title: Comparing photosynthetic and photovoltaic efficiencies and recognizing the potential for improvement.
abstract: Comparing photosynthetic and photovoltaic efficiencies is not a simple issue. Although both processes harvest the energy in sunlight, they operate in distinctly different ways and produce different types of products: biomass or chemical fuels in the case of natural photosynthesis and nonstored electrical current in the case of photovoltaics. In order to find common ground for evaluating energy-conversion efficiency, we compare natural photosynthesis with present technologies for photovoltaic-driven electrolysis of water to produce hydrogen. Photovoltaic-driven electrolysis is the more efficient process when measured on an annual basis, yet short-term yields for photosynthetic conversion under optimal conditions come within a factor of 2 or 3 of the photovoltaic benchmark. We consider opportunities in which the frontiers of synthetic biology might be used to enhance natural photosynthesis for improved solar energy conversion efficiency.
authors.affiliation: Department of Biology, Washington University in St. Louis, St. Louis, MO 63130, USA. blankenship@wustl.edu
authors.forename: Robert E
authors.initials: RE
authors.lastname: Blankenship
authors.forename: David M
authors.initials: DM
authors.lastname: Tiede
authors.forename: James
authors.initials: J
authors.lastname: Barber
authors.forename: Gary W
authors.initials: GW
authors.lastname: Brudvig
authors.forename: Graham
authors.initials: G
authors.lastname: Fleming
authors.forename: Maria
authors.initials: M
authors.lastname: Ghirardi
authors.forename: M R
authors.initials: MR
authors.lastname: Gunner
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Junge
authors.forename: David M
authors.initials: DM
authors.lastname: Kramer
authors.forename: Anastasios
authors.initials: A
authors.lastname: Melis
authors.forename: Thomas A
authors.initials: TA
authors.lastname: Moore
authors.forename: Christopher C
authors.initials: CC
authors.lastname: Moser
authors.forename: Daniel G
authors.initials: DG
authors.lastname: Nocera
authors.forename: Arthur J
authors.initials: AJ
authors.lastname: Nozik
authors.forename: Donald R
authors.initials: DR
authors.lastname: Ort
authors.forename: William W
authors.initials: WW
authors.lastname: Parson
authors.forename: Roger C
authors.initials: RC
authors.lastname: Prince
authors.forename: Richard T
authors.initials: RT
authors.lastname: Sayre
mesh_terms: D018533:Biomass; D004560:Electricity; D004572:Electrolysis; D006859:Hydrogen; D010788:Photosynthesis; D063245:Plant Development; D010944:Plants / Q000378:metabolism; D012993:Solar Energy; D013472:Sunlight; D058615:Synthetic Biology
chemical_list: D006859:Hydrogen