Solar efficiency

To measure the efficiency of a whole window, special testing takes into account all heat transfer from conduction, convection, and radiation. Certain values are used to represent the thermal and solar efficiency of high-performance windows by measuring reduced thermal heat loss (measured by the U-... 

Cenis JL (1987) Double plastic sheet for improving soil solarization efficiency. In Proceedings of the 7th congress of the phytopathological Mediterranean Union, Granada, Spain, 20-26 September 1987, p 73... 

Another important photocatalytic application is the synthesis of hydrogen from water. However, low solar efficiency and photocorrosion have proven to be hindrances limiting the process economics of photocatalysis [325], The most efficient systems to date consist of compound semiconductor heterostructures that operate with efficiencies of approximately 16%, however, cost and stability are still problematic [325],... 

Where ria and r c are, respectively, the anodic and cathodic overpotentials. Considering all these losses an optimum bandgap of 2.0 to 2.25 eV is required for the materials used as photoelectrodes for water photoelectrolysis. In practical cases, a reasonable value of overall solar efficiency is 10% for single bandgap devices involving two photons and 16% for dual photosystem devices involving 4 photons [102,103,110,111]. 

Green MA, Emery K, King DL, Hishikawa Y, Warta W (2006) Solar efficiency Tables (version 28). Prog Photovolt Res Appl 14 455-461... 

Guiflard, C., Disdier, J., Monnet, C., Dussaud, J., Malato, S., Blanco, J., Maldonado, M.I. and Herrmann, J.-M. (2003a) Solar efficiency of a new deposited titania photocatalyst Chlorophe-nol, pesticide and dye removal applications. Appl. Catal. B Environ. 46, 319-332. 

Indium Phosphide.—Exciting developments in photoelectrochemical cells have come from the Bell Laboratories group, and the material of the year is without doubt p-InP. Heller et al have given details of the first efficient p-type photoelectrochemical cell, p-InP/VCl3-VCl2-HCl/C, with a 9.4% solar conversion efficiency. The success of this cell came as a surprise, since previous studies of InP has suggested that it was rather unstable in aqueous solution. Subsequently Heller et announced an 11.5% solar efficiency for the same cell after... 

Our Reporter, Dr. Laurence Peter, nominated GaAs as the material of the year for Volume 12. This year, the award goes to p-type InP, largely on the basis of work carried out at the Bell Laboratories. Thus Heller et al. have described the first really efficient p-type photoelectrochemical cell based on p-InP/VClj-VClj-HCl/C. After treatment of the InP photocathode with alkaline peroxide, and then aqueous potassium cyanide, the solar efficiency rose to 11.5%. The stability of such cells, coupled with the ability to function well under intense irradiation, makes them some of the more promising candidates for future large-scale use. Further developments will be awaited with great interest. 

J. Rostalski and D. Meissner. Monochromatic versus solar efficiencies of organic solar cells. Sol. Energ. Mater. Sol. Cells, 61(l) 87-95, February 2000. 

Cell 23 [46]. This is a detailed study of a thin film cell with moderately high outdoor solar efficiency, high storage efficiency, and an output that is highly invariant despite changing illumination. This study provides extensive details of the choice... 

New photosynthetic and photocatalytic reactions. As shown in Table 3, a number of reactions have been carried out at irradiated semiconductors. As energy costs increase, production of useful chemicals such as H2O2 and various organic molecules by this route may become competitive. It is probably not too far fetched to consider the possibility of production of amino acids and proteins by artificial photosynthetic systems. The solar efficiency for the growth of most crop plants is only about 1% in the field. The swelling world population may make it necessary to have chemical systems for food production that operate at higher efficiencies and semiconductor materials may well play a role in such systems. 

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