I. FAQ- SOLAR WATER HEATING SYSTEM
1. What is Solar Thermal Energy?
Energy in the form of heat (thermal energy) is required for many purposes in the domestic, agricultural, industrial, and commercial sectors of the economy. Solar thermal energy can meet many of these needs in a cost-effective and reliable manner. A solar thermal system basically absorbs the heat in solar energy and transfers it to a medium such as water or air. When used for purposes such as heating of water, cooking, drying of various commodities and products, and distillation of water, solar thermal systems can partially or fully replace the conventional fuels such as coal, oil, and electricity. Solar thermal technology has a tremendous potential for saving conventional energy in India.
2. What is Solar Water Heating System?
A solar water heating system is a device that uses solar energy to heat water for domestic, commercial, and industrial needs. Heating of water is the most common application of solar energy in the world. A typical solar water heating system can save up to 1500 units of electricity every year, for every 100 liters per day of solar water heating capacity.
3. What Kind of Solar Water Heating Systems are available in market?
Flat Plate Collector (FPC) and Evacuated Tube Collector (ETC)
Flat Plate Collectors (FPC) based Solar Water Heaters
The solar radiation is absorbed by Flat Plate Collectors which consist of an insulated outer metallic box covered on the top with glass sheet. Inside there are blackened metallic absorber (selectively coated) sheets with built in channels or riser tubes to carry water. The absorber absorbs the solar radiation and transfers the heat to the flowing water.
Evacuated Tube Collectors (ETC) based Solar Water Heaters
Evacuated Tube Collector is made of double layer borosilicate glass tubes evacuated for providing insulation. The outer wall of the inner tube is coated with selective absorbing material. This helps absorption of solar radiation and transfers the heat to the water which flows through the inner tube.
4. What is the working principle of Solar Water Heating System?
A solar water heating system consists of a flat plate solar collector, a storage tank kept at a height behind the collector, and connecting pipes. The system is generally installed on the roof or on open ground, with the collector facing the sun and connected to a continuous water supply. The collector usually comprises copper tubes welded to copper sheets (both coated with a highly absorbing black coating) with a toughened glass sheet on top and insulating material on the back. The entire assembly is placed in a flat box. In certain models, evacuated glass tubes are used instead of copper; a separate cover sheet and insulating box are not required in this case. Water flows through the tubes, absorbs solar heat, and is stored in a tank. The hot water so stored can be used for various applications at homes, such as bathing, cleaning, and washing. It can also be used for a variety of industrial applications. The water stored in the tank remains hot overnight as the storage tank is insulated and heat losses are small. Flat-plate solar collectors are manufactured by MEGAPOWER; however, the tubes for evacuated tube collectors are imported.
SCHEMATIC OF SOLAR WATER HEATING SYSTEM (Fig. 1)
SCHEMATIC OF SOLAR WATER HEATING SYSTEM (Fig. 2)
5. Can a solar water heating system be used in place of a conventional gas or electric heating system?
Yes, MEGAPOWER Solar water heating system is the perfect replacement of conventional water heating.
6. Do solar thermal systems produce hot water in the winter?
MEGAPOWER solar systems will operate and produce hot water during the winter months but may require anti-freeze protection (depending upon geographic location).
7. Do solar thermal systems produce hot water on a cloudy day or in rainy season?
In India, out 365 days 280 to 320 days are sunny and in rainy season every day is not cloudy. MEGAPOWER solar systems will be able to provide water heating during cloudy or in rainy season, but sometime it may require the use of traditional gas or electric heating system to produce required temperatures.
8. What happens if one of the solar tubes is broken in ETC water heating system?
The tubes are very strong and not easily broken, but can be replaced very easily. They are inexpensive and available though your local MEGAPOWER dealer or directly from MEGAPOWER. One advantage of evacuated tubes systems is that breakage, for example, will typically disable only a single tube instead of an entire collector as would be the case with a flat plate collector design, the system will continue to produce hot water with one or even several broken tubes. There is no leakage from the system as a result of a broken tube.
The tubes are very strong and not easily broken, but can be replaced very easily. They are inexpensive and available though your local MEGAPOWER dealer or directly from MEGAPOWER. One advantage of evacuated tubes systems is that breakage, for example, will typically disable only a single tube instead of an entire collector as would be the case with a flat plate collector design, the system will continue to produce hot water with one or even several broken tubes. There is no leakage from the system as a result of a broken tube.
