When Rolls-Royce built the Phantom-based 102EX in 2011, it seemed a very curious project.

No buyer had asked for such a car and no production model was planned. Though we wouldn't know it for another decade, the dual-motor layout would go on to become widely adopted by rivals, and its 71kWh battery would be surprisingly close to the typical capacity of a modern premium EV.

At the time though, an electric Roller seemed like a long way away from being anything other than a proof of concept. 

Now the project is very real.

An electric Rolls will be on sale by mid-decade, and it’s certain to demonstrate the extent of EV progress made since 2011.

It’s likely to have a twin-motor, all-wheel drive set-up, rather than the 102EX’s rear drive. Power should comfortably be double that of the 102EX's 390bhp, which was noticeably down on the marque's contemporary V12 (albeit with higher peak torque).

Its lithium ion battery might not weigh much more than the prototype’s 640kg one, but technology advances will boost its capacity well beyond 71kWh, perhaps into the 120kWh region.

This and other measures can be expected to double the cruising range from an unexceptional 124 miles, although Rolls-Royce will doubtless insist its first EV is for short-haul use.

More impressive will be the reduction in charging times. While the 102EX relied on three separate 3kW chargers and needed at least eight hours to fully recharge, the latest EVs support 350kW ultra-rapid charging that could manage the same in half an hour.

But there will be one major similarity between the 102EX and the new production car: super refinement, first described in Autocar as ‘waftability’, will be the top priority.