HAWI, Big Island — With its ocean breezes, ample sunlight, pounding waves and a continuously erupting volcano, Hawai'i seems blessed with the means to produce clean electricity and achieve energy independence.

But that isn't anywhere close to happening. For one thing, the technology isn't quite ready.

The big drawback with wind and solar energy, for example, is that the flow of electricity stops when the breeze dies down and the sun sets. Since there is no good way to store the power for use later, homeowners need conventional electrical service — meaning fossil fuel-burning plants — as a backup.

"Our community understands the time is now to think about these things, and yet we demand that they keep the lights on," said Mike Gresham, vice president for UPC Hawaii Wind Partners, which runs the state's largest wind farm, consisting of 20 turbines on Maui.

And so, despite rising prices, oil and coal are still the most reliable and convenient energy sources in Hawai'i.

In fact, Hawai'i relies on imported fossil fuels more than any other state, with about 90 percent of its energy coming from foreign countries and most of the rest coming from renewable resources, according to state data for 2005.

The United States as a whole imports 30 percent of its energy, with 6 percent from renewables, according to the Energy Information Administration.

The major reason Hawai'i is so dependent on foreign oil is that it is way out in the middle of the Pacific, far from the pipelines, electrical transmission lines and coastal oil fields on the Mainland. Fuel can be easily delivered aboard Asian tankers instead.

With world demand for electricity climbing ever higher, Hawai'i passed a law last year that calls for one-fifth of the state's energy to come from renewable sources by 2020.

Things are clearly moving in that direction. Among the renewable-energy projects under way is a $200 million Maui wind farm that will power 15,000 homes starting in 2008.

But solar and wind power still account for a very small percentage of the energy consumed in Hawai'i.

The problem with solar power is that the sun sets just when electricity customers need electricity the most, between 5 p.m. and 9 p.m. So far, solar power has not proven feasible for producing electricity in Hawai'i, but an estimated 80,000 homes and other facilities are served by solar water heaters.

As for wind, "you need a storage method that can come in and back that up" whenever the breeze dies down, said Karl Stahlkopf, president of Renewable Hawaii, a subsidiary of Hawaiian Electric Co.

The Big Island, for example, has a wind farm in Hawi with 16 windmills turned by the tropical breeze. The 100-foot turbines can generate enough electricity for more than 1,200 homes.

During one recent afternoon, however, the trade winds were so weak that only eight of the turbines were turning.

"The potential is huge. We're not lacking the resources," said Maurice Kaya, chief technology officer for the state Department of Business, Economic Development and Tourism. "There may be technological solutions to this intermittence, but we're not there yet."

One potentially more reliable source of clean power is geothermal energy. Geothermal equipment draws heat from the molten rock deep within the Earth's crust to drive turbines. The Big Island, the home of Kilauea, is a place of great volcanic activity.

The big advantage of geothermal energy is that it is an uninterrupted source of power.

"Unlike wind, geothermal is just like fossil fuel — we keep on producing," said Barry Mizumo, a consultant for Puna Geothermal Venture, which contributes 15 percent of the Big Island's peak power capacity.

Several businesses are also working on early efforts to take advantage of Hawai'i's world-famous waves and harness the power of the tides. And Hawai'i's electric utilities plan to convert plants to burn biofuels such as palm vegetable oil, by 2009, Stahlkopf said.