In the spirit of the COP 31 Presidency’s emphasis on its Action Agenda Priorities – the Business Council for Sustainable Energy (BCSE) will lead a business delegation to COP 31 in Antalya, Türkiye that will bring forward credible solutions, partnerships, investments, and ideas to accelerate the energy transition and decarbonize agriculture, buildings, industry, and transportation. This case study is part of BCSE’s Solutions Showcase to deliver emissions reductions, increase resilience, and meet energy transition goals worldwide.
Highlights:
- 1.72 billion kWh of power generation in the first year
- 519,000 tonnes of standard coal avoided each year
- 1.424 million tonnes of CO₂ cut each year
- At least 16,000 cycles and an operating life of around 25 years
Case Study:
The Challenge
Across northwest of China, solar generation is growing fast. Output peaks in the middle of the day, while demand often rises later in the evening. In Jimusaer county, this creates a risk that clean electricity goes unused while fossil fuels are still relied on to meet peak demand.
As renewable capacity expands, limited grid flexibility and transmission constraints are making this challenge more urgent. Long duration energy storage helps bridge the gap by storing excess renewable power and delivering it back to the grid when it is needed most.
Clean power, when it counts
Rongke Power’s Jimusaer project places long duration energy storage at the centre of a large-scale solar development. By pairing a 1000 MW photovoltaic power plant with GWh scale vanadium flow battery storage, the project captures surplus solar power when generation is high and holds it ready for when the grid needs it most.
Vanadium flow batteries store energy in a liquid electrolyte, rather than in solid battery cells: this makes them well suited to charging and discharging extensively every day, without losing capacity quickly over time. Their water-based electrolyte also supports safer operation in extreme temperatures, making the system well suited to local conditions and the demands of utility scale infrastructure. Under normal operating conditions, the system can support at least 16,000 cycles and an operating life of around 25 years.
The project is part of a wider regional push to expand renewable energy and energy storage across northwest of China. Policy support and electricity market reforms are helping storage projects earn revenue through ancillary services and participation in electricity markets.
In this context, the Jimusaer project helps balance supply and demand, smooth power flows before electricity enters long distance transmission lines and reduce reliance on coal fired generation when renewable output fluctuates. This helps make solar power more predictable, flexible and dependable for the grid.
Technology at work
The project deploys a vanadium flow battery system connected to the solar plant, allowing excess daytime solar power to be stored for hours and used later. This is how the storage system works:
- Solar energy is captured and stored
- Electricity generated by the solar plant is sent to the battery system.
- Energy is stored in liquid form
- Unlike conventional batteries, vanadium flow batteries store electricity in a liquid electrolyte kept in external tanks, rather than inside solid battery cells.
- Charge and discharge through a chemical process
- The system stores and releases energy through a reversible chemical reaction, allowing the same liquid to be used again and again.
- Built for repeated, long-term use
- Because the electrolyte is reused through reversible redox reactions, the system supports repeated full charge-discharge cycles with minimal energy capacity fade.
- Safe and flexible by design
- The water-based electrolyte removes fire risk, and storage capacity can be increased simply by adding more liquid, making the system easy to scale.
Conclusion
As the first vanadium flow battery project to reach GWh scale, Rongke Power’s Jimusaer project shows how long duration energy storage (LDES) can help stabilise the grid, increase the use of renewable electricity and reduce the need to fall back on fossil-fuel generation when clean power is not available.
The project provides several economic and environmental benefits. Combined with the adjacent photovoltaic plant, it represents around 1.9 billion Chinese yuan in investment, supports annual solar generation of approximately 1.72 billion kWh and strengthens the local renewable energy value chain.