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

Both ETC and FPC System perform well,

• ETC (Evacuated tube collectors): ETC Solar Water Heaters 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.

Differences between ETC and FPC

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 solar water heater 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.

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.

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. Electricity Saving: 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.

• Free from Power cuts to save electricity
• One time investment
• Less Maintenance
• How solar water heaters deliver hot water? When?

At least 6 hours is required to heat water to a temperature of 60-65 degrees centigrade. Example: From morning to evening a 100 LPD solar water heater gets fully heated, if we utilize 100 litres at the end of the day you will not get hot water on next day morning. The solar water heater tank can store hot water up to 48 hours with some heat losses even in cloudy conditions.

Cost of solar water heater depends on size and type of system installed. Smallest size of a system is 100 liter per day, which means that it can deliver 100 litres of hot water in a day at 60 C. A 100 lpd capacity system is sufficient for a family of 3-4 members and it may cost Rs. 15,000 to Rs.22,000 in plains depending on the type of system. In hilly & N-E region, the cost may be 15 to 20% more.

The system cost does not include the cost of cold water tank, & its stand which is required if overhead tank is not installed in a house/ building. Cost of hot water insulated pipe line also, may be extra if number of bathrooms is more than one. Additional cost towards all these components may increase by 5 to 10%.

The cost, however, does not increase linearly with increase in capacity; rather it comes down proportionately as we go for higher capacity system.

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.

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.

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.

FPC solar water heater provides better efficiency compare to ETC solar water heater. 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.

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

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.

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.

Both ETC and FPC system perform well.

Durability and efficiency wise one can opt for FPC system. These systems are slightly more expensive and are suitable for warmer climates.

Most of used in colder climate and it requires less maintenance can choose ETC system.

Depending on the number of members, we can select the right capacity system. A 100 LPD (litres per day) capacity of solar water heater is suitable for 4 members.

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.

No. The subsidy scheme has been discontinued w.e.f 12.08.2014.