THE PHOTOVOLTAIC MODULE

Hello steemians, I'm here as promised from my last post on solar power system to have subsequent posts on the solar power system principles

This Post will give an insight into Photovoltaic Modules which is an essential part f the system that converts sunlight directly into DC electricity

The use of Solar cells to produce energy has increased in the last few decades and keeps growing as their manufacturing cost decreases and as the world becomes more concerned about energy use.

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The photovoltaic module popularly known as solar panel is a collection of individual silicon cells that generate electricity from sunlight. The fundamental unit of the photovoltaic module is a solar cell which usually consist of one or two layers of silicon based semiconductor wafers.

Due to photoelectric effect, these solar cell generates an electric charge when it's struck by photons in Sunlight The flow of these electrons moves in a steady electric current from one side of the cell to another. The solar panel comprises many smaller units of solar cells. The combination of this cells make up a solar panel.

There are two main types of solar panel which are based on silicon semiconductors. The variety of solar power system technologies available run on a scale of efficiency, durability, price and flexibility depending upon the need. The two main types of solar panel are the crystalline silicon solar panel and the thin-film solar panel.

Crystalline silicon solar panel are currently the most common solar cells in use mainly because crystalline-silicon is stable, it delivers efficiency in the range 15% - 25%, it relies on established process technology with an enormous database, and in general, it has proven to be reliable.

To make up the photovoltaic cells which make up a crystalline solar panel, crystalline silicon is sliced into thin disk (wafers) a few millimetres thick or thinner. The wafers are then cut to shape and polished. Dopants are thereby added to the silicon wafer in order to generate electricith . Typically a layer of phosphorus is coated onto the wafer and the surface is heated. Phosphorus atoms then diffuse throughout the silicon wafer contaminating it as required. The doped silicon wafer are then aligned together to make up a solar cell, and the solar cells are arranged on a backing panel to make a solar panel. Strips of conductive metals are fixed to the sunward face of each solar cell.

Finally, a layer of glass is glued over the top of the collection of solar cells to provide protection from element while permitting sunlight to pass through to the completed crystalline solar module.

The crystalline solar panels are of the monocrystalline and the polycrystalline types.

The monocrystalline cell is made from single silicon crystal whereas a polycrystalline cell is made from multiple crystals. Growing a large crystals takes longer and costs more money than polycrystalline, but monocrystalline cells are more uniform and more efficient.

A monocrystalline solar panel is black in colour, typically square cells with corners chopped off.

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Polycrystalline panel has a distinctive dark blue colour, typically square cells with corners.

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ADVANTAGES OF MONOCYSTALLINE SOLAR PANELS

• Monocrystalline solar panels have the highest efficiency rates, they are made of highest grade silicon, the efficiency rate of monocrystalline solar panels are 15% - 20%

• Monocrystalline silicon panels are found to be space-efficient. Thesw these solar panels yield the highest outputs, they also require the least amount of space compared to any other types

• Monocrystalline solar panels live the longest and tends to perform better than similar rated polycrystalline solar panels at low-light conditions

ADVANTAGES OF POLYCYRSTALLINE SOLAR PANELS

• The process used in making polycrystalline is simpler and cost less

• Polycrystalline solar panel tends to have lower heat tolerance compared to monocrystalline solar panels

Generally, monocrystalline solar panels have a setback of being more expensive compared to polycrystalline while polycrystalline as well has its setback of lower space efficiency i.e. one needs to cover a large surface to output the same electrical power as one would with a solar panel made of monocrystalline silicon and the efficiency of polycrystalline is typically 13% - 16% as compared to the monocrystalline.

On the other hand, The Thin-film solar panel is manufactured by depositing one or several thin layer onto a substrate. The types of thin-film solar cells are categorized by which photovoltaic material is deposited onto the substrate.

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Thin-film solar panels have efficiency between 7% - 13%. They are relatively cheap, but they also require a lot of space.

CONCLUSION

Monocrystalline solar panel produce up to four times the amount of electricity as thin-film solar panel for the same amount of space. Thin-film solar panels tends to degrade faster than monocrystalline and polycrystalline solar panels which is why they typically come with a shorter warranty

Monocrystalline silicon solar is the best technology to deliver efficiency but this efficiency can come with costs . The best value of photovoltaic technology is polycrystalline silicon, offering efficiency levels close to monocrystalline panels, but at half the costs in some cases .

References

• Energyinformative

• ‎Solar Power World

• ‎LiveScience

• ‎Greenage

• SolarNavigator‎

• Popflock‎

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