A team from Argonne and Oak Ridge National Laboratories in the US and the Fraunhofer Institute for Systems and Innovation Research ISI and German Aerospace Center in Germany has reviewed and compared 40 market diffusion models for plug-in vehicles to find similarities or differences and make recommendations for future improvements in modeling in this field.

The team reviewed models from 16 countries, including the United States, Germany, China, South Korea, the United Kingdom and Ireland. These studies modeled the decision factors that drive consumers to purchase PEVs: vehicle and energy prices, operating costs, available charging infrastructure and range, among others.

In an open-access paper in the journal Renewable and Sustainable Energy Reviews, they report that important input factors for the US are the purchase price and operating costs, while for Germany energy prices and the charging infrastructure are mentioned more often. Larger sales shares of plug-in hybrid electric vehicles than battery electric vehicles are often found in the short term results (until 2030) while the picture is not so clear for the medium- to long-term.

The value of the models is not in their predictive power, but in connecting ‘important’ factors in a way that enables us to construct some possible future based on what we know about consumer behavior and other factors.

—Thomas Stephens, Argonne National Laboratory

The studies provided vastly different projections of future PEV market shares, mainly in the US and Germany. Estimates ranged from a few percent to more than 50% by 2030. This disparity results, in large part, from the models’ diverse assumptions about market conditions, vehicle and fuel prices, and other factors.

Sales shares in base scenarios of models for 2020, 2030 and 2050 distinguished by PEV type. Gnann et al. Click to enlarge.

We found that many models handled factors very differently or even neglected some that seem to be important, so a wide range in market projections is not surprising.

—Thomas Stephens

The study focused on addressing the following specific questions:

• What are the projected market shares for a particular region?

• What are consumers’ primary purchase considerations?

• What is the effect of rebates, tax credits, battery research and development and high-occupancy vehicle lane access?

• What is the potential effect of PEV sales on petroleum demand, emissions and demand for electricity?

Though researchers cannot predict if or when PEVs could reach a tipping point in the US, they can help identify factors that could speed or hinder the adoption process, according to Stephens.

Based on their study, the team offers several findings for future PEV models that address important considerations neglected by many of the models they reviewed: the limited range, available charging infrastructure and the technological and projected cost improvements of batteries over time.

Resources

• Till Gnann, Thomas S. Stephens, Zhenhong Lin, Patrick Plötz, Changzheng Liu, Jens Brokate (2018) “What drives the market for plug-in electric vehicles? - A review of international PEV market diffusion models,” Renewable and Sustainable Energy Reviews, Volume 93, Pages 158-164 doi: 10.1016/j.rser.2018.03.055