Plug it in!

The complete transition to electric vehicles will happen over the next few decades. Many countries and regions have put dates in place for final sale of new internal combustion engine (ICE) vehicles. These phase out dates start as soon as 2030 in the UK. However, the rules for the end date for the sale of hybrid electric vehicles are not so clear. For example, sales of hybrid cars "that can drive a significant distance when no carbon is coming out of the tailpipe" will be allowed to be sold in the UK until 2035. Hybrid vehicles contain both an ICE and electric motor. The batteries in an HEV are smaller than a fully electric vehicle, and therefore provide less range. Hybrid vehicles can be plugged in overnight and if the driver only needs to do a short journey of 10 to 20 miles, the vehicle will operate entirely in electric mode. For longer journeys the ICE will kick in as the battery runs short of charge. Since the vast majority of vehicle journeys are short, HEVs should almost always be using the electric motor, reducing emissions to a minimum - in theory!

The reality is somewhat different. You would think with petrol being much more expensive than the electricity required to charge the HEV battery, that it would make sense to squeeze every mile out of the battery possible. However, that doesn’t seem to be the case. In fact, a new white paper by Patrick Plötz, Cornelius Moll, and Yaoming Li from Fraunhofer ISI and Georg Bieker and Peter Mock from the International Council on Clean Transportation has analysed real-world usage and fuel consumption of approximately 100,000 PHEVs in China, Europe, and North America. The research found that HEV fuel consumption and tail-pipe CO2 emissions in real-world driving, on average, are approximately two to four times higher than type-approval values. This effect is due to some drivers relying on the ICE for driving instead of the electrical motor.

Apparently a relatively high percentage of HEV drivers have never charged their vehicles after the initial charge was used. Others charge them rather infrequently. The study found that business users were worse that private users, but not by much. Delving deeper into the phenomenon, Debapriya Chakraborty, Scott Hardman and Gil Tal from UC Davis looked at 5418 HEV owners in California and found the main reasons for not charging HEVs included high home electricity prices, lower electric driving range, lower electric motor power to vehicle weight ratios, lower potential cost savings from charging, and living in an apartment.

It seems counter-intuitive, to spend money on an HEV in the first place, when you could buy an ICE vehicle for probably a lower price if you don’t intend to take advantage of the lower cost of running it. Is electricity actually more expensive than petrol in California? Do green discounts and tax breaks justify the purchase of an HEV over an ICE automobile? I’m not sure the extent of these incentives, but since HEVs are being promoted for their environmental benefits, they don’t seem to be working for their intended purpose.

https://theicct.org/sites/default/files/publications/PHEV-white%20paper-sept2020-0.pdf

https://iopscience.iop.org/article/10.1088/1748-9326/ab8ca5/pdf