Over the last several years, algae has been seen as the great green hope to make biofuels a truly viable option that wouldn’t affect food supplies. In part, this is because algae has the potential to yield up to 100 times as much fuel per acre as soy or corn feedstocks. Unfortunately, progress been slow so far, and a new study by Andres Clarens of the University of Virginia indicates making algae requires much more energy to produce than crops.

The study is based on computer models of the entire production process and reveals that current algae production takes six times the energy of growing crops and emits more greenhouse gases. The problem is apparently the amount of fertilizer required to grow the algae. The fertilizer requirements are dramatically reduced if the algae is fed with sewage waste water which contains nutrients that help it grow. Getting the waste water to the algae ponds or reactors does require some infrastructure investment, though. —green.autoblog.com