9. What is the payback period of the system?
There are several factor is to be taken in account while calculating pay back period like geographic location of the system, incentives or rebates, insolation levels (amount of solar radiation) in that area and annual usage of the system, an average household of 4 can expect to recover the cost of a solar system within 3 to 4 years.
For Example:
COMPARISION ELECTRIC GEYSER Vs 125LPD SWHSCost of electricity | RS. 4.50 per unit (kWh) |
Total heat gain kcal/ day | System capacity x Temp. difference |
= 125 x 40 = 5000 kcal/day | |
= 5000 x 4.2 kJ/ day = 21,000 kJ/day | |
Total heat gain | = 21000/ 3600 kWh/ day |
Saving in electricity | = 5.83 kWh / day |
Saving in electricity cost | = Units saved x cost / unit |
= 5.83 x 4.50 | |
Saving / day | Rs. 26.23 |
Saving per year | = 26.23 x 300 |
= Rs. 7869 | |
Payback period | = Total cost/ saving per year |
= 22000/7869 | |
Payback period | = 2.79 years |
Actual payback period becomes much shorter if the periodic rise in the cost of oil/ electricity, maintenance and handling charges for geysers or boilers and depreciation allowance available are accounted for.
10. What is the life of the solar collector systems?
MEGAPOWER solar systems have a life expectancy of greater than 20 years with a manufacturer's warranty of 5 to 7 years.
11. Do MEGAPOWER solar heating systems require any maintenance?
Maintenance of the system is negligible; however, an annual assessment of the solar system is recommended to help to maintain efficiency levels and to help avoid potential long term problems with the system.
12. If I order a solar water heating system, what do I get?
You will get Solar Panel, Hot Water tank, and other component which are responsible to work the solar water heating system.
13. How much does a solar system cost?
It is depends on the requirement. Kindly take a help of our Sales and service team for more support.
14. Where can I purchase MEGAPOWER solar water heating System?
Contact us to find a dealer near you:
MEGAPOWER, Wing-J, 605, Megacentre, Magarpatta city, Pune-28
Give us a call on:
+91-9226279397; +91-9822330789; +91-9665555090;
II. FAQ- PHOTOVOLTAIC (PV) SOLAR SYSTEM
1. What is Photovoltaic (PV) technology?
Solar photovoltaic (SPV) is the process of converting solar radiation (sunlight) into electricity using a device called solar cell. A solar cell is a semi-conducting device made of silicon or other materials, which, when exposed to sunlight, generates electricity. The magnitude of the electric current generated depends on the intensity of the solar radiation, exposed area of the solar cell, the type of material used in fabricating the solar cell, and ambient temperature. Solar cells are connected in series and parallel combinations to form modules that provide the required power.
2. What is a PV panel?A PV solar panel, referred to in the industry as a solar module, is constructed by connecting photovoltaic cells (or PV cells) to produce electricity. The cells are a semiconductor-based technology that converts solar radiation into direct current (DC) electricity.
3. 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 avoiding the harmful pollution generated by traditional methods of generating electricity. The owners can forget the dependency on regular power supply and can be master of his own electricity.
4. What is a grid-tied solar system?
The system is tied to the power grid (local electric power Service Company). The solar power is added to the grid power, reducing the amount of power that must be purchased from the company for ex MSEB (Maharashtra state electricity board) INDIA.
5. What is an off-grid solar system?
An off-grid solar energy system is where there is no connection to the service company (example: -MSEB) 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.
6. What are the different types of PV panels?
There are currently four main types of solar PV panels:
1. Mono-crystalline - In single crystal silicon, the crystalline framework is homogenous, which can be recognized by an even external coloring (mostly black). In single crystal silicon, also called mono-crystal, the crystal lattice of the entire sample is continuous and unbroken with no grain boundaries. Large single crystals are exceedingly rare in nature and can also be difficult to produce in the laboratory .In contrast an amorphous structure where the atomic position is limited to short range order. The efficiency of these panels is higher than polycrystalline and thus cost of mono-crystalline panel is higher than poly-crystalline.
