Getty Images

Fossil Fuel Alternatives

Algal Oil

Oil from algae is a sort of Holy Grail of energy researchers. Algae naturally produce oil, and can be bred to make more. They can also be bred in conditions where plant crops would perish—in salt water or water that's brackish or even contaminated by waste. Without any leaves or bulky stalk, water-borne algae should be easier to harvest than terrestrial plants, as well. Cambridge (Mass.) startup GreenFuel Technologies is experimenting with ways to channel CO₂-rich exhaust from power plants to feed crops of algae to make bio-oil.