Novel Alloy Could Produce Hydrogen Fuel from Sunlight
ScienceDaily (Aug. 30, 2011) — Scientists from the University of Kentucky and the University of Louisville have determined that an inexpensive semiconductor material can be "tweaked" to generate hydrogen from water using sunlight.
The research, funded by the U.S. Department of Energy, was led by Professors Madhu Menon and R. Michael Sheetz at the University of Kentucky Center for Computational Sciences, and Professor Mahendra Sunkara and graduate student Chandrashekhar Pendyala at the University of Louisville Conn Center for Renewable Energy Research. Their findings were published Aug. 1 in the Physical Review B.
The researchers say their findings are a triumph for computational sciences, one that could potentially have profound implications for the future of solar energy.
Using state-of-the-art theoretical computations, the University of Kentucky-University of Louisville team demonstrated that an alloy formed by a 2 percent substitution of antimony (Sb) in gallium nitride (GaN) has the right electrical properties to enable solar light energy to split water molecules into hydrogen and oxygen, a process known as photoelectrochemical (PEC) water splitting. When the alloy is immersed in water and exposed to sunlight, the chemical bond between the hydrogen and oxygen molecules in water is broken. The hydrogen can then be collected.
"Previous research on PEC has focused on complex materials," Menon said. "We decided to go against the conventional wisdom and start with some easy-to-produce materials, even if they lacked the right arrangement of electrons to meet PEC criteria. Our goal was to see if a minimal 'tweaking' of the electronic arrangement in these materials would accomplish the desired results."
SolarStrong, supported by DOE, will put PV on over 100,000 military homes
SolarCity military solar project could be world's biggest residential contract
SEP 09, 2011
The U.S. military is getting a lot more green, and not in terms of new camouflage patterns. The homes of U.S. military personnel on bases across the country will soon have their own solar arrays.
On Sept. 7, the Department of Energy (DOE) issued a $340 million loan guarantee to SolarCity and U.S. Renewables Group Renewable Finance and Bank of America Merrill Lynch’s $1 billion SolarStrong project, which will put solar on the homes of service members living on base across all branches of the U.S. military. Under the expansive project, 160,000 homes on military bases across the country will soon have solar systems under the SolarStrong project, which will likely be the largest residential project in the world.
Okayama Solar Absorbers Use “Green Ferrite” to Generate Super-Cheap Electricity from Heat
8 comments September 20, 2011 in Quickies, Solar Energy
Okayama Graduate School of Science and Technology is one of many developing solar cells and batteries, but its research team, led by one Professor Naoshi Ikeda, has a unique approach. Instead of silicon, currently the standard component in solar cells, the Okayama team is using an iron oxide compound it calls “green ferrite,” or GF. Professor Ikeda has gone so far as to claim his product will produce 100x the amount of energy as a traditional silicon solar cell.
Part of the increase in energy production would come from the infra-red spectrum — solar cells do not currently convert heat into electricity, but apparently the green ferrite has that capability. Professor Ikeda speculates that any area collecting waste heat (the ceiling of your kitchen, for example) could serve as a home for a GF solar cell.
The team’s goal is to create a battery capable of generating 1KW of energy for 1/1000th of the cost of a traditional silicon solar cell, which comes out to about 1000 yen ($12 American) per GF cell. The GF cells, which currently use green ferrite in a powdered form, should also allow for some flexibility in solar panel shape, which means they could be wrapped around things like chimneys or telephone poles.
As the early tests have been fairly successful, the Okayama team is hoping for a usable product by 2013.
Source | Picture: MSN Sankei
Source: Clean Technica (http://s.tt/13imq)
DaS Energy wrote:
Requiring a minimum heat input of minus 10* and not calculated above plus 100* C.
A one litre hydro turbine rotating at 60 RPM using CO2 liquid heated into gas of 100*C produces 720 Kw. Kw ouput decreases with lower heat. The turbine itself will work with any fluid however the heat to Kw ratio remains unknown.