Terrestrial solar

Solar cells have been used extensively and successfully to power sateUites in space since the late 1950s, where their high power-to-weight ratio and demonstrated rehabiUty are especially desirable characteristics. On earth, where electrical systems typically provide large amounts of power at reasonable costs, three principal technical limitations have thus far impeded the widespread use of photovoltaic products solar cells are expensive, sunlight has a relatively low power density, and commercially available solar cells convert sunlight to electricity with limited efficiency. Clearly, terrestrial solar cells must be reasonably efficient, affordable, and durable. International efforts are dedicated to obtaining such devices, and a number of these activities have been reviewed (1). 

J. E. Clifford and E. W. Brooman, Asessment of Nickel—Hydrogen Batteries for Terrestrial Solar Applications, SAND80-7191, Sandia National Laboratories, 1981. 

The ordinary monomer units of PVC are not expected to absorb any terrestrial solar radiation (1>.2>.3 A) Thus, under the usual ambient conditions, photodegradation of the polymer must be initiated by chromophoric impurities. These impurities may simply be structural defects in the PVC itself, or they may be extraneous substances that have been incorporated into the polymer. Several of these potential photosensitizers are discussed in the following sections. 

But, such a system has its disadvantages. A terrestrial solar station intercepts only one third of the solar energy that an array of equal size could intercept in space, since no power is generated at night and less light strikes the panels when the Sun is low in the sky. 

Blank, D.A. and Wu, C., Performance potential of a terrestrial solar-radiant Ericsson power cycle from finite-time thermodynamics. International Power and Energy Systems, 15(2), 78-84, 1995. 

Bird RE, Hulstrom RL, Lewis LJ (1983) Terrestrial solar spectral data sets. Solar energy 30 563-573... 

Costogue EN, Yasui RK (1977) Performance data for a terrestrial solar photovoltaic/water electrolysis experiment. Sol Energy 19 205-210... 

Emery KA, Osterwald CR (1986) Solar-cell efficiency measurements. Sol Cells 17 253 Matson RJ, Emery KA, Bird RE (1984) Terrestrial solar spectra, solar simulation and solarcell short-circuit current calibration - a review. Sol Cells 11 105... 

GOME is a nadir sounding spectrometer which observes the up-welling radiance from the top of the atmosphere and the extra-terrestrial solar irradiance between 240 and 790 nm. The resolution of the measurements is chosen to be suitable for the application of the differential optical absorption spectroscopy (DOAS) technique, which was developed for long-path measurements and zenith sky observations (e.g. Platt and Pemer, 1980 Mounter a/., 1987 Eisinger etal., 1997). 

From the discussion in the preceding Sections, even without addressing the influence of clouds, it is clear that the terrestrial solar spectrum is highly variable. So, how can... 

Table 1 Energy distribution in the terrestrial solar spectrum (AM 1.5)...

The remaining 19.1% of the energy required to split water has to be supplied for the production step. Figure 4 depicts the terrestrial solar direct normal spectral irradiance distribution computed using SMARTS version 2.9.2 model with input file from ASTM Standard Table G 173-03. ... 

Figure 2. Irradiation wavelength spectra in Suntest CPS andXXL- in comparison to the terrestrial solar spectrum.

Fig. 2. DNA absorption, erythema effectiveness curve (E) and typical terrestrial solar spectrum (S). UVA and UVB are wavelength regions in which phototherapy and photochemotherapy are applied...

The feedstock silicon for FZ growth has to be of high purity and structural perfection and is rather expensive. The development of low-cost feed rods is crucial for the commercial terrestrial solar application. 

Henry C. H. (1980), Limiting efficiencies of ideal single and mnltiple energy-gap terrestrial solar cells , /. Appl. Phys. 51, 4494-4500. 

The flux in the Extreme Ultraviolet (EUV) portion (10-100 nm) of the solar spectrum (see Figure 4.8a) directly affects the chemistry and dynamics of the thermosphere. Its value, and hence the ionization rate in the upper atmosphere, varies substantially with solar activity. Richards et al. (1994) have developed a model that provides the extra-terrestrial solar actinic flux from 5 to 105 nm as a function of a solar proxy P which is the average between the instantaneous radiowave flux F10.7 emitted by the Sun at 10.7 cm and its average value Fio.7,4 over 81 days. The 10.7 cm flux is routinely monitored and reported in units of 10-22 W m 2Hz 1 its value ranges typically from 70 (solar minimum) to 200 (solar maximum), and is highly correlated with other indicators of solar activity (e.g., sunspot number). 

Cuddihy, E.F., Baum, B., and Willis, P., "Low-Cost Encapsulation Materials for Terrestrial Solar Cell Modules", Solar Energy, Vol. 22, p. 389 (1979). 

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