The promise of Life Cycle Assessment and its limits. Approaches to comparative rating of vehicles

Life Cycle Assessment (LCA) is the principal way to achieve clarity over the environmental credentials of varying drivetrains, and may become the basis of primary legislation in Europe and beyond over the next decade.

The purpose of this newsletter is to consider how LCA can work in practice, bringing clarity to the automotive sector both as an efficient market, the producer of environmentally sensitive products and in respect of consumer choice, i.e. how vehicles might be rated and ranked for their ‘greenness’.

LCA has existed as a concept since the 1970s and is by now a well-established field of academic inquiry. Contrary to common perception in 2019, LCA is not necessarily about CO2 emissions and the climate ‘friendliness’ of one car over another, say diesel versus electric. LCA can equally apply to other impact categories such as social justice or supply chain efficiency, and indeed ‘non-climate’ environmental impact categories such as water use. It is a method for considering the total lifespan of a product, but the chosen theme and system boundaries can be many, and they can be divergent. It can be applied to any product and not just cars. Owing to their material and commercial complexity, cars are among the most challenging products to apply LCA to.

A useful historical note is to remember that a precursor of LCA was Technology Assessment (TA) in the US in the 1960s. The aim of this nascent philosophy was to brief Congress on the likely impact on society and economy of new technologies, to inform intelligent policy decisions.

LCA offers a not dissimilar service today. Conventionally, it relies on a modelling of a vehicle’s impact in four areas: fuel (from source to distribution); vehicle production, vehicle use and end-of-life.

Until recently the greatest emphasis was on the fuel because the use-phase of an internal combustion engine vehicle (ICEV) is the dominant source of emissions. With electrification, the emphasis has swung to vehicle production (batteries) and end-of-life (batteries), both about which there remains a lack of usable data. There is no utility scale automotive battery recycling, but it takes place on a small scale. Meanwhile, the estimate of embedded emissions from manufacture as a proportion of total emissions are 15-20% for a gasoline car, but 20-60% for a battery electric car. Recent studies have emphasised the larger figure in that wide range, citing not just the batteries but supporting, high emission components such as aluminium. Meanwhile the fuel question is displaced to the energy grid and looms large in any credible assessment of the environmental claims of EVs.

LCA also casts doubt on the industry’s claim that diesel is better than gasoline in climate terms. In fact a diesel car’s embedded emissions are higher than a gasoline car’s (the range of estimates is 20-30% versus 15-20%, respectively) thanks to the heavier engine block and typically greater emissions controls. Like an electric car it then has to ‘break even’ over its lifetime by offering lower in-use CO2 emissions.

It is worth noting that the academic field of LCA has already moved somewhat beyond these basic LCA applications even though they remain in their infancy and are not typically understood or applied by policy makers, consumers or even parts of the car industry. Current LCA trends are to move beyond product life cycles to consider user patterns and behavioural dimensions.

Rebound effects suffice here as a cautionary note. If a consumer saves fuel costs by buying an electric car, but spends the proceeds on a long-haul flight to the Caribbean, that’s a negative environmental rebound effect. Such whole system thinking demonstrates that beyond the application of LCA to cars there remain wider considerations, including the very desirability of private car ownership given projected global urbanisation rates, resource scarcity and the political imperative towards liveable cities.

Despite all such concerns, the advent of variously electrified drivetrains makes an LCA approach essential, in our view, for the achievement of basic consumer clarity around product claims as well as policy maker insight.

One central objective, echoing previous Emissions Analytics newsletters, is achieving the greatest reduction of CO2 emissions in the shortest possible time, in the real world and not just on paper, so as to achieve the promise of the Paris climate accord and the stated goals of the IPCC in containing climate change.

Unfortunately, almost all existing vehicle regulation in OECD countries is out of sync with this climate objective, having arisen in an era in which the internal combustion engine was overwhelmingly dominant. Existing regulation concerns fuel economy and tailpipe emissions. Because EVs have tank-to-wheel emissions of zero, they have caught the policy-makers’ ear for being ‘zero emission’. Partly as a result, numerous countries have now declared their intention to halt the sale of ICE drivetrain vehicles in coming decades.

Our view of this development is one of caution, partly because of the insight afforded by the application of LCA.

In short, countries such as the UK, India, France and China are moving towards outright bans on internal combustion engines before regulators have established even rudimentary frameworks for lifecycle carbon emissions of vehicles.

It is not widely understood in the West that China’s push into rapid electrification is primarily to address poor air quality rather than combat climate change. In LCA terms its electric cars are at best roughly on par with their ICEV equivalents, with small gains predicted by 2020.[1]

This helps to explain why one of the themes of 2019 has been a series of reports identifying the high upfront embedded emissions in electric cars and the perils of grids not yet weaned off coal and lignite.

Bloomberg NEF, with Berylls Strategy Advisors, recently claimed that by 2021, ‘capacity will exist to build batteries for more than 10 million cars running on 60 kilowatt-hour packs’, with ‘…most supply … from places like China, Thailand, Germany and Poland that rely on non-renewable sources like coal for electricity.’[2]

Modelling the climate emissions of the manufacture of these batteries led the analysts to claim that the 500kg + battery pack for an SUV emits up to 74 percent more CO2 than producing an efficient conventional car if it’s made in a factory powered by fossil fuels in a place like Germany.

Several other similar reports in 2019 have pinpointed the environmental achilles heel of electric cars – their batteries – some pointing out not just their manufacturing emissions but to other impact categories relating to the mining of battery materials at scale. In some of these reports the claim is that electric cars can be dirtier than diesel cars on an LCA basis, under certain scenarios.

