Falling battery costs could make electric cars the cheaper choice by 2022

Electric cars could rival petrol on cost by 2022, according to a new tool that predicts the cost of storing energy in future.

It also predicts that home batteries – for storing power from solar panels in individual households – could become competitive on price by the 2030s.

The study, conducted by researchers at Imperial College London, predicts costs savings as new technologies for storing energy become more established. “Energy storage has been recognised by leading figures such as Barack Obama and Bill Gates as one of the key technologies of a low-carbon 21st century,” said Oliver Schmidt, a researcher at the university’s Grantham Institute for Climate Change and the Environment. “With this analysis tool we can quantify when energy storage becomes competitive and identify where to invest to make it happen, thereby minimising investor and policy uncertainty."

The team built their tool by using data from previous forms of energy storage, to build a model of how costs fall as capacity increased over time. Using this data, they could make predictions about what might happen in the future, as renewable energy fulfils its potential.

Iain Staffell from the Centre for Environmental Policy, who worked on the research, said the tool allowed researchers to combat one of the biggest uncertainties in the future energy system, “and use real data to answer questions such as how electricity storage could revolutionise the electricity generation sector, or when high-capacity home storage batteries linked to personal solar panels might become cost-effective."

The researchers compared the cost of driving one mile using electric cars with the cost of using petrol, factoring in the cost of the batteries or fuel tanks. They found that electric cars will catch up with petrol by 2034 at the latest, and possible as early as 2022.

They also looked at the Hinkley Point C nuclear power plant, which is projected to cost £19.6bn and produce 3.2 gigawatt of power when it is completed in 2025. Investing the same amount of money in large-scale lithium ion batteries could provide 21-41 GW of power, according to the researchers.

Of course, the batteries would still need to be charged, but it’s hoped that the falling cost of storage could drive further uptake of renewable energy such as solar and wind power.

According to Staffell, it’s the fall in technologies such as wind turbines and solar panels that gives the team confidence that energy storage technology will get cheaper in future. "What we've shown is how the cost of all these different technologies has come down in the past," he told Professional Engineering. “It's just a guideline. I suppose it's things like solar PV panels and wind turbines - because the cost reduction for them has been so consistent over the last 30 or 40 years it leads you to think that it will be similar to that in the future.”