The evolution has seen the development of a bifuel system for the range extender engine, allowing it to adopt alternative and renewable fuels in place of petrol. These fuels are compressed natural gas (CNG), liquefied petroleum gas (LPG), biomethane and biopropane.
Adopting these fuels allows carbon emissions from the range extender engine to be reduced by 10% when LPG is used, 20% when CNG is used and by 99% for these fuels renewable counterparts of biomethane (in place of CNG) and biopropane (in place of LPG). Biomethane and biopropane can both be made from waste feedstocks such as food waste, farm waste and sewage and both are in volume production already. Biomethane and biopropane are ‘drop in’ replacement fuels for CNG and LPG and require no changes to refuelling infrastructure or to a vehicle already evolved with a bi-fuel fuel system (CNG or LPG).
The evolution of the TX and VN5 was first revealed during London Climate Action Week and on 27 June 2022.
The bi-fuel system consists of the following components: • Prins VSI-3 DI system • LPG/biopropane fuel tank or CNG/biomethane fuel tank • LPG/biopropane vaporiser or CNG/biomethane pressure regulator (both warmed by engine coolant) • Gaseous fuel injectors • Bi-fuel ECU.
The LPG/biopropane evolution of the TX adopts a 50-litre fuel tank and the CNG/biomethane evolution adopts two 40 litre fuel tanks. Considering the vehicle range using petrol, the LPG/biopropane tank provides a further 90% of this range and the CNG/biomethane tank provides a further 70% of this range. Based on LEVC’s WLTP drive cycle based range figures of 64 miles using the battery and a further 319 miles using the 36 litre petrol tank (so total range 383 miles) the bi-fuel evolutions therefore deliver a further 287 miles for LPG/biopropane and 223 miles for CNG/biomethane. Total range is therefore 670 miles for the bi-fuel LPG/biopropane evolution and 606 miles for the bi-fuel CNG/biomethane evolution.
A number of fuel tank solutions are also being developed for the VN5 including placing the tanks under the floor rather than in the payload area.
The companies say that they are also working with fuel manufacturers and suppliers to grow the existing refuelling station network for CNG, biomethane, LPG and biopropane.
Conversion costs are still in development but we target the system paying for itself in 12 to 18 months. This of course depends on the number of miles driven, the miles per gallon achieved and future changes in the price of the fuels. Prices for biomethane and biopropane are expected to decrease in the future as production volumes continue to ramp up.