China’s largest supercapacitor-based hybrid energy storage system has been successfully connected to the grid in northwest China, marking a major milestone in the integration of supercapacitor and lithium-ion energy storage technologies at utility scale.
The Jiayuguan NingSheng 500 MW/1,000 MWh independent energy storage project, invested by China National Nuclear Corporation (CNNC), completed commissioning and achieved grid connection in the early hours of December 30, 2025, according to official disclosures. The project is located in Jiayuguan, Gansu province, within the Jiaxi photovoltaic industrial park, one of China’s key renewable energy hubs.
Hybrid Architecture Combining Energy and Power Functions
The project adopts a hybrid configuration consisting of 475 MW / 1,000 MWh of lithium iron phosphate (LFP) battery storage and a 25 MW supercapacitor system capable of delivering 60-second discharge.
While the LFP battery system provides long-duration energy shifting, peak shaving, and arbitrage, the supercapacitor segment offers millisecond-level response, enabling frequency regulation, inertia support, and rapid grid stabilization. This dual capability allows the system to simultaneously address both energy-type and power-type requirements, a combination increasingly regarded as critical for power systems with high renewable penetration.
At 25 MW, the supercapacitor installation is currently the largest in China and among the largest globally integrated into a grid-scale energy storage project.
Grid Connection and Construction Progress
The facility is connected to the power grid via a 330 kV transmission line, feeding into the Jiayuguan Jiaxi solar power aggregation station. Construction began in September 2024 and reached full commissioning in approximately 15 months, despite the challenges posed by the region’s desert environment.
Designed for Extreme Climate Conditions
Engineered specifically for Gansu’s harsh climate, the energy storage system is designed to operate across a –40°C to 60°C temperature range. It features liquid cooling, enhanced sand and dust protection, and reinforced enclosures tailored for long-term operation in Gobi Desert conditions.
Market Participation and Grid Services
Beyond conventional peak shaving, the project supports primary and secondary frequency regulation, grid-forming control, and participation in China’s electricity and ancillary services markets. According to project documentation, the system can store 1 GWh per cycle, with a maximum hourly charge or discharge capacity of 500 MW.
Project Partners and Suppliers
CNNC’s Ningxia subsidiary serves as the project owner and operator, while China Nuclear Industry Huaxing Construction acted as the EPC contractor. The LFP battery energy storage systems were supplied by Sermatec, and the supercapacitor systems were provided by Herong New Energy, alongside multiple PCS and EMS suppliers.
Environmental and Economic Impact
From an economic perspective, the project is expected to generate revenue through ancillary services, peak–valley price arbitrage, and power market trading. Official estimates indicate annual carbon dioxide emission reductions of nearly 200,000 tons, alongside significant reductions in coal consumption, reinforcing the project’s role in supporting China’s energy transition.
