Solar cells are capable of producing less than 1 V of electricity each. This voltage is not enough for applications.Hence solar cells are assembled together to form a solar panels of desired power and voltage rating.
How solar panels work?
The basic unit of a solar panel is the solar cell. These solar cells are silicon based and they absorb photons in sunlight. This absorption of energy makes them release electrons from silicon atoms and when the electrons are captured, produce electricity.
The major categories of Solar Panel are:
Monocrystalline: High purity silicon is used to make Monocrystalline solar panels. Here each solar cell is cut from a single, continuous piece of silicon crystal. They are the most efficient as well as expensive technology.
Polycrystalline:Polycrystalline (also called multicrystalline) solar panels are also based on silicon. This type of solar panel consist of multiple small silicon crystals unlike the homogenous structure that the Monocrystalline technology has.
Thin-Film technology:Thin-film solar panels are usually either amorphous Silicon based or Cadmium Telluride based. As the name suggests, they use a much thinner level of photovoltaic material than the other technologies. They are therefore relatively cheaper but come at an expense of compromised efficiency.
There is a very big problem with choosing solar panels. A solar panel must have high quality performance over a long period.
Criteria for choosing solar panels
Quality and Warranty
Solar panel’s quality is determined by statements of warranty and conformance to quality standards.
The type of panel (mono/poly crystalline or thin film) will be influenced by the installation area.
For example, if solar panel is installed at the front of house there might be aesthetic concerns.If it is a large unshaded roof, choose mono/poly crystalline to maximise the energy yield, because they have higher efficiencies.
If solar panel is installed on a roof that is partially shaded for part of the day, but want to maximise what can get out, choose thin film modules because they operate better than crystalline modules under shading.
Solar Panel Efficiency
Efficiency would be 50% if the solar panel captured half the energy in the sunlight. Conventional panel efficiencies in real-world conditions, range from about 12% up to just over 21%.Higher the efficiency, the more watts of electricity will get per square meter of panel. Same electrical output is produced if the efficiency is higher for even the small solar panel.The disadvantage of high efficiency panels is that they tend to cost more.
Cost of Solar Panel depends upon the kilowatts of electricity generated by solar panel.
Country Of Origin
Some people choose solar panels based on the countries.They insist the best solar panels made in Germany and all Chinese solar panels are crap.
Solar panels can have different specifications.Some points to be noted are:
The power tolerance on panels. Some are much better than others.
The voltage rating and coefficient of temperature. Panels should be rated to 100V DC minimum for safety.
A good temperature coefficient rating indicate a solar panel that performs slightly better in higher temperatures.
Thin film panels look more uniform and some people feel these look best. But they take up much more space due to their lower conversion efficencies. Some suppliers can integrate the panels into roof, others can supply solar roof tiles.
For solar products Visit Alphazee Systems.