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See FISITA Library items from Harry Watson
FWC2023-SEL-003
Prof. Harry Watson, Part Time Prof, University of Melbourne
Abstract
Paper Title Extra CO2 Emitted when In-Service Life not Optimized for Minimum CO2 – Comparison of ICEs, BEVs and H2 (FCEV and ICE)
Harry Watson, Emeritus Prof. University of Melbourne, Australia
KEYWORDS Vehicle life, Life cycle analysis, hydrogen fuel, electric vehicles, cars, sustainability
ABSTRACT
Research /Engineering Questions It was recognised by ‘The Club of Rome’ in 1948 that the earth’s resources were limited and by 1971 in the book ‘Fundamentals of Exhaust Emissions’ I concluded that we should also have concern for CO2 levels in the air and consequent global warming caused by transport emissions. So, what is the optimum strategy for minimizing energy use and emissions, recognizing that the car is the prime source of personal space for mobility, and although many governments support a focus as EVs the embodied CO2 in batteries, H2 fuel tanks etc. are significant contributors to Life Cycle Analysis (LCA) or carbon footprint.. What are the optimum lifetimes compared with traditional in-service lives and the consequences in CO2 emissions.
Objective To demonstrate that in-service whole-of-life mileage has a significant influence on the optimum life cycle CO2 for BEVs and for two classes of H2 fueled cars as well as ICEs. Thus, to determine how much present, typical in-service mileage differs from the optimums against a back drop of steadily improving energy efficiency, as new vehicle designs enter the market along with the greening of manufacturing, electric power supply and battery manufacturing energy,
Methodology Using the best available energy production and usage data, life cycle analysis (more than ‘well-to-wheel’ as the energy content and manufacture of consumables and recycling/reuse is included) is performed for the vehicles, accounting for the change in vehicle use as the vehicle ages, and in which new vehicles replace older, scrapped ones in the market, with improvements in energy efficiency (and reductions CO2 emissions). The present in-service mileage at the time of vehicle scrapping/recycling varies around the world. Europe is taken as the focus, where end of life mileage is around 170,000 km and 18 years, but it is shown how other regions may be easily considered.
Results Depending on the vehicle size and configuration, the optimum vehicle life ranges from 11 years to more than thirty; significantly different from 18 years. For all forms of EVs the greater the installed battery kWh or H2 tank size and hence range capability, the longer is the optimum service life. As the incremental energy efficiency trend for new vehicles entering the market reduces, as it must according to the law of diminishing returns, vehicles need to stay in use for longer to amortize the embodied energy in manufacturing even though this continues to improve.
Limitations The analysis is only as reliable as the data. However the sensitivity analysis allows the results to remain useful as the user can adjust the scenario according to updated information. No economic analysis is performed but such analysis is more complex because costs are more variable than the regional variety in global vehicle design.
Novelty The sensitivity analysis allows the reader to apply the results for regional variables such as the proportion of renewable energy in electricity generation and, included is the consequence of EVs reduced annual travel compared with conventional and hybrid light duty vehicles.. The application of the most recent input data is also novel. Finally, the author is not aware of analyses of this type that includes reducing annual travel as vehicles’ age, rather constant km of travel per year has previously been assumed throughout the vehicle life.
Conclusion This paper extends the concepts developed in FISITA’s upcoming white paper. On the basis of the median results from the projections, short to moderate range EVs offer the best path to minimizing CO2 emissions which conflicts with the general consumer desire for increased range to reduce ‘range anxiety’ and frequency of recharging. The benefits of up to 20% reduced life cycle emissions by optimal age recycling of the vehicle. Under these conditions of optimum age usage it can be seen that the switch to EVs is not so urgent (in line with the white paper message) if policies are in place that encourage best use of all vehicles.
FISITA World Congress 2023
Sustainability, circular economy & LCA
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FWC2023-PPE-019
Prof. Harry Watson, Part Time Prof, University of Melbourne
Abstract
Mitigating Hydrogen Internal Combustion Engine Losses and the Flow on Benefits
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Prof Harry Watson School of Engineering, University of Melbourne.
ABSTRACT
Evidence suggests that the hydrogen ICE is not much different from a dedicated natural gas engine or even gasoline engines. Therefore, as green hydrogen becomes available the lower cost and lower carbon footprint of the conventional light duty vehicle derived system, compared with the fuel cell, can be beneficial in the transition to fully green transport. The purpose is to review the problems of the hydrogen vehicle based on many decades of hydrogen engine and vehicle development which began with a world record holding car exhibited at the FISITA X1X Congress.
The issues begin with the hugely different properties of the fuel compared with all others. Combustion-wise, problems of backfire, surface ignition, flame speed, flammability limits, thermal conductivity and more that lead to different approaches to engine design detail from the conventional SI engine. Moreover, appropriate hybridisation of the H2ICE, as with the fuel cell, enables significant gains in efficiency already highlighted by our long-time research into the always lean burn gasoline engine, now evidenced by F1 engine technology.
The review of hydrogen’s unique properties leads to answers as to why hydrogen engines respond differently to increased compression ratio as evidenced in several of our engine studies with an optimum around 11:1. Mitigation of abnormal combustion is described including the influence of surface coatings, surface finish and deposits, Quantitative evidence of the mechanisms are addressed and results presented. Moreover, ultimate solutions are proposed through detailed energy analysis of the whole of engine losses. This includes the trade off in losses through entirely quality (air-fuel ratio) governing against partial throttling (Lambda 6 and leaner is possible) and measures to compensate for the slow flame speeds that determine the technology applied for best efficiency. These trade-offs guide the described optimum path in the engine efficiency map to compliment the availability of battery energy storage. The results have diesel like similarities but without the limitations of particulate and NOx emission control compromises.
Throughout the paper we draw on evidence from our extensive experiments, validated modelling and detailed analysis, and award-winning publications in this field as well as relevant complimentary literature. Even so, hydrogen engine design is still work in progress to specify an engine that can be integrated into a Renault Ecolab type concept that innovatively reduces complexity and drive train losses.
This paper will rely heavily on the insight provided by our previous research, not only benefitting from the long-term perspective but adding the findings from the most recent unpublished research from the Centre in Mechanical Engineering at the University of Melbourne.
It appears that the hydrogen ICE can be a complimentary, cheaper and have a lower carbon footprint way to the first use of green (and blue) hydrogen. The solution and mitigation of some of the hydrogen specific fuel delivery and combustion related issues, or strategies for their solution are described with potential peak efficiencies within a few percent of those of the fuel cell, with much less sensitivity to hydrogen contamination and therefore durability. At this critical time in history, options which build on traditional automotive engineering with much lower embodied CO2 than BEVs can provide the earliest possible transition to a renewable energy world that is so vital to implement.
(564 words)
FISITA World Congress 2023
Propulsion, power & energy efficiency
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Australia
Professor of Automotive Engineering
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Mr. Harry Watson

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Education Committee, Member

FISITA Council, Member
News on FISITA Spotlight
16 July 2021
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