A rooftop solar power plant requires about 100 Sq.Ft for every 1 kW of panels, generating about 4 kWh per day. If you require 100 kWh of solar power per day you will need 25 kW of solar panels occupying 2,500 Sq.Ft. of shadow free roof area.
In India it is quite common for the roof to be used for other purposes as well e.g., some of our clients are companies who have their lunch room on the roof as a temporary structure. They are concerned that they will not be able to use the roof space for their lunch room if they install solar panels on the roof.
In such cases we recommend using elevated mounting structure for the solar panels. These are metal structures that can raise the panels 2 metres or even more above the roof, allowing the roof to be used for many other purposes. The other advantage of elevated mounting structures is that the solar panels may be raised above shadows, increasing the amount of roof space available for the solar plant.
When designing an elevated mounting structure it is important to provide access routes for cleaning and maintenance, as well as ensuring that the structure is strong enough to withstand high wind speeds. This can particularly be a concern in cyclone prone areas.
Elevated mounting structures do add to the cost of the project due to greater use of materials, particularly steel. The weight of the steel and concrete may also be a concern depending on the kind of roof and any other loads placed on it. We recommend verifying the mounting structure design with your architect.