Algae alert

On the imagination scale, algae-made biofuel probably deserves a nine. Grown in vast quantities in ponds or in vats inside greenhouses, scientists can use algae to convert sunlight and nutrients into fuel that runs engines—a seemingly limitless energy supply. After years of research, though, algal biofuel production remains inefficient and expensive, and a new analysis suggests the industry could do more harm than good.

An October report from the U.S. National Research Council, a body tasked with advising the government on scientific matters, summed up the problem: “With current technologies, scaling up production of algal biofuels to meet even 5 percent of U.S. transportation fuel needs could create unsustainable demands for energy, water, and nutrient resources.”

Depending on the manufacturing technique, producing a single liter of biofuel from algae, the report noted, could require anywhere from three to 3,650 liters of freshwater. By comparison, it only takes two to seven liters of water to produce a liter of gasoline from crude oil.

Growing algae requires heavy fertilization with nitrogen and phosphorus. The National Research Council estimated that producing enough algal biofuel to meet 5 percent of U.S. fuel demand could require up to 15 million metric tons of nitrogen—about the same amount already used for all agriculture in the United States. It could require a 50 percent bump in the amount of phosphorus currently used, too.

The report didn’t dismiss the potential of algal biofuel entirely. Bioengineered algae or improved cultivation techniques might make the production process more efficient. But those improvements need to be made before the biofuel can rightly be called “sustainable.”

The Algae Biomass Organization says over 150 companies are working with algal biofuel, and argues some are already making the efficiency improvements the report recommends. Four companies are approaching commercial-scale production, including Sapphire Energy in California, which plans to produce 100 barrels of algal biofuel a day at its facility in New Mexico by 2014. Taxpayers should wish the company success: Sapphire has received $104 million in federal grants and loan guarantees.

Hot fish

Radioactive fish are still swimming along the east coast of Japan a year and a half after an underwater earthquake and deadly tsunami caused a meltdown at the Fukushima Daiichi nuclear plant. Ken Buesseler, a researcher from the Woods Hole Oceanographic Institution in Massachusetts, found that 40 percent of bottom-dwelling fish near Fukushima contain radioactive cesium exceeding the Japanese government’s conservative safety limit for human consumption. In August two fish called greenlings caught near the plant were found with amounts of cesium 250 times the limit. However, the “vast majority” of tested fish in the area don’t pose any safety risk to humans, Buesseler said. Japanese fishers are currently prohibited from selling bottom-dwelling species caught along the Fukushima coast.

The long-term contamination implies the fish are ingesting radioactive sediment from the seafloor, or that the damaged Fukushima reactors are leaking cooling water into the ocean. A spokesman for the plant’s operator, Tokyo Electric Power, admitted unknown leaks might remain at the site. The company is building a concrete barrier 2,400 feet long between the ocean and the reactors that will contain leaks as deep as 100 feet below ground. —D.J.D.