Solar will become increasingly important in the future as we begin to rely less on fossil fuels and turn to renewable energy sources for our power needs.
Are you confused in selecting the best solar panel for your home or commercial establishment? Don’t worry; you are at a right place for getting the best solar panel which suites your requirement.
There are some criteria that should take into account when you are buying a solar photovoltaic (PV) system. We will discuss about different types and selection criteria of solar panels in this article.
Let’s know about solar panels first and their basic working principle:
Solar Panel – This is the key component of any solar photovoltaic system, which takes the sun’s energy and converts it into the electrical current.
Photovoltaic solar cells (PV) convert sunlight directly into solar power (electricity). They use thin layers of semi-conducting material that are charged differently between the top and bottom layers. The semiconducting material can be encased between a sheet of glass and or a polymer resin.
When exposed to daylight, electrons in the semi-conducting material absorb the photons, causing them to become highly energised. These move between the top and bottom surfaces of the semi-conducting material. This movement of electrons generates a current known as a direct current (DC).
Basically, there are three main types of solar panel (based on silicon semiconductors) presently in commercial production in the market.
• Mono-Crystalline solar cells
• Poly-Crystalline solar cells
• Amorphous solar cells
Mono-Crystalline solar cells :
Solar cells made of Mono-crystalline silicon (mono-Si), also called single-crystalline silicon (single-crystal-Si), are quite easily recognizable by an external even colouring and uniform look, indicating high-purity silicon.
Image source: Exportatv
They are among the oldest, most efficient and most dependable ways to produce electricity from the sun. This type of solar cell is made from thin wafers of silicone cut from artificially grown crystals in isolation.
It’s most expensive of the three varieties (approximately 35% more expensive than equivalent poly-crystalline cells), but they have the highest efficiency rating of between 15-24%.
A good way to separate mono- and poly-crystalline solar panels is that poly-crystalline solar cells look perfectly rectangular with no rounded edges.
Poly-crystalline solar cells:
It consists of multiple interlocking silicon crystals grown together, hence they are cheaper to produce, but their efficiency is lower than the mono-crystalline solar cells, currently at 13-18%.
Image source: BL Power
Unlike mono-crystalline-based solar panels, polycrystalline solar panels do not require the Czochralski process. Raw silicon is melted and poured into a square mold, which is cooled and cut into perfectly square wafers.
Amorphous solar cells:
Because the output of electrical power is low, solar cells based on amorphous silicon have traditionally only been used for small-scale applications such as in pocket calculators.
Image source: Ontario Solar Farms
With a manufacturing technique called “stacking”, several layers of amorphous silicon solar cells can be combined, which results in higher efficiency rates (typically around 6-8%). Only 1% of the silicon used in crystalline silicon solar cells is required in amorphous silicon solar cells. On the other hand, stacking is expensive.
There are two real benefits of the amorphous solar cell; firstly the layer of silicon is so thin it allows the solar cells to be flexible and secondly they are more efficient in low light levels.
Selection criteria for solar panels
Once you make the commitment to go solar, the next step is determining how big your solar PV system must be to meet your home electricity needs. “There’s no one-size-fits-all,” says John Ogrodny, general manager of Photon Works, an installer and manufacturer of photovoltaic (PV) systems.
Roof area requirement for Solar PV module (Credit: Solar Reviews)
The appropriate sizing of a solar power system to supply all a home’s electricity needs is one of the most common questions people considering buying solar panels ask.
To work out the wattage correctly, the panel needs to be sized according to how much power you are going to use.
As a general rule, if you have a caravan you’ll need a panel between 20-60W, whereas most motorhomes are fitted with panels of 80W and above. (There tend to be more gadgets needing power in a motorhome than in a caravan).
For laptop charging, you need at least 25W to provide a useful trickle charge. The typical solar panel selection based on wattage is shown in the below Energymatters Image.
Credit: Energy Matters
It’s very important when selecting the best solar panels to use for your solar power system installation to bear in mind a few crucial factors aside from the price tag; after all, your purchase decision is one you’ll be living with for a very long time. The important factors which you should consider while buying the solar panels such as:
• Cost of solar panels
• Installation size and watts
• Conversion efficiency
• Durability / Longevity / Warranty The size of a solar panel plays a major for panel installation in your home.
Finally, the following key points need to be considered while selecting any solar panel from the market.
- Consider how the module is manufactured and the materials used.
- Go into detail – how the panels perform in real world situations – including positive tolerance, temperature co-efficient rating, PID and LID resistance and efficiency.
- Compare the warranty details of the solar panels you are considering buying.
- Learn more about the company that manufactures the modules and compare with well established companies in the market.
Remember that for the equivalent wattage a crystalline panel will be smaller than an amorphous panel.
The most installations polycrystalline cells are most suitable as they are value for money while still also being relatively efficient.