EV charging utilization forecast
How busy a site is likely to be, worked out from the traffic or people already there and how many of them drive EVs. You get a range, because anyone who gives you a single number for a site that doesn't exist yet is either guessing or selling something.
How the forecast works
There are two starting points, depending on the site.
- Highway and retail sites start from the road. EVs passing per day are traffic times EV share. Sessions are EVs passing times a capture rate, adjusted for site quality and for competing ports nearby.
- Hotels, workplaces and apartments start from the people already there: rooms, employees or units, times the share present on a given day, times vehicles per person, times EV share, times the share of those EVs that plug in.
Both are capped at what the ports can physically serve, and you get a low, expected and high case instead of one number. EV share grows every year, up to a ceiling. The details are on the method page.
Where the inputs come from
- Traffic: the live lookup pulls counts from state DOT maps and picks the busiest nearby road, with the next few listed so you can choose the one your driveway is on.
- Competing ports: counted from the federal station database within your radius.
- EV share: your county or state registration share is the place to start.
The honest part
Capture rates and charging propensity are the least certain numbers here. The defaults are informed judgment, not measurements. If you have session data from a similar site, use it. That one change will improve the forecast more than everything else combined.
Questions people ask
How many sessions per day does a public charger get?
Anywhere from under one to well into double digits. In the benchmark data, the best site did about forty times the daily sessions per charger of the worst, with the same kind of hardware. Location explains most of the gap.
What is a good utilization rate?
It is a ceiling check, not a goal. Past about half the hours open, drivers start to queue or leave. Below that, profit depends as much on price, energy cost and the demand charge as on how busy the ports are. Send the forecast to the site planner to see what it is worth.
How accurate is it?
About as accurate as the capture rate you give it, which is why you get a range. Use it to rank sites and size them. Don't use it to promise a lender a number.