FAQ’s

1. To enjoy practically free power for 25 years.
2. Increasing tariff rates of Electricity from DISCOMS
3. Reduction in carbon emissions, contribution towards clean and green environment.
4. Decreasing prices of Solar PV Panels.
5. Easy to Install.
6. No requirement of additional land.

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 440/220 Volt three/single phase line or 33 kV/11 kV three phase lines depending on the capacity of the system installed at residential complex or institution/commercial establishment 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.

Yes, in Haryana it is mandatory for all commercial buildings, schools, hospitals, offices, factories and residential premises bigger than 500 sq yards. Other states are also likely to make it mandatory.

There is a provision of Central Financial Assistance of 30% of the total cost or Rs. 12 to Rs. 18 per watt or Rs. 1.20 crore per MWp under the Grid Connected Rooftop and Small Solar Plants Programme of the Ministry. This is available on First come First Serve basis and with a limited budget.

Solar inverters are designed to block power outflow in the event of grid failure. But if the inverter senses that the power is available (Let’s say from DG Set) then it will start flowing power to load. This means that solar inverter needs to sense that power is available. Some people assume that even if a DG of 1 KVA is installed to send signal to solar plant , it will suffice and solar plant will start giving power. This is theoretically correct but it is not practically possible and practically one needs to connect DG set of 1.25 time load to take benefit of solar power also where in Solar installation should not be more then 80% of DG Capacity. In such a scenario DG will continue to run may be at almost NO load condition so as to consume minimum fuel and power shall be supplied by solar and fluctuations in solar power shall be taken care by DG set.

If above precautions are taken then it is possible to design a system to exploit solar generation and save on fuel costs while DG set is running.

However, recommended settings are - if load is 1KVA then DG capacity should be 1.5KVA and solar capacity which can be installed should not be more than 0.6KVA.

The net metering based rooftop solar projects facilitates self-consumption of electricity generated by the rooftop project and allows for feeding the surplus energy into the network of the distribution licensee. In net metering 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.

Average maintenance cost is almost nil since the components used are having the MTBF (mean time between failure) of 23-25 years.

The life of solar panels is about 40 years but the manufacturers give a warranty for 25 years.

Each KW system will generate about 1300 units of electricity in a year. However, it would depend on specific area.