The biological hydrogen generation with algae is a method of splitting water Photobiological qui is done in a closed photobioreactor based on the generation of hydrogen as a solar fuel by algae .   Algae produce hydrogen under certain conditions. In 2000 it was discovered that C. reinhardtii algae are deprived of sulfur in the production of oxygen , as in normal photosynthesis , to the production of hydrogen.   
Photosynthesis in cyanobacteria and green algae splits water into hydrogen ions and electrons. The electrons are transported over ferredoxins .  Fe-Fe-hydrogenases (enzymes) combines them into hydrogen gas. In Chlamydomonas reinhardtii Photosystem II produces in direct conversion of sunlight 80% of the electrons that end up in the hydrogen gas.  Light-harvesting complex photosystem II light-harvesting protein LHCBM9 promotes efficient light energy dissipation.  The Fe-Fe-hydrogenases need anaerobic environment as they are inactivated by oxygen.Fourier transform infrared spectroscopy is used to examine metabolic pathways. 
The Chlorophyll (Chl) Angle size in green algae is minimized, or truncated, to maximize photobiological solar conversion efficiency and H 2 production. The truncated Chl Angle size of the photosynthetic productivity by the cells of the world. 
In 1939 Hans Gaffron observed that the algae was studying, Chlamydomonas reinhardtii (a green-algae), would sometimes switch from the production of oxygen to the production of hydrogen.  He never discovered the cause of this change and for many years other scientists failed in their attempts to discover it. In the late 1990s, Anastasios Melis discovered that the algae is a medium for the production of oxygen (normal photosynthesis), to the production of hydrogen. He found that the enzyme responsible for this reaction is hydrogenase, but that the hydrogenase lost this function in the presence of oxygen. Melis found that depleting the amount of sulfur in the atmosphere can be reduced, allowing the hydrogenase an environment in which it can react, causing the algae to produce hydrogen.  Chlamydomonas moewusii is also a good strain for the production of hydrogen. 
It would be about 25,000 square kilometers of algal farming to produce biohydrogen equivalent to the energy provided by gasoline in the US alone. This area represents approximately 10% of the area devoted to growing soy in the US. 
Bioreactor design issues
- Restriction of photosynthetic hydrogen production by accumulation of a proton gradient .
- Competitive inhibition of photosynthetic hydrogen production by carbon dioxide.
- Requirement for bicarbonate binding at photosystem II (PSII) for efficient photosynthetic activity .
- Competitive drainage of electrons by oxygen in algal hydrogen production.
- Economics must be competitive with other sources of energy and economics are dependent on several parameters.
- A major technical obstacle is the efficiency in converting solar energy into chemical energy stored in molecular hydrogen.
Attempts are in progress to solve these problems via bioengineering .
- Hydrogen production
- Timeline of hydrogen technologies
- Jump up^ 2013 – Gimpel JA, et al Advances in microalgae engineering and synthetic biology applications for biofuel production
- Jump up^ Hemschemeier, Anja; Melis, Anastasios; Happe, Thomas (2009). “Analytical approaches to photobiological hydrogen production in unicellular green algae” . Photosynthesis Research . 102 (2-3): 523-540. doi : 10.1007 / s11120-009-9415-5 . ISSN 0166-8595 . PMC 2777220 . PMID 19291418 .
- Jump up^ Algae’s Wired-Mutant Is Hydrogen Factory ArchivedAugust 27, 2006, at theWayback Machine.
- Jump up^ “Archived copy” . Archived from the original on 2008-10-31 . Retrieved 2009-03-11 .
- Jump up^ Melis, Anastasios; Zhang, Liping; Forestier, Marc; Ghirardi, Maria L .; Seibert, Michael (2000-01-01). “Sustained Photobiological Hydrogen Gas Production on Reversible Inactivation of Oxygen Evolution in the Green AlgaChlamydomonas reinhardtii” . Plant Physiology . 122 (1): 127-136. doi : 10.1104 / pp.122.1.127 . ISSN 1532-2548 . PMC 58851 . PMID 10631256 .
- Jump up^ Peden, EA; Boehm, M .; Mulder, DW; Davis, R .; Old, WM; King, PW; Ghirardi, ML; Dubini, A. (2013). “Identification of Global Ferredoxin Interaction Networks in Chlamydomonas reinhardtii” . Journal of Biological Chemistry . 288 (49): 35192-35209. doi : 10.1074 / jbc.M113.483727 . ISSN 0021-9258 . PMC 3853270 . PMID 24100040 .
- Jump up^ Volgusheva, A .; Styring, S .; Mamedov, F. (2013). “Increased photosystem II stability promotes H2 production in sulfur-deprived Chlamydomonas reinhardtii” . Proceedings of the National Academy of Sciences . 110 (18): 7223-7228. doi : 10.1073 / pnas.1220645110 . ISSN 0027-8424 . PMC 3645517 . PMID 23589846 .
- Jump up^ Grewe, S .; Ballottari, M .; Alcocer, M .; D’Andrea, C .; Blifernez-Klassen, O .; Hankamer, B .; Mussgnug, JH; Bassi, R .; Kruse, O. (2014). “Light-Harvesting Complex Protein LHCBM9 Is Critical for Photosystem II Activity and Hydrogen Production in Chlamydomonas reinhardtii” . The Plant Cell . 26 (4): 1598-1611. doi : 10.1105 / tpc.114.124198 . ISSN 1040-4651 . PMC 4036574 . PMID 24706511 .
- Jump up^ Langner, U; Jakob, T; Stehfest, K; Wilhelm, C (2009). “An energy balance of absorbed photons to new biomass for Chlamydomonas reinhardtii and Chlamydomonas acidophila under neutral and extremely acidic growth conditions” . Plant Cell Environ . 32 (3): 250-8. doi :10.1111 / j.1365-3040.2008.01917.x . PMID 19054351 .
- Jump up^ Kirst, H .; Garcia-Cerdan, JG; Zurbriggen, A .; Ruehle, T .; Melis, A. (2012). “Truncated Photosystem Chlorophyll Antenna Size in the Green Microalga Chlamydomonas Reinhardtii upon Deletion of the TLA3-CpSRP43 Gene” . Plant Physiology . 160 (4): 2251-2260. doi : 10.1104 / pp.112.206672 . ISSN 0032-0889 . PMC 3510145 . PMID 23043081 .
- Jump up^ Algae: Power Plant of the Future?
- Jump up^ Reengineering Algae To Fuel The Hydrogen Economy
- Jump up^ Yang, Shihui; Guarnieri, Michael T; Smolinski, Sharon; Ghirardi, Maria; Pienkos, Philip T (2013). “De novo transcriptomic analysis of hydrogen production in the green alga Chlamydomonas moewusii through RNA-Seq” . Biotechnology for Biofuels . 6 (1): 118. doi : 10.1186 / 1754-6834-6-118 . ISSN 1754-6834 . PMC 3846465 . PMID 23971877 .
- Jump up^ Growing hydrogen for the cars of tomorrow