FREQUENTLY ASKED QUESTIONS

How much time does it take to install a solar PV system?

On average, installing a rooftop solar PV system takes about 4-6 weeks.

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Will I have to change my electrical fittings after the solar panel installation?

No, there is no need to change the electrical fittings in your house. The inverter converts the DC output of the panel into AC power, which is further supplied to the appliances in a home, and also synchronizes with the grid so that the generated power can be fed into the grid.

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How much rooftop area will be required for 1KW installation?

A minimum of 100 square feet, which is shadow-free,  is required for every Kilowatt of installation.

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What are the different models for implementation?

1. CAPEX - In this model, the consumer bears the cost of the system and owns it.

2. Power purchase agreement (PPA)- In this model, the entire system is owned by a third-party developer. The consumer buys the power at a fixed tariff from the developer as per the power purchase agreement. The responsibility of maintaining the system is also with the third-party developer. 

3. Deferred payment agreement (DPA) - In this model, the cost of installation is initially borne by the installer. The consumer then pays monthly instalments at a pre-decided interest rate and at the end of full payment, the ownership of the system is transferred to the consumer.

The CAPEX and DPA model have added benefits like Accelerated depreciation and relaxation in taxes for the consumer as the ownership of the system is with the consumer.

 

What is a feed-in tariff?

Feed-in-tariff is a policy that is adopted nationwide. It enables anyone who generates electricity from renewable energy sources – be it a homeowner, small business or a large electricity utility - to sell it to the grid and receive guaranteed long-term payments at a predetermined rate for energy transferred. In feed-in tariff, the Government offers a tariff for the purchase of solar power generated from such plants.

 

What is gross metering?

The total electricity generated by the solar system is injected into the grid, and the consumer imports electricity from the grid for consumption. A unidirectional meter or gross meter is used to measure the solar energy generated and injected into the grid. The import meter is used to measure the electricity imported by the consumer from the grid. At the end of the settlement period, the consumer is compensated for the electricity exported to the grid at the Feed-in-Tariff (FiT) rate (which is generally lower than the retail rate) determined by the State Electricity Regulatory Commission.

 

What is net metering?

The electricity generated by the rooftop solar system is consumed by the user and any excess electricity is injected into the grid. In case more power is required, the consumer can draw that power from the grid. A bi-directional meter is used to measure the net consumption. The consumer is only charged for the ‘net’ energy utilised – the difference between the energy produced through the rooftop system and the energy consumed from the grid over the billing period. This is very beneficial for the consumer as the compensation is at the retail rate.

 

What is net billing?

While net metering will compensate you at the retail rate, net billing will compensate you at the lesser supply or wholesale rate. In this system too, a bidirectional meter is used to measure the import and export of electricity. In case, the export from the rooftop is more than the import of electricity from the grid, the consumer is compensated at a fixed rate/ wholesale rate. In case, the export is less than the import, the excess consumption is billed at the retail rate. This benefits the distribution company as they receive power from the rooftop system at a lower rate and sell power from the grid at a higher rate.

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How to clean solar panels?

Solar panels get dirty due to dust, bird droppings and other materials. This can reduce the efficiency of the panels, hence panels need to be cleaned regularly. 

Use a non-abrasive sponge and soapy water to clean the panels. Wash it with running water. Do not use any high-pressure water because this might damage the panels. There are several agencies that provide professional cleaning services as well as cleaning machines available in the market. It is advisable to clean your panels almost every day on your own and get the panels cleaned professionally twice every month.

 

What is the average life of a single solar panel?

The average life of a single solar panel is about 25 years.

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Which appliances run on a rooftop solar system?

On a typical 3KW, you can run all appliances like a fan, refrigerator, washing machine, cooler, lights and mixer. You will mostly not be able to run a one-ton AC, only from the power generated by the rooftop. However, you can always draw this power from the grid during summer when the usage of AC is required or install a higher capacity rooftop system to run your ACs.

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Can solar rooftop system charge EV?

EV charging can be done using solar power. There are several factors that need to be taken into account-

1. Type of charger used

2. Rooftop solar system size: Typically needs 5KW and more capacity

3. The vehicle battery level

4. How often do you travel and how far do you drive?

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What permits and approvals are required to install a solar PV system?

No permits are required for installing solar on your rooftop. Permission would, however, be required for installing the net meter or gross meter (whichever is applicable for your state) at your premise. This permission is given by your power distributor after your fill in your application form, submit the required documents and receive permission to install the meter at your premise from the distributor.