Frequently Asked Questions

In a solar rooftop system, the solar panels are installed on the roof of any Residential, Institutional, Social, Government, Commercial, Industrial buildings etc.. This can be of two types:

I. Grid Connected Solar Rooftop System.

II. Solar Rooftop System with storage facility using battery.

Grid connect systems, which are the most common in built up areas, supply solar electricity through an inverter directly to the household and to the electricity grid if the system is providing more energy than the house needs. When power is supplied to the main grid, the house owner usually receives a credit or a payment for the electricity supplied to the grid. This is called a feed-in tariff.

A 1 kW rooftop system generally requires 10 sq. meters of shadow-free south facing area. Actual sizing, however, depends on local factors of solar radiation and weather conditions, efficiency of solar module, shape of the roof etc.

The benchmark cost of grid connected rooftop solar systems for FY 2021-22 varies from Rs. 42 per watt – Rs. 55 per watt.(India specific). 

Yes, you can get additional solar panels at any time to increase generating capability, but you might have to upgrade to a larger inverter. Alternatively you could purchase a larger inverter when installing the system initially and then plan to add some extra solar panels later.

In a grid connect system, as you are still tied to the mains power supply, any deficit will come from the mains grid. 

In order to install a grid connected solar power system at your premises, you will need to have a compatible switchboard and meter. A meter exchange may be necessary after the installation of your new solar system. The energy that your solar system produces interacts with the main power grid and the loads in your house.

Grid connected systems directly supply excess electricity produced during the day back into the local electricity grid. You then receive a credit for any power that your system supplied to the grid. During the night when your system does not produce any electricity you draw your power from the grid and your electricity meter measures your consumption. Battery banks are also used to store electricity for use in the night.

The grid connect inverter will automatically shut itself off within a few milliseconds of a grid failure. This avoids the potential of a serious accidents to any maintenance staff that might be working on the line and to prevent back feeding into the grid. Therefore even though you have a solar system during a grid failure you will not have power available. If you want to keep on having electricity available during a grid failure then you would need back up batteries. This will add to the cost of the system.

Yes, battery backup systems require additional components such as hybrid inverter and the batteries – which can be costly; although pricing is rapidly dropping.

I. Solar PV modules used in solar power plants /systems must be warranted for their output peak watt capacity, which should not be less than 90% at the end of 12years and 80% at the end of 25 years.

II. The mechanical structures, electrical works including power conditioners/inverters/charge controllers/maximum power point tracker units/distribution boards/digital meters/switch gear/storage batteries, etc. and over all workmanship of the SPV power plants/ systems must be warranted against any manufacturing/ design/ installation defects for a minimum period of 5 years or as per the MNRE and Govt. of India Regulations.

The strength of the solar energy (radiation) available depends on the time of year, the time of day, and the latitude of the generation point. The amount of energy that the system generates can change due to:

I. the amount of dust and water vapors in the air,

II. how much cloud cover

III. any shading of the solar panels

IV. and the quality of the solar modules.

 When you install a solar energy system on your property, you save money on your electricity bills and protect yourself against rising electricity rates in the future. How much you can save depends on the utility rates and solar policies in your area, but going solar is a smart investment regardless of where you live.

Solar power, like other renewable energy resources, has many environmental and health benefits . Going solar reduces greenhouse gas emissions, which contribute to climate change, and also results in fewer air pollutants like sulphur dioxide and particulate matter, which can cause health problems.