Frequently Asked Questions

A Solar Power Plant produces electricity directly from Sun by the interaction of sunlight with a solar panel made of semiconductor material. The power provided is direct current (DC) electricity. A Solar Power Plant consists of an array of modules generating DC electricity, an inverter and sometimes battery storage back up.

(a) Stand Alone System: It is off grid solar power plant which are further of two types
     (i) Stand Alone System with Battery Bank and
     (ii) Stand Alone System without Battery Bank
(b) Grid Connected SPV Plant: It is grid connected solar power plant which are further of two types
     (i) Grid Connected Hybrid System with Battery Bank and
     (ii) Grid Connected System without Battery Bank
     (c) Grid-Export System: It is a grid connected system with 100 % export to the Grid

Solar Power Plant of capacities ranging from 500 Watts to 500 kWp may be installed under MNRE Scheme. However Solar Power Plant of any capacity can be installed.
A Solar Power Plant can be installed in a shadow free area either in open ground or on the roof top.
For installation of Solar Power Plant shadow free area of about 10 square meter per KWp area is required. However area requirement depends on the capacity of solar modules used. KWp : 1000 Watts per square Meter ( Under Set Standard Test Conditions)
Any electric operated devices/ gadgets can be operated from a Solar Power Plant depending on the capacity of the plant, however heavy load are not advisable to operate from a small capacity Solar Power Plant with battery bank.
For every kWp power installed on a South facing rooftop, the system will generate around 1200 to 1600 units in a year.
On clear sunny day a Solar Power Plant can generate electricity for about 6 hours daily.
Electric power may be available from the solar power plant if battery bank is installed.
Yes, it can be used in combination with the grid power by installing a grid connected or grid tied Solar Power Plant.
Solar Power Plant with battery bank will work even when grid power (Electricity Supply) is not available but the power from solar power plant cannot be exported to grid in absence of grid power. However, the Solar Power Plant without battery bank will not work or give the power in absence of grid power (Electricity Supply).
Yes, existing inverter can be attached with the Solar Power Plant by adding charge controller. The charge controller can manage the variation in voltage. In Solar Inverter the charge controller is inbuilt.
The user may install the Solar Photovoltaic Power Plants either through the registered companies/Entrepreneur/firm.
Once material is supplied at site Solar Power Plant up to 50 kWp can be installed within 5 days.
Tentative cost of Solar Power Plant without battery bank may be at the rate of Rs. 75-80 per watt while that of with battery bank may be @ Rs. 110-130 per watt, the cost depends on the type and capacity of battery bank. However, the cost of the systems reduces as the capacity of the system increases.
Solar Panels/Modules, Power Conditioning Unit (PCU)/Inverter, Battery (in case system with battery bank) and DC & AC cables are the major parts of the Solar Power Plant.
The complete Solar Power Plant shall be guaranteed for 5 years while solar panels shall be guaranteed for 25 years for 80% power output as per the MNRE guidelines.
Solar Power Plant can be transported/ installed at any other place by technical person but not easily.
If system is grid connected, having net-metering facility, then it the surplus power can be fed into the grid through a Bi-Directional meter. In case of off grid system the surplus power after charging battery bank fully will go waste.
Yes, in a net metering system surplus electricity generated from a Solar Power Plant be given to the power utilities which can be adjusted within the financial year.
The “grid-connected” Solar Power Plant may connected to the grid power by installing bi-directional meter with the permission of power utilities under “Net Metering” regulations of the State.
Solar Power Plant can directly be connected from the Grid. The “Net Metering” allows you to feed the excess electricity to the grid when your system is generating more power than you are consuming. The power exported to the grid may be credited to his account and can be used by the consumer during the financial year. However carry forward beyond the financial year is not allowed under net metering regulations. Detailed Net-metering Regulations can be downloaded from the web site of State Nodal Agency.
These are safe from wind for a wind velocity of about 150 KM per hour and also safe from hailstorms to a great extent, if installed properly, as per specifications of MNRE.
The roof mounted Solar Power Plant do not need any permission from the Municipal Authorities.
Most roofs are strong enough to take a solar installation without any reinforcement. However, in case of larger systems, it is suggested to obtain the opinion of a qualified Structural Engineer.
The roof mounted off grid Solar Power Plant no permission is required, however for a grid connected system permission will be required from Power Utility.
The nodal point of contact for technical help for installation of Solar Power Plant is the office of Addl. Deputy Commissioner-cum Chief Project Officer at district level and the Director, Renewable Energy Department at state level.
(i) Monocrystalline.
(ii) Polycrystalline
(iii) Thin film/ amorphous.
Monocrystalline solar panels tend to be slightly more expensive than polycrystalline panels, however monocrystalline panels are regarded as having a higher efficiency than others. The degradation level is more in case of Thin film/amorphous solar cells.
Normally weight of a 250 Watt panel/Module about 15-20 kg.
Solar PV panels are very robust and can with stand the normal stresses subjected by nature.
There are two kinds of electricity, DC and AC. Homes that are connected to utility power use AC electricity. Flashlights, small radios and automobiles use DC electricity. In order to use solar power to operate the appliances in your home, an inverter will convert PV power from DC to AC. Inverters can be further classified as units that use batteries (UPS) and those that use the utility grid as power storage (Grid-connected). For grid connected solar power plants with battery bank, Power Conditioning Unit (PCU) is required having various features, while for system without battery bank shall require inverter.
Yes. The various components of SPV system shall have IEC/ISI/BIS Certification and confirm to technical standards specified by MNRE.
For residential Solar Power no tax benefits. For Commercial Institute 40% accelerated depreciation.
Following may be the options in the OCU:
A. Grid Export System Hybrid PCU( Grid Connected with battery bank):

Condition # 1:
SPV present, Grid available
Battery Charged through MPPT* charger + mains & Load supplied through Grid
MPPT – Maximum Power Point Tracker
SPV – Solar Photo Voltaic

Condition # 2
PV available, Battery charged, Grid available surplus power exported to grid connected loads

Condition # 3
SPV not available, Grid available,
Battery charging through Mains

Condition # 4
SPV not available, Grid OFF,
Inverter supplying power to grid connected loads through Battery

Condition # 5
SPV & Grid not available
Battery discharged. Start DG command
Battery charging through DG

B. Grid-Connected Power Plant (Having Net Metering facility)without battery bank:

Condition # 1:
PV present, Grid available
Load supplied through PV upto level of PV and draws more if required from Grid

Condition # 2
PV available, Grid available
If load is less then PV available then surplus power exported to grid

Condition # 3
PV not available, Grid available,
Load supplies from Grid.

Condition # 4
PV available, Grid Not available
The power plant will not work

Advantages of A Hybrid System (Grid Connected with battery bank):

•High level of reliability to Battery bank.
•Lesser battery discharge and hence longer life of battery.
•Reduced electricity bills.
•Highly reliable system and can be used in wide range of URBAN/Industrial/Institutional application. Also improves the quality of AC power and can be called solar UPS. Limitations of a Stand-Alone (Off Grid Plant):
•High Cost.
•High cost on maintenance
•Works on battery charge-discharge leadings to:
•Wastage of precious PV power generated.
•Reduced battery life.
•Worst performance when used with VRLA Battery
•Does not ensure optimum yield from PV panels.
•Thus stand-Alone system is suitable only for RURAL where AC Power is not available at present and is not likely in near future.

Advantages/Disadvantages of Grid-Connected Power Plant without battery bank:
•High conversion efficiency of PV Power into usable AC power
•Simple system with longer life i.e. no battery life issue.
Works only when grid power is available.