Ask consumers about the idea of switching from fossil fuel to biodiesel and two questions are likely to come up: Will biodiesel production hurt the environment? How much will the cost at the pump pinch their wallets?

Scientists are trying to produce biofuels that will answer both questions the same way: "As little as possible."

For now, soybean oil is the most widely used oil in biodiesel, but an easy-to-grow crop is being studied extensively as a possible fuel source - alga.

Among those researching algae is Greg O'Neil, an associate professor at Western Washington University who recently received a five-year, $430,000 grant from the National Science Foundation. The grant will support his groundbreaking research, as well as integrate renewable energy topics into Western's chemistry curriculum and the campus' own energy initiatives.

In a nutshell, algae are mainly aquatic, plantlike organisms that range from single-celled forms to seaweeds 100 feet long. Algae contain chlorophyll, but lack the roots, stems and leaves common to land plants.

"Here in Whatcom County we don't do a very good job of growing soy, but we can actually grow a lot of algae," O'Neil says. "That's something that's attractive; it's not restricted to a particular region."

To create biodiesel from algae, most scientists isolate lipids - oils that can make up a large percentage of algae's mass.

O'Neil, who teaches organic chemistry, hopes to pioneer a new way of creating biodiesel by using components of algae that have previously only been studied as indicators of salinity and past temperatures in bodies of water. About 10 to 15 percent of the extracted mass of certain algae is made up of these components, called "alkenones."

Last year, O'Neil, working with students, helped to develop a way to synthesize alkenones. He now hopes to find an affordable way to isolate alkenones from algae and convert them into biofuel, with the idea that eventually most of the algae can be put to use for fuel.

No other lab has yet published research into alkenones as a possible fuel source, so O'Neil's work is on the front line of algal fuel research.

O'Neil and his crew are studying a type of algae called "Isochrysis." Compared to soy and other food crops, which require large amounts of water, fertilizer and land, Isochrysis can be grown in salt water with few added nutrients.

Isochrysis is one of a few species of algae that produce alkenones in addition to other oils. However alkenones have a high melting point, so biodiesel contaminated with them could solidify inside an engine if the temperature became too cold.

"It turns out the mixture of oils and alkenones doesn't make a very good biodiesel," O'Neil says. "If you make biodiesel from Isochrysis, it also contains these alkenones, and that's bad for the fuel properties."

O'Neil's challenge is to find a way to convert alkenones into fuel that's affordable as well as usable.

"If you're using something that previously was discarded, that 10 or 15 percent, that's really valuable," he says. "That would help improve the cost ratio."

On the plus side, Isochrysis is already being commercially produced for marine feedstock, so it's that much closer to being a feasible replacement for fossil fuels.

"The cultivation's cheap, it's really the harvesting and processing that's a challenge," O'Neil says. "Because the algae are aquatic, a huge amount of water removal has to go into making algae into biofuels, and that's actually currently where the greatest cost is."

For a successful switch to renewable energy sources, many scientists want to create what's known as "drop-in" fuels - meaning ones that can be handled the same way as existing fuels. That's a goal for O'Neil, too.

"The process that we're envisioning for these alkenones is that we could actually select for the different type of fuel," he says. "So we could select for diesel, we could select for gasoline, or jet fuel, for instance, all from a single starting material, depending on which process we use."

Samantha Wohlfeil is a freelance writer in Bellingham.