On Grid Solar Power Plant
The on-grid plant is also known by the name grid connected plant or grid tied plant. This is the most common type of photovoltaic system. Both the grid and the solar panels will provide the electricity if the demand is higher than the power produced by the solar panels. The grid will compensate for the shortfall. If the demand remains low, then the excess power produced will be sent to grid.
Advantages of Grid Tied Solar PV Plant
1. Cost effective
2. Efficient
3. Does not require expensive batteries or storage devices to store the excess power produced by the panels.
4. The grid behaves as virtual battery, as the excess power produced is sent directly to the grid.
5. With net metering, a lot of money can be saved as the excess power is sold out to the utility.
6. As there is no involvement of storage devices, the maintenance required is also low.
Disadvantages of Grid Tied Solar Power Plant
1. The major disadvantage of a grid tied system that it shuts down when the utility grid shuts down due to some fault. This is called “anti-islanding” requirement which means the inverter must stop feeding when the grid experiences an abnormal condition. This shut down is important for the protection and safety of the workers or professionals who would be trying to repair the grid.
2. Before installing this system, the person should get cleared with the net metering solar policies by the utilities. The person can consult experts in the field to get knowledge about the policy.
Off-Grid Solar Power Plant
This type of system is not connected to the utility grid, instead a battery bank or storage devices to store the solar power. In an off-grid system, the battery is charged through a charge controller/MPPT (Maximum Power Point Tracker) circuitry. The energy stored in the battery is fed to the inverter which in turn feeds the AC load. Thus, an off grid PV system can deliver power even during night with a condition that the battery has enough stored power. So, the system designed should be in such a way that it handles the peak load when the PV array is not able to produce that much amount of power ensuring that there will be continuous supply of power. This is called autonomy of the off grid system, and usually off grid systems are designed for 2 or 3 days autonomy backup, i.e. over sizing of the battery bank and Solar PV system to ensure enough power is available even when there is a week of over cloudy and hazy daylight. (monsoon & winters in India)
Advantages of Off Grid Solar Plant
The system is suitable with:
1. The places with frequent power cuts and shortage of power.
2. In rural areas or underdeveloped communities, where the grid lines not present to export the excess amount of units produced by the solar PV array.
Disadvantages of Off Grid Solar Plant
1. The installation of battery makes the system costlier for the first investment compared to Grid Tie system..
2. The efficiency of the system is low as compared to the on grid system. ( DC-AC-DC-AC conversion cycle)
2. Regular maintenance is required from the day of commissioning.
3. The batteries have relatively a pre decided life span and degrade over time depending on Depth of discharge and Charge cycle usage.
Varies for Different battery chemistries- lead acid, SMF, VRLA gel, Lithium ion, Lithium Ferro Phosphate etc….
TMK Systems Pvt. Ltd., is an ISO 9001-2015 certified company, empaneled with MNRE National Solar Subsidy Programme, whose business philosophy lies in the commitment to creating total customer satisfaction with the best business practice.