9653005099, 9560088622 info@famsolar.com


Frequently Asked Questions

What is a Solar Rooftop System?

A Solar Rooftop System, as the name suggests, is a solar power generation system installed on the roof of any building. A solar rooftop system can be installed on the roof of any commercial, industrial, domestic, government, or social institution building. There are majorly 2 types of solar rooftop systems;

  1. Solar Rooftop System with battery storage 
  2. Solar Rooftop system connected to power grid


What are the Main Components/Parts of a Solar Rooftop System?

An SPV Power System is installed using the following components;


Photovoltaic Modules (PV) or Solar Panels

Photovoltaic or PV Modules are arranged together to make a single Solar Panel. PV Modules are responsible for converting solar energy into electrical energy. One can find different types of PV Modules that use different technologies like- CIGS, HIT, CdTe, Thin Film, etc. Fam Solar holds expertise in installing high-quality Monocrystalline PV modules that produce optimum power for decades, and are the best option for rooftop solar power systems.


Mounts & Clamps

This includes a strong and robust structure that holds the Solar Panels and other electricals at place.



Inverter converts the Direct Current (DC) power of the SPV system into Alternating Current (AC) power. Inverter is a crucial component in grid-connected solar power systems.


System Balance Components

These include switchboards, cables, meters, junction boxes, monitoring & tracking system, earthing breakers, circuit breakers, fuses, etc. required to operate an SPV power system.

What is the minimum area requirement for the installation of 1 kW SPV rooftop power system?

A 1 kW Rooftop Solar Power system requires an average of 10 sq. meters of open-area without any shadowfall. However, the actual area and system size requirements depend upon the amount of incoming solar radiation, the efficiency of the PV Panels, shape of the roof and overall weather conditions

Are there any subsidy benefits on the solar rooftop systems?

The Indian Government has fiscal provisions on the installation of solar rooftop systems, namely;


  • Concession on the import duty of the PV Panels and system components
  • Tax benefits for grid-connected rooftop PV power plants
  • Accelerated depreciation to minimize the taxable income through the PV power system

What is the estimated potential of rooftop solar power production for India?

As per National Institute of Solar Energy (NISE), India has a potential of 43 Giga Watts for Grid-connected SPV systems.

What is a Grid-Connected Solar Rooftop System?

A Grid-Connected Solar Rooftop System feeds and draws excess or balance power from the main grid. Usually installed as a small SPV system, this system is either connected to the 440/220 volt single/three-phase grid line or 33 kV/11 kV three-phase lines. This connection depends upon the capacity of the solar rooftop power system and the regulations of the state.


During the day, grid-connected solar rooftop power system powers the captive loads and sends excess power to the grid as long as it is available. During the times when solar power generation is limited due to cloud cover, etc., the SPV system draws required power from the main grid.

What are the different models of implementation of Rooftop Solar Power Systems? Which model will be best for me?

There are 2 models of implementation of Rooftop Solar Power systems. They are;

CapEx Model

CapEx stands for ‘Capital Expenditure’ and is one of the common rooftop solar power system implementation model. In this model, the entire cost of the system procurement, operation and maintenance is borne by the rooftop owner. The Developer only installs the system and usually provides operation & maintenance services for first 2 years. The warranty provision varies with each supplier.


RESCO stands for Renewable Energy Service Company, and is an energy distribution model where the full ownership of the system belongs to the Developer. The Developer operates and maintains the SPV system throughout its life-cycle and bears all the costs. Rooftop owners can utilize the generated power on a monthly tariff basis, and the operator transfers any excess energy to the grid. 

As far as the suitability is concerned, both CapEx and RESCO models are preferable depending upon the end-user.

CapEx model is much more suited to the users who have the technical know-how for O&M of the system, rooftop security concerns, and capacity to pay the upfront costs for long-term feasibility.

RESCO model, on the other hand, is better suited to the users who don’t want any hassle in the operation & maintenance of the SPV system, have no security concerns with third-party rooftop access, and wish to pay for the power consumption on a monthly basis.


How does the metering system work/Power generation & Consumption Calculated?

There are two types of metering methods used to measure the power-generation, consumption and its net balance- Net metering method & Gross metering.

Net Metering

In case of a grid-connected SPV system, the consumer pays to the system owner on the net-meter reading basis. Another way to measure the consumption is installation of two separate meters that can measure the excess supply to the grid and power drawn from the grid.


Gross Metering

Gross metering is the direct measure of the power supplied to the main grid. The owner of the system is paid a pre-agreed tariff in exchange of the power supplied to the grid.


What are the major benefits of a grid-connected rooftop solar system?

Rooftop solar system, no matter what the implementation model is, serves manifold advantages to the beneficiaries.

Cost & Savings Benefits

A grid-connected SPV power system gives significant cost-saving advantages. Following is a break-up of costs and savings for a 1 kW SPV rooftop system;


  • Cost of a Grid-connected Solar Rooftop system- INR 60,000 per kW
  • Government Subsidy- INR 18,000 per kW
  • End-user Cost with CapEx model- INR 42,000 per kW
  • Power generated by a 1 kW system per annum- 1200-1500 units
  • Cost savings per annum (at an average tariff of INR 5 per unit)- INR 6000 to 7500
  • Break-even period for the investment- 5-7 Years.


    If the user chooses the RESCO model, no investment is required and the solar power can be consumed on monthly tariff basis.


Eco-friendly Energy Benefits;


  • Solar energy is a naturally renewable source of energy
  • Clean energy production & consumption- No fumes or harmful by-products
  • Efficient power production

Contact Us

Ask a question or book an appointment below.