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FAQ for

Solar PV Power Plant

What are the benefits of using PV solar systems?

By utilizing PV solar cells, home or business owners are able to generate electricity from sunlight, saving money and minimizing our carbon footprint on this planet hence doing their bit to saving the planet. This solar generated energy is used to offset or replace power that would normally be purchased from the utility.

What is a grid-tied solar system?

Most of the systems installed in the Urban areas are Grid Tie system, As the name suggests, with the help of an Inverter the electric load for the Owner’s premises is shared between the Solar PV system and the Grid. Power from the Grid is taken only if the power consumption for the house exceeds the PV system capacity.

What is an off-grid solar system?

An off-grid solar energy system is where there is no connection to the utility company power grid. This type of installation requires a charge-controller, a bank of batteries and in most cases an inverter, so that electric power requirements can be met at night or during cloudy conditions

How much roof space does a PV system need?

A typical solar panel of 200Wp will measure about 17 square feet. Depending on installation factors, the required square footage of roof space will be somewhat larger than simply the area of the panels. Based on your information, once our engineering department has determined the required angle, shading factors, etc. we can give you a more accurate number.

How do I decide how large my PV solar system should be?

Typically the best return on investment is when you target the average power in watts used during the month with the lowest electric bill.

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.

Are the solar PV panels fragile?

Solar PV panels are very robust and can withstand the normal stresses subjected by nature.

Why should I purchase a PV system?

People decide to buy solar energy systems for a variety of reasons. For example, some individuals buy solar products to preserve the Earth’s finite fossil-fuel resources and to reduce air pollution. Others would rather spend their money on an power-producing system on their property. Some people like the security of reducing the amount of electricity they buy from their distribution companies, because it makes them less vulnerable to future increases in the price of electricity.

Can it be installed any where?

It can be installed on: Roof tops, Building terraces, Open grounds, balconies facing south. There should be no shadowing.

How much subsidy does the Government offer for a Solar PV plant for residential and Commercial buildings?

The government offers:

For residential places: 30% subsidy on the benchmark cost.
For commercial (income generating) buildings: No subsidy.

Solar Water Heaters

What is Solar Water Heater?

A Solar Water Heater is a device which provides hot water for residential, commercial & industrial purpose using solar energy. It is generally installed at the terrace or where sunlight is available and heats water during day time which is stored in an insulated storage tank for use when required including mornings.

How does it work?

A Solar Water Heater comprises of an array of solar collectors to harness solar energy and an insulated tank to store hot water. Both are connected to each other. During the day time, water in solar collectors gets heated which is either pumped or flown automatically on thermosyphon principle to the storage tank. Hot water then stored in the tank can be used for various applications.

What are different types of Solar Water Heaters?

Two types of Solar Water Heaters are available; one based on flat plate collectors and the other based on evacuated tube collectors. Flat plate collector (FPC) based systems are made of copper tube and copper fins, whereas ETCs are made of glass tubes with vacuum in between two tubes.
Both these systems are available with and without heat exchanger. They can also work with and without pump. Systems without pump are known as thermosyphon systems and those with pump are known as forced circulation systems.

How do I know the suitable capacity of the system that i will require?

Capacity Suitable number of people 100 2 200 4 250 5 300 6 500 10

Which type of solar water heater is suitable for different places/ category of users?

ETC based systems are cheaper than FPC based system. They perform better in colder regions and avoid freezing problem during sub-zero temperature. FPC based systems also perform well with anti-freeze solution at sub zero temperature but their cost increases. In other regions, both perform equally well. Systems working on thermosyphon principle are simple and relatively inexpensive. They are suitable for domestic and small institutional applications, provided water quality is good and it doesn’t have large chlorine contents. Forced circulation systems are generally preferred in industries or large establishments. At places where water is hard and have larger chlorine content, if FPC based system is being installed, it must be with heat exchanger as it will avoid scale deposition in copper tubes of solar collectors which can block the flow of water as well reduce its thermal
performance. ETC based systems will not block the flow of water but its performance may go down due to deposition of salt contents on inner surface of glass tubes, which could be cleaned easily once in a year or so.

Why should I go for a Solar Water Heater? What do I save from it?

A 100 litre per day capacity system suitable for 2-3 people can save upto 1500 units of electricity in a year, depending on hot water used. It can also save around 140 litres of diesel in an establishment using oil fired boiler besides reducing green house gas emissions in the atmosphere. Higher capacity systems will save higher amount of electricity/fuel oil besides reducing higher amount of GHG emissions. Electricity is expensive and is not available due to power cuts in many areas when required for heating water. Solar Water Heater, since it stores hot water in an insulated tank, provides water all the time when required. Fuel oil is also expensive and creates pollution. Storing the fuel oil for long term use in commercial establishments is another problem.

What happens on cloudy/rainy day? Do I still get hot water?

On cloudy days also, if it is for a day or two, you still get warm water as water gets heated due to diffused radiation available in the atmosphere. The system, however, is either connected to an electric geyser in the house or an electrical back-up is provided in the storage tank of the system which is switched on when water is not sufficiently hot. So, you get hot water all the time even on rainy days.

Are there any maintenance requirements?

Domestic solar water heating systems do not need significant maintenance requirements. Occasional leakages in the plumbing could be easily repaired by common plumbers. In case quality of water is hard, scale deposition in the collectors may result over the years. This may require de-scaling with acids for which it is best to contact the suppliers. Broken glass may also have to be replaced by the suppliers. If outside exposed surfaces are painted, the paint may have to be redone every 2-3 years to prevent corrosion of the surfaces.

Can it be installed any where?

It can be installed on: Roof tops, Building terraces, Open grounds, balconies facing south. There should be no shadowing.

You said that the hot water will be available for 300-325 days in year. How about the rest of the days?
Every SWHS can be provided with auxiliary back up heating system by Electrical heater at extra cost.

Is there any subsidy available from Government?

No, currently, the Government Does Not Provide any subsidy on Solar Water Heater.


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