternating current (AC) from power plants and local grids into direct current (DC), which flows steadily in one direction. This makes long-distance transmission more efficient and allows operators to adjust power flows quickly, helping manage frequency variations like those seen last year.
The transformer’s design includes the capability to handle rapid changes in input from wind and solar sources, fibre-optic sensors to monitor internal temperatures in real time, and magnetic field management to reduce energy loss.
The development team conducted extensive testing of their machine under extreme conditions, including lightning strikes and rapid AC/DC switching. Test results confirmed the system remained stable beyond its intended design limits.
According to Chinese media reports, this innovation, “can effectively address the instability of high-proportion renewable energy generation at the sending end.”
The transformer is a part of an HVDC (high-voltage direct current) system. Such systems are designed to convert AC from power plants into DC for long-distance transmission, and then back to AC at the receiving end.
As countries worldwide increase reliance on renewable energy, HVDC systems hold great significance because they lose less power over long distances and allow finer control of electricity flows.
The smart transformer will be installed as part of China’s west-to-east power transmission project, which moves electricity from renewable-rich western provinces to energy-demanding eastern regions.
Covering 2,370 kilometres (1472 miles) from Gansu to Zhejiang, it is expected to deliver more than 36 billion kilowatt-hours per year. It is described as the first ultra-high-voltage flexible DC transmission system combining long distance, high capacity, and real-time control.
This record-breaking transformer points toward the future of grid engineering. Looking ahead, researchers are exploring multi-terminal DC networks, which could dynamically route electricity across multiple regions, making renewable energy more reliable and predictable at large scales.
Here’s a link to the Interesting Engineering article:
https://interestingengineering.com/energy/china-record-breaking-transformer