Is it legal to charge for electricity?

Short Answer

Even though reselling electricity is often illegal, some jurisdictions may allow a flat rate, a time-based rate or a blended rate (parking + charging together). Be sure to check your local jurisdictions for laws & regulations regarding EV charging rates.

More Details

For the sake of consumer protection, there is an ongoing debate between utilities and EV charger manufacturers over who can charge for electricity and how. Not having a proper way to charge for the usage of electricity for EV charging hinders the growth of electric vehicles, on the other hand allowing anyone using an unapproved power measurement device to charge for electricity is a recipe for disaster.
For years the middle ground was to reserve the right to charge for unit of power (i.e. kWh, Joules or etc) to utilities (or approved vendors) AND allow EV supply equipment to act as a service provider (not an electricity provider) and let them charge per time of usage (like parking).

Two problems arise with charging per time of usage instead of unit of power:

Problem #1: variable charging rates

The amount of power delivered to an electric vehicle from Level 2 and Level 3 charging stations is not fixed and depends on many factors, including but not limited to:
  • How full the battery is. As the battery gets more full, especially after 80% capacity, the rate of charge drops significantly. According to  Forbes  "The last 20% of a fill-up can take as many minutes as the middle 50%, and thus cost as much, for much less electricity."
  • The weather conditions. Temperature of the battery is an important factor affecting the charging rate.
These factors make it unfair for electric vehicles to have to pay for time-based rates as the rates are always calculated based on the maximum power the EV charger can supply to the EV rather than the actual power the electric vehicle is receiving. This type of unfairness only applies to Level 2 & Level 3 chargers.
When it comes to Level 1 charging though, our Plugzio data shows the rate of charge is always constant and doesn't depend on any external factors which makes it fair for consumers to pay time-based rates.
Here is a snapshot for a 25 hour charging session run by one of Plugzio users before their battery reached full capacity. As you can see, the amount of power delivered to the vehicle is always constant.