Algae

a large and diverse group of simple, typically autotrophic plants, ranging from unicellular to multicellular forms, such as the giant kelps that grow to 65 meters in length. The US Algal Collection is represented by almost 300,000 accessioned and inventoried herbarium specimens.[3] The largest and most complex marine forms are called Sea Weed-s. They are photosynthetic, like other plants, and "simple" because they lack the many distinct organs found in land plants. http://en.wikipedia.org/wiki/Algae

BioFuel? http://en.wikipedia.org/wiki/Algae_fuel

Commercial and industrial algae cultivation has numerous uses, including production of food ingredients, food, fertilizer, bioplastics, dyes and colorants, chemical feedstock, pharmaceuticals, and algal fuel, and can also be used as a means of pollution control. http://en.wikipedia.org/wiki/Algaculture

DIY photo reactor http://www.inventgeek.com/Projects/Photo-Bio-reactor-V2/OverView.aspx

May'2013: Exxon Mobil Corp. (XOM), which has invested more than $100 million to develop algae-derived BioFuel-s, is refocusing its research with SyntheticGenomics Inc. (Craig Venter) after almost four years of work failed to produce economically viable results... Results since 2009 have indicated that “simple modifications of natural algae would not provide a level of performance that we believed would be economical or viable for a commercial solution,” Flatt said yesterday by telephone... Exxon Chief Executive Officer Rex Tillerson said March 7 on PBS television’s “Charlie Rose” show that its investments in algae biofuels may not succeed for at least another 25 years.