What is Solar Water Heater?
Solar water heaters are energy saving system can provide hot water by utilizing high intensity of sunlight. Tubes or collectors absorb sunlight radiations and turn it to heat energy in liquid form. And finally, hot water stored in the tank can utilize
Which type is better, ETC or FPC? How is different from one another?
Both ETC and FPC System performs well,
- ETC (Evacuated tube collectors): ETC Systems comes with three-layered evacuated glass tubes which provide insulation and the outer wall is coated with high-grade absorption material. By evacuated tubes absorbs the sunlight even in cloudy season, results in warm water for your home.
- FPC (Flat Plate Collectors): The Sun-Powered radiation is consumed by Flat Plate Collectors which comprise of a protected external metallic box secured on the best with the glass sheet. Inside there is blackened metallic absorber (selectively coated) sheets worked in channels or riser tubes to convey water. The absorber ingests the sun oriented radiation and exchanges the warmth to the streaming water.
Difference between ETC and FPC
ETC system | FPC system |
1. ETC based system performs better in colder regions keep away from freezing problems during sub-zero temperature. | 1.FPC based system performs well in anti-freezing at sub-zero temperature |
| 2. Cost is low as compare to FPC based systems | 2. Cost is high as compare to ETC based systems. |
| 3. Less maintenance like protect tubes from dust. | 3. It requires maintenance like to prevent Corrosion issue. |
| 4. ETC can get hot water up to 800c | 4. FPC can get hot water up to 700c |
| 5. Frequently used in colder climates. | 5. Frequently used in warmer climates. |
| 6. Heat loss is less even in a night because of vacuum inside the tube. | 6. Heat loss is more compared to ETC system because the collector is used. |
| 7.ETC is made of glass no corrosion issue Occurred | 7. Scaling due to hard water otherwise leads to Corrosion. |
| 8. Anyone of the tube breakage, the entire system can be drained however can replace tubes with lower price | 8. Breakage in the flat plate can entire glass should be replaced with a higher price. |
How does Solar Water Heater work?
When sunlight radiations fall into collectors or tubes absorb sunlight radiations and turn it to heat energy in liquid form. Cold water flows through in tubes or collectors from the tank, absorbed sunlight energy can transfer heat to water flows from inlet tank. The cold water from tank flows in tubes up to end and reverse back in same tubes when it heats. A hot water storage at top of the tank and whereas cold water is in the bottom. Due to gravitation heated water with lower density moves up words and cold water with higher density moves down in the tank. A minimum of 6-8 hours time required to get complete tank capacity (100 LPD) of hot water. To retain hot water up to 48 hrs tank is made of a high density of compressed PUF insulation.
What is the significance ?
Solar water heaters are budget-friendly one-time investment water heaters. Solar systems payback time is within the 2-3 years based on your usability and electricity tariffs. Using solar water heaters for bathing and other purposes decrease your electricity bill, resulting in long-term savings.
Why should I go for a Solar Water Heater? What do I save from it?
Solar Energy is a renewable free source of energy that can use in the form of a solar water heater, solar PV panel power generation, and many others. Usage of solar water heater we can protect our environment by generating power from different sources of hydro, wind and coal-based plants emissions.
To save electricity: A 100 litre per day (LPD) solar water heater system is suitable for 4 members, as everyone using electricity in morning for hot water purpose. Instead of using electricity we go for solar water heaters to save power.
Reasons to buy a Solar Water Heater?
- Free from Power cuts to save electricity
- One time investment
- Less Maintenance
- How solar water heaters deliver hot water? When?
At least 6 hours required to charge collector or tubes to provide hot water.
Example: From morning to evening a 100 LPD solar water heater gets fully charged, if utilize 100 litres at the end of the day you will not get hot water on next day morning. Suppose a fully charged 100 LPD solar water heater can store hot water up to 48 hours with some heat losses even in cloudy conditions.
How much does it cost to fix a Solar Water Heating system?
Cost depends on capacity (100LPD-500LPD), type (ETC, FPC, GLASS LINE) and place. A normal 100 LPD solar water heater system costs 15K -20K. As we go for higher capacity, costs get increased.
Is Solar Water Heater expensive?
When compared to an electric heater the solar water heater system cost may sound slightly expensive. But a solar heater will pay back its investment in 2-3 years; through recurring energy savings. You may also be eligible for rebates on your electricity bills in some States.
IHow about on rainy/cloudy days?
A tank can provide storage hot water up to 48 hrs, even in cloudy conditions you get warm water. It depends on sunlight radiation absorbed by the tubes or collectors. Alternatively, go for an electrical heater which can be fitted with the solar water heater.
How many litres of hot water will be generated ?
Solar water heating system capacities are defined in litres per day (LPD), which means with good intensity of sunlight, a 100 LPD system can deliver 100 litres of hot water suitable for 4 members with approximate 600 temperatures.
What is the life expectancy ?
FPC provides better efficiency compare to ETC . FPC systems can durable up to 15 or more years with major maintenance. ETC systems can sustain up to 5 or more years. However, system life expectancy generally depends on the quality of water.
What are standard warranties applicable ?
Most of the companies come up with 5-10 years of manufacturing warranty for some parts of solar water heaters and however system lifetime generally depends on the quality of water
What are regular maintenance requirements?
To get optimum output by solar water heater surface of the collector or tubes should be clean regularly. It requires less maintenance, only to clean tubes or panels, check with any leakages and protect tubes or panels from dust.
At what maximum temperature water gets heated?
Sunlight with good intensity for a whole day can get up to 800 c temperature of hot water for ETC based systems whereas FPC systems can maximum get up to 700 c temperature of hot water.
Which category should install with right capacity?
Both ETC and FPC system perform well.
Durability and efficiency wise can go for FPC system. These systems little bit expensive and suitable for warmer climates.
Most of used in colder climate and it requires less maintenance can choose ETC system.
Depends on members can select right capacity system. A 100 LPD (litres per day) capacity of solar water heater suitable for 4 member’s usage.
Does location matter ?
To fixation of solar water heater location can be considered because of climate condition and type of water (hard or soft).
An ETC system performs better heat generation even in cloudy condition and no issue of corrosion using hard water.
FPC systems provide better efficiency and long life for the warmer climate. In case of non-pressurized FPC systems, scaling due to hard water leads corrosion might affect system efficiency.
How to trust product and is any certification by the government?
Solar energy (solar water heaters) it comes under Ministry New and Renewable energy (MNRE). People can trust solar water heater products which certified and approved by MNRE department