Algae has been grabbing the lion’s share of attention in Hawaii’s effort to develop a home -grown biofuel industry.

As a feedstock for biofuel production, its credentials are impressive. Potential oil yields from certain algae strains can be at least 60 times higher than from soybeans and five times higher than from palm oil, currently the most efficient large-scale source of biofuel feedstock, according to a report from the U.S. Department of Energy. The promise of algae has prompted the federal government to pour millions of dollars into research and development to jump-start production in Hawaii.

Local companies such as HR Biopetroleum Inc., Hawaii Bioenergy LLC and Phycal LLC have put teams of scientists to work conducting experiments to find the most productive algae strains and most efficient harvesting methods.

The financial incentives are high, with Hawaiian Electric Co. and the U.S. military waiting in the wings to buy large quantities of the renewable fuel for their operations when it becomes available. HECO’s power plants can burn crude bio-fuels and more refined biodiesel made from renewable sources, while biofuel extracted from algae and other feedstocks can be refined into jet fuel. Biodiesel also can be burned in any vehicle that runs on petroleum-based diesel.

As the algae companies slowly move forward with their research and development, however, another source of renewable energy is blossoming — literally — on the Big Island. Hawaii Pure Plant Oil, or HIPPO, is midway through the second harvest of oil-rich jatropha seeds on a 250-acre test plot in Keaau.

Father-and-son partners Christian and James Twigg-Smith planted the jatropha bushes two years ago on fallow sugar cane land, and discovered that the plant, originally from Central America plant thrives in the humid Keeau climate.

While not quite at the level of algae, the potential oil yield from jatropha is among the highest of any crop except palm oil, according to the U.S. Department of Energy.

The Twigg-Smiths, who also grow coffee commercially under the Kona Blue Sky brand, are planning on eventually selling oil from the jatropha seeds to Big Island Biodiesel, which broke ground last week on a processing plant in Keeau. Big Island Biodiesel is a subsidiary of Maui-based Pacific Biodiesel, the state’s largest processor of biodiesel from waste restaurant oil.

The elder Twigg-Smith said the yield from the current jatropha harvest is greater than last year’s initial harvest. The plants should be fully mature in four to five years, he said, adding that the plans are to expand the plantation to 1,000 acres if all goes well.

The company picks the jatropha seed pods using an "over-the-row" mechanical harvester similar to what is used to pick coffee, Twigg-Smith said.

The jatropha plantation hasn’t generated the kind of interest from investors that algae projects have, Christian Twigg-Smith said. HIPPO is trying to raise $1.3 million to build a storage building and buy more equipment, including a large-scale cold press to extract the oil from the jatropha seeds.

Big Island Biodiesel hopes to have its Keeau biodiesel processing plant finished by the fall of 2011, said Kelly King, vice president and marketing director for parent Pacific Biodiesel.

The plant will be the most sophisticated of all of the company’s processing facilities, able to accept a variety of feedstocks, from restaurants’ waste "trap grease" to jatropha and algae oil, she said.

King said she’s been hearing about the promise of algae-based biofuel for some time, but has yet to see any of the producers come up with a firm timetable for production.

"I have a standing offer to pay $500 for the first gallon of algae oil," she said.

Of all the Hawaii-based companies, HR Biopetroleum may be closest to commercial production of biofuel from algae. The company is doing its R & D in a joint venture with Shell Oil at the Natural Energy Laboratory of Hawaii Authority in Kona.

HR Biopetroleum CEO Edward Shonsey said the company has received all the permits it needs to build a processing facility near Maalaea on Maui, and could begin producing algae-based biofuel in two to three years.

"Algae is a wonderful, indigenous source of biofuel for Hawaii. We’re moving along well with the progress and continuing to work on yield," Shonsey said.