US retail electricity prices ranged from a high of 21.21¢ a kilowatt hour in Hawaii to 6.08¢ a kilowatt hour in Wyoming.

The four most expensive states after Hawaii are Connecticut, New York, Massachusetts and New Hampshire. All New England states, except Vermont, are in the top 10 states in terms of high electricity prices. Vermont is number 13.

The two states where rooftop solar developers are gaining the most traction are California and New Jersey. California ranks eighth with an average retail price of 13.24¢. New Jersey ranks sixth at 14.52¢.

The figures are for 2009. The US Energy Information Administration released them in late April. Total US generating capacity in 2009 was 1.025 million megawatts.

Keith Martin