Rooftop Solar PV Systems- Common Questions

Rooftop Solar PV Systems is one of the most common thing talked about whenever we think about Solar PV Systems. So, there are a lot of questions which come to mind regarding the Rooftop Solar PV Systems. Let’s see some of the commonly sought-after questions regarding the same which people generally ask.

1. What is a Rooftop Solar PV System?

A Solar PV System where the Solar Panels are installed in the roof of any residential, institutional, commercial and industrial buildings.

2.What are the benefits of Rooftop Projects over Ground Mounted Projects?

Since land is not used; can be used for other multiple uses being a scare resource

Savings in transmission & distribution losses as electricity generation happens at the consumption centre

Can be setup faster

Easier operation & maintenance

Local employment generation

Improvement in tail-end grid voltage

3.What is the market potential of Rooftop Solar PV in India?

The estimated realistic market potential for rooftop solar PV in urban settlements of India is about 124 GWp

4.What are the different types of Rooftop Solar PV Systems?

Rooftop Solar PV Systems can be of two types:
(i) System with storage facility using battery, and
(ii) Grid Connected System.

5.What is a Rooftop Solar PV System with storage facility?

System with battery as storage facility. The energy from the Solar is stored in the battery and can be used even when the sun is not available

6.What is a grid connected solar rooftop solar PV system?

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.

7.How can it be accepted widely?

The following 03 (three) drivers are important to make it widely acceptable:

Availability- the product should be available in a range of acceptable capacities

Accessibility- the product should be backed by a wide network of distributors and service centres

Affordability- the product should be affordable through easy financing

8.Where can such a plant be installed?

Rooftop Solar PV systems can be installed on the roofs of residential, commercial complex, housing societies, community centres, government organizations, private institutions etc.

9.How much area is required for 1 kW rooftop solar PV system?

A 1 kW rooftop solar PV system generally requires 12 sq. metres (130 square feet) of flat, shadow-free area (preferably south-facing).

10.What is the average cost of grid connected rooftop system?

Approximately Rs.55-65 per Wp depending on the plant capacity

11.What are the models for implementation of rooftop solar PV systems?

CAPEX Model: Here, the entire system is owned by the rooftop owners. Responsibility of O&M for the system lifetime (25 years) is also with the rooftop owner. Developer is responsible for installing the system and initial 2-5 years O&M.
RESCO Model: Here, the entire system is owned by the developer. Responsibility of O&M for the system lifetime (25 years) is also with the developer. Rooftop owners may consume the electricity generated, for which they have to pay a pre-decided tariff on a monthly basis. Excess generation may be exported to the grid, subject to availability of requisite state regulations.

12.Which model is best for me?

For consumers that have adequate manpower for O&M, rooftop space & fund are available, CAPEX model is better.

Otherwise, OPEX is better.

13.What are the subsidies/ capital support available from the Govt?

Capital Subsidy at the rate upto 30% of the benchmark cost for general category states (upto 70% of the benchmark cost for special category states i.e., North-Eastern States including Sikkim, Uttarakhand, Himachal Pradesh, Jammu & Kashmir and Lakshadweep, Andaman & Nicobar Islands) is being given in residential, institutional (hospitals, educational institutes, etc.), social sector etc.
Commercial and Industrial sectors are not eligible for the above-mentioned subsidies.
Government Institutions including Public Sector Undertaking (PSU) shall not be eligible for subsidy; instead they will be given achievement-linked incentives/awards.
Subsidy support is also available in various states. The percentage of subsidy varies according to the state policies.

14.What are the other fiscal incentives being available for Rooftop Solar PV Systems?

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

15.What is net metering?

The system owner consumes solar electricity and receives retail value for any excess electricity fed into the grid, as recorded by a bi-directional electricity meter and obtained over the billing period.


We’ll be taking up more such questions on Solar PV Systems in future. Meanwhile if you have any specific questions to ask, please email your question to and we’ll get back to you with the answers to your questions.


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