Solar Hot Water Systems
Solar Hot Water Systems
Solar water Heating System is structured to reduce the conventional type of water heating techniques and instead use renewable form of energy that is solar thermal energy which also reduces the fossil fuel consumption and green house gases emission and there by managing the carbon footprint.
COMPONENTS OF SOLAR WATER HEATING SYSTEMS:
The Key Components of a Solar water heating systems are as follows:
- Solar Collectors and Absorber Plates
- Heat Transfer Fluid
- Heat Exchanger
- Storage Tank
- Controller and Sensors
- Pumps
- Expansion Tank
- Back up Heating System
- Pipes and Fittings
- Valves
- Insulation
TYPES OF SOLAR WATER HEATING SYSTEMS:
1. Active Solar Water Heating System | 2. Passive Solar Water Heating System |
It contains Circulating Pumps and Controls | It do not contain Circulating Pumps and Control |
· Direct Circulation Systems · Indirect Circulation Systems | · Integral collector-storage passive systems · Thermosyphon Systems |
Direct Circulation Systems: In this Pumps circulate household water through collectors and then to home. Works in moderate to high temperature areas | Integral collector-storage passive systems In these systems solar heat is allowed to pass through the transparent covering material covering the storage tank. And then water passes from plumbing systems to serve hot water during day and evening times for household requirements. |
Indirect Circulation Systems: In this an antifreeze heat transfer fluid circulates through collectors and then to a heat exchanger and this water flows into the home without getting mixed up with potable water supply. Suitable in low-freezing temperature areas.
| Thermosyphon Systems Here the water is heated in the 40gallon capacity collector majorly on the roof top and supplied to plumbing system when faucet is opened. |
SOLAR WATER COLLECTORS AND TANKS
SOLAR WATER TANKS :
TWO TANK SYSTEM
Water is preheated by the Solar Water Heater before entering the Conventional Water Heater.
ONE TANK SYSTEM
In this type of System Back up Heater is connected to the Solar Storage Tank.
SOLAR COLLECTORS:
- FLAT PLATE COLLECTOR:
Glazed Flat Plate Collectors: A dark Plate Absorber insulated and Weatherproofed box under glass or plastic cover layers.
Unglazed Flat Plate Collectors: A Dark Metal or Polymer Plate without a cover used for solar pool heating
Most commonly used for domestic solar water heating systems.
- INTEGRAL COLLECTOR STORAGE SYSTEMS:
Dark colored tanks or tubes are integrated with Solar collector into one unit, Water is heated in the collector and stored in the tank within the same unit.
- EVACUATED TUBE SOLAR COLLECTORS
A series of Glass tubes made up of two layers of glass are arranged in a parallel manner with vacuum sealed and acts as insulator.
Not commonly available but used in domestic solar water heating systems.
HEAT EXCHANGERS AND ITS TYPES:
Heat exchangers are used to transfer solar energy absorbed in solar collectors to water.
These are made up of thermal conductors like copper and stainless steel.
Types of Heat Exchangers:
Liquid to Liquid Heat Exchanger | Air to Liquid Heat Exchanger |
Thermal energy transferred between Two fluids i.e, from hot liquid to cool liquid without mixing them. | Thermal Energy Transfer takes place between air and liquid, through a metal surface which separates them. |
TYPES | TYPES |
1. Shell and Tube Heat Exchanger | 1.Fin and Tube Heat Exchanger |
2. Plate Heat Exchanger | 2.Plate Heat Exchanger |
3. Spiral Heat Exchanger | 3.Air cooled Heat Exchanger |
4. Double pipe Heat Exchanger | 4.Cross flow Heat Exchanger |
5. Air cooled Heat Exchanger | 5.Evaporative coolers |
BENEFITS OF SOLAR WATER SYSTEMS:
- Eco friendly and sustainable energy form.
- Reduces Global Warming by decreasing Greenhouse gas emissions.
- Financial smartness and also improves the value of property
- Low maintenance and Significant Savings
- Financial incentives are provided in the form of Tax credits.
- High Durability when compared to Conventional water heating Systems
GOVERNMENT SCHEMES AND INITIATIVES:
SOLAR WATER HEATING (SWH) PROGRAMME:
The Ministry of New and Renewable Energy (MNRE) designed this Programme to promote the installation of solar water heating systems.
Subsidy Provided:
30% subsidy for general category states
60% subsidy for special category states like North eastern states, Hilly areas and islands, Limited to
Rs 3000 per sq mt for Evacuated Tube Collector Systems
Rs 3300 per sq mt for Flat Plate Collector Systems
Interest free Loan up to 2-5% provided to the Special Category States and Chhattisgarh, Jharkhand and Uttarakhand States.
Capital Subsidy Upgraded to Rs 1750 from Rs 1100 for Institutions and Rs 1400 from Rs 825 for Commercial Establishments on Solar Hot Water Systems.
Government passes on the Subsidy to the MNRE approved Companies and in turn Consumers get the subsidy upon purchasing the Solar hot water systems only from them.