FAQ

• 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 RooftopSystem with storage facility using battery, and (ii) 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.

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

• The kind of roof determines if solar panels can be installed. Ability of the roof to support the weight of the panels and mounting structure even in strong winds is the critical parameter.

1. Concrete Roofs – Solar PV plants can be easily installed on flat concrete roofs. Inclined roofs may pose a challenge depending on the angle and direction of inclination.
2. Metal Roofs – This will depend on the type of structure and the weight it can withstand.
3. Asbestos/Other Sheet Roofs – These are the least likely of the 3 to be able to support solar panels, though it is possible in some cases.

• There is a provision of Central Financial Assistance of 15% of the total cost or Rs. 12 per watt orRs. 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 kWpupto 500 kWp or in combination can be set up on the roofs.

• About 10sq.m area is required to set up 1 kWp grid connected rooftop solar system.

• Electricity generation at the consumption center and hence Savings in transmission and

• distribution losses

• Low gestation time

• No requirement of additional land

• Improvement of tail-end grid voltages and reduction in system congestion with higher

• self-consumption of solar electricity

• Local employment generation

• 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 major the export and import of power separately. The mechanism based on gross metering at mutually agreed tariff can also be adopted.

• In feed-in-tariff the Government offers a tariff for purchase of the solar power generated from such plants.

• Net metering mechanism is more popular among States.

• In case the grid fails, the solar power has to be fully utilized or stopped immediately feeding to the grid so as to safe-guard any grid person/technician from getting shock (electrocuted) while working on the grid for maintenance etc. This feature is termed as ‘Islanding Protection’.

• So far, 13 States/UTs namely Andhra Pradesh, Chhattisgarh, Delhi, Gujarat, Haryana, Karnataka, Kerala, Punjab, Rajasthan, Tamil Nadu, Uttarakhand, Uttar Pradesh and West Bengal have notified policies that include promotion of grid connected rooftop solar systems with net metering. Regulation from the State Electricity Regulatory Commission is also required to allow net metering/ feed-in-tariff.

• 20 State/UT Regulators from Andhra Pradesh, Chhattisgarh, Delhi, Gujarat, Haryana, Karnataka, Kerala, Odisha, Punjab, Rajasthan, Tamil Nadu, Uttar Pradesh, Uttarakhand and West Bengal, Andaman & Nicobar, Chandigarh, Dadra & Nagar Haveli, Daman & Diu, Lakshadweep, Pondicherry and Goa have so far issued these regulations for netmetering/gross metering.

• There can be many possible business models, some of which can be considered are as follows:

(a) Solar installations owned by consumer
i) Solar Rooftop facility owned, operated and maintained by the consumer(s).
ii) Solar Rooftop facility owned by consumer but operated and maintained by the 3rd party.

(b) Solar installations owned, operated and maintained by 3rd PartyIf the 3rd party implements the solar facility and provides services to the consumers, combinationscould be:
i) Arrangement as a captive generating plant for the roof ownersThe 3rd party implements the facility at the roof or within the premise of the consumers; the consumer may or may not invest as equity in the facility as mutually agreed between them. Thepower is then sold to the roof owner.
ii) Solar Lease Model, Sale to Grid The 3rd party implementing the solar facility shall enter into a lease agreement with theconsumer for medium to long term basis on rent. The facility is entirely owned by the 3rd partyand consumer is not required to make any investment in facility. The power generated is fed into the grid and the roof top owner gets a rent.

(c) Solar Installations Owned by the Utility
i) Solar installations owned operated and maintained by the DISCOM The DISCOM may own, operate and maintain the solar facility and also may opt to sub contractthe operation and maintenance activity. The DISCOM may recover the cost in the form ofsuitable tariff. The electricity generation may also be utilized by DISCOM for fulfilling the solarrenewable purchase obligation.
ii) Distribution licensee provides appropriate viability gap funds The DISCOM may appoint a 3rd party to implement the solar facilities on its behalf and provideappropriate funds or viability gap funds for implementing such facility.

• A solar PV plant must have another source of power (grid/DG/battery) to function – the other source is used to provide a reference voltage as solar power is continuously varying. In the absence of reference power, the solar plant will not generate electricity even in bright sunlight.

1. A grid-tied plant synchronizes only with the grid and will shut down in the absence of gridpower.
2. A hybrid plant can synchronize with either gird or DG or battery and will shut down if allthree are absent.

• Solar panels have at least 5-year manufacturing defect warranty and a 25-year output warranty (typically 90% of power output at year 10 and 80% of power output at year 25). The warranty of the panels may also extend up to 10 years.