Frequently Asked Questions

In a solar rooftop system, the solar panels are installed in the roof of any residential, commercial, institutional and industrial buildings.
This can be of two types

  • Solar Rooftop System with storage facility using battery
  • Grid Connected Solar Rooftop System

Such rooftop system has battery as storage facility. The solar electricity is stored in the battery and can be utilized during night also when the sun is not available.

In grid connected rooftop or small SPV system, the DC power generated from SPV panel is converted to AC power using power conditioning unit and is fed to the grid either of 33 kV/11 kV three phase lines or of 440/220 Volt three/single phase line depending on the capacity of the system installed at institution/commercial establishment or residential complex and the regulatory framework specified for respective States.

These systems generate power during the day time which is utilized fully by powering captive loads and feed excess power to the grid as long as grid is available. In case, where solar power is not sufficient due to cloud cover etc., the captive loads are served by drawing power from the grid.

Such rooftop systems can be installed at the roofs of residential and commercial complex, housing societies, community centers, government organizations, private institutions etc.

The average cost of grid connected rooftop solar systems is about Rs. 80 per watt or Rs. 8.0crore per MWp capacity.

There is a provision of Central Financial Assistance of 15% of the total cost or Rs. 12 per watt or Rs. 1.20 crore per MWp under the Grid Connected Rooftop and Small Solar Plants Programme of the Ministry. This CFA has been reduced from 30% to 15%.

There are provisions of concessional import duty/excise duty exemption, accelerated depreciation and tax holiday for setting up of grid connected rooftop power plants.

Department of Financial services has instructed to all Public Sector Banks to encourage home loan/ home improvement loan seekers to install rooftop solar PV plants and include cost of system in their home loan proposals. So far, nine PSBs namely Bank of India, Syndicate Bank, State Bank of India, Dena Bank , Central Bank of India, Punjab National Bank, Allahabad Bank, Indian Bank and Indian Overseas Bank have given instructions to extend loan for Grid Interactive Rooftop Solar PV Plants as home loan/ home improvement loan.

The rooftop solar systems from 1 kWp upto 500 kWp or in combination can be set up on the roofs.

Vigor Solar evaluates the options of various technologies, configurations and selected sites to bring the best returns and savings to the solar energy project. As your trusted partner, we will listen to your needs and concerns, and identify the best solution for your facilities. A program manager will guide you through our decision process, ensuring that your needs are fully met.

Take a look at the position of your site - and particularly your roof. Ask the following questions:

  • Is there good southern exposure? Orienting solar panels to the south maximizes the effectiveness of energy collection.
  • Is the exposure free of trees or buildings that could shade the panels or drop debris on them? Shading photovoltaic panels dramatically reduces their effectiveness.
  • What is the pitch of your roof? Most roofs, from flat to 60-degrees can accommodate photovoltaic panels.

Shading a photovoltaic system decreases its output. Though technology has progressed considerably to reduce the negative impact of shading, it is best to avoid shading.

The size of the photovoltaic system is correlated to your energy-use needs, available space for a system, and overall costs for the system components and installation. Please contact us for us to help you determine the best size for your solar photovoltaic system.

There is a helpful rule of thumb for calculating a rough estimate of how much area you might need. For example, a 1KW watt system may need 100 square feet of area, depending on the type of PV module used.

Depends on your particular needs. A backup battery bank can add as much as 25% in cost to a residential solar PV system. If you want to just save on the electricity costs then On Grid system without Battery is sufficient. If the power is unreliable and you also want backup or night time use, then Off Grid system is suitable.

Solar photovoltaic panels require little maintenance - periodic wash with clean water to remove dust and debris.