On-grid systems, also known as grid-tied or net-metered solar rooftop systems, operate by synchronizing with the grid through an inverter, ensuring seamless power supply. In this setup, the grid serves as a backup, supplying additional energy during periods of low solar generation (such as rainy or cloudy weather) and absorbing excess solar energy during peak production hours.
Distribution companies (DISCOMs) calculate the net energy balance — the difference between total energy imported from the grid and exported to the grid — at the end of each billing cycle. Consumers are billed only for the net energy consumed, effectively reducing their electricity costs. In cases where consumers export more energy to the grid than they import, DISCOM's compensate consumers for the surplus energy.
On-grid systems are highly cost-efficient for solar rooftop installations, particularly recommended for those aiming to significantly reduce their electricity bills.
Why choose On-grid
Reduce Monthly Electricity Bills: On-grid systems allow you to offset your electricity usage with solar power, reducing the amount you need to purchase from the grid and hence lowering your monthly electricity bills.
Minimal Maintenance: Besides regular cleaning of solar modules, on-grid systems require little to no additional maintenance compared to other types of solar setups.
Earn Money through Net Metering: By exporting surplus energy back to the grid, you can earn credits or payments from your electricity provider. This makes on-grid systems financially beneficial as they allow you to monetize excess energy generated.
Affordability: On-grid solar systems are typically the most affordable option for rooftop installations. They are cost-effective to install and operate, making them a practical choice for reducing overall energy costs.
How does it work?
In an on-grid system, the energy generated by the PV panels is initially in the form of DC (Direct Current), which is then converted into AC (Alternating Current) by the inverter. This AC power is supplied to power the house loads. If the solar-generated power is insufficient to meet the household demand, the deficit is supplemented by drawing power from the grid. Conversely, any surplus energy generated beyond immediate household needs is fed back into the grid.
Since the inverter in an on-grid system is synchronized with the grid, the system automatically shuts down in the absence of grid power. This safety feature is mandated by DISCOM's (Distribution Companies) to prevent accidents during maintenance of the grid lines. It ensures that solar systems do not continue to export power to the grid when grid power is unavailable, which could pose risks to maintenance personnel.
In summary, on-grid systems provide seamless integration of solar power with the existing grid infrastructure thereby optimizing energy use.
Components
Here's a breakdown of the components involved in a solar PV system:
- PV Panels (Photovoltaic Panels): Absorb sunlight and convert it into DC (Direct Current) electricity.
- Inverter: Converts DC power from the PV panels into AC (Alternating Current) power, which is used by household appliances and can be fed into the grid.
- DCDB (DC Distribution Board): Includes components like MCB (Miniature Circuit Breaker) and SPD (Surge Protection Device) to protect the system from current and voltage spikes on the DC side.
- ACDB (AC Distribution Board): Contains MCB, SPD, and fuses to protect against voltage and current spikes on the AC side of the circuit.
- Bidirectional Meter: Replaces the traditional unidirectional meter to accurately record both the import and export of energy to and from the grid.
- Electrical Panel: The existing panel in the customer's premises where the solar power output is connected to the household circuits for consumption and potential export to the grid.
- Lightning Arrestors: Installed to safeguard the PV panels and the entire system from damage caused by lightning strikes.
- Earthing: Ensures safe dissipation of surge currents, whether from lightning or within the system itself, to protect against electrical hazards.