An alternative energy is ready to bloom
Craig Cox | December 2006 issue
Marlborough is a picturesque coastal city on New Zealand’s South Island known for wineries and whale-watching. But oddly enough it’s the town’s sewage ponds that are getting the most attention these days, as a company tests the energy-producing power of algae.
The company, Aquaflow Bionomic Corporation, announced last May it had produced the world’s first biodiesel fuel made from algae outside the controlled conditions of a laboratory. The algae were extracted from Marlborough’s municipal sewage-treatment system.
Using algae for rather than soybeans or other crops means that millions of acres of farmland will not be taken out of production for food and fibre. According to the U.S. Department of Energy’s National Renewable Energy Laboratory, enough algae-based biodiesel can be produced each year to power the current U.S. fleet of vehicles (140 billion gallons or 550 billion litres) using a mere 9.5 million acres [3.8 million hectares] of cultivation space. That may sound like a lot of real estate, but it’s a tiny fraction of the 3 billion acres of farmland needed to produce the same amount of oil from soybeans.
Algae contains lipid oil, which can be extracted and combined with ethanol or methanol to produce biodiesel fuel to power diesel engines in cars, trucks, buses and other vehicles
And Aquaflow’s tests show that algae not only create sustainable energy but, in the case of the Marlborough sewage ponds, help to clean the water. This system could be used to clean waste water at dairy farms, food processors and other sources of pollution.
“Although algae are good at taking most of the nutrients and chemicals out of sewage, too much algae can taint the water and make it smell,” Aquaflow spokesperson Barrie Leay said in Scoop Independent News (May 11, 2006). So local governments “have to find a way of cleaning up the excess algae in their outflow and recycling the water product. And that’s where Aquaflow comes in.”
The company is preparing to test its biodiesel in a range of engines and has already begun small-scale production. It expects to produce 1 million litres [250,000 gallons] of biodiesel a year at its first plant in Blenheim, New Zealand, and hopes to expand to several other facilities around the country.
The U.S. Department of Energy has been studying high-oil algae species since 1978 as part of its biodiesel fuels research. Those studies have concluded that large-scale algae farms could produce enough oil for a biodiesel supply that would replace petroleum as a transportation fuel. But, as physicist Michael Briggs of the University of New Hampshire notes, several obstacles stand in the way.
Federal research has focused on growing algae in large, shallow saltwater ponds located in desert regions, such as the Sonora Desert in Arizona. The sunny weather there would accelerate algae growth, but the arid climate would increase evaporation rates and necessitate regular water replacement in the ponds. Briggs estimates that 9.5 million acres of ponds (about 12.5 percent of Arizona’s Sonora Desert, as an example) could supply all of America’s fuel needs at half the current petroleum costs.
But this so-called “open pond” approach, however, has some limitations. While cheaper to maintain than enclosed “photobioreactors” that produce algae, these ponds have been troubled by temperature fluctuations, high evaporation rates and takeover by less effective strains of algae—all of which reduce yields. So researchers like Briggs are looking for ways to make the closed systems more cost-effective.
That’s precisely what a Cambridge, Massachusetts, company is hoping to prove with an algae bioreactor system that since August 2004 has been growing algae with the emissions from a pair of cogeneration power plants and harvesting it daily for the production of biodiesel.
As reported in the Toronto Star (Feb. 6, 2006), GreenFuel Technologies has a bioreactor system that removes nitrogen oxide and carbon dioxide from the power plant’s emissions and feeds it to the algae. Theoretically, the algae could then be used to power the facility—thus creating a sustainable energy system that could “enable a power plant to meet emerging state regulations for both CO2 reduction and renewable power generation.”
Small-scale field trials are already underway, according to GreenFuel founder Julianne Zimmerman, and the company plans to announce its first full-scale installations in 2008.
All this activity heralds a rather high profile for the lowly green organism most people associate with late-summer scum in ponds and lakes. But given the increasing promise of biodiesel, we might do well to abandon our aesthetic biases and embrace the modest algae. It may not be pretty, but it’s got power to spare.
