Surplus electricity is sold on Kauai Electric. Sugar companies operate four hydroelectric plants on Maui. During 1992 these plants supplied about 2 percent of Maui's electrical needs. The Island of Hawaii has nine hydroelectric plants. Ocean Thermal Energy Conversion Ocean thermal energy makes use of the temperature difference of the warm ocean surface water and cold water in depths below 2,000 feet to generate electricity.
Net power can be generate electricity.
Net power can generated so long as a difference of 40 or more degrees Fahrenheit exists between the warm upper layer and the cold deep water. Although OTEC has been successfully tested in small plants, a pilot plant of commercial size needs to be built to further document economic feasibility. Using this radiation, solar thermal power or PV power can provide Hawaii with several alternative sources of power to replace imported petroleum. About 55,000 households in Hawaii use solar water heaters, making Hawaii the state with the nation's highest per capita installation of these solar devices. An estimated 1,000 or more residential and commercial PV installations are in use throughout the state.