Depending on when you charge your Plug-in Hybrid Electric Vehicle (PHEV) and the price of gas, it may be more economical to buy gas according to a soon-to-be-released study. Future PHEV owners might actually find it's more costly for them to plug in their cars, hurting adoption of PHEVs and discouraging PHEV owners from plugging them in. I came across this conclusion in a report (the link is to a PDF file) commissioned by the state of California. Here is exactly what it said.

"If PHEV owners bought electricity according to this tariff, they would not save money by charging at peak hours unless gasoline cost more than $3.73 per gallon. And they would want to charge their vehicles during off-peak hours as long as gasoline prices remained above $1.96 per gallon or they were using more than twice their baseline allowance and so paying more than $0.149/kWh. PG&E's experimental EV tariff would likely deter PHEV owners from charging during summer afternoon hours, but this effect depends upon the actual adoption of such a tariff by the vehicle owner, upon the specific peak hour rates, and upon the current prices of substitutable liquid fuels."

Go below the fold for more.

[Source: Low-Carbon Fuel Standard for California study]