Energy Storage Primer

In our modern world, we are used to energy convenience, and that means energy on tap, when we are ready to use it. We are familiar with many of these energy storage mediums. For example:

• Petrol is a convenient way of storing energy for our motor cars (in the on-board fuel tank); and
• Coal is a store of thermal energy, easy to produce and transport and then use as needed to run large scale electricity generation plants.

But storing electricity is a lot harder. Of course, at a small scale, we do it all the time when we recharge our mobile phones and laptop computers. And that familiar black box under your car's bonnet is a conventional lead-acid battery which stores enough electricity to run the starter motor to start your car.

It is difficult to store electricity at a large enough scale for household or business use in a cost effective way. In fact, the global electricity generation industry is designed around an accepted paradigm that electricity must be generated as it is used. So, in simple terms, when you switch on the air-conditioning system in your house (drawing say 3 kW), somewhere in the electricity generation system, a coal, gas, nuclear or hydro power station increases its output to match.

So the ability to store large quantities of electricity is highly prized. There are a limited number of solutions already in large scale commercial operation, such as pumped hydro. Several other alternatives are undergoing development. The promising options include:

• Batteries. These are electro-chemical systems, each with advantages and disadvantages. Alternative types include:
  • Zinc bromine flow battery;
  • Lead acid battery;
  • Vanadium redox flow battery;
  • Sodium sulphide battery; and
  • Lithium ion battery
• Flywheels
• Compressed air energy storage

Each of these technologies has its strengths and weaknesses. The key to developing commercially viable energy storage solutions is to match the technologies strengths with existing market needs, while minimising the effects of their weaknesses.

RedFlow specialises in high performance zinc bromine flow batteries. This technology is ideally suited to heavy daily charging and discharging cycles, as required to reduce peak demand on the electricity grid or for storing and releasing renewable energy generated by the sun.
Our designs enhance the performance, and lower the manufacturing cost of zinc bromine flow batteries for these applications.