In a Chevy Volt, a full charge from zero takes four hours on 240 volt. On this full charge, you can drive an average of 38 miles before the gasoline engine kicks in. Coincidentally, at that point the Volt can run an average of 38 miles per gallon of gasoline (the car takes 9 gallons), so it makes our math easy: In California, a gallon of premium now sells for $4.40. Therefore, one hour of charging the Volt is equal to $1.10 of gasoline-equivalent value ($4.40 divided by 4). Let's say someone charged you $1 per hour to "fill" your Volt with electricity on a 240 volt circuit. At that rate, you might as well just not bother, simply going to the gasoline station instead, since the price is approximately similar. As you can tell from this, it might not be easy to bother charging someone for electricity per se. Are you really going to bill someone for well under 50 cents for stopping by for 30 minutes while shopping? What's the moral of this story? We need a very large number of electric car chargers in order to serve the 100,000 to 125,000 incremental cars that are being sold in the U.S. just this year. However, you basically can't charge people for the electricity, because it's such a small amount per charge, and because people driving plug-in hybrids can always price-arbitrage against gasoline. Someone else will have to pick up the bill, whether in terms of general parking garage fees, advertising, or some other economic incentive. Yes, it has come to this. With "only" 70,000 electric cars on the U.S. roads, several electric car charging stations are now congested, and the situation is becoming more acute by the day. If nothing is done about this looming calamity, the U.S. electric car market risks grinding to a screeching halt. It is really amazing how quickly the goal posts, and the pain points, are shifting in this fast-growing industry. At the time of submitting this article, the author was long TSLA.Follow @antonwahlmanThis article is commentary by an independent contributor, separate from TheStreet's regular news coverage.