Rising oil prices, a surplus of agricultural land in Hawai'i and growing concern about the vulnerability of our isolated fleet of islands has created a perfect storm of interest in ethanol as an answer to our energy future.

These are exciting times, but as with anything else that seems too good to be true, they must be approached with caution.

There's no doubt ethanol (a fuel derived from plants such as corn or sugar cane) will be part of our energy future. Indeed, it already is since the law mandates that ethanol be blended into the gasoline sold at Island pumps.

But that's a baby step compared to what could happen, and what might be possible if the right combination of policy decisions, economic choices and environmentally sound thinking takes place.

Today, more than 90 percent of our energy comes from imported oil. Long-term, that makes no sense.

Oil prices continue to rise, and demand is soaring. Think India and China. In this context, the needs of tiny, out-of-the-way Hawai'i will hardly be of major concern to the global oil industry.

So it is time to focus more seriously on our own energy self-sufficiency and sustainability. The value of true energy self-sufficiency cannot be measured solely in the cost of a gallon of oil versus a gallon of something else.

There are also issues of economic independence, preservation of agricultural open space, jobs and even water use that play into any cost-benefit analysis.

The truth is that Hawai'i has been studying these matters at least as far back as the oil crisis of the 1970s, but we have yet to truly turn the corner toward alternatives and self-sufficiency.

Gov. Linda Lingle recognized this need with her ambitious energy program sent to the Legislature this year. Portions of that program, which extends all the way toward a hydrogen fuel future, did make it into law, but there is much more to be done.

As with any successful venture, this demands both public and private enterprise. One strong signal that the private sector is about to come on board was news that three major local landowners, Maui Land & Pineapple Co.; Grove Farm Co.; and Kamehameha Schools along with Mainland venture capitalists, will launch a major biofuels initiative. These are serious people who obviously see serious opportunities.

A problem facing any alternative fuel business is that it is tough to capitalize any project unless there is demand, and it is tough to create demand if there is no guaranteed product.

That problem may be solved in a variety of ways. Government, meaning the state and counties, should lead by example by requiring that their energy demands (largely transportation) be satiated by alternative fuels as they become available.

(Federal law already requires that large public fleets be at least 75 percent "ready" to run on alternative fuels when available). A more aggressive stance on this could help push demand.

The other big users of fossil fuel are our utilities.

Hawaiian Electric has already said it willing to burn ethanol or another alternative fuel in its new plant planned for Campbell Industrial Park and also will retrofit existing plants for non-fossil fuel sources as they become available.

The utility says it would happily accept a mandate from the Public Utilities Commission to burn at least 50 percent alternative fuel, most likely ethanol. Such a mandate might not be necessary if a sound market emerges, as it should, on its own. And as utilities switch to alternatives, new uses must be found for the residual oil now sold to the power plants.

Alternative energy is no miracle solution, of course. There are concerns that the energy costs of making ethanol are greater than the energy produced, although those studies tend to focus on corn. Prospects for ethanol from sugar cane appear much more promising.

And any focus on alternative fuels must not diminish the pressure for other energy alternatives, including conservation and wind, solar, wave, hydroelectric and geothermal.

Policymakers must consider these and other concerns carefully. But as they do, they must remember that Hawai'i has not and will not ever produce a drop of its own oil.

What happens next in terms of our energy future is entirely up to us.