The team developed an experience curve dataset to show that residential storage plus PV could be competitive with grid-electricity in Germany in little over a decade.
The study found that regardless of technology, capital costs are on a trajectory towards $340 ± $60 per kilowatt hour for installed stationary storage systems once 1 TWh of each technology were installed.
Oliver Schmidt, a PhD researcher on energy storage at Imperial and a lead author of the paper, said: “How costs come down as a function of installations within the next few years will be crucial to getting more certainty on whether, and if so when, residential storage becomes competitive with grid electricity.”
The researchers crunched data from the US Department of Energy’s Global Energy Storage Database and historical price data, which included manufacturer information, ministry and industry reports and academic publications.
Using these sources, the researchers hope their resulting experience curve dataset will enable academics, policymakers and industry to make evidence-based cost projections for electricity storage technologies.
Schmidt said the price prediction was identified by looking at how much of these technologies had been installed so far, and how prices had come down in relation to that. They then projected this historical trend (ie experience rate) into the future.
“This allows us to say, if TWh of each technology were to be installed, capital costs for all these technologies would lie between $340 ± $60 per kilowatt hour.”
While pumped hydro is already within this range today, with more than 1 TWh installed globally, it would take between 10 to 20 years for other stationary storage technologies to reach that level of installation according to market growth forecasts, said Schmidt.
The study, which was published in the journal Nature Energy on July 10, also indicated that EVs would be competitive with fossil-fuel powered vehicles in the US between 2022 and 2034.