3 Types of Solar Rooftop system
Solar Performance Specialist
Solar energy is an inexhaustible source of energy that is being used to generate electricity. Depending upon the type of solar system we can either store the surplus energy generated or it can be fed into the electricity grid for energy credits.
The basic principle on which solar energy is converted to electricity is the same for all types of systems. A solar cell is a basic unit for converting light energy into electrical energy. When a beam of light strikes the surface of the solar panel electrons are being ejected resulting in current.
There are basically three kinds of solar power systems through which electricity can be generated. They are:-
On-Grid or Grid-tied
Off-Grid or Stand-alone power system
Hybrid(Grid connected with battery storage)
An On-Grid system comprises a solar panel, Solar inverter or Micro inverter, meter and Grid. On being exposed to sunlight the solar panels generate electricity that is DC in nature. As most of our home appliances run on AC, to use the energy produced by solar panels it has to be converted into AC energy via an inverter. The AC energy obtained from an inverter flows through an electric meter through which we get the energy to run our devices. The Excess solar power generated is exported to the grid and can get paid as the credits for the energy exported.
During the night or when the solar power system is not generating, the electricity needs can be fulfilled using power from the grid.
The On-Grid system is suitable for locations having very little or no power outages. As the battery is not used in this system, we can’t store electricity for immediate backup.
An off-Grid system also known as a stand-alone power system, it is connected to the battery instead of the electricity grid. This type of system comprises Solar panels, battery, charge controller (for regulating the battery charging and prevents it from overcharging) & inverter. The DC energy that is produced through solar panels is fed into the Charge controller and the controlled voltage is used to charge the battery which powers the inverter. The inverter converts the DC to AC, which can be used for running the appliances.
This stored energy in the battery can be used during night times and during the time of power outages.
The Off-Grid System is suitable for remote areas with no electricity grid. However, the high cost of batteries makes this system an expensive one.
Hybrid System is a combination of Grid and battery. It comprises Solar panels, a charge controller, battery, inverter and the grid. In this system, the extra energy produced by the solar system after the consumption by appliances is transferred to the battery bank. Once they are completely charged, they can export the extra energy to the grid.
This system is an amalgamation of On-grid & Off-grid. During the day, the excess power generated will be stored in batteries that work off-grid. If there is surplus power stored then the stored power is fed into the grid just like an on-grid.
During power outages or night time batteries can be an immediate backup. If there is no solar power and the battery is also discharged, the power can be taken from the grid and the battery can also be charged simultaneously.
Solar photovoltaic systems are renewable sources of energy designed to meet the electrical power needs of the user. The different types of PV systems i.e. ongrid, Off-Grid and hybrid are useful in different areas according to one's requirement. Choosing the right type of system is essential and must be based on one’s need, capital investment and the availability of the grid in that area. Before choosing a system, the energy consumption profile of the user must be known.
If there are no or very few power outages the user should definitely go for an on-grid system, which is cheaper than the other two. For rural areas having no grid(electricity connection), an Off-grid system is most suitable. The hybrid system is pretty expensive as there are multiple electrical components involved. Users can go for hybrid systems to become completely self-sufficient for power generation. Although for places like Delhi, it is not required as there are very few power cuts. Adoption of a solar photovoltaic system will definitely be the right decision for a clean & green generation.
Also Read: Solar Net Metering – Features & Benefits