At the opposite end of the spectrum, critics of these reports have been up front in admitting that fulfilling the promise of clean transportation rests on decarbonising the wider energy grid, both in respect of EV manufacturing and EV use-phase. The true potential of electric cars therefore lies in the future.[3]

[1] ‘Life cycle greenhouse gas emission reduction potential of battery electric vehicle’. Zhixin Wu, Michael Wang, Jihu Zheng, Xin Sun, Mingnan Zhao, Xue Wang. Journal of Cleaner Production 190 (2018) p462-470.
[2] 2018-10-16/the-dirt-on-clean-electric-cars; Berylls Strategy Advisors,
[3] ‘The Underestimated Potential of Battery Electric Vehicles to Reduce Emissions.’ Auke Hoekstra, Joule 3, 1404-1414, June 19, 2019.

Broadly expressed, we acknowledge elements from both sides of this debate and incorporate them in the preparation of individual vehicle assessment. The lowest GHG emission is from hydropower and on this basis an EV in Sweden, as early as 2010, emitted just 6g CO2/km in use; the highest GHG is from lignite and produces an equivalent figure of 353g CO2/km.[1] The authors of this respected academic paper consider that with the current EU grid mix, the emissions of BEVs are between 197 and 206g CO2-equivalent/km, depending on battery chemistry.

At this juncture it is important to emphasise the very promising middle ground occupying the space between ICEV and BEV, the land of the hybrid and plug-in hybrid. In many situations a part-electrified drivetrain can outperform both ICE and BEV owing to the very high embedded emissions in the BEV and its underperformance in cold weather and/or when fuelled from a fossil heavy grid.

In this observation we have in mind one particular paper breaking down drivetrain performance by US regions. The ICE drivetrain had the worst GHG emissions in almost all scenarios, demonstrating the imperative of electrification for climate mitigation in a broad sense; but where cold weather and part-coal grids came into play (typically in parts of the Midwest) the worst performer overall was a BEV, while in all regions the best performing drivetrains were hybrids and plug-in hybrids, partly owing to their ability to scavenge waste heat from an ICE to operate the HVAC system in low temperatures.[2]

As such our default position is technology neutrality respecting acknowledged unknowns. Whereas some reports have claimed that in-use battery degradation could add as much as 29% to the real emissions of a medium size BEV over its life, other studies have noted that the existing durability of batteries in some hybrids suggest that the industry assumption of a lifetime of 150,000km or 8 years (the ‘functional unit’ in LCA language), is excessively cautious, with some early hybrids achieving multiples of this. The truth is that we don’t know because there is not yet enough real-world data to draw on for real-world results.

Where Emissions Analytics will contribute is by modelling an LCA approach premised on the use-phase emissions attained through real-world testing, allowing for a rising scale of other inputs that permit worst-through-best scenarios instead of being captive to a particular model or paradigm.

As things stand there is an emergent consensus view that BEVs can potentially be 30-50% better in GHG emissions, in a whole life LCA perspective, with extensive renewables at manufacturing and in-use, but this is certainly not invariably so.[3] For now, deeming EVs as the cleanest simply by virtue of what they are is misleading.

It’s equally important to note in passing that while climate considerations have become imperative, electrification is something of a devil’s bargain owing to other environmental impact categories that remain far worse than for ICEVs no matter how far projected into a golden future – these include terrestrial acidification; freshwater eutrophication; human toxicity and non-exhaust particulate emissions.[4]

Discrimination by battery origin and market of operation will quickly become an important consideration, and forms the underlying basis of Emissions Analytics’ approach to a ratings model for vehicles.

The other emerging theme is the importance of the duty cycle. The emissions ‘breakeven’ potential of an EV rests on its mileage. It may well be that a small hybrid car remains in LCA terms much more efficient for the occasional or low mileage driver than a full EV.

These and other themes will emerge rapidly as an LCA approach comes to dominate thinking and the regulatory environment. Communicating ratings to car buyers in a comprehensible way will remain Emissions Analytics’ mission.

[1] ‘Environmental life cycle assessment of electric vehicles in Poland and the Czech Republic.’ Dorota Burchart-Korol, Simona Jursova, Piotr Folega, Jerzy Korol, Pavlina Pustejovska, Agata Blaut. Journal of Cleaner Production 202 (2018) 476-487, p485.
[2] ‘Effect of regional grid mix, driving patterns and climate on the comparative carbon footprint of gasoline and plug-in electric vehicles in the United States.’ Tugce Yuksel, Mili-Ann M Tamayao, Chris Hendrickson, Inêz M L Azevedo and Jeremy J Michalek, Environ. Res. Lett. 11 (2016) 044007, p8.
[3] This was the finding of BMW in its LCA for the BMW i3 BEV, conducted according to ISO 14040/44 and independently certified in October 2013. The 30% figure assumed the EU-27 grid mix, while the 50% figure assumed 100% renewables. In this study almost 60% of the vehicle’s GHG footprint resulted from manufacturing despite enormous efforts of the company to source renewable energy for production, including all carbon fibre production and the use of re-cycled aluminium.
[4] ‘Environmental life cycle assessment of electric vehicles in Poland and the Czech Republic.’ Dorota Burchart-Korol, Simona Jursova, Piotr Folega, Jerzy Korol, Pavlina Pustejovska, Agata Blaut. Journal of Cleaner Production 202 (2018) 476-487. See Table 9 on p484.