Ricardo’s Head of Engine and Emissions Control Products, Phil Hopwood explains why, when it comes to sustainability, the internal combustion engine still has an important role to play.
Ricardo is confident that Internal Combustion Engines (ICE) will continue as a central element within propulsion systems for future road transport. Their position will be maintained via further development focused on sustainability measured on a full life-cycle basis.
ICE based propulsion systems are well established in all road transport sectors due to a strong balance of attributes including low cost, high power density, proven durability, and fuel use flexibility with established fuel networks. These attributes are strengthened by a wide range of electrification options.
Electrification is growly rapidly within the light-duty sector where solutions range from low-voltage mild hybrids, through high-voltage full hybrids to battery and fuel cell electric vehicles. The next generation of light-duty ICE products for dedicated hybrid applications are being designed in line with more sustainable requirements including operation with ‘zero impact’ to air quality for urban operation, operation at high efficiency and suitability for future fuels.
ICEs benefit from being a mature product with a low-cost, high-volume supply base
The combustion system, at the heart of the ICE, has a higher optimisation potential when the operating boundaries can be constrained by the hybrid architecture. Ricardo’s Magma xEV is an example of a high efficiency combustion system designed specifically for series hybrid or range extender ICE applications. The Magma xEV combustion system is designed to achieve up to 50% peak thermal efficiency via a focus on reducing heat losses with ultra-lean combustion ignited by an active pre-chamber and waste-heat recovery.
Electrification is less established within other transport sectors such as heavy-duty long haul as the attribute requirements continue to favour non-hybrid ICE solutions. Although there is significant development ongoing for fuel cell electric propulsion, the total cost of ownership remains in favour of the well proven ICE even with a price premium for more renewable fuels in comparison to fossil fuels. The next generation of heavy-duty ICE products will deliver increased sustainability via thermal efficiency gains and renewable fuel types. Research in the field of future fuels includes increasing bio content and developing new e-fuels which make use of excess renewable electricity. The most promising e-fuels are those which have the lowest energy cost for production allied to the highest energy and storage densities and most favourable combustion properties. In particular, Ricardo is focusing on synthetic methane (with a manageable transition via natural gas) and green hydrogen from electrolysis and is developing optimised spark-ignited combustion systems for these fuels.
When considering the sustainability of vehicles due to their Green House Gas (GHG) impact, it is critical to compare on a product life-cycle assessment basis to include the contribution from vehicle and fuel production and vehicle disposal as well as the vehicle use phase. There are many studies comparing GHG emissions for different vehicle segments, propulsion system architectures and fuel types. It is instructive to compare when an ICE-based vehicle with higher in-use emissions exceeds the GHG contribution of a battery electric vehicle with higher production emissions. This point of parity will depend on many factors including battery size and embedded carbon factor, ICE efficiency, hybrid architecture, vehicle duty cycle, electricity and fuel carbon intensity and the lifetime mileage. The transport industry already considers the life-cycle impact of its products within corporate strategies but GHG legislation is yet to shift on this basis meaning consumers are not informed on the true impact when comparing products.
ICEs benefit from being a mature product with a low-cost, high-volume supply base. Significant development opportunities still exist to increase sustainability, enabled via electrification, continued technology evolution and the advent of renewable fuels.