The Mack Institute’s Program on Vehicle and Mobility Innovation (PVMI) sponsored a technology forecasting challenge in 2016 and again in 2017 focused on the question of when (and whether) automotive innovations such as electric vehicles will achieve mass market acceptance. This Challenge included questions on consumer behavior, technological developments, and government policies that have the potential to propel the trend forward — or hold it back.
One key factor affecting consumer adoption of electric vehicles is the price and performance of batteries, so the Challenge included a question about the cost per kilowatt-hour (KwH). Read more about the original question here.
Here we describe the methodology and the results for the industry-wide average cost estimate of lithium-ion (Li-ion) battery packs in 2017, based on the same methodology as reported in a 2015 article in Nature Climate Change (Nykvist and Nilsson, 2015). Our analysis shows a 16% annual decline in the cost of battery packs between 2007 and 2017, and the industry-wide average cost of battery packs in 2017 was US $236 per kWh.
Replicating the methodology in the Nature Climate Change article, we used “Electric vehicle Lithium Ion battery cost” as keywords to identify recent articles, news items, and expert and industry statements from Google’s search engine and reviewed the first 100 hits. We also used the same keywords in the Web of Science database and identified recent academic journals and publications and reviewed the first 100 hits.
Since the battery requirements for hybrid vehicles are different from those for electric vehicles, the data on costs of battery packs used only in hybrid vehicles was not included in the analysis. However, when information on battery packs for both types of vehicles were combined into one cost estimate, that estimate was included in the analysis.
This data was supplemented with additional cost estimates for individual car models such as Tesla Model S, Chevrolet Bolt Electric Vehicle, Nissan Leaf, BMW i3, and Ford Focus Electric Vehicle based on public statements made by the company. Furthermore, the battery pack replacement costs, found in articles and public company statements, were also included in the analysis.
The method yielded 34 new cost estimates. Cost estimates that duplicated data from another reference source were omitted from the analysis. Also, cost estimates for battery cells was not included as these costs are only a fraction of the costs for the battery packs. Finally, cost estimates prior to 2014 were also not included in the analysis to preserve the comparison with the Nature Climate Change article.
For references that provided a range of costs, the mean value of the highest and lowest values in the range was used. All costs in foreign currencies were converted into US$ based on historical exchange rate data from US Federal Reserve, and all costs were inflation adjusted to 2017 US$. The final dataset for the analysis comprised of 69 unique cost-estimates between 2007 and 2017 (53 estimates from the original article, 16 estimates for the years 2014-2017). The cost data was then log transformed and fitted using a simple regression equation of the trend line of the form shown in the figure below.