Hydrogen gas is considered to be the ideal fuel for combating environmental degradation. However the biggest obstacle to hydrogen replacing petroleum as the world\'s primary source of energy is the high cost of cleanly producing this gas. The most cost-effective current method for producing H2 is to use nuclear energy -- but that has environmental issues. Likewise using solar power is not cost-effective and using wind power is limited to a few regions. To address this challenge researchers at the University of California Berkeley have developed a photosynthetic method for producing H2. This patented H2 production method is based on depriving algae of sulfur which in turn inhibits oxygen flow and augments its natural H2 production. Using a bioreactor comprised of a network of sealed tubes for cultivating algae and extracting pure H2 researchers were able to produce the gas for about $0.31 per kilowatt-hour. That is much higher than natural gas-fired methods that produce H2 for about $0.05 per kilowatt-hour. However the Berkeley team is pursuing research to address bottlenecks in this photosynthetic process which would in turn improve efficiency and reduce costs. These cost savings from the more efficient photosynthetic process along with refinements to the bioreactor design could make this algae production method cost competitive with the natural gas-fired production approach.