The global energy storage market is experiencing tremendous growth with analysts such as Wood Mackenzie predicting a thirteenfold increase in grid-scale storage over the next six years. Driven by the need to mitigate the intermittent nature of renewable energy sources, energy storage solutions are not only growing – but becoming more diverse in the tech that they use. The question is, which of these storage technologies is best? Here’s what EngineeringPro’s readers thought.

As you can see from the graph above, we received a broad range of answers, with no one technology taking the lead. That there is not yet a broad consensus as to which storage tech is best is probably down to the fact that many of these technologies are still early stage with few examples being deployed at scale on active grids.
Nevertheless, three forms of storage tech did receive more votes than the rest.
(Image via Hornsdale).
Surprisingly Redox Flow Batteries received more votes than Lithium-Ion batteries (22.22% of votes cast compared to 11.11% of votes). This is despite the fact that Lithium-Ion batteries are currently the most common example of energy storage systems in real-world use.
(Image via Wikipedia).
Thermal Energy Storage tied for the lead with Redox Flow Batteries, also receiving 22.22% of all votes cast. Thermal energy storage systems are widely used and can be found supporting grids across the world. One of the largest examples is the Crescent Dunes Solar Energy Project in Nevada which stores heat from 10,000 billboard sized mirrors in a hot tank which then feeds a generator when required.
(Image via KBB).
The third form of storage tech which tied for the lead with 22.22% of all votes was Hydrogen (Power to Gas) Energy Storage. Whilst not widely deployed, analysts expect hydrogen energy storage to experience significant growth over the next five years, reaching $18.2 billion. Using Hydrogen Storage for largescale projects is a relatively new development. Examples include Germany’s Energiepark Mainz – a 6MW electrolysis and storage project – and the USA’s Markham Energy Storage Facility.
(Image via Energy Vault).
At the opposite end of the scale is Mechanical Energy Storage which received zero votes! This comes as a bit of a surprise given the amount of hype that has surrounded this form of energy storage in recent months. Perhaps, given the rather complex and imaginative forms that mechanical energy storage takes, you aren’t quite convinced that it’s a realistic option! Perhaps the most interesting example of mechanical energy storage that we’ve seen is Swiss company Energy Vault which is proposing to create a tower of concrete blocks which can be lifted and lowered by a series of cranes – thus storing and transferring power when required.
On a final note, we must highlight reader Colin Megson’s comment which informed us about the world’s first ‘Giga-Scale Cryogenic Battery’ which has been developed by Highview Power. Take a look at their website to
find out more.
Whichever form of energy storage technology you prefer, it’s clear that the energy storage market is set to experience strong growth over the coming decade – creating jobs and new opportunities for engineers and technical professionals across the globe.
Express your opinion!
What do you think of these various energy storage technologies? Is there one which stands out for you? Or will we see the development of further energy storage technologies to meet the challenges of different grids across the world?
Let us know your thoughts in the comments below! The best comments will be featured in the weekly
EngineeringPro Newsletter.