What is a Solar Rooftop System?
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
(i) Solar Rooftop System with storage facility using battery, and
(ii) Grid Connected Solar Rooftop System.
What is a Grid Connected Solar Rooftop 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 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.
Where can such plants be installed?
Such rooftop systems can be installed at the roofs of residential and commercial complex, housing societies, community centers, government organizations, private institutions etc.
How much area is required for a 1 kW rooftop Solar PV system?
A 1 kW rooftop system generally requires 10 sq. metres (100 square feet) of flat, shadow-free area (preferably south-facing). Actual sizing, however, depends also on local factors of solar radiation and weather conditions and shape of the roof.
What are the subsidies/capital support available from the Government?
Subsidies are available from multiple channels for setting up Rooftop PV projects.
Subsidy/Support from Central Government through MNRE:
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 will not be 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 from State Government through State Nodal Agencies (SNAs):
Subsidy support is also available in various states. The percentage of subsidy varies according to the state policies.
What are the other fiscal incentives are available for Solar Rooftop Systems?
There are provisions of concessional import duty/ excise duty exemption, accelerated depreciation and tax holiday for setting up grid connected rooftop power plants.
What efforts is the Government making to provide loans for solar rooftop systems?
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.
What are the models for implementation of Rooftop 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 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.
What is net-metering?
The grid connected rooftop system can work on net metering basis wherein the beneficiary pays to the utility on net meter reading basis only. Alternatively two meters can also be installed to measure the export and import of power separately. The mechanism based on gross metering at mutually agreed tariff can also be adopted.
What is feed-in-tariff?
In feed-in-tariff the Government offers a tariff for purchase of the solar power generated from such plants.
What are requirements from State to promote grid-connected rooftop solar systems?
(i) States should have conducive solar policy to allow the grid connectivity.
(ii) State Regulators have issued tariff order for appropriate tariff, net metering/feed-in tariff and the grid connectivity, and
(iii) The Distribution Companies agree to allow grid connectivity and purchase the electricity on feed-in-tariff or through net metering arrangement.
What are the advantages of Grid-Connected Rooftop Solar System?
(i) Electricity generation at the consumption center and hence Savings in transmission and distribution losses
(ii) Low gestation time
(iii) No requirement of additional land
(iv) Improvement of tail-end grid voltages and reduction in system congestion with higher self-consumption of solar electricity
(v) Local employment generation