In solar energy use, people focus on somewhere on earth daylighting can intercept solar irradiance. The size of the solar irradiance depends on the following four aspects. ( 1) Day distance; ( 2) The sun somewhere on earth the relative position of a moment; ( 3) Solar radiation into the
in the solar energy utilization, attention to somewhere on earth daylighting can intercept solar irradiance 【 Solar irradiance refers to the absorption and scattering solar radiation through the atmosphere, such as reflection effect after reach the surface of the solid earth on unit area per unit time of radiation energy. 】 。 The size of the solar irradiance depends on the following four aspects.
( 1) 【 solar-terrestrial distance Solar-terrestrial distance, also called the sun distance, refers to the heliocentric to the geocentric straight line length. 】 ;
( 2) The sun somewhere on earth the relative position of a moment;
( 3) Attenuation of solar radiation into the atmosphere;
( 4) Solar azimuth and dip Angle on the surface of the receiving.
solar radiation spectrum' Solar radiation spectrum - - Is to describe the sun radiation a spectrum of various wavelengths of light radiation ability, it has very important significance on the study of solar radiation. 】
distribution of solar radiation is a kind of electromagnetic wave radiation, which have volatility, there are particles, its main wavelength range of spectral ( 0. 15 a 4 um, and ground and atmospheric radiation [ Atmospheric absorption surface long-wave radiation at the same time, and outward radiation energy in the form of radiation, atmospheric this outward radiation energy, called atmospheric radiation ( 大气辐射) 。 】 The main wavelength range is 3 ~ 120 um. In meteorology, according to the different wavelengths, usually called the solar radiation shortwave radiation, and called the atmospheric radiation and the ground long-wave radiation.
solar radiation spectrum of solar street lamps light pole long wave band divided into: wavelength less than 0. 4 pum for ultraviolet band 【 Ultraviolet astronomy proper nouns. 】 : from 0. 4 - 0. 75. Um for optical wavelengths, wavelength is greater than zero. 75 um is infrared wavelengths. Within the scope of the wavelength of visible light spectrum, different wavelengths of electromagnetic radiation to the human eye to produce different color feeling. Table 1 - 1 lists the various color wavelength and spectral range
solar panel is ordinate with radiation energy, the abscissa denotes the wavelength of the solar spectrum energy distribution curve as shown in figure 1 3. The figure shows that although the solar radiation wavelength range is wide, but most of the energy is focused on. 22 ~ 4. 0) Within the band PM accounted for 99% of the total energy. Accounts for about 43%, among them, the visible light band infrared wavelengths accounts for about 48. 3%, ultraviolet accounts for about 8. 7%. Wavelength of the energy distribution of the maximum value is 0. 475 um, belongs to the blue and green light