2. Polycrystalline- Polycrystalline are composed of a number of smaller crystals or crystallites. Polycrystalline silicon (or semi-crystalline silicon, polysilicon, poly-Si, or simply "poly") is a material consisting of multiple small silicon crystals. Polycrystalline cells can be recognized by a visible grain, a “metal flake effect”. Semiconductor grade (also solar grade) polycrystalline silicon is converted to "single crystal" silicon – meaning that the randomly associated crystallites of silicon in "polycrystalline silicon" are converted to a large "single" crystal. Single crystal silicon is used to manufacture most Si-based microelectronics devices. Polycrystalline silicon can be as much as 99.9999% pure. Ultra-pure poly is used in the semiconductor industry, starting from poly rods that are five to eight feet in length. In microelectronics industry (semiconductor industry), poly is used both at the macro-scale and micro-scale (component) level. They are easy to spot because they have an uneven color, usually blue.
3. Thin film – these are made by depositing a thin layer of very finely powdered silicon (amorphous silicon) or other photovoltaic material, on a substrate. These are much lower in efficiency that crystalline cells, and somewhat cheaper per watt. They are a good choice for large ground mounted utility scale solar arrays where real estate is plentiful. Their low efficiency makes them undesirable for commercial and residential applications because they consume a large amount of roof space compared to mono or poly panels.
7. How do I decide how large my PV solar system should be?It totally depends upon average power in watts used during the month with the lowest electric bill. Kindly take a help of our technical support team for further details.
8. How are solar panels tested and rated?
They can be tested and certified by any NRTL (nationally recognized testing laboratory) like UL, CSA, ETL, TUV etc. For consumer purposes, the main rating to consider is the watts rating, which is expressed at watts-peak (Wp) which is the amount of peak power produced under STC (standard test conditions).
9. What are Standard Test Conditions (STC)?
STC is the main set of conditions used in testing solar PV modules. Conditions are considered standard when cell temperature is 25°C and you have 1000 W/m^2 of direct insolation. STC also assumes a panel is oriented to the proper angle, elevation.
10. How much power will a solar PV system produce?
You would calculate the total production of a system by determining the annual production of a single panel and multiplying it by the number of panels, then reduce this value to account for inefficiencies. Consider the expected weather and temperature conditions, the orientation (angle and azimuth) of the installation and other factors. For more details contact our Technical support team.
Each system will produce a different amount of power based on the system size, orientation, insolation, etc. MEGAPOWR’s R & D and technical support team will give you an idea of average annual sunlight conditions for your area. A quick, free telephone or email consultation with our team will help you be able make a good estimate of your potential. Just give us a call.
11. What is insolation?
Insolation refers to a daily total of direct sunlight. In the solar industry it usually refers to the average daily hours of sunlight equaling 1000 watts per square meter. On average, locations within the INDIA will get between 4 and 6 hours of insolation per day depending on season and location.
12. How does shade affect the performance of a PV solar system?
One of the primary causes of power loss in a solar PV system is when part of the panel or array becomes out of the sun or shaded. In a panel there will usually be 36, 60 or 72 cells connected together. Each cell produces a certain voltage and current; the cells are organized and connected in a combination of series and parallel connections to produce the correct amount of power. If any individual cells performance is degraded by shade, the performance of the entire panel will fall to a point relative to the worst performing cell. Similarly, in a string of panels, the entire string suffers performance reduction to that of the lowest performing panel. A solar installation should be designed in a way such that none of the panels are even partly shaded at any point of the day.
13. 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 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.
14. Do solar panels have to be installed on the roof?
Solar panels can be installed on the roof, on the side of a building, on the ground or on a pole. The most cost effective installation will usually be on a roof, but if roof or shading conditions prevent the use of the roof we can help you review other options.
15. Do installed solar panels have to face a southerly direction?
In the INDIA, facing south at the correct angle of elevation(22.5°to 30°) will provide the best performance (most KWh per Rs.) however solar panels can also be installed facing towards the east or west as long as proper considerations are made. Solar panels should not ever face north.
16. What about cloudy days or rainy season?
In India, out 365 days 280 to 320 days are sunny and in rainy season every day is not cloudy. PV solar panels will generally produce electricity at a reduced rate under cloudy conditions. Severe clouds will interrupt the production of power.
17. How long will a solar panel system last?
Solar panels are known to last more than 25 years typically 40 years. Typical guarantees of a solar panel include ten years workmanship and materials warranty and a 20-25 year performance warranty. The typical PV panel performance warranty will guarantee 90% of rated production for 10-15 years, and 80% for 15-20 years. Solar panels are designed to withstand hail, severe wind and weather conditions assuming proper installation.
18. How do I know if a solar PV system is a good choice for me?
If you live in an area where the sun shines and electricity is costly, chances are that PV solar panels will make financial sense for you, especially if there are tax credit, rebates or other incentives available. Contact our sales team to get assistance in evaluating your situation.
