Solar On-Grid Solutions
What are Solar On-grid Solutions? Why is it called a Grid connected system?
The solar on-grid solution consists of the solar system connected to an utility grid(usually the public electricity grid) that powers the system without battery backup. The system only works when there is grid supply. Hence the name Grid connected PV system.The system is customized to use small battery bank as buffer to provide robustness and deliver quality power to the customer.
How does the system work?
A solar system generates electricity using solar power utilizing solar panels. The power generated is Direct Current(DC) and needs to be converted to Alternating Current(AC) for external appliances to use. So the system is connected to one or more inverters to convert DC to AC. The inverters also help to regulate the current generated.
Major components of the system:
- Solar modules
- Grid- Electicity supply
- Grid Tie inverter
- AC disconnect
- DC disconnect
- AC distribution panel
- Solar meter
The system consists of AC and DC disconnects. They are used to switch the current flowing between the components. It helps to maintain and protect against electric fires. The solar meter measures the the power generated in the system.
This system enables the user to avail Net Metering. In case of extra power generated by the solar PV system, the power is sent back to the grid. The user can then avail credit for the surplus power supplied from the power distribution companies. A Bi-directional meter is employed which measures both the inflow & outflow of power.
Net Metering benefits
- Get paid by DISCOM(Power distribution companies) for excess energy exported to grid at attractive rates
- Up to 90% reduction in electricity bill is possible
- Net Units = Imported Units – Exported Units
Benefits of Solar On-grid Solutions
- Solar on-grid solutions harnesses the solar energy for sustainable & cost effective power solutions using underutilized rooftops.
- Syncs and shares energy with Grid
- Turnkey solutions including Net metering
- Without battery, economical with no recurring cost
- Export generated unutilized energy to grid
- Best in class solar modules
- Solutions available from 1KW and above
- Highest performing inverters
- Single phase and Three phase Solutions
- Customized solutions to suite site conditions
- Individual Houses
- Places of Worship
- IT / BT Companies
- Farm Houses
Frequently Asked Questions(FAQ)
Feed-in tariff or NetMetering is a method by which electricity produced from the Solar PV system is supplied to the Grid, and the building recieves power from the grid. The difference in energy units (Power Fed – Power consumed) is credited to the building owner. This is called Feed-in Tariff.
There are 2 types of Feed-In Tariff –
- Gross Feed-In tariff – In this case the building owner is paid a premium for all the electricity produced.
- Net Feed-In tariff – In this case the building owner is paid a premium for surplus power produced.
Both are methods by which the building owner is credited for supplying extra power from the Solar PV system to the grid. In simple terms the difference between the two is: Feed-in tariff requires 2 meters and Netmetering requires 1 meter. In case of Feedin tariff there is one meter for measuring consumption and another for generation. In case of NetMetering there is single meter which measures the difference between the energy units consumed from the grid and the energy units fed into the grid.
The average cost of grid connected rooftop solar systems is about Rs. 80 per watt or Rs.8.0crore per MWp capacity. The prices vary from any where between 70,000 – 90,000 per kWp and these can rise to higher ranges with higher brands.
A roof area of 10sqm is needed to set up 1kWp grid connected solar PV systems on the roof.
There are different business models used:
- The Solar installation can be owned, operated and maintained by the owner completely by himself.
The power completely rests with the owner in this case.
- Build Operate Transfer – BOT – In this model the Solar Installation funding is done by the customer
and then the operation and maintenence are taken over by the 3 party vendors.
- Build Operate Own – BOO – In this model the funding, opperation and maintenence are done by
the 3 rd party vendors but the customer has to pay for the current utilization. The client pays on a
- Build Operate Own Transfer – BOOT – This model works like a BOO model working for a
stipulated/contracted period(for ex -10 to 12 years) after that the ownership is transferred to the
- Also the Solar installation can be owned operated and maintained by the DISCOM’s.
The size of the Solar PV system depends on a number of factors like:
- The Energy requirements of the building
- Solar PV site orientation
- Efficiency of the Solar Panels
- Rooftop space.
After analyzing these factors do a proper Solar sizing. This involves considering the sizing of the different components that make up the solar PV system.
For more information about the system sizing check out this blog.
In case of a Grid connected system, when there is a blackout , the system switches off. For a grid connected system to work there needs to be the grid power. Otherwise a battery backup can be provided to store power in case of power failure. This then becomes a Hybrid Solar PV system.
In a Grid connected system there is no battery used. Here the grid acts as a Virtual battery. At night when the Solar PV system does not provide power, its the grid power that is used.
- Convert DC power generated from Solar panels to usable AC power.
- Sync the Ac power voltage with that of the grid power.
- Maximize the power output with MPPT
The Grid connected system is made of different components and each lasts for different time periods.
- Solar Panels – The Solar Panels last for more than 40 years. But warranties given by the manufacturers would be around 20-25 years. Even after the warranty periods, the efficiency of the Solar panels are quite high. The efficiency drops by 1% every year.
- Solar Inverters which are important components of the Solar PV system come with a life time of 10-12 years with warranties for 1-2 years.
- Batteries – Deep batteries which are used with Solar PV systems come with a lifetime of 5-6 years with warranties for 1-2 years. These need to be replaced to provide good battery backup.
The capacity of the Solar PV system to installed depends on the energy requirements of the building and rooftop space available.
There is very less maintenance required to maintain Solar PV systems. Ensure regular cleaning of the Solar Panels and checkup of Solar Inverters for a smooth Solar PV system functioning.
No Solar regulator is not needed in case of Grid connected system. A Solar regulator or Charge controller is needed in case of an On-grid system to regulate the amount of current and voltage when current flows into batteries. Since there are no batteries involved in Ongrid systems there is no need for Solar regulators.
If you are availing Net Metering yes, there is a need for installing a new bidirectional meter which measures the difference of energy units feeding into the grid and fetching from the grid. [ Power going into Grid – Power supplied from the grid]. Based on this the building owner is credited for supplying power to the grid.
Yes you can upgrade the Solar On-grid system. If the Solar Ongrid system is upgraded then the inverter needs to be replaced with a higher capacity. The capacity of the Inverter should be equal to that of the Solar panel capacity or greater than that of the Solar panel capacity.
Consider the different features of the different types of Solar Panels. Also consider factors like rooftop space requirements, shading and other. Know more about the different types of Solar Panels and what best suits you from this article.