On Grid Solar PV System

Basics

The solar photovoltaic On-Grid systems produces, converts and transfers solar electricity to local grid in 230/400V environment. Typical characteristic of an On-Grid system is the connecting and integration with a local electric grid. On-Grid systems can be used as source of electricity for homes or factories. The user can decide to consume it’s own solar electricity or transfer (sell) electricity to the local grid. Both processes can be handled simultaneously.

In this solar system, solar inverter converts the DC electricity produced by solar panel into AC electricity. Which can then be used directly at home or business.

If system is producing more power than is being consumed, the surplus is fed into the main electrical grid via solar net metering. At the time of electricity billing government or power provider company will adjust the exported units in your electricity bill.

The power supply gets completely cut-off in case of the grid outage. Hence, one needs to depend on back-ups such as DG sets for emergency power supply. The power shut down happens, mostly in case of safety and technical reasons.

System Components:

1.  Photovolatic Modules:

Mono crystalline solar cells are simply referred as Si-mono. Si-mono photovoltaic modules or cells are made from a single cylindrical crystal ingot having high purity. From the single crystal, wafer can be sliced and cut in octagonal shapes. At Standard Test Conditions i.e. STC 1000 W/Sq. m, Si-mono cells shows the best performance but the same cell shows poor perfor-mance when temperature levels rise.

Poly crystalline solar cells are simply referred as Si-poly. Si-poly modules or cells consist of small crystals which make the cell or module to look as “crystal grain known as crystallites”. Si-poly cells are “produced by sawing a square cast block of silicon first into bars and then into wafers”.

These cells performs better at STC and the performance reduces as the temperature rises. These also perform better under elevated temperature conditions when compared with crystalline silicon cells.

Amorphous silicon solar cells are simply referred as Siamorph. Si-amorph PV generator is configured with the combinations of the Si-amorph PV modules. These modules are of thin film based and made by sandwiching the Si-amorph materials of 1 ȝm thickness between the two panes of glass. 

2.  Junction Box:

The junction boxes were used majorly in two different places in PV systems i.e. one is at the interconnection to power converter. Here, all the PV strings are joined together. Another place is at solar PV where this junction is used comprises the bypass diodes allowing the power flow only in one direction i.e. from solar panel to the utility system.

3. On-Grid Inverter:

On-grid inverter is the one which converts the DC power to AC power. This is one of the essential components of PV system to inter connect with the present day power sector. We have various type of inverter available in the market whose rating is from small kVA to larger kVA. The present available inverter are coming with MPPT enabled and wider input Vdc range. 

Sealed batteries require only little maintenance in order to keep them working properly, the FLA batteries have a longer lifespan.

4. Net Meter:

Net meter is a device that is used to monitor the inflow and outflow of electricity between the electrical power generating system to electric utility grid. In photovoltaic systems if excess energy is generated that can be sold to the utility by means of this.

5.Electrical Grid:

It is an electrical power network interconnecting the load centers and energy providers. It is one of major parts of electrical power system network acting as interface between power generation plant, power transmission line, and distributing lines. It transmits electric power that is generated using any source (renewable or non-renewable) at any place and distributes finally to the consumers as per the requirement (either in 1-ɮ or/and in 3-ɮ).

Benefits of On-grid solar:

1. Zero Electricity Bills — Though the solar power system is connected to the grid, the consumer has to pay only for the surplus electricity he consumes. The bill generated on a monthly basis determines whether the consumer has any payments to be made. However, at the same time if the consumer utilizes less electricity, the excess is fed back in the grid.

2. Easy maintenance — The on grid solar power system has the least number of parts along with simple installation. The elimination of batteries makes the maintenance quite easy.

3. Passive income generation — With connection to the grid, the consumer can charge for the surplus electricity he has generated. It not only eliminates your electricity bills but also avail the cost benefits for the excess electricity generated.

4. On-grid solar systems are most cost-effective and convenient to install. These are ideal systems for households as the cost charged can be recovered easily through the additional power transmitted to the grid