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VRFB System

What is Vanadium Redox Flow Battery?

Vanadium Redox Flow Battery (VRFB) is the most common and commercialized flow battery technology. The flow of vanadium electrolyte in the positive and negative tanks go through an electro-chemical process of oxidation and reduction which allows the battery to charge and discharge repeatedly with extremely minimum degradation. The main difference from other types of batteries is that the charge and the discharge occurs during the circulation of the electrolyte, where energy is stored in the electrolyte. The electro-chemical reaction of charge and discharge occurs in a component called the ‘stack’

Scalable
The decoupled power and energy allows completely independent scaling.

The power output is determined by the number or size of the stacks, and the energy capacity is determined by the amount of electrolytes stored in a separate tank.
Long life-span
VRFB energy storage has negligible degradation regardless of the depth and number of cycles operated. It can cycle 20,000+ with over more than 20 years of operation retaining its original energy capacity.

Due to this long life-span, it can dramatically reduce the total cost of ownership.
Safe & Sustainable
VRFB is inherently a stable chemistry based on aqueous electrolyte which is risk-free of fire hazard from thermal runaway.

It is also very sustainable due to it’s indefinite reusable and recyclable electrolytes.

Core Components

Stack - Single cell components
A single-cell comprises of several components to create a positive and negative side . The electrolytes flow through each side of the electrode separated by the membrane. Several single-cells may be stacked together to create a single unit stack which decides the power capacity.
Vanadium electrolytes
Energy is stored in the water-based vanadium electrolyte through an electro-chemical process in the stack. The electrolyte shows four different valence states, V5+ and V4+(positive), V2+ and V3+(negative). The colors of the electrolyte represents the actual charged state of the electrolyte. The electrolyte shows no change in composition during the repeated cycling of charge and discharge and does not require supplements in the electrolyte.

Solutions

Micro-grid
- Areas with unstable grid interconnection or off-grid locations need locally operated distributed energy sources. Hybrid generation systems such as solar + energy storage can provide locally sustained clean generation sources to provide microgrid solutions for these areas. Especially, in remote areas where grid connection is either unstable or not available, diesel generators are the main source of energy. Maintaining the delivery and usage of fuel to run diesel generators are not only very costly but also carbon emission intensive. To replace inefficient diesel generation, daily cycling, long-duration VRFB energy storage can replace or reduce the usage of diesel generators to slim operations costs and carbon footprint.
Renewable Integration
- Continuous integration of renewables can only be sustained by paring with large-scale energy storge technology. Energy storage co-located with renewable generators can address the daily variability and shift the solar production to match the peak demand capacity. It also assists the reduction of renewable curtailment optimizing the asset’s revenues stream. VRFB technology, with its long-duration capability and non-degrading cycling characteristics provides the key requirements needed to support the vast penetration of renewable energy. The short-term volatility and long term Intermittency. The excess renewable generation can cause electricity grid congestion Being forced for curtailment. which was originally handled by fossil fuel peaker plants, to act in replacement of conventional fossil fueled peaker power plants.
Utility
- Massive adoption of renewable energy will continue to replace old gas peaker and coal power plants to decarbonized the grid. But aggressive renewable integration and excess generation can cause grid congestion and instability in the power grid forcing renewable curtailment. Energy storage can provide congestion relief for network operators in constrained transmission & distribution capacity conditions and can mitigate costly investment in grid infrastructure
Commercial and Industrial
- Reducing electricity consumption and carbon footprint is now a key agenda for many commercial and industrial customers globally. Renewables paired with daily deep cyclable energy storage can reduce both energy costs and carbon footprint. VRFB storage enables extended use of on-site generated renewable energy, avoid peak hour charges to lower energy cost and at the same time improve site resiliency. Customers with sensitive sites to fire hazard can take the advantage of the safety features and flexible cycling operations of VRFB energy storage to adapt to the changing business environment.