|Proportion of lifecycle CO2e emissions for future cars 2020-2030. The new study projects the increasing dominance of the production phase in terms of lifecycle CO2 impacts. Click to enlarge.|
The introduction of new energy technologies in road transport will mean that the current tailpipe measures of the climate impact of vehicles will become increasingly inadequate in future.
A new report—“Life Cycle CO2e Assessment of Low Carbon Cars 2020-2030”—prepared for the UK’s LowCVP Low Carbon Vehicle Partnership by PE International and validated by Partnership stakeholders—shows how total life cycle CO2e emissions will change for different vehicle technologies in the future and estimates how the balance of emissions will alter for different stages in the life cycle for the varying technologies.
The report builds on an earlier study, “Preparing for a Life Cycle CO2 Measure” written for the LowCVP by Ricardo. The main conclusions of that study were that future CO2e metrics for passenger cars need to go “beyond the tailpipe” and take account of whole life cycle CO2e emissions to more fully account for environmental impacts.
It clearly shows that there are a range of potential routes to deliver significant carbon reductions, including both increased electrical mobility with battery vehicles and plug-in hybrids but also low carbon liquid and gaseous fuels. However, current measurement methods do not reflect the real impacts.
This new report indicates that it is time to move on from the current tailpipe carbon measure, but whole vehicle life cycle analysis is a very complex process and further work is needed. With the in-use phase continuing to dominate vehicle impact for at least the next decade the LowCVP is calling for the UK to lead the way in incorporating the new test-cycle and a well-to-wheel approach to fuel consumption and vehicle efficiency to provide both industry and consumers with better information on the carbon impact of their vehicles.—Andy Eastlake, LowCVP Managing Director
The PE International study suggests that the embodied impacts of the vehicles themselves will become more of a focus for further decarbonization in future. Manufacturers are already beginning to turn more of their attention to vehicle component materials and production processes. The materials used in production have differing amounts of embodied carbon and their choice, for example, of lightweight steel and aluminium also impacts on emissions occurring during the operation phase.
|Life cycle CO2e emissions, “Typical” scenarios for future cars 2020-2030. Click to enlarge.|
The report says that the clear trend is that the use of tailpipe CO2 emissions as an established comparator for different vehicles will become less effective, and almost irrelevant in terms of identifying the true carbon profiles and reduction potential, for future vehicles.
The report highlights that with ambitious policies, reductions in excess of 60% in lifetime CO2e impacts can be achieved by 2030 through a combination of factors from the production phase, use phases and end-of-life phase. In addition to a greater emphasis on the embodied impacts of the vehicles, recycling/re-use of high-impact vehicle components such as electric vehicle battery packs may have the potential to contribute significantly to decarbonization efforts of the embodied impacts of future vehicles.
To select the most appropriate future technologies and products, we need to take a more holistic view of their environmental impacts and it is increasingly clear that we need to look beyond the tailpipe. However, it is also evident that many assumptions need to be made to arrive at a broader CO2 measure and significant research work will be needed to explore and agree a new set of measures that we can use. The LowCVP report is a significant contribution to this agenda—Professor Neville Jackson, LowCVP Chair
The report was published to coincide with the LowCVP’s Annual Conference, the theme of which is “Beyond the Tailpipe”.
Life Cycle CO2e Assessment of Low Carbon Cars 2020-2030. The new study is a “streamlined” LCA based largely on secondary data available from published literature. It is a “cradle to grave” study covering:
Extraction of raw materials, production of fuels & production of vehicle component parts;
Assembly of vehicles;
Use phase of vehicle over a defined lifetime (including replacement parts - i.e. lubricants, tires etc.); and
“Cut off” end of life of vehicle (considered to end just after vehicle shredding including limited disposal of wastes arising).
The vehicle technologies considered in this project are:
Gasoline internal combustion engine vehicle (ICEV) with gasoline-biofuel blend;
Hybrid electric vehicle (HEV) with gasoline-biofuel blend;
Plug-in hybrid electric vehicle (PHEV) with gasoline-biofuel blend; and
Battery Electric Vehicle (BEV).