19. What are the maintenance requirements or other costs for a PV system?
For a grid-tied system where no batteries need be replaced, there is typically little or no maintenance required. You might consider a periodic inspection to ensure that the panels remain clear of leaves, dirt, bird droppings etc. Other than that, unless there is an equipment failure there should be no maintenance required.
20. What is the warranty on a PV solar system?
MEGAPOWER gives 10 years replacement guarantee of solar panel and 15-20 year performance warranty. The typical PV performance warranty will guarantee 90% of rated production for 10-15 years, and 80% of rated performance for 15-20 years.
21. Besides the solar panels, what else is needed for a complete system?
The system will include the panels, mounting hardware, connecting wires, and an inverter to convert the DC power from the panels into the correct AC voltage. 22. What are solar inverters?
An inverter is any device that inverts DC (direct current) into AC (alternating current). In a solar installation, an inverter is a centralized device that connects to and manages the performance of the solar panel array; it aggregates the DC power coming from the panels or strings of panels and inverts the DC power into single phase (or three phase) AC power at the correct voltage for delivery into the users electrical system, and provides equipment protection and safety features. The better inverters on the market also allow for data logging and web-based remote monitoring of important performance metrics and power generation.
23. Will the solar electric system (on grid) function as “back up” power when the regular power supply is not available?
Not in a normal grid-tied (on grid) PV solar installation. In a grid-tied system, the inverter will shut off if the regular power supply is not available. Here the inverter is used for safety purpose. To have a back-up battery system, you would need to have some type of UPS system. Another approach would be to install a hybrid on/off-grid system through the use of a special charger-inverter and batteries.
Off grid solar system works on the same principle.
24. Can I make my building independent of regular power supply (MECB); How?
Yes you can. In an off-grid installation, you must have batteries, a MPPT charge controller and an inverter – in some cases the batteries will cost nearly as much as the solar panels and only last 6-8 years before replacement becomes necessary. Off-grid solar is achievable, but is very costly and only recommended for locations where there is no grid to connect to. Or hybrid solar system is recommended in such cases. It includes both electric power supply and solar power supply in specific ratio, say ,30:70 respectively. 25. What is a charge controller and what is its function?
A charge controller is a device used to control the voltage and current coming from a PV solar panel array and into a battery bank. Many of newer models employ Maximum Power Point Tracking (MPPT) which looks at the battery bank and configures the PV output to allow for the best combination of voltage and current to enter the battery bank. While using a typical charge controller might result in a power loss of 30%, charge controller using MPPT are 95% efficient.
26. How do the solar panels stand up to hail, wind, hurricanes and other natural cause?
Solar panels themselves are built using tempered glass for durability and safety and are designed to withstand hail and high winds. Depending on the wind-load requirements in your area, heavier mounting hardware may be required.
27. Will solar panels damage my roof?
Properly installed solar panels will not damage your roof. If your roof is near the end of its expected life, it might be a good idea to consider replacing the roof before adding solar panels, because removing and reinstalling the panels can add to the cost of a roof replacement.
28. How long does it take to install a PV system?
A typical residential roof installation can be completed in 3-4 days. The number of panels and type of installation will affect the installation process.
29. Can I install the solar panel system myself?
It may be permissible to do so. It is possible for a home owner to install a solar panel system however there are many technical and safety issues to be aware of. If a homeowner is experienced with home improvement projects and is comfortable working on a roof, it is possible for a homeowner to do most or all of the work. But it is recommended to take assistance from the company for installation.
30. What does a solar PV system cost?
Because of the wide range of variables in system size and installation requirements it is impossible to state the cost of a system. It is important to realize that the cost of the panels themselves usually represent about 1/3 of the total turn-key cost. Kindly call us to our sales and service support team for more details.
31. How much will I save, how quickly will a system pay for itself?
This will vary depending on the local cost of electricity, state and local rebates or incentives, and the installed cost of the solar panel system. The range can be from 3-4 years up to 20 years depending on these factors.
32. Does a solar PV system affect the resale value of my property?
Yes it does. Available real estate property resale value data indicates that money spent on solar panel installations is recoverable and may actually increase the value of the home beyond the amount spent.
33. Where can I purchase MEGAPOWER solar PV System?
Contact us to find a dealer near you:
MEGAPOWER, Wing-J, 605, Megacentre, Magarpatta city, Pune-28
Give us a call on:
+91-9226279397; +91-9822330789; +91-9665555090;
.
