Hawaii has becomes the first US state to require new homes to have a solar water heater.
Under a law enacted in 2008, but which went into effect at the start of the year, a building permit cannot be issued for a new single family structure if i does not include a solar water heater.
The executive director of the nonprofit Blue Planet Foundation, Jeff Mikulina, told the Honolulu Advertiser that with a solar
water heater, the typical homeowner will pay 30 percent to 40 percent less on their electricity bills.
For a new house, a system would cost roughly US$5,000 to $6,000, so it should pay for itself within 10 years.
The state's energy conservation programme manager, Carilyn Shon, says petroleum experts are estimating that oil prices will more than double in the coming two years, providing additional
incentive for people to save energy spending and switch to solar water heating.