Rolls-Royce looks to smash speed record with the world's fastest electric airplane

The electric aircraft will fly at over 300 mph (480 km/h)
The electric aircraft will fly at over 300 mph (480 km/h)
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The electric aircraft will fly at over 300 mph (480 km/h)
The electric aircraft will fly at over 300 mph (480 km/h)
The world's most energy-dense flying battery pack
The world's most energy-dense flying battery pack
ACCEL will utilize three 750R lightweight e-motors
ACCEL will utilize three 750R lightweight e-motors
The powertrain is the key to achieving 90 percent energy efficiency and zero-emission flight
The powertrain is the key to achieving 90 percent energy efficiency and zero-emission flight
Sensors collect in-flight information
Sensors collect in-flight information

A partnership led by Rolls-Royce is building an all-electric aircraft that may smash into the record books with a top speed of over 300 mph (480 km/h) – beating the previous record of 210 mph (338 km/h) set in 2017 by Siemens. Scheduled to fly in 2020, the zero-emission electric speedster is being developed as part of the Accelerating the Electrification of Flight (ACCEL) and is billed as a leader of the "third wave" of aviation.

Gloucestershire airport outside of Cheltenham, England may seem like just another provincial airfield, but it's the base for an attempt by engineers, designers, and data specialists from Roll-Royce, electric motor and controller manufacturer YASA and the aviation start-up Electroflight to create a single-seater prop-plane that will take electric aircraft to a whole new level.

Partly funded by the British government, ACCEL draws on Formula E expertise in an effort to build an electric aircraft that tops out at over 300 mph to set a new e-plane record, and potentially one day even exceed the 1931 Schneider Trophy record set by a Supermarine S.6B that used a Rolls-Royce "R" engine to reach 343 mph (552 km/h) in 1931.

The world's most energy-dense flying battery pack
The world's most energy-dense flying battery pack

To achieve this, the Rolls-Royce team is working on a battery pack of 6,000 cells that the company claims is the most energy-dense to ever be installed in an aircraft. When up and running, the powertrain will run at 750 V and the aircraft will boast a maximum power of 750 kW – that's enough to power 250 homes. This will be cooled by an Active Thermal Management System Cooling radiator and carry enough charge to fly from London to Paris nonstop.

According to Rolls-Royce, the key to the design is to not just make a big enough battery, but also one that won't overheat, is light enough for flight, and can be installed in a stable airframe. The batteries feed into three 750R lightweight e-motors built by YASA. The three electrically-actuated blades of the single propeller operate at 2,400 RPM for a more stable ride with an efficiency of up to 90 percent and zero emissions. Meanwhile, sensors will monitor 20,000 points in the powertrain to provide the engineers with plenty of data on performance.

"This plane will be powered by a state-of-the-art electrical system and the most powerful battery ever built for flight," says Matheu Parr, ACCEL Project Manager for Rolls-Royce. "In the year ahead, we're going to demonstrate its abilities in demanding test environments before going for gold in 2020 from a landing strip on the Welsh coastline."

Source: Rolls Royce

Derek Howe
Nice. Wonder how big the battery is, and what it's range is, I'm guess it's range isn't very good. But I'm thrilled to see electric aircraft progressing forward.
"Efficiency of up to 90 percent and zero emissions",? Zero - always, a dubious description for ev's. It mentions, 750kw, enough to power 250 homes. That's a lot of energy from the grid by a single user. It's zero if it's taken from a renewable source - anything else is playing semantics. That said, nice to see progress being made for electric aircraft and racing/record attempts are where new ground is often made. It's very possible, most student pilots will be learning to fly in them in another 20 years or less. Much cheaper to fly around the pattern than gas. Cross-country? Not yet, but anything is possible.
1,000 hp delivering only 300mph in that slippery airframe ?!?!? What gives?
The record for propeller-driven aircraft is somewhere north of 530 mph, so there's a touch of headroom available here.
This article leaves a lot of questions. Monitoring 20,000 data points sounds horribly redundant. 1000hp that only gives 300 mph also sounds a little off unless the plane is extremely heavy. Another problem with electric power is all the wasted heat just like an internal combustion engine. This always reminds me of the Freon engine booster from the 1960s that was supposed to use the wasted heat from a gas engine to up the overall efficiency. A small Freon powered generator could add to the power and range while utilizing some of that wasted heat energy.
Jay E.
It looks like a Jon Sharp Nemesis NXT that has been modified to electric power. With an airframe proven to be able to reach 575mph with 1000 HP, they are shooting awfully low with their goals. Perhaps the battery weight is the problem. The racer had twin turbos and produced huge amounts of heat, cant imagine why cooling should be an issue.
Good points all,, The future may very well eliminate most of; the weight problem, the heat problem, the efficiency problem, the range problem, the emissions problem and the cost problems in manufacture operation & maintenance, plus the sound problems. How? By the very strong potential of Atmospheric Ion Propulsion [AIP] where simulations show well over 80% efficiency possible when only 25% efficiency is needed to lift 300 pounds vertically with only 1 square meter of jet exhaust. Solar hydrogen fuel cells pushing warm air reaction thrust jet exhaust from a very light weight frame that is also the entire engine carrying a pod for live loads using NO MOVING parts,,, is only limited by the weight of power. Lets here it for Hydrogen fuel cell batterie evolution,,,
It would definitely be nice to have more information, like what is the range and how many people does it carry. It looks like a one or two seater in the picture.
F. Tuijn
It looks as if the battery pack is built into the fuselage instead of in the wings, giving a much larger weight than necessary.
Where in the article does it say it's 1000hp? If you read the source it clearly says that the combined continuous power output of the engines is 500hp.