Solar energy is considered the most practical way to produce electricity. Over the years, the invention of solar panels has helped us use the most clean and renewable energy, which is the solar energy. With the emergence of global warming and the numerous problems it causes, as responsible citizens of Mother Earth, it is important that we do whatever we can to reduce the carbon footprint on our atmosphere. Solar panels can be called the heart of any solar light fixture. They are composed of particles of energy, called photons, which convert solar energy into electrical energy to power solar lights. Over the years, solar panels have helped to light up both residential and commercial properties.
History of Solar Panels
It has been more than 100 years since the world identified the benefits of solar energy and ever since, the usage of solar energy has been evolving. Earlier, solar energy was predominantly used for the production of steam, to be used in the operation of machinery. It was not until the discovery of the photovoltaic effect by the French physicist, Alexandre-Edmond Becquerel, in 1839, to convert sunlight into electric energy that the benefits of solar energy were explored. The photovoltaic effect is also known as Becquerel effect. In 1893, American inventor, Charles Fritts, created the first genuine solar cell which was formed by coating sheets of selenium with a thin layer of gold, which can be called the first ever solar panel. The first patented silicon solar cell was invented by Russel Ohl, an American engineer and this led to production of solar panels in 1954 by Bell Laboratories.
Function of solar panels
Solar panels gather clean renewable energy in the form of sunlight and convert that into electricity; this can then be used to provide power for electrical loads. Solar panels are made up of several individual solar cells which are composed of layers of silicon, phosphorous (for negative charge) and boron (for positive charge). When solar panels absorb the photons, electric current is generated and when the energy generated from photons strike the surface of the solar panel, electrons are released from their atomic orbits into the electric field generated by the solar cells, which then draw these free electrons into a direct current. This process is known as the photovoltaic effect. During the operation of solar lights, the panel sends this direct current (DC) through the charge controller to the battery. The battery gets charged throughout the day and since the solar cells stop producing power at night, the photo-resistor detects the absence of light and activates the battery, which turns the light on.
Features of solar panels
- Consistent power source
- Unbreakable glass
- Energy security
- Silent operation
- Durable material
- IP65 waterproofing
- Low maintenance
Types of solar panels
- Monocrystalline solar panels: The monocrystalline solar cells are made from single-crystal silicon. They are produced from one large silicon block manufactured in silicon wafer formats. The cells tend to have cylindrical shape and are often colored. The back sheet of the solar panel is mostly black, silver or white and the metal frames are typically black or silver. Since the cells are composed of a single crystal, the electrons that generate electricity have more room to move.Therefore, monocrystalline solar panels tend to generate more power and are more efficient compared to their counterparts because they come in higher wattage modules. Due to their sleek aesthetics, monocrystalline solar panels are considered to be a premium solar product.
- Polycrystalline solar panels: The polycrystalline solar cells are composed of fragments of silicon crystals that are melted together in a mold before being cut into wafers. Polycrystalline solar cells have a bluish hue due to the light reflecting off the silicon fragments in the cell in a different way than it reflects off a pure monocrystalline silicon wafer. Usually, the frames of polycrystalline panels are silver and the back sheets are either silver or white. Polycrystalline solar panels tend to have lower wattages of power capacity when compared to monocrystalline panels. Due to their low cost and portable nature, polycrystalline solar panels are largely used in solar lighting systems.
Both monocrystalline and polycrystalline solar panels come in standardized 60, 72 or 96 silicon cell variants but monocrystalline solar panels tend to produce more electricity even with the same number of cells because of the purity of the material used. To make both these panels, wafers are assembled into rows and columns to form a rectangle, covered with a glass sheet and framed together.
- Thin-film solar panels: Think-film solar panels are made from different materials such as cadmium telluride (CdTe), amorphous silicon (a-Si) and copper indium gallium selenide (CIGS). As the name suggests, thin-solar panels are slimmer than the other two panel types simply because the cells within the panel are a lot thinner than the crystalline wafers used in other panels. Thin-film solar panels come in both black and blue hues and they do not come in standardized sizes. Thin-film solar panels have relatively low efficiency in comparison with monocrystalline and solar crystalline solar panels.
Each type of solar panel has its own advantages and disadvantages, and one may choose the solar panel type depending on your own property and desired system characteristics.
|Type||High efficiency and aesthetics||Higher costs|
|Monocrystalline||Low cost, portable and flexible||Lower efficiency|
|Polycrystalline||Light weight||Lowest efficiency|
The latest entrant in the solar panel industry is the bifacial solar panels. These panels can produce more electricity as they can capture sunlight from both the front and back of the panel. Bifacial solar panels are usually manufactured with monocrystalline solar cells but polycrystalline solar cells are used too in some of the bifacial solar panels. Even though these panels offer higher efficiency, extended durability and flexibility, the bifacial solar panels are quite expensive and a lot heavier compared to the other types of solar panels.
Installation of solar panels in solar street lights
There is a variety of solar lights available in the market now. The solar lights can be largely classified into two categories, all-in-one solar lights and integrated solar lights. No separate installation of solar panels is needed in all-in-one solar lights as the solar panel is integrated along with the controller, battery and LED as a single unit. For integrated and semi-integrated solar lights, since the solar panels come as a separate entity, they need to be fixed as per the manufacturer’s instructions. Only basic tools like wrench, screwdriver and cutters are needed for installation of solar panels. The most important element to keep in mind is that the solar panel should be installed at a shadow free location where maximum direct sunlight falls on the panels.
Maintenance of solar panels
Although almost no maintenance is needed for solar panels, for longevity and for retaining efficiency of solar panels, cleaning the solar panels occasionally is necessary. Ensure the panels remain out of shade. The cleaning may be done using a soft cloth or mild detergent. You may also do the cleaning by spraying water using a hose. Inspect for any damaged parts and repair or replace if necessary. Trim down the tree branches or shrubs, if any, covering the solar panels and blocking the sunlight.
Solar panels - FAQs
What is the average lifespan of solar panels?
Most of the solar panels come with around 25 to 30 years of life.
Do solar panels need to be installed with a tilted angle?
Solar panels should be tilted at a certain angle to attain maximum performance of the solar fixture. Moreover, keeping the panels tilted avoids water stagnation during rain.
Can solar panels survive rains?
Yes, solar panels are designed to be operated outdoors; therefore, they can survive the different climatic conditions. IP65 rating waterproofing is used to withstand the rough weather.
Can the solar panels generate current even if the glass on top of the panel is cracked?
As long as the panels are intact, they can generate current even if the glass is shattered.
How frequently should I clean the solar panels?
Solar panels do not need frequent cleaning. Most of the dust and dirt get washed off in rain. For tough stains, you may use a mild detergent and warm water and wipe off the dirt using a soft cloth or spray water using a garden hose.
Do solar panels need constant sunshine to work?
Solar panels work at their best if they get maximum direct sunlight, even without direct sunlight solar panel generate current. Solar lights in general offer longer operating hours. Due to this reason, solar panels will continue to work during monsoon even when they produce less energy.