Formula E starts its fifth season next week, braced for a big breakthrough but already looking far down the road to a future when its all-electric cars could rival Formula One machines and race on similar circuits.

FILE PHOTO: Francesco Starace (L), CEO and general manager of Enel Group, shakes hand with Alejandro Agag (R), Formula E CEO, during a news conference to present their partnership at the MAXXI National Museum in Rome, Italy May 17, 2016 REUTERS/Alessandro Bianchi/File Photo