Environmental assessment of electrification of road transport in Norway: Scenarios and impacts

https://doi.org/10.1016/j.trd.2013.09.002Get rights and content

Highlights

  • Life-cycle assessment of business-as-usual Norwegian road transport suggests a 10% increase in greenhouse gases by 2020.

  • Lower than expected GHG benefits with EV deployment in life cycle perspective.

  • Zero tail pipe emissions from EVs provide local environmental benefits.

Abstract

The study develops scenarios regarding the introduction of electric vehicles to the passenger vehicle fleet of Norway to reach the 2020 Norwegian greenhouse gas reduction target and a more extreme target to limit global temperature increase to two degrees. A process-based life cycle assessment approach is integrated with a temporally variable inventory model to evaluate the environmental impacts of these scenarios. We find that greenhouse gases in the reference scenario increase by 10% in 2020 in comparison to 2012; while for the more intensive improvements in conventional vehicles, this increase is reduced to 2%. For electric vehicles deployment scenarios, although the fleet share will reduce the tailpipe greenhouse gas emissions by 8–26%, with the upper end representing the two-degree reduction target, emissions reductions over the entire life cycle are only 3–15%. Electric vehicles also reduce emissions of NOx, SO2 and particulates reducing acidification, smog formation and particulate formation impacts, however, with addition of large numbers of electric vehicles significant trade-offs in toxicity impacts are found.

Introduction

Electric vehicles (EVs) reduces greenhouse gas (GHG) emissions firstly, because they are four to five times more energy efficient compared to conventional fossil fuelled vehicle, and secondly the electricity to power EVs can be produced using renewable sources. Norway has established a climate agreement to reduce emissions by about 16 Mt CO2 eq in 2020, compared with a baseline (Norwegian Pollution Control Authority, 2007), where no measures are taken to reduce such emissions. This reduction requires lowering emissions by 25% and the road transport sector is expected to reduce its emissions correspondingly (Norwegian Ministry of Transport and Communications, 2010).1 Further, Norway has the advantage that its electricity is largely produced from hydropower allowing a relatively easy transition from liquid fossil fuels used in conventional internal combustion engine vehicles (ICEVs) by renewable hydroelectricity.

EV production, however, releases more GHG emissions compared to the ICEVs production, and Hawkins et al., 2013a, Hawkins et al., 2013b have show that this life cycle phase also generates significantly higher toxicity impacts compared to conventional vehicles. The electricity source used to power the EV is also a central consideration, with electricity from coal negating any life cycle GHG reduction benefits from EV. In the case of Norway, however, because electricity is mainly produced from hydropower, the climate change benefit of employing EVs on a large scale may be expected to be positive. There are, though, other environmental impacts associated with their production.

We develop scenarios for the introduction of EVs in Norway until 2020 and evaluate their environmental impacts using life cycle assessment method. In addition to the Norwegian government’s target scenario for attaining a 25% reduction in GHG emissions from passenger car, we also develop a scenario to achieve the target emission reductions required to limit the global temperature increase to two degrees. This temperature increase has been highlighted as the maximum permissible temperature increase to avoid irrevocable damage to humans and ecosystems by climate change.

Section snippets

Methodology

Four vehicle population scenarios for 2012–2020 are considered; a reference scenario (R), an EU goal ICEV scenario (S1), a Norway goal scenario (S2), and a 2-degree goal (S3).

The vehicle population is estimated assuming an average constant annual stock-increase between 2012 and 2020, based on historic data on vehicle population statistics (Statistics Norway, 2012). GHG emissions for R are then evaluated with a 1% efficiency improvement for new ICEV vehicles added to the existing vehicle stock.

Results

Fig. 2 presents the life cycle impacts between 2012 and 2020 for the various scenarios over six impact categories. Table 1 presents the amount of selected stressors, emitted from tail-pipe exhaust and over the complete life cycle. Fig. 3 shows the process contribution to global warming and Table 2 presents the process contribution to environmental impacts in 2012 and 2020 under the various scenarios.

  • Overall life cycle GWP from 2012 to 2020 (Fig. 2a) shows a steady increase in the reference

Conclusions

This study confirms the benefit of large-scale use of electric vehicles in reducing GWP from the Norwegian passenger vehicle transport sector. However, the benefit is only 3–15% for the EV scenarios, when the complete life cycle is considered. Since EVs also have zero tailpipe emissions, they contribute to overall reductions in the tail-pipe exhaust emissions in addition to GWP reductions from the passenger vehicle fleet. This provides a co-benefit of improving the local air quality,

Acknowledgements

This study has been financed by the Norwegian Research Council under the E-car project (Grant number 190940).

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