In my last article I tried to explain why large battery packs are inefficient. Besides packaging and safety issues, added weight reduces a BEVs efficiency. BEVs that provide less range to drivers usually outperform the Tesla Model S in energy efficiency. Again, this is mainly due to the reduced weight these cars carry around. While long range provides peace of mind, in this article I want to explain how much range an average US driver actually needs.
The National Household Travel Survey provides the largest database of individual trips taken in the US. The latest survey dates back to 2009 and has >1M individual trips recorded. It is assumed to represent the US population well. The database allows us to estimate US driving behavior. For example, the average driver took 3.8 trips per day and averaged 13,543 miles in 2009.
Based on the database I created a distribution for individual trips in the US. The distribution was used to develop a random generator that produces individual trips over a year based on the actual distribution in 2009. Moreover, I anticipated that US drivers put on 10-15% more miles per year in 2015 than six years ago. In the example above that simulation ended with 15,200 miles after one year.
With this single random simulation we can easily see why most car manufacturers still produce "low" range EVs. On 260 days that simulation produced <25 miles of driving distance. Now say what!? Less than 25 miles on 260 days of the year!? That is not representing my driving habits! Well, the simulation is based on real world data and thus variances of >1M actual trips taken in 2009 (and adding >1 mile per trip). Moreover, today's "low" range BEVs (<75 miles with one charge) would be sufficient for 301 days without charging anywhere else than home.
301 days without charging anywhere other than home! Now what if we had the possibility of charging at work. Hmm, we are getting close to the full year... dreaming... Lets get back to reality: in the example above the largest battery pack in a Tesla ModelS would have advantages on 58 days over an average BEV (without at work charging capability). On 6 days even the Tesla would have needed some extra charging. Now you might say that stopping 58 times or more per year to charge your car is a lot. Well, that is once a week. As often as we fill up our gasoline cars today.
In 2009 US drivers averaged 3.8 trips per day and 9.8 miles per trip
Current BEVs (<75 miles range) are sufficient for daily usage even when adding >1 mile per trip
Current BEVs (<75 miles range) need to be charged outside of home at least once per week
I might not have convinced you yet into buying an electric car based on my short analysis here. I will follow up with more in-depth research to make dealing with range anxiety more comfortable for you. Also, do me a favor, imagine for a second, the next generation of BEVs (2017) will reach 175 miles of range as announced. Now look back at the graph... Why do we need those 300 miles again?
Expect more research on range needs soon. Stay charged until then!
Sini Ninkovic analyzes the EV market and its customers since 2012. He helped bringing BMW's i3 and i8 to market and currently works as Product Planner for Lucid Motors.