The push for renewable energy in the U.S. often focuses on well-established sources of electricity: solar, wind and hydropower. Off the coast of California, a team of researchers is working on what they hope will become an energy source of the future — macroalgae, otherwise known as kelp. The Pacific Coast is known for its vast kelp forests. It's one of the fastest-growing plants on Earth, and farming it requires no fertilizer, fresh water, pesticides, or arable land. "It can grow 2 to 3 feet per day," says Diane Kim, one of the scientists running the kelp research project at the University of Southern California. Kelp is transformed into biofuel by a process called thermochemical liquefaction. The kelp is dried out, and the salt is washed away. Then it's turned into bio-oil through a high-temperature, high-pressure conversion process. Some small companies are growing kelp as a substitute for kale in the U.S., but that's exactly the problem – very, very few are doing it. Thus, the
↧