By: Sunita Satyapal, Energy.gov
Recently, the Department of Energy hosted Dr. Tasios Melis, the UC Berkeley scientist behind a Department of Energy funded innovation that promises to triple the productivity of photosynthesis in plants and algae.
If you remember from high school biology class, photosynthesis is the process used by plants and many other organisms to convert sunlight into chemical energy. A molecule called chlorophyll serves to absorb sunlight for use in photosynthesis. Chlorophyll molecules can be stacked in arrays to help plants or algae absorb as much sunlight as possible. By tripling the productivity of photosynthesis, Dr. Melis’ breakthrough will dramatically improve light absorption and utilization, which could yield a 300 percent improvement in the conversion of sunlight to chemical energy. That chemical energy – read “fuel” – which can be harvested from algae, can come in different forms: bulk biomass (plant matter), hydrocarbons (the stuff of fuels like natural gas and petroleum products) or pure hydrogen gas, which fuel cells employ as an efficient way to store and deliver energy.
How did he do it? Dr. Melis, a top researcher in the field of Photobiological Hydrogen Production, identified three unique genetic pathways in algae, which will triple the efficiency in potential fuel production. He found that by decreasing the size of the chlorophyll arrays in algae, he could increase the number of cells that actually catch the sunlight and convert it into chemical energy. Essentially, smaller arrays allowed sunlight to strike deeper, reaching more sunlight-to-fuel conversion machines. This technology is already being employed and improved upon by several industrial and university laboratories around the world, and serves as the platform for further hydrogen production research in the field.
The range of applications for Dr. Melis’ findings goes far beyond coaxing fuel out of algae: Last year, the Melis lab found a way to use photosynthesis to create a different hydrocarbon, the molecule isoprene, which is used in the manufacture of synthetic rubber. That pioneering process serves as a case study in the development of new and promising technologies for renewable biofuels and other useful products that can change the way we use and produce energy.
Sunita Satyapal is the Program Manager for the Fuel Cell Technologies Program.