 we are a worthy investment, from a technology and capability standpoint,’ says Matthew Walz, vice-president of business development at Invinity Energy Systems. ‘It is pretty widely recognised that there is a need for some sort of policy support,’ says Woodward, but it is likely to be through backing and commercial guarantees rather than direct subsidies. One tool that was used for the roll-out of grid interconnector technology is the ‘cap and floor’ mechanism, which provides a minimum floor on returns for investors, under which revenue would be topped up, but coupled to a maximum revenue cap. The UK government is yet to decide on this, but Woodward says ‘more than anything, what people need is clarity… to know what sort of environment they’re going to be operating in and what sorts of support will be available.’
With so many potential solutions in the mix, are we likely to see one eventually becoming dominant? ‘I don’t think we have a clear winner,’ says Gray. Mezzavilla thinks many electrochemical systems are still in their infancy and we can expect large improvements in cost and performance.
Ultimately, Walz says, ‘there is no one size fits all for energy storage’. The grid will need shorter term storage, in the region a few hours, to help smooth the variability of renewables generation all the way through to large scale seasonal storage. Flow batteries like Invinity’s are likely to provide medium-term storage capabilities that allow for charging and discharging several times a day and Walz thinks once we have this capability we have 95% of the solution. Schmidt agrees that flow batteries will be ‘the workhorses’ that will allow us to successfully transition to a predominantly renewable energy infrastructure.
For longer duration storage there is still everything to play for. ‘I think eventually, there will be one [dominant technology],’ says Schmidt. ‘Someone will be the winner here and that’s going to be very interesting to see in the next few years’.
Rachel Brazil is a science writer based in London, UK
Updated 26 April 2023 to clarify the future power needs