Did you know that many scientists would like to identify light-catching elements in order to convert more of the sun's power into carbon-free electric power?

 A new analysis announced in the magazine Applied Physics Letters in August this year (published by the American Institute of Physics), explains how solar energy could potentially be collected by using oxide materials that contain the element selenium. A team at the Lawrence Berkeley National Laboratory in Berkeley, California, embedded selenium in zinc oxide, a relatively low-cost component that could make more successful use of the sun's power.

 The team found that even a relatively small amount of selenium, just 9 per cent of the mostly zinc-oxide base, substantially boosted the material's performance in absorbing light.

 The main author of this analysis, Marie Mayer (a 4th-year College of California, Berkeley doctoral student) suggests that photo-electrochemical water splitting, that signifies employing power from the sun to cleave water into hydrogen and oxygen gases, could possibly be the most interesting future application for her work. Utilizing this reaction is key to the eventual generation of zero-emission hydrogen powered motors, which hypothetically will run only on water and sunlight.

 The conversion productivity of a PV cell is the amount of sunlight energy that the photovoltaic cell converts to electrical energy. This is very important when discussing Photovoltaic devices, because enhancing this efficiency is vital to making Photovoltaic electricity competitive with more common sources of energy (e.g., classic fuels).

  For comparison, the very first Photo voltaic units converted about 1%-2% of sunlight power into electrical energy. Today's Pv systems convert 7%-17% of light energy into electrical energy. Of course, the other side of the equation is the money it costs to produce the PV devices. This has been improved over the years as well. In fact, today's PV systems generate electricity at a fraction of the cost of first PV systems.

  In the 1990s, when silicon cells were 2 times as thick, efficiencies were much lower than today and lifetimes were shorter, it may well have cost more energy to make a cell than it could generate in a lifetime. In the meantime, the technological know-how has progressed considerably, and the energy payback time (defined as the recovery time necessary for generating the energy spent to produce the respective technical energy systems) of a modern photovoltaic module is typically from 1 to 4 years depending on the module type and location.

  Commonly, thin-film technologies - despite having comparatively low conversion efficiencies - achieve significantly shorter energy repayment times than traditional systems (often < 1 year). With a typical lifetime of 20 to 30 years, this means that contemporary solar cells are net energy producers, i.e. they generate significantly more energy over their lifetime than the energy expended in producing them.

 The author - Rosalind Sanders contributes articles for swiming pool solar covers the blog, her personal hobby website centered on guidelines to help home owners to spend less energy with solar energy.