Sunlight is converted to electricity directly when made to fall on solar photovoltaic(SPV) modules. Systems or devices are made for various applications based onSPV modules connected with suitably designed power conditioning units formeeting electricity requirements. These systems or devices are designed to work inoff-grid mode (usuallysupported with batteries to allow use when sunlight is low orduring night).

Grid connected roof top solar PV System

In recent years solar PV systems became viable and attractive. Utility scale plants are being set up worldwide with promotional mechanisms which areset up on ground surface. Available roof-top area on the buildings can also beused for setting up solar PV power plants, and thus dispensing with the requirementof free land area. The electricity generated from SPV systems can also be fed tothe distribution or transmission grid after conditioning to suit grid integration.

Schematic lay out of roof top PV system

The roof top solar PV systems:
- Are easy to install and maintain
- Have long life of 25 years
- Are modular in nature
- Capacity can be enhanced in future to meet increased requirement of electricity.

How does it Work?

Based on available roof area solar PV panels will be installed on the roof of thebuilding. The output of the panels (DC electricity) connect to the power conditioningunit / inverter which converts DC to AC. The inverter output will be connected to thecontrol panel or distribution board of the building to utilize the power. The inverter synchronizes with grid and also with any backup power source to producesmooth power to power the loads with preference of consuming solar power first. Ifthe solar power is more than the load requirement, the excess power isautomatically fed to the grid. For larger capacity systems connection through stepup transformer and switch yard may be required to feed the power to grid.

Operation and Maintenance Requirements

There are no moving parts in the system and it requires only minimal attention. Depending upon the dust level, the system requires periodic cleaning.


The grid connected roof top solar PV system would fulfill the partial/full powerneeds of large scale buildings. The following are some of the benefits of roof topSPV systems:

  • Generation of environmentally clean energy
  • Consumer becomes generator for his own electricity requirements
  • Reduction in electricity consumption from the grid
  • Reduction in diesel consumption wherever DG backup is provided
  • Feeding excess power to the grid