The base case scenario for this study is 2012; future scenario cases considered are for the years 2020 and 2030. For each of the future scenarios, the authors defined a “Typical case” and “Best case” scenario.
Vehicular lifetime mileage was set to 150,000 km (93,205 miles) under conditions of the New European Driving Cycle (NEDC). All vehicles are based on the “average mid-sized gasoline” car as detailed in a 2008 JRC IMPRO-car study.
Future grid mix intensities in this study were estimated using information from EU statistics, the EC Roadmap, the UK Carbon Plan and the UK 2012 Draft Energy Bill. Electricity grid mix carbon intensities are assumed to be at the point of consumption. The carbon intensity of gasoline was assumed to remain constant for all scenarios i.e. no change from the present situation. No advanced/second generation biofuels were considered.
The carbon intensities of ethanol derived from the feedstocks assessed in this study were adjusted for improved production efficiency assumed to come into effect in the future. All adjustments take into consideration the 60% GHG intensity savings threshold for biofuels in 2020 set by the EU Renewable Energy Directive (RED) as well as the 70% GHG intensity savings threshold for 2030. Indirect Land Use Change (ILUC) was not considered.
The study found all technology options showing reductions in life cycle impact in the period to 2030 compared to the 2012 situation.
For “Typical case 2020” scenarios, there is a 5-12% range of savings in life cycle CO2e impacts for all vehicles compared to the “Base 2012” scenarios. These savings mainly result from the expected reductions in the carbon intensity of the future grid mixes, fuel/electricity consumption savings from light-weighting and improved automotive technology as well as improvements in battery pack technology that are predicted to lead to lower embodied carbon impacts of this component.
For “Best case 2020” scenarios, the savings range from 9-24% for all vehicles compared to the “Base 2012” scenarios. These additional savings are from the additional reductions to fuel consumption, grid mix carbon intensity etc. that are modelled in the “Best case 2020” scenarios.
For “Typical case 2030” scenarios, there is an 18-36% range of savings in life cycle CO2e impacts for all vehicles compared to the “Base 2012” scenarios.
For “Best case 2030” scenarios, even further light-weighting, reductions in the carbon intensity of the future grid mixes etc are coupled with the use of 100% bioethanol in vehicles with internal combustion engines and a low carbon intensity electricity grid mix. This leads to a 55-70% range of savings in total life time CO2e impacts for all vehicles when compared to the “Base 2012” scenarios.
The “total use phase” (accounting for emissions from the production and combustion of gasoline and bioethanol, and from generation of electricity for battery-powered vehicles) will be the dominant phase contributing to life cycle GHG emissions for at least the next decade, the report found.
However, in the 2020 to 2030 timeframe, emissions from the production phase becomes steadily more important and dominates in some scenarios, particularly for increasing levels of vehicle electrification.
In the “Best Case 2030” scenario, the production phase could account for up to 75% of the total impact. Vehicle production is dominated by raw material extraction and component manufacturing with vehicle assembly accounting for only 6-8% of lifetime CO2e impacts for all vehicles over all scenarios.
The report noted in particular that EV battery pack production and recycling are increasingly critical because the battery pack is the largest single element contributing to production phase impacts for the PHEV and BEV.
While recycling/re-use of such high-impact vehicle components may have the potential to contribute significantly to decarbonization efforts of the embodied impacts of future vehicles, there are little available data on this topic, the report found.
In summary, there appear to be clear possibilities for reducing the potential lifetime CO2e emissions in the future for all vehicles considered. Greater reductions in lifetime CO2e impacts can be achieved by adjusting a combination of factors from the production, use and end of life phases for the vehicles assessed in this study. Particular emphasis should be made on decarbonization of the embodied impacts of the vehicles as well as factors that contribute to use phase impacts as these two phases drive overall lifetime impacts.
The findings presented in this report should be considered in the context of the limitations of the high level, streamlined nature of this study. These findings serve as an indicator of the potential lifetime CO2e emissions of future C-segment ICEVs, HEVs, PHEVs and BEVs. The results from this study can also be used to highlight areas of further work or improvements in future studies of a similar nature.—“Life Cycle CO2e Assessment of Low Carbon Cars 2020-2030”