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1、The Basics of Solar Power for Producing ElectricityUsing solar power to produce electricity is not the same as using solar to produce heat. Solar thermal principles are applied to produce hot fluids or air. Photovoltaic principles are used to produce electricity. A solar panel is made of the natural
2、 element, silicon, which becomes charged electrically when subjected to sun light.Solar panels are directed at solar south in the northern hemisphere and solar north in the southern hemisphere (these are slightly different than magnetic compass north-south directions) at an angle dictated by the geo
3、graphic location and latitude of where they are to be installed. Typically, the angle of the solar array is set within a range of between site-latitude-plus 15 degrees and site-latitude-minus 15 degrees, depending on whether a slight winter or summer bias is desirable in the system. Many solar array
4、s are placed at an angle equal to the site latitude with no bias for seasonal periods.The intensity of the Suns radiation changes with the hour of the day, time of the year and weather conditions. To be able to make calculations in planning a system, the total amount of solar radiation energy is exp
5、ressed in hours of full sunlight perm, or Peak Sun Hours. This term, Peak Sun Hours, represents the average amount of sun available per day throughout the year.It is presumed that at peak sun, 1000 W/m of power reaches the surface of the earth. One hour of full sun provides 1000 Wh perm = 1 kWh/m -
6、representing the solar energy received in one hour on a cloudless summer day on a one-square meter surface directed towards the sun. To put this in some other perspective, the United States Department of Energy indicates the amount of solar energy that hits the surface of the earth every +/- hour is
7、 greater than the total amount of energy that the entire human population requires in a year. Another perspective is that roughly 100 square miles of solar panels placed in the southwestern U.S. could power the country.The daily average of Peak Sun Hours, based on either full year statistics, or ave
8、rage worst month of the year statistics, for example, is used for calculation purposes in the design of the system. To see the average Peak Sun Hours for your area in the United States, U.S.-Solar Insolation Choose the area closest to your location for a good indication of your average Peak Sun Hour
9、s.For a view of global solar isolation values (peak sun-hours) use this link: Global Peak Sun-hour Maps , then, you can use back or previous on your browser to return right here if you want to.So it can be concluded that the power of a system varies, depending on the intended geographical location.
10、Folks in the northeastern U.S. will need more solar panels in their system to produce the same overall power as those living in Arizona. We can advise you on this if you have any doubts about your area.The four primary components for producing electricity using solar power, which provides common 120
11、 volt AC power for daily use are: Solar panels, charge controller, battery and inverter. Solar panels charge the battery, and the charge regulator insures proper charging of the battery. The battery provides DC voltage to the inverter, and the inverter converts the DC voltage to normal AC voltage. I
12、f 240 volts AC is needed, then either a transformer is added or two identical inverters are series-stacked to produce the 240 volts.The output of a solar panel is usually stated in watts, and the wattage is determined by multiplying the rated voltage by the rated amperage. The formula for wattage is
13、 VOLTS times AMPS equals WATTS. So for example, a 12 volt 60 watt solar panel measuring about 20 44 inches has a rated voltage of 17.1 and a rated 3.5 amperage.V A = W 17.1 volts times 3.5 amps equals 60 wattsIf an average of 6 hours of peak sun per day is available in an area, then the above solar
14、panel can produce an average 360 watt hours of power per day; 60w times 6 hrs= 360 watt-hours. Since the intensity of sunlight contacting the solar panel varies throughout the day, we use the term peak sun hours as a method to smooth out the variations into a daily average. Early morning and late-in
15、-the-day sunlight produces less power than the mid-day sun. Naturally, cloudy days will produce less power than bright sunny days as well. When planning a system your geographical area is rated in average peak sun hours per day based on yearly sun data. Average peak sun hours for various geographica
16、l areas is listed in the above section.Solar panels can be wired in series or in parallel to increase voltage or amperage respectively, and they can be wired both in series and in parallel to increase both volts and amps. Series wiring refers to connecting the positive terminal of one panel to the negative terminal of another. The resulting outer positive and negative terminals will produce voltage the sum of the two panels, but the amperage stays the same
