Chronicle readers already know they pay the highest electric rates in the US.

What they may not know is that our state is the least energy efficient in the US.

The U.S. Department of Energy finds the average US family spends at least $2,000 a year on utilities. Heating and cooling account for more than half.

We are 48th only because figures for Alaska and Hawaii were not available.

This year the average consumer spent another $1,968 on motor fuel and oil, up $59 from last year.

DOE estimates that energy efficiency could cut a family’s utility costs as much as 25%. It found a more fuel-efficient vehicle could save the average driver $708 a year.

To gauge the impact on energy use, online research company WalletHub measured auto and home-energy consumption.

SC was least efficient, followed by Louisiana, Alabama, Tennessee, Arkansas, Mississippi and Kentucky.

This may be hard to believe, but the most energy efficient in heating, cooling and gasoline efficiency were New York, Vermont, Utah, Rhode Island, Massachusetts and Colorado.

The researchers calculated the ratio of total home energy consumption to annual degree days.

To determine vehicle fuel efficiency they divided annual miles driven by gallons of gas consumed and measured annual vehicle miles driven per person.