Libertine to develop a renewable-fuelled range extender for electric trucks

Libertine has been awarded a £2.6 million funding package from Innovate UK to develop free piston range extenders for electric trucks.

Free piston engines are said to offer the efficiency of fuel cells, the durability of conventional engines and achieve carbon reductions using renewable fuels.

Libertine’s free piston engines contain pairs of pistons which are free to slide within a linear combustion cylinder. The introduction of a fuel mixture and a carefully timed spark drives the pistons down the cylinder where they rebound off air springs, enabling the cycle to repeat. Magnets in the pistons energise coils around the cylinder, generating electricity with an efficiency far above that of conventional engines and generators.

Sam Cockerill, Libertine’s CEO, said: “As a director of a major haulier, I have first-hand knowledge of the hurdles the industry faces in reducing emissions. The impact of a pure electric powertrain on payload, productivity and up-front costs, combined with limited charging infrastructure and restricted new vehicle choice, are real challenges.

“The combination of a smaller battery and an efficient onboard generator using 100% renewable fuels has the potential to solve these pain points and drive significant uptake of net zero trucks before the end of the decade.”

Discussions with prospective OEM customers identified the need for a performance validation prototype as a key development milestone. The 2021 development will integrate Libertine’s technology with MAHLE Powertrain’s pre-chamber ignition system to form a multi-cylinder opposed Free Piston Engine, optimised and calibrated to start and run cleanly on renewable alcohol fuels. The project will also integrate multiple enhancements for thermal management, durability and electrical power conversion efficiency, enabling performance validation against OEM-specified requirements.