Solar energy is the technology used to harness the sun's energy and make it useable. Solar photo-voltaic or PV cells are made of semiconductor materials like those found in computer chips. When sunlight hits the cells, loosens electrons from their atoms. As the electrons flow through the cell, they generate electricity!
Solar energy is an inexhaustible fuel source that is pollution- and often noise-free. The technology is also versatile. Take for instance how solar cells generate energy for satellites in space or for deep underground caves, and they can also power buildings and futuristic cars.
Here's a short introduction to solar PV systems for rooftops of homes and businesses. The technology is pretty straightforward, very accessible, and easy to maintain and operate right after installation.
Solar PV modules or Solar Panels
PV stands for Photo Voltaic. As these panels convert light (i.e. photo) into electrical power (voltage), so they are known as Photo Voltaic modules. The most commonly available PV modules are of two types- Crystalline and thin-film.
Inverter
The inverter is the brain of a solar power system and serves primarily two purposes:
to convert the DC power generated from Solar Panels into AC power that is used by our electrical appliances.
to ensure that solar power generated is used at priority over grid supply.
Solar inverters are essentially Grid-tied or Off-Grid/Hybrid.
The Grid-tied inverters are directly connected to the grid supply. With net metering, excess power can be exported and used later when required. There is no limitation to the size and type of equipment that can be run with this type of inverters. These are suitable where the power supply is reliable.
Off-grid or Hybrid inverters are connected to the specific loads to be run. Their size is based upon connected loads and their surge requirement. These are suitable for areas with a load shedding problem.
The inverters require very little space and can be easily mounted in a convenient location. They can have a working life of around 10 years or more.
Battery
Batteries are required to make the power available in the absence of the sun.
Charging of batteries is done by solar power or grid power. The inverter allows us to choose between the two sources based on application. They also help smoothen power delivery during the daytime.
Of all solar panel parts and components, the battery is optional for the grid-tied installation type.
Mounting structures
These are fixtures that hold the solar panel in place. Their appropriate design is essential to as to make sure, the panels get maximum sunlight. The mounting structures are usually made of galvanized iron or aluminum. They have to be designed for wind loads applicable in the region. There are two types of mounting structures: the triangular mount: for flat roofs and, flush mount for inclined roofs.
Solar Modules
Also called solar panels, a solar module is a single photovoltaic panel that is an assembly of connected solar cells.
Solar cells
Monocrystalline solar panels are produced from one large silicon block and are produced in silicon wafer formats. The manufacturing process involves cutting individual wafers of silicon that can be affixed onto a solar panel. Many silicon molecules are melted and then re-fused together into the panel itself.
Photons in sunlight hit the solar panel and are absorbed by semiconducting materials, such as silicon. Electrons (negatively charged) are knocked loose from their atoms, allowing them to flow through the material to produce electricity.
Poly vs Mono vs Thin Film
Warranty
The majority of solar panels available on the market today come with a 25-year long warranty (also known as a performance guarantee). In most cases, this means that the panels can be guaranteed to have an electrical production for 10 years at 90% of rated power output, and 25 years at 80%.