China connects its largest battery-supercapacitor hybrid storage plant
Source：pv magazine
A 100 MW hybrid frequency-regulation plant in northern Shanxi province, North China, was connected to the grid at the end of August and is expected to enter full commercial operation following testing in September, according to its developers.
Touted as the world’s largest supercapacitor-based installation, the facility combines a 58 MW/30-second supercapacitor array with 42 MW/42 MWh of lithium-ion battery storage, spanning a footprint of approximately 16,800 square meters. The total capital investment was reported at CNY 670 million.
Located in a village within Xinzhou city, the plant is situated in a region known for abundant solar irradiation and water resources -conditions conducive to large-scale renewable energy plus storage deployments. The project was developed by Shenzhen-based Tigstor, which also supplied the core supercapacitor technology and delivered a turnkey solution. Shanghai Tunnel Engineering Co., Ltd. (STEC), a state-owned enterprise, served as the EPC contractor.
The system is controlled by an energy management system (EMS) that dynamically allocates tasks between the supercapacitor and batteries: millisecond-scale events are handled by the supercapacitor while minute-scale regulation is delivered by the battery pack.
The developers underscore the strategic rationale for hybridization. Supercapacitors provide ultrafast response times – specified at 0.001 seconds – and maintain over 85% capacity at –40°C, significantly outperforming lithium-ion batteries in extreme cold. By offloading rapid-response tasks to the supercapacitor, the system is expected to extend battery lifespan and reduce lifecycle costs by around 30%.
Operational targets include maintaining grid frequency within ±0.02 Hz and responding to system changes within one second. According to developers, this rapid-response capability enables the grid to absorb up to 1.6 GW of variable renewable energy – roughly 20 times the plant’s instantaneous output.
The plant is projected to generate annual revenues exceeding CNY 120 million ($16.5 million), contribute over CNY 12 million in taxes, and achieve a payback period of approximately seven years. It has reportedly created over 500 local jobs.
The project has been listed in the second batch of green, low-carbon demonstration projects by the National Development and Reform Commission (NDRC), making it eligible for central budget support of up to 30% of total costs, the company said. National-level discussions have also highlighted the facility as a model for standardized grid-side storage solutions.
A planned second phase would double total capacity to 200 MW, and the hybrid model is being positioned for replication in other resource-rich regions such as Inner Mongolia and Xinjiang, as China accelerates its rollout of large-scale renewable energy infrastructure.