1. What is a photovoltaic (PV) system?

PV technology produces electricity directly from electrons freed by the interaction of sunlight with a solar panel made of semiconductor material. The power provided is direct current (DC) electricity. The basic building block is known as a Solar cell. Many cells put together are known as a module, and many modules assembled together form an array. A PV system will consist of an array of modules generating DC electricity, an inverter and can be stored in battery storage banks.

2. Are the solar PV panels fragile?

Solar PV panels manufactured as per National and International standards are robust and can withstand the normal stresses subjected by nature.

3. What are the components of a photovoltaic (PV) system?

A PV system is made up of different components. These include PV modules (groups of PV cells), which are commonly called PV panels; one or more batteries; a charge regulator or controller for a stand-alone system; an inverter for a utility-grid-connected system and when alternating current (ac) rather than direct current (dc) is required; wiring; and mounting hardware or a framework.

4. What is an inverter?

Majority of electrical equipment's used for domestic/commercial/ Industrial purposes are of AC system. So, it is necessary to convert solar power generated at DC system to AC system. An inverter will convert DC to AC system.

5. What is a "grid-tied" PV system?

Connecting your solar system directly into the utility (Your Electricity supply Company).

6. What are the different types of rooftop solar PV systems?
  • Grid Connected: These systems have no storage other than the grid itself. Any excess electricity generated from solar system is fed back into the grid. At night or during times of intense cloud cover, the installation draws power from the grid.

  • Hybrid (Grid tied with Storage): These systems are grid connected, but also have some storage capacity by way of a small battery bank. They provide some measure of continuity when the grid goes down at the same time as there is not sufficient solar input.

  • Off-grid: These systems are suited to remote locations where a grid connection is not available/when there will be no continuous power supply in the grid. The battery bank is sized to provide a certain number of days of storage in the installation and the installation draws power from the storage batteries during the night or during days of intense cloud cover.

7. Can I use Solar PV system to power my home?

Solar PV system can be used to power your entire home's electrical systems, including lights, cooling systems, and appliances.

8. What is net-metering?

Net-meter (bi-directional meter) is having provision to record energy imported from the grid to meet the load and energy exported to the grid after self-consumption. Both energy import and export records in the net-meter. The difference between Export and Import readings is the actual energy consumed/delivered.

The net meter records surplus energy exported to utility grid. When your system generates less energy than your consuming load, the meter records energy imported from utility grid.

9. What guarantees will I receive?

The SPV GT system will be normally having 25 years of guaranteed life and same is guaranteed by us 25 years for PV modules and 5 years for Inverter.

Utility company will sign a Power Purchase Agreement with Solar rooftop PV generator which will be in force for 25 years.

10. How much space on my roof do I need for a solar PV installation?

The grid connected SRTPV system of 1 kW peak power capacity requires about 100 sq. ft. / 10 metre square shadow free area on the rooftop.

11. How much electricity does a PV system generates?

For every kW peak SRTPV system installed on a South facing roof, the system will generate 4 to 5 units per day. However, the energy generation depends upon the weather conditions and reduces by around 20% for an East or West facing roof.

12. Making use of Solar Power

Solar Power is one of the naturally occurring energy sources of the planet. There are lots of advantages in using the natural energy sources because they are pollution free, easily obtainable and they are also renewable.

If you wondering how the simple sunlight is converted to electricity then you will be less than amazed to realize that the process is very straightforward. Basically, all you need is a cell which converts sunlight into electrons and that cell is called as the Photovoltaic cell.

13. Components of a Solar Energy System

In order to construct a solar energy conversion system in your home, you would need four main components namely the Solar Panel, Batteries, Charge Controller and the Inverter. Let us see in brief about all of these components.

14. What is photovoltaic or PV?

The process of converting light from the sun into electricity is called solar "photovoltaic" or PV for short. The term "photo" comes from the Greek "phos " meaning light. "Voltaic " is named for Alessandro Volta (1745-1827), a pioneer in the study of electricity for whom the term "volt " was named. Photovoltaic, then, means "qlight electricity".

15. How can we get electricity from the sun?

When certain semiconducting materials, such as certain kinds of silicon, are exposed to sunlight, they release small amounts of electricity. This process is known as the photoelectric effect. The photoelectric effect refers to the emission, or ejection, of electrons from the surface of a metal in response to light. It is the basic physical process in which a solar electric or photovoltaic (PV) cell converts sunlight to electricity.

Sunlight is made up of photons, or particles of solar energy. Photons contain various amounts of energy, corresponding to the different wavelengths of the solar spectrum. When photons strike a PV cell, they may be reflected or absorbed, or they may pass right through. Only the absorbed photons generate electricity. When this happens, the energy of the photon is transferred to an electron in an atom of the PV cell (which is actually a semiconductor).

