Solar Water Heater [Solar Geyser]

I made this presentation for a friend.

1. Solar Water Heater (Solar Geyser)

2. Asif Mostofa ID# 1621379 Azizul Bari Chowdhury ID# 1620066

3. What is Solar Energy? Solar energy is, simply, energy provided by the sun. This energy is in the form of solar radiation, which makes the production of solar electricity possible. The  spectrum of Solar light at the Earth's surface is mostly spread across the visible and near infrared ranges with a small part in the ultraviolet region.

4. Electromagnetic spectrum Electromagnetic spectrum is a continuum of all electromagnetic waves arranged according to frequency and wavelength. The sun , earth and other bodies radiate electromagnetic energy of varying wavelengths. Electromagnetic energy passes through space at the speed of light in the form of sinusoidal waves.

5. Solar water heating (SWH) is the conversion of sunlight into heat for the purpose of water heating, using a solar thermal collector. Main power is Solar power. Primarily no electricity is needed. Gravity is the main driving force.  Solar Water Heater:

6. Solar Water Heater

7. Parts of SWH Insulated tank Collectors Insulator box Supports Copper pipes Temperature valve

8. Thermal Collector A solar thermal collector collects heat by absorbing sunlight. A collector is a device that is used for capturing solar radiation. Solar radiation is energy in the form of electromagnetic radiation from the infrared to the ultra violate wavelengths. Collectors can be of a integrated form, used as both collector and storage (ICS). Two types of collectors : Flat plate and Evacuated tube. Collectors can also have fluids. Thermal energy heats the fluid then the heat from this fluid is transferred to the water.

9. How does a Solar Water Heater Work?   A Solar Water Heater comprises of an array of solar collectors to collect solar energy and an insulated tank to store hot water . The hot water with lower density moves upwards and cold water with higher density moves down from the tank due to gravity head. Both are connected to each other. During the day time, water in solar collectors gets heated which is either pumped or flown automatically on T hermo sim phon principle (propulsion energy) to the storage tank. Hot water then stored in the tank can be used for various