Photos: MIT Energy Conference talks money, coal, and 'Enertech'

Algae fuel from GreenFuel Technologies. The company has developed a process for growing algae from carbon dioxide emissions at power plants. It also recently signed a deal to grow algae at an ethanol facility in Iowa, according to Cary Bullock, vice president of business development.

Once the algae is grown, it can be dried and burned to make electricity, or turned into biodiesel. The company is said to be negotiating with a European company for what would be one of the first large-scale algae-biodiesel facilities.