With its newfound energy, the electron escapes from its normal position in an atom of the semiconductor material and becomes part of the current in an electrical circuit. By leaving its position, the electron causes a hole to form. Special electrical properties of the PV cell a built-in electric field provide the voltage needed to drive the current through an external load (such as a light bulb).

16. How long do photovoltaic (PV) systems last?

A PV system that is designed, installed, and maintained well will operate for more than 20 years. The basic PV module (interconnected, enclosed panel of PV cells) has no moving parts and can last more than 30 years. The best way to ensure and extend the life and effectiveness of your PV system is by having it installed and maintained properly. Experience has shown that most problems occur because of poor or sloppy system installation.

17. What are the benefits of using solar energy to heat water in my home?

First, the fuel is free! Once you recover the higher initial costs of a solar system through reduced or avoided energy costs (that is, lower utility bills), your solar system will require expenditures only for maintenance. And when you include the cost of a solar water heater in a mortgage on a new home, the system often provides a positive monthly cash flow from the first day of ownership.

Second, solar water heaters and other solar technology applications do not pollute. They do not add to the carbon dioxide, nitrogen oxides, sulfur dioxide, and other air pollutants and wastes produced by most of today's power plants, even those that run on natural gas. And they allow you to burn less natural gas in your home, as well.

18. What is the difference between "solar energy" and "photovoltaic"?

Photovoltaic is one form of solar energy. The term solar energy can refer to something as simple the energy gathered in your parked, sealed car (solar collector) and converted into heat. Photovoltaic refers specifically to the practice of converting the sun's energy directly into electricity using photovoltaic cells. Photovoltaic cells are often referred to as PV cells or solar cells.

19. Why use Solar Energy?

Solar energy is a viable alternative to fosil fuels and some alternative energy sources, as it gives off no carbon dioxide waste and uses the natural energy from our sun to generate electricity.

  • Increases the value of your home
  • More financial benefits since using solar energy for electricity, heating, cooling and lighting
  • Positive impact on the environment
  • Energy independence
20. How much does a solar water-heating system cost?

Unfortunately, there is no one answer to this question. The cost of a solar system depends on a number of factors, such as the size of the system and the particular system manufacturer, retailer, and installer. However, any solar rebates and other incentives available in your area will reduce that total cost.

For solar water heaters and space heaters, you will also be taking into consideration the price of the fuel used to back up the system. In most cases, you will have to add in the cost of supplemental natural gas or electricity to get a fairly accurate estimate of how much you can expect to pay for a solar system.

21. How much money will a solar water-heating system save on my utility bill?

It is difficult to say how much you will save with a solar system. That depends on several factors, including how much you already pay your local utility for electricity or natural gas. You can ask your solar system professional how much heat your new system will produce on an annual basis and then subtract that number from your current annual consumption the total amount of electricity and gas you use to get an idea of how much you will save. Data on your current annual consumption should be available from your utility.

Advantages of Solar Power

Solar Energy provides the best viable solution to ensure long term energy sustainability with the following advantages:

  • Abundant, constant and perennial source, predictable.
  • Solar resource is much more evenly distributed across the state.
  • Low gestation period
  • Available during the day time, helping in peak demand.
  • Can be generated at the point of consumption.
  • Reduced Transmission & Distribution losses.
  • No fuel cost.
  • Clean & green power i.e. no emission of CO2, Sox, Nox etc.
Solar Energy Plants, the following are inevitable:
  • Suitable Land
  • All permissions
  • Civil Construction Work
  • Selection of international standard Technologies.
  • Selection of Modules and other equipments.
  • Power generation.
  • Commissioning of the Plant.
  • Starting power generation and supply to the grid in a short span of time.
  • Administrative body required for power generation.
  • Selection of third party for power sale
  • Sale of power and its related correspondences.
  • Operation and Maintenance of the Plant for 25 years with R&D Facilities.

Interesting Facts

  • Solar radiation takes approx. 8:19 minutes to travel ~150 million kilometres from the Sun to the Earth
  • Our distance from the Sun: 147 million km at Perihelion (3 January) and 152 million km at Aphelion (4 July)
  • Physical characteristics of the Sun
  • Diameter of the earth: 7,900 miles (12,7 km); Diameter of the sun: 870,400 miles (1,392,700 km)
  • Compared to the Earth, Sun’s diameter is 110x Earth, Sun’s volume is 1,300,000x Earth and mass is 333,000x Earth
  • Amount of solar energy reaching the earth’s surface in a year is about 885 million TWh
  • Earth’s primary energy supply in 2008 was 142,712 TeraWatt-Hours (TWh)
  • Sun provides about 6,200x times more energy needed by the earth
  • Solar panels first appeared on the market in 1956
  • Space programs started using photovoltaic powered systems in 1958, and are still used today
  • In July 2010, Solar Impulse became the first manned solar aircraft to fly overnight; completing its first intercontinental flight from Spain to Morocco in June 2012

Why Do We Need to Utilize Solar Power

solar energy. Top 10 reasons to consider utilizing solar energy as you evaluate ways to meet your energy needs.

  1. Attractive Financial Return: With only upfront costs is installation and non-existent maintenance capital expenditures, solar energy provides an attractive way to realize long term financial benefits and attractive rates of return. Our advisory professionals can show you the math, if you are interested in the details.
  2. Sell Excess Power: Through Power Purchase Agreements (PPA) and other methods, you can sell any excess power to the utility providers or electricity boards. Some developers are building solar power generation units solely for the purpose of supplying to energy companies, through contractual agreements that guarantee a solid return on their investments.
  3. Government Rebates and Financing: In many cases, local and central governments offer incentives in the form of direct funds, financing and tax rebates to promote and support the installation of solar power units.
  4. Energy Independence: Is there a better feeling that not having to worry about external factors to provide for your electricity needs? Solar power lets you generate electricity right in your backyard.
  5. Rising Electricity Rates: Conventional power is dependent on natural resources, which are further dependent on global pricing, geopolitical challenges and technology issues. Historically, price of conventional electricity has consistently risen over the last four decades, whereas price of solar power has reduced driven by rising demand and technological advances.
  6. Minimum Maintenance: With no moving parts, solar power generation units require minimum maintenance efforts and expenditure. Even a strong torrential rain will only help in cleaning up the solar panels, and making them more efficient.
  7. Creates Jobs: One of fastest growing sectors, recognized by governments across the globe, in terms of creating new job opportunities.
  8. Preserve Mother Nature: As debates over sustainability wrangles on, this is one of man’s initial efforts to supplant hydrocarbon based energy sources and generate power in the least disruptive methods.
  9. Unlimited Distribution to Remote Areas: Sun shines equally on everyone. Remote and rural areas are unique benefactors to solar energy as the power generation units could be located in the vicinity of end-users, eliminating the need to install elaborate infrastructure (and associated costs) to transmit the power over long distances.
  10. It is the Future: Believe it or not, this is where the future of energy is headed. If you are not convinced, you just need to wait a little before history unfolds before your eyes.

Links to External Sites


Central Electricity Authority (CEA)
Indian Renewable Energy Development Agency (IREDA)
Ministry of New and Renewable Energy (MNRE)
National Bank for Agriculture and Rural Development (NABARD)
Solar Guidelines


Intergovernmental Panel on Climate Change (IPCC)
the United Nations Environment Programme (UNEP)
World Meteorological Organization (WMO)
International Energy Agency (IEA)
ABT Availability Based Tariff
BIS Bureau of Indian Standards
BOM Bill of Material
BOQ Bill of Quantity
BPC Bid Process Co-ordinator
C-WET Center for Wind Energy Technology
CAPEX Capital Expenditure
CCD Concessional Customs Duty
CDM Clean Development Mechanism
CEA Central Electricity Authority
CED Concessional Excise Duty
CEI Chief Electrical Engineer
CEIG Chief Electrical Engineer (to Government)
CERC Central Electricity Regulatory Commission
CSP Concentrated Solar Power
CTE Consent to Establish
CTO Consent to Operate
CUF Capacity Utilization Factor
DGCA Directorate General for Civil Aviation
DGFT Directorate General of Foreign Trade
DNI Direct Normal Irradiance
DPR Detailed Project Report
DSCR Debt Service Coverage Ratio
EPC Engineering, Procurement and Construction
FI Financial Institution
GBI Generation Based Incentive
HT High Tension
IEC International Electro technical Commission
IEGC Indian Electricity Grid Code
IMD India Meteorological Department
IREDA Indian Renewable Energy Development Agency
IRR Internal Rate of Return
JNNSM Jawaharlal Nehru National Solar Mission
kWp kilo Watt-peak
LoA Letter of Award
LoI Letter of Intent
LT Low Tension
MNRE Ministry of New & Renewable Energy
MoU Memorandum of Understanding
MW Mega Watt
NASA National Aeronautics and Space Administration
NGO Non-Governmental Organisation
NLDC National Load Dispatch Centre
NREL National Renewable Energy Laboratory
NSM National Solar Mission
NVVN NTPC Vidyut Vyapar Nigam
NVVNL NTPC (National Thermal Power Corporation) Vidyut Vyapar Nigam Limited
O&M Operation & Maintenance
OPEX Operational Expenditure
PIA Project Implementation Agreement
PPA Power Purchase Agreement
PSA Power Sale Agreement
PV Photovoltaic
REC Renewable Energy Certificate
REDA Renewable Energy Development Agency
RFP Request for Proposal
RFQ Request for Quotation
RFS Request for Selection
SEC Solar Energy Center
SECI Solar Energy Corporation of India
SERC State Electricity Regulatory Commission
SLP Sea Level Pressure
SNA State Nodal Agency
SPV Solar Photo Voltaic
SRRA Solar Radiation Resource Assessment Station
STU State Transmission Utility