How A Solar Roof Water Heater System Works

solar water

A cost-effective way to reduce electricity bill

We recommend the use of solar energy in every possible field. Let’s start with solar water heaters, its composition, applications, benefits, and other relevant information.

1.   Solar Water Heater:

The main working principle is the conversion of sunlight into heat for heating the water by using any system of solar thermal collectors (evacuated tubes or modules). In a solar water heater, a system is installed on the roof or any area where it can receive maximum sunlight for grasping the sunlight which on conversion generates thermal energy that heats the water. No electricity or any fuel is required for heating water in this way, thus not only saving electricity but energy conservation and reduction in overall carbon footprint can also be achieved by opting for this over conventional electric geysers or fuel-based boilers. 

2.   Types of Solar water heaters:

Basically, there are five different types of solar water heaters available in the market. Major categories of solar water heaters are as follows:

1.   Thermosiphon System: In this type of system, working fluid or water rises up from the collectors to the storage tank by natural convection. Hence, water pumps are not required. As this system is based on heat convection, heat transfer increases with temperature. It is most suitable for areas that receive higher solar radiation.

2.   Direct-Circulation System: In this system, water is driven from the storage tank to collectors during a sunny day and heated.

3.   Drain-Down System: It is an indirect way to heat water. Water is circulated through closed loops and heat is transferred to it by heat exchangers.

4.   Indirect Water-Heating System: In this system, additional fluid is used which via heat transfer method transfers heat to water.

5.   Air System: In this system, firstly air is heated by solar collectors and that heated air is moved by using fan into an air-water heat exchanger. This type of system is less efficient (50% efficiency) in comparison to the above-discussed system.

If we discuss solar water heaters that are available for commercial and residential use in the market, they can be categorized as follow:

1.    Flate Plate Collector: In this type of collector, metallic boxes with plastic or glass cover at top and absorber plate at the bottom is used. It has a longer life span.

2. Evacuated Tube Collector: This type of collector contains an evacuated tube (mostly made up of glass) for heating water. These are fragile and need proper care.

Both the system can operate with a pump or without a pump for driving water from the collector tank to a storage tank. Using a thermosiphon, a pump can be effectively removed. An electric power backup can be provided additionally to provide hot water in a situation of non-sunny days for a longer period. Normally electric backup is attached in such a way that it can get activated when storage tank’s temperature reaches a certain lower limit (say 40 degrees).

3.   Point’s to consider while deciding a solar water heater system:

a.    ETC system is way cheaper than FPC, but is fragile and has a less effective life span. Both the systems can be operated in even sub-zero temperatures but require regular cleaning if there is more salt content in water as salt flakes stick to the system.

b.   FPC system needs antifreeze solutions, also heat exchanger if there is more salt in the water that makes the overall system expensive.

c.    For residential or small scale purposes, choosing a system without a pump is more cost-effective while pumps are required for large scale operations.

d.   Consider composition type, heat collector’s type & specification, effective life span and expected performance of the system.

e.   Always give priority to certified and globally known brands with a good performance record. Also, an appreciable warranty should be associated with the solar water heater.

    4.   General FAQs associated with Solar Water Heater:

a.    Does Solar Water Heater work in rainy or overcast days?
Yes, it performs well if overcast is not much long (mostly up to 2 days, it works), as it operated on diffused radiations. Also during a cloudy day, it performs well.

b.   Does Solar Water Heater provide Hot water only during day time?
No, you can get hot water even at night. As heated water during day timings are stored in the storage tank which is insulated. That stored water is available for utilization during the night.

c.    Should I solely rely on Solar Water Heater and remove all other kinds of heating facilities?
Yes, you can solely rely on Solar Water Heater if you live in an area which receives optimal sunlight throughout the year, but we recommend to attach an electric backup or keep an additional geyser in case of longer overcast or any wear-tear in the system

d.   Does Solar Water Heater cost-effective?
For details, please check the benefits of the solar water heater. Yes, it is cost-effective.

    5.   Advantages of Solar Water Heater:
Here are some the advantages of solar water heater:

a.    A Huge Electricity Saving: If a person chooses to use a solar water heater of just 100 liter per day capacity at a full scale, he can save up to 1000 units of electricity. Saving is much more for people in the southern and western areas. For specifically in central Indian locations – like Uttar Pradesh or Madhya Pradesh, approximately 1500 units can be saved yearly.

b.   Reduction of Monthly Electricity Bill: The saved electricity units show the direct result in figures for the electricity bill. Conventional electricity consumes a lot of energy so that it can be saved by using a solar water heater. 

c.    Reduction of carbon footprint: At industrial scale or for more commercial purposes, mostly gas or fossil fuels are used for heating applications. Also in case of the use of electricity, fossil fuel and coal are chief sources which generate a huge carbon footprint and cause environmental pollution while the solar water heater is harnessing freely available solar energy.

    6.   Approximate Cost:

On the basis of the type of system (EPC or FPC), Capacity, warranty period and brand name, cost of solar water heaters varies ranging from 12,000 to lakhs. You can call our toll-free number +1800 1205 55830 or or more information.

   7.   Government Subsidies:

For enhancing the use of solar technology and appreciating it, both central and state government provides various subsidies under different schemes. Normally, it covers up to 30% in general category states, 60% in hilly regions and even more in northeastern states. 

Hope, this article will help the readers in getting vital information regarding solar water heater. For more, please click or call us at +1800 1205 55830.