Benefits

The VRFB competition can generally be grouped into the following 2 categories:

1. Short Duration (30 – 90 minutes): Fast-reacting, shallow discharge devices which are mobile and modular. Typically, Li-ion battery, Lead acid battery, flywheel, super capacitors.

2. Long Duration (6+ hours): Deep discharge, not mobile and modular. Typically, pumped hydro, compressed air energy storage (CAES).

Each of these products has a place in the market. However, there is a clear gap for a ‘hybrid’ product such as the REVOX23 VRFB which provides Medium Duration (3 – 6+ hours) storage, fast reacting, deep discharge, mobile and modular (allowing it to be located close to the generator or consumer as required).

On review against the competition the VRFB scores favourably in all departments when considering safety, environmental impact, total cost trajectory (CAPEX and OPEX), durability, reliability, design flexibility, ease of transport and installation.

Without doing a ‘face off’ with all competitors, the diagram above shows a representative comparison against the commercially recognised Li-ion battery

Distilling down to what generally makes the VRFB so attractive produces the following:

• Offers almost unlimited energy capacity simply by using larger electrolyte storage tanks.
• VRFBs can be left completely discharged for long periods with no ill effects.
• The electrolyte is aqueous and inherently safe and non-flammable.
• VRFBs can operate over wider range of temperatures.
• VRFBs could be repeatedly discharged at more than 90% without detrimental effect and reducing the battery life contrary to conventional battery.
• VRFBs exhibit long cycle lives: common cycle durability more than 15,000-20,000 charge/discharge cycles, however infinite cycle life is plausible. These values are far beyond the cycle lives of solid-state batteries, which is usually in the order of 4,000-5,000 charge/discharge cycles.