European and U.S. cities planning to phase out combustion engines over the next 15 years first need to plug a charging gap for millions of residents who park their cars on the street.

For while electric vehicle (EVs) sales are soaring in Europe and the United States, a lag in installing charging infrastructure is causing a roadblock.

Often cash-strapped local authorities have other priorities than a curbside network of charging points which would allow owners to ensure their EVs are always topped up.