For decades, scientists have attempted to replicate natural photosynthesis in an artificial plant leaf and create fuels directly from the atmosphere, powered by sunlight. The inspiration is obvious: Almost all energy comes from the sun, and most of that comes from photosynthesis.
Imagine if you could make fuel from water and carbon dioxide, wherever you and the water reside. That is the goal of the artificial leaf project, founded by Daniel Nocera, a Harvard professor of energy science. Throughout his career, Nocera has been determined to invent an energy source and technology accessible and affordable to all.
In June 2016, Nocera and his colleague Pamela Silver announced that they had successfully created energy-dense fuel by combining solar energy, water, and carbon dioxide. First, a solar-electric current runs through a cobalt-phosphorus catalyst to break water into hydrogen and oxygen. Then, an engineered bacteria (Ralstonia eutropha) consumes the hydrogen, along with carbon dioxide, and synthesizes fuel. When fed pure carbon dioxide, the process is ten times more efficient than photosynthesis.
This breakthrough is a giant step toward the goal of inexpensive energy made with sunshine, water, air…and bacteria. Nocera wants to develop the technology in India, where distributed renewables could have an outsized impact.
energy efficiency [of photosynthesis]: Blankenship, Robert E., David M. Tiede, James Barber, Gary W. Brudvig, Graham Fleming, Maria Ghirardi, M. R. Gunner et al. “Comparing Photosynthetic and Photovoltaic Efficiencies and Recognizing the Potential for Improvement.” Science 332, no. 6031 (2011): 805-809.
corn-based ethanol: Charles, Chris, and Ivetta Gerasimchuk, Richard Bridle, Tom Moerenhout, Elisa Asmelash, Tara Laan. Biofuels—At What Cost? A Review of Costs and Benefits of EU Biofuel Policies. Winnipeg: The International Institute for Sustainable Development, 2013; Conca, James. “It’s Final—Corn Ethanol Is of No Use.” Forbes. April 20, 2014; Smith, Pete, Mercedes Bustamante, Helal Ahammad, Harry Clark, Hongmin Dong, Elnour A. Elsiddig, Helmut Haberl et al. “Agriculture, Forestry and Other Land Use (AFOLU).” In Climate Change 2014: Mitigation of Climate Change. Contribution of Working Group III to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge, UK, and New York: Cambridge University Press, 2014.
pound of hydrogen…[vs.] gasoline: U.S. DOE. “Hydrogen basics.” Alternative Fuels Data Center. http://www.afdc.energy.gov/fuels/hydrogen_basics.html.
energy source…shared by everybody: Owen, David. “The Artificial Leaf: Daniel Nocera’s Vision for Sustainable Energy.” The New Yorker. May 14, 2012.
breakthrough [by] Nocera and…Pamela Silver: Liu, Chong, Brendan C. Colón, Marika Ziesack, Pamela A. Silver, and Daniel G. Nocera. “Water Splitting–Biosynthetic System with CO2 Reduction Efficiencies Exceeding Photosynthesis.” Science 352, no. 6290 (2016): 1210-1213.
more efficient than photosynthesis: Richard Martin. “A Big Leap for an Artificial Leaf.” MIT Technology Review. June 7, 2016.