With the rise of clean and sustainable energy sources, solar panels are growing in popularity. But how do they work? Solar cells, also known as photovoltaic cells, activate when they absorb sunlight and turn it into a current. This is done through semiconductor material which can produce electron waves that flow from positive to the negative electrode. This flow of electrons creates an electric potential that can power your home for hours. SEM Power is a leading provider of residential and commercial solar systems and believes in educating customers on the functioning and use of this renewable source of energy.
Understanding How Solar Panels Work
The first type of Solar Panel uses ‘Concentrated Photovoltaics’ or C-PV, which is basically a combination of mirrors and lenses. The mirrors align with the sun and bounce light towards the lenses, which magnify the light. The lenses direct a focused beam of sunlight at a photovoltaic absorber where electrons are released into an external circuit.
The second type of Solar Panel uses ‘Monocrystalline’ cells. These panels have more surface area exposed to the sun than C-PV Panels, but they also contain fewer layers. The light coming from the sun passes through several layers before reaching the absorber. The cell’s photovoltaic phase, which is the band between two crystalline regions (called d-d), allows it to absorb up to 10%. Some Monocrystalline Cells also contain boron, which forms highly stable crystal lattices.
Polycrystalline Panels, on the other hand, are made of several smaller wafers. They are cheaper to manufacture than Monocrystalline Panels and have a slightly higher conversion rate. Polycrystalline Solar Panels traditionally resembled the shape of a ‘seed grain’ before new techniques allowed manufacturers to create them in less symmetrical shapes.
Using Solar Panels In Conjunction With Other Modes
Solar power can also be used in combination with other modes. For example, in some applications, such as at the University of Oregon where it is important to harvest solar energy during daylight hours and when there is little to no cloud cover, both solar panels and water pipes have been used to harvest energy from the sun. These hybrid systems are more efficient than using only one method but tend to be more expensive.
The amount of energy that a solar panel can absorb is determined by the material that is used to make up the cells. For applications such as domestic Hot Water Heating and Hydronic Heating, which are normally used for home and business usage, the cells will need to be as efficient as possible, given weather conditions and environmental factors.
What Determines The Efficiency Of Solar Panels?
The efficiency of a solar panel is based on the amount of energy that it converts into electricity. There are several factors that affect its efficiency. These include the cell material and manufacturing technology, the manufacturing processes and production techniques, and the environment outside of which it operates.
Solar panel efficiency, when compared to fossil fuel power plants in terms of cost per unit of energy produced or cost per unit of greenhouse gas emissions produced, has come down significantly in recent years due to new technologies like thin-film solar panels.
Lumens Per Watt
The efficiency of sunlight is measured in lumens per watt. This indicates the amount of light that is absorbed and converted into electricity. Solar panels have lumens per watt figure that ranges from 10 to more than 230,000, depending on the type of solar panel being used. The higher the lumen per watt figure, the more efficient the cell will be at converting solar energy into electricity. In turn, this means less power will be required to generate the same amount of electricity from a fixed area of panels.
Types Of Solar Panels Available
There are several types of solar panels available on the market today. Some of the most common are silicon, thin-film, monocrystalline, polycrystalline, and amorphous. Each type is made up of different materials and has its own set of advantages and disadvantages.
The silicon solar cell accounts for a large proportion of solar cell production, due to its high-efficiency level with an average figure of up to 20%. However, the silicon solar cell has a relatively short life and produces low amounts of energy over its lifetime.
Thin-film solar cells are cheaper than silicon cells and have a significantly higher efficiency rating; therefore, it is used as the second most common type of solar cell. However, thin-film solar cells have some disadvantages in regards to their use and production techniques. Substandard quality panels are often produced or used in certain locations due to the semiconductor manufacturing processes being prone to error.
