For those of us who are interested in the technical side of our solar panel installations this article gives an insight into the process , from sunlight to electricity production in your home.
I also included an incredible ( and incredibly long) infographic with some very revealing figures about the real value of solar power.
The infographic contains some astonishing figures and really does put solar energy production into perspective.
Solar Panels and Electromagnetic Energy
A solar panel is used to produce electricity from electromagnetic energy through the photovoltaic effect, usually in the form of sunlight. Solar panels consist of a layer of semiconducting material, such as crystalline silica, or a thin layer of cadmium telluride, sandwiched between glass panels. The photovoltaic effect is the process in which electromagnetic energy impacts a semiconducting material, causing electrons in the material to break free of their orbit and move through the semiconducting material, causing a flow of current. This current flows to fully conducting electrical wires, to be stored in batteries, or converted to alternating current.
Watts and kWa
A Watt (W) is the rate of doing work that is equivalent to one ampere acted upon by an electromotive force of one volt.
Explained another way, voltage is similar to the water pressure in a hose.
The amperes, or electrical current, is like the amount of water passing through the hose. Solar panels are rated by their DC power output, this typically ranges from 100 to 450 Watts. Panel efficiency and thus the power output is dependent on the usable surface area of the panel. Individual panels are limited in power output by their size. This requires multiple panels to be installed together in a larger photovoltaic system consisting of several panels, along with an inverter, to transform the direct current to alternating current. Storage batteries or sunlight tracking devices may also be installed in the system.
Solar Panels and kPa
Solar panels are rated by the highest amount of power produced, measured in kilowatt peak (kPa). This is a measure of peak power output under standardized laboratory conditions. The standard test conditions are: insolation level of 1,000W/m2, the incident electromagnetic energy is of the spectrum of natural sunlight striking the earth’s surface at latitude 35°N in the summer, or exactly perpendicular to the solar panel. The ambient air mass is 1.5 and the temperature of the cells is 25°C. Weather, intensity of incident radiation, and panel orientation and size all affect the peak power rating. Another useful characteristic of solar panel design is the efficiency rating. This is obtained by dividing the maximum power rating in kPa by the surface area of the panel in square feet. Typical efficiencies for current solar panel technology ranges from less than 10 to 20 percent.
Sunlight and Output
Insolation, or incoming solar radiation, is a measure of the electromagnetic energy incident upon given surface area over a period of time. Insolation determines the power output of a photovoltaic cell.
In other words, the more sunlight that is absorbed by the solar panel, the higher the power output.
Note that kWp is a measure of maximum power output at standard conditions. It is possible for a solar panel to exceed its rated kWp by increasing the incident angle of the incoming radiation, this is done using devices that track the motion of the sun to ensure the maximum amount of incident radiation possible.
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source: Solar Gaines LLC a solar panels maryland provider