Dear All,
How can I calculate how much energy converted from Solar Energy to Electricity? Does it based on the how strong of the sunlight? Does it based on how many solar cell? Any detail equations for this purpose?
Thanks a lot.
Holly
Dear All,
How can I calculate how much energy converted from Solar Energy to Electricity? Does it based on the how strong of the sunlight? Does it based on how many solar cell? Any detail equations for this purpose?
Thanks a lot.
Holly
Energy conversion efficiency:
A solar cell’s energy conversion efficiency (η, "eta"), is the percentage of power converted (from absorbed light to electrical energy) and collected, when a solar cell is connected to an electrical circuit. This term is calculated using the ratio of Pm, divided by the input light irradiance under "standard" test conditions (E, in W/m2) and the surface area of the solar cell (Ac in m²).
At solar noon on a clear March or September equinox day, the solar radiation at the equator is about 1000 W/m2. Hence, the "standard" solar radiation (known as the "air mass 1.5 spectrum") has a power density of 1000 watts per square meter. Thus, a 12% efficiency solar cell having 1 m² of surface area in full sunlight at solar noon at the equator during either the March or September equinox will produce approximately 120 watts of peak power.
There are four types of photovoltaic cells, each representing an improvement over the previous generation:
First
The first generation photovoltaic, consists of a large-area, single layer p-n junction diode, which is capable of generating usable electrical energy from light sources with the wavelengths of sunlight. These cells are typically made using a silicon wafer. First generation photovoltaic cells (also known as silicon wafer-based solar cells) are the dominant technology in the commercial production of solar cells, accounting for more than 86% of the solar cell market.
Second
The second generation of photovoltaic materials is based on the use of thin-film deposits of semiconductors. These devices were initially designed to be high-efficiency, multiple junction photovoltaic cells. Later, the advantage of using a thin-film of material was noted, reducing the mass of material required for cell design. This contributed to a prediction of greatly reduced costs for thin film solar cells. There are currently (2007) a number of technologies/semiconductor materials under investigation or in mass production. Examples include Amorphous silicon, Polycrystalline silicon, micro-crystalline silicon, Cadmium telluride, copper indium selenide/sulfide. Typically, the efficiencies of thin-film solar cells are lower compared with silicon (wafer-based) solar cells, but manufacturing costs are also lower, so that a lower cost per watt can be achieved. Another advantage of the reduced mass is that less support is needed when placing panels on rooftops and it allows fitting panels on light or flexible materials, even textiles.
Third
Third generation photovoltaics are very different from the previous semiconductor devices as they do not rely on a traditional p-n junction to separate photogenerated charge carriers. These new devices include photoelectrochemical cells, Polymer solar cells, and nanocrystal solar cells.
Fourth
Fourth generation Composite photovoltaic technology with the use of polymers with nano particles can be mixed together to make a single multispectrum layer. Then the thin multi spectrum layers can be stacked to make multispectrum solar cells more efficient and cheaper based on polymer solar cell and multi junction technology by NASA used on Mars missions. The layer that converts different types of light is first, then another layer for the light that passes and last is an infra-red spectrum layer for the cell – thus converting some of the heat for an overall solar cell composite.
Taken from wiki:
"At solar noon on a clear March or September equinox day, the solar radiation at the equator is about 1000 W/m2. Hence, the "standard" solar radiation (known as the "air mass 1.5 spectrum") has a power density of 1000 watts per square meter. Thus, a 12% efficiency solar cell having 1 m² of surface area in full sunlight at solar noon at the equator during either the March or September equinox will produce approximately 120 watts of peak power."
No solar cell is 100% efficient. For example. most commercially available solar cells are only 14-16% efficient. Meaning that they can only convert 14-16% of the sunlight that shines on them into electricity. As stated above, in good conditions the sun shines down about 1000 watts on every square meter of ground. But due to inefficiencies, a typical solar cell that has a surface area of 1 square meter, will probably only produce 150 watts of power. formula: 1000 watts per square meter times .15( 15%)=150 watts. The exact number of solar cells doesn’t matter. Just add up the size of all your cells and figure out how many total square meters of solar cells you have. and then multiply that number times the efficiency of your cells, around 15% perhaps and multiply that times 1000. If you have 2 small cells that both have .25 square meters of surface area. add them together. .25 + .25 =.5 The formula becomes .5(square meters of solar cell X 1000(watts of light per square meter from the sun) X 15%(typical solar cell efficiency) = .5 * 1000 * .15 = 75 watts of electricity. Not sure if that answers your question. If not. please say so.