Fast chargers: over-rated?

Many assume that adoption of light-duty electrical vehicles (EV) will be limited until EVs recharge as fast as combustion vehicles refuel at a gas station. That’s not quite true. The truth will not surprise many EV drivers, but (warning!) some combustion vehicle drivers might be shocked.

For EV drivers to experience a gas station-like experience, charging needs to be complete within minutes, i.e. fast charging, the faster the better, it seems. The need largely arises from the possibility of cross-country road trips, leading to an accent on fast charging along highway corridors. Who doesn’t dream of cruising top-down in a roadster on highway 66 or the Trans-Canada highway?

What’s the real need? The share of energy provided by public fast charging is around 10% to 15%, depending on where you are, and most of this is in cities, not along highway corridors. This breakdown is not surprising, as most EV drivers charge at home, which is also the least expensive place to charge. After home, workplace is the second least expensive place to charge, with some employers providing free charging. For public charging, level 2 chargers are much more economical than fast chargers to install and operate, cost less than half as expensive for drivers to use, are easier to handle (having lighter cables) and may often be more convenient (no need to wait, just park, plug and come back some hours later or the next morning). Given this, plus the fact that the range of modern EVs is more than most people usually need in a day, level 2 chargers at destinations (as well as “slow” fast chargers, like 25 kW or 50 kW) are likely to retain a higher share of charging energy than public super fast charging. Note that 25 kW or 50 kW chargers at commercial destinations like grocery stores are very convenient: you may get a week worth of veggies, milk, meat and driving in one visit, all without waiting.

Corridor fast charging is a last resort, used if other alternatives (home, workplace, and destination charging) are not suitable. This means that fast corridor chargers have relatively low time utilization, but the pattern is peaky, resulting in congestion at certain times, such as Friday afternoon as people leave town for the weekend. The low market share of fast chargers will clearly be a challenge for operators of gas stations, as 100% of fuel is now sold at gas stations. And, with high peaks, congestion will occur even with low average utilization. Operators of fast corridor chargers will have no choice but to increase prices further for captive drivers who have no other alternatives.

However, a good fast charging infrastructure along highway corridors is nevertheless essential, as EV drivers sometimes need it, when they go on road trips. Furthermore, the fast charging infrastructure is also a major showcase for people considering buying an EV. Without it, as infrequently it might be used, few combustion drivers would consider an EV.