# Huaneng Commissions Dual-Flywheel Frequency Regulation System in China New flywheel storage technology enhances grid stability for coal-fired power plants. - **Source:** [pv magazine](https://www.pv-magazine.com) - **Published:** 2026-11-10 - **Topic:** [Business](https://brifing.si/c/business) - **Original article:** - **On Brifing:** https://brifing.si/s/0fe1e130-f63b-4159-a7a5-86af4385415e ## Grid Integration Milestone Huaneng Group officially connected a dual-flywheel frequency regulation system to the grid at its Lanzhou thermal power plant on November 6. This commissioning follows a year-long testing phase designed to validate large-scale flywheel storage for coal-fired assets. The project marks a significant step in integrating mechanical storage into traditional power generation. ## Record-Breaking Technical Specifications The system features a primary 5 MW, 1.25 MWh flywheel unit spinning at 3,200 rpm using five-axis active magnetic levitation. Huaneng claims this is the highest-power single flywheel unit currently operating in China. A secondary 0.5 MW unit manages smaller frequency deviations, ensuring the primary machine remains protected from continuous, minor mechanical wear. ## Superior Response Performance The dual-flywheel architecture achieves a grid response time of under 100 milliseconds with a regulation accuracy exceeding 99.5 percent. These metrics significantly outperform standard lithium-ion battery systems, which typically respond in several hundred milliseconds. This speed allows the thermal plant to react to grid disturbances faster than its mechanical inertia permits. ## Strategic Control Integration Performance figures are attributed to proprietary control integration with the plant’s existing distributed control system. Developed by the Xi’an Thermal Power Research Institute, the technology builds on experience from previous thermal-storage demonstration projects. The system successfully completed a mandatory 168-hour continuous trial run in December 2025 before its formal commercial grid connection. ## Addressing Renewable Volatility The Lanzhou facility is located in Gansu province, a region experiencing rapid growth in wind and solar capacity. As variable renewable energy outpaces dispatchable generation, grid frequency stability has become a persistent challenge. Thermal plants are increasingly pressured to function as regulating assets rather than traditional baseload power providers for the grid. ## Economic and Regulatory Drivers Huaneng aims to reduce financial penalties incurred under China’s two-part ancillary services assessment rules. By improving frequency response, the plant avoids these costs while simultaneously generating revenue through ancillary services. The investment reflects a strategic shift in how thermal assets are managed to remain compliant with modern grid stability benchmarks. ## Structural Advantages of Flywheels Flywheel technology offers distinct benefits over chemical batteries, including no fire risk and the absence of chemical degradation. The system boasts a claimed cycle life of tens of millions of charge-discharge cycles. Despite these advantages, flywheels remain more capital-intensive per megawatt than lithium battery alternatives at current market price levels. ## Future Market Scalability The long-term viability of this dual-flywheel architecture depends on the evolving valuation of millisecond-range response in the ancillary services market. While the technical performance is validated, economic replicability across other thermal plants remains to be proven. Future adoption will hinge on whether grid operators prioritize speed over lower initial capital expenditures. ## Sources covering this story - https://www.pv-magazine.com/2026/11/10/huaneng-commissions-dual-flywheel-frequency-regulation-system-claims-china-single-unit-power-record/ — --- _Summary written by Brifing from the original reporting. Copyright in the original article belongs to its publisher; read the full piece at the link above._