With a small number of EVs on the road, free public charging at restaurants or hotels is a perk for attracting customers, and the corded parking spots are not costing the property owner that much. It would be totally different if there were millions of EVs out there roaming for electrons.
For example, Tesla Motors is offering Model S owners free fast charging at its Supercharger network. Masson says that Tesla could be giving away $5,000 of free electricity per Model S based on rates in the area he lives, if it drove 100,000 miles solely on Supercharger power (not a likely scenario). Masson assumes the Model S would consume 300 watt hours per mile, which would make for 30,000 kilowatt hours after 100,000 miles. If a lot of the Model S electric car get sold, how long can Tesla afford to give away electricity? How long can anyone? The answer is that sooner or later, there needs to be sales and profit involved, somehow, Masson argues.
So, more private investors are needed to expand public charging networks as EV sales numbers grow. Pat Romano, CEO of EV-charging station maker Coulomb Technologies, said that EV owners are willing to pay somewhere around $1 an hour for charging, and think that $2 an hour is "expensive." In the US, most EVs are charged for a rate of about 3.3 kilowatts per hour, and that much energy usually costs about 50 cents. The days of free charging are coming to an end, but so far, EV owners expect to see the fee stay at a low level.