Rolls-Royce is gunning for a new world record in electric aircraft propulsion, with aspirations of flying a battery-powered propeller plane reaching speeds in excess of 300 mph this spring. The pet project is part of a broader company initiative dubbed "ACCEL" - Accelerating the Electrification of Flight - and it's spawned this highly specialized aircraft.
Now, to be clear, this electric aircraft is not the work of Rolls-Royce Motor Cars, which today is part of the BMW Group. Rather, it's the product of that other Rolls-Royce - the one that develops power and propulsion systems for aviation and other uses - although Rolls-Royce Motor Cars of course lays claim to a common heritage.
The battery pack that will power Rolls-Royce's ACCEL plane is nothing short of awe-inspiring. It was developed with aerospace battery startup Electroflight, and it has 6,000 cells packaged in a way that minimizes weight and maximizes thermal protection. It's the most power-dense battery pack ever made for an aircraft, Rolls-Royce says, with enough energy on a full charge to fly from London to Paris - a 200-mile distance.
Those batteries will supply power to three axial electric motors, sourced from electric motor and controller supplier YASA, all connected to a single propeller. During the ACCEL plane's record attempt, they'll run at relatively low speeds, only delivering a combined 500 horsepower or so and achieving something like 90% energy efficiency.
That 500 combined horsepower is nothing to sneeze at, but at full chat, the three motors are capable of a total system output of around 1,000 hp - nearly twice what you'd get from a 2019 Rolls-Royce Phantom and its petrol-burning V12.
Of course, a Rolls-Royce Phantom isn't liable to ever fall out of the sky, and it's here that we start to understand the limitations of battery-propelled flight. As power-dense as the Rolls-Royce ACCEL plane's battery pack is, lithium-ion batteries are still innately heavy, bulky things and the potential costs of a catastrophic battery pack failure are high.
That said, a bit of redundancy and lightweighting could go a long way in addressing such concerns, and Rolls-Royce's attempts to build a plane capable of setting a new world record for electric flight top speed are worth undertaking.