Sustainability and self-sufficiency have become popular buzzwords in Hawaii.

But what would it take for the state to become self sufficient on the food and energy front? Do we have enough land to feed ourselves and replace the fossil fuel that powers everything from our air conditioners to the jets that connect us with the rest of the world?

While this might seem like an impossible question to answer, it’s at least worth pondering for a very simple reason: The state is constantly being asked to reclassify farmland to clear the way for growth into agricultural areas. Yet those areas could be essential for growing food and energy crops necessary for self sufficiency.

Since the early 1960s, more than 80,000 acres have been reclassified from either conservation or agricultural into urban. More than a million acres remain, but the locations that are best for food or energy production are also best suited for development — they are flat, have access to water and are near roads and markets.

By one estimate, just 150,000 acres of the 1.9 million in the State Land Use Agricultural District — about 8 percent — are suitable for crop growth, and another 100,000 acres are described as “good farmland” that can support grazing, forestry, pasture, parks and gardens.

Hawaii is meeting approximately 15 percent of its food needs today, the Hawaii Department of Agriculture‘s Food Self Sufficiency Report states. In 2008, 92,000 acres were used for crops, but the vast majority of that total was being used for exports like sugar, pineapple, coffee and macadamia nuts.

To even approach 100 percent self-sufficiency for food, almost all of the quality farmland would need to be devoted to agriculture, say two professors in the University of Hawaii’s College of Tropical Agriculture and Human Resources. C. N. Lee teaches in the Department of Human Nutrition, Food and Animal Sciences, while H.C. “Skip” Bittenbender specializes in Fruit and Beverage Crops, Tropical Plant and Soil Sciences.

“By extrapolating from data about consumption habits and acreage needed per product, we calculate that near self-sufficiency would require an estimated 243,000 acres — and that does not include frozen, canned, or dried fruits and vegetables sold in restaurants and stores and is only to meet projected resident needs in 2007, not those from the swelling visitor and resident populations expected by 2050,” the two professors wrote in the “Agriculture” section of the Hawaii 2050 Issue Book.

Food demands will require a substantial portion of Hawaii’s available land. But the challenge of achieving self sufficiency becomes more complex because the state is also searching for ways to replace imported fossil fuels that provide roughly 90 percent of local energy needs.

If the state were to use fallow agricultural land for food production, that would preclude its use for energy production. The two issues are interrelated, and pushing energy production can hurt food production.

The energy equation is in many ways more complicated than the food question, because energy consumption is more easily curtailed than food consumption and because there are so many different ways to make up the gap. Efforts are already under way to maximize fuel efficiency, limit consumption and improve biofuel crop yields.

Technologies like solar, wind, hydroelectric, geothermal and perhaps someday wave energy will also contribute to the energy picture. Maybe nuclear one day, too. And yes, technological advancements that have yet to be dreamed up will change our ability to produce energy.

Still, even recognizing the limits to this type of prognostication, it’s possible to give a rough ballpark of the energy challenge the state faces. There is no exact answer to the question whether Hawaii has enough of the right type of land to meet its needs, but the answer can be narrowed down to an order of magnitude.

We know that Hawaii consumed about 53 million barrels — more than 2 billion gallons — of petroleum products in 2007, which provided nearly 90 percent of the state’s 343 trillion BTU energy usage, according to the U.S. Energy Information Administration.

It would take three to five acres of solar photovoltaic to generate one gigawatt-hour of energy each year (enough to power 100 homes). To put that into perspective, the state would need to cover 300,000 to 500,000 acres with solar panels to meet its energy needs.

Wind energy generally requires more land, and might need on the scale of 1 or 2 million acres devoted to windmills to accomplish the same task. Hawaii’s landmass is just over 4 million acres, with 95 percent in the agricultural and conservation districts.

Hawaii could meet more than half its diesel fuel needs with biofuels, according to the Biodiesel Crop Implementation Report, produced by the Hawaii Agriculture Research Center in September 2006. If lands from various islands were used for biofuel production and expected yields were attained, the state could produce more than 150 million gallons of biodiesel per year. But researchers warned “it should not be expected that Hawaii can produce enough biodiesel to completely abandon the need for petroleum-based diesel.” (Diesel is only a portion of Hawaii’s fuel consumption.)

Earlier this year, the U.S. military put its significant heft behind what could be the most important technology for fuel production: algae. Advocates say the small photosynthetic organisms can yield 5,000 gallons of oil per acre per year or more, and could help solve the military’s demand for jet fuel in Hawaii. Even this new technology, purported to be hundreds of times more efficient than alternatives, would still require perhaps as much 400,000 dedicated acres to fill the state’s energy quota.

In reality, none of these single technologies will be relied upon to fill the state’s entire energy quota. Instead, some combination will be used to fill a portion of the state’s energy needs. The Hawaii Department of Business, Economic Development and Tourism‘s Energy Division has produced a catalog of potential sites for solar, wind, biofuels and others.

Wherever different technologies are placed, they will require hundreds of thousands of acres to yield a meaningful amount of alternative energy. The numbers are obviously not cast in stone. Nobody knows the final answer. But they do give a framework with which to evaluate the questions we face today about what to do with our agricultural land.

While Hawaii may never get to 100 percent self-sufficiency, it’s obvious that it’s going to need a huge amount of land if it wants to take significant strides in that direction. Every acre of quality agricultural land preserved could mean a little less food or fuel that needs to be brought to the islands on a boat.

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