Date: 29/03/2015

Vanadium batteries based energy storage by US company for rural India

The leading solar energy company SunEdison said it has Purchases 1,000 Energy Storage Systems from Imergy to supply electricity to Villages in rural India. These energy storage systems are built using a new battery technology called Vanadium batteries (also called vanadium redox batteries).

To give you some information on the technology of vanadium batteries used for energy storage:
It is the newly emerging battery technology for large scale energy storage. The advantages Vanadium batteries include the batteries can be left uncharged for many days without worrying about batteries losing their capacity. The capacity of batteries can simply increased by increasing the storage size of the unit and by flowing extra electrolyte into it. The charge and discharge cycles of vanadium batteries is lot more higher compared to typical 500 cycle of lead acid or lithium ion batteries. A lifetime of 15 to 20 year is expected in case of vanadium batteries compared to 3-4 years in case of lithium ion batteries. The total cost of the battery storage system is going to be much more cheaper in case of vanadium batteries compared to lithium ion batteries.

The only issue/disadvantage with vanadium batteries is the energy density it can store, it is less compared to other technologies. But for solar and wind where the space is not such a big issue vanadium batteries fit the bill.

There is one company which is doing well in this area is Imergy of USA. It has installed huge number of storage systems based on indium batteries all over the world including India.

The four key technology points on vanadium batteries mentioned in the Imergy website includes:
1. A flow battery is charged and discharged by a reversible reduction-oxidation reaction between the two liquid electrolytes of the battery.

2. Unlike conventional batteries, electrolytes are stored in separated storage tanks, not in the power cell of the battery.

3. During operation these electrolytes are pumped through a stack of power cells, in which an electrochemical reaction takes place and electricity is produced.

4. The design of the power cell can be optimized for the power rating needed, since this is independent of the amount of stored energy.
Fast charging and also no-fire risk are other two important benefits using these batteries.

More information on Imergy's Vanadium Flow Storage Systems can be found at www.imergy.com/technology.
Author: Srinivasa Reddy N
Author: Srinivasa Reddy N