Road transport is in a period of significant change in order to meet emissions targets to try to combat climate change. There are a number of options for improvement, not least in the drivetrains that can be utilised. There are a number of different drivetrain options available for road transport but it is not yet clear which are most appropriate and for which applications. One area of growing interest to Far-UK is in new drivetrain options and the potential for light weighting of these components.
This report compares two drivetrain technologies for the use with bio-hydrogen, and analyses the suitability of these drivetrains compared with conventional engines and battery electric vehicles for a range of vehicle applications. The technologies are the hydrogen internal combustion engine and the proton exchange membrane fuel cell.
Transport is a major contributor to global greenhouse gas emissions and oil consumption and must be reformed to provide cleaner, less polluting solutions to mobility. The use of hydrogen as a transport fuel has advantages including low or zero emissions, high efficiencies and increased energy security. However, it is not without its complexities such as production methods and storage. There is uncertainty as to the best drivetrain technology to use hydrogen fuel, which is the focus of this report.
This report found that, fuel cell vehicles offer the greatest emissions savings, highest efficiencies and have long term potential, they are however, not fully commercialised and require significant development in infrastructure and service support. The hydrogen internal combustion engine is less polluting and more efficient that the fossil fuel equivalent, yet it is not as beneficial in terms of efficiency and emissions as the fuel cell. The hydrogen internal combustion engines requires only basic alterations to the technology available today and is seen as a commercial technology with widespread service and support infrastructure. The internal combustion engine offers considerable flexibility in the fuels it can accept, which is a major advantage. Conversely fuel cells require high purity hydrogen that is complex and expensive to obtain. The progress of both technologies is hindered by limited refuelling infrastructure and developing storage options.
It is concluded that the hydrogen internal combustion engine is the best option for a bio-hydrogen fuel stream because of the flexibility in the fuel content and purity. As a technology it can be easily and cheaply manufactured and installed, and there is a widespread service and support network in the UK. Additionally the hydrogen combustion engine can remain “bi-fuel” allowing for petrol to be used in the absence of hydrogen.