Build A Kinder Earth

Could sea-based nurseries be a solution to developing alternative energy sources?

Like coffee, algae is currently being explored as a biofuel.  Recently, NASA has been getting in on the act. NASA wants to farm algae at sea for multiple reasons. Benefits to this plan include the fact that algae is oil-rich and easy to grow, that ocean nurseries leave land free for food production and that process should take out more carbon than it contributes from the environment. Another benefit is that this process purifies waste water pumped into the ocean.

Algae is typically grown in a bioreactor. NASA is currently exploring other environments in which to grow algae.

Algae is typically grown outdoors in large tanks of moving water, or inside bioreactors. The plants produce far more oil per acre than other biofuel products as soybeans. One problem, however, with algae farming is efficiently draining the water in which the algae grows.

Jonathan Trent, a researcher at NASA’s Ames Research Center in Moffett Field, California plans to to grow freshwater algae in nutrient-rich waste water inside semi-permeable plastic membranes. The membranes will keep salt water out so that it cannot kill the plants. The waves will keep the algae mixed and thriving. This process also treats sewage water. The plastic bags are recycled once the algae has been harvested.

This proposition has already has been tested in laboratories, partially supported by $400,000 from Google for NASA sustainable energy projects. Meanwhile, the city of Santa Cruz expressed support for letting its municipal waste water be used in a pilot demonstration project in the Pacific Ocean, Trent said. Currently the project is being considered for an $800,000 alternative energy grant from the state of California.

However, this idea has never been done before, other than laboratory experiments and the Santa Cruz pilot. Several problems face this concept. One problem is that it will take a large amount of algae to replace traditional oil sources, perhaps more than can be produced. In addition, treated waste water probably wouldn’t have enough nutrients to grow algae, and untreated waste water could pose a threat if the membrane rip. Algae farms could also be an issue for boaters.

Only time will tell how effective algae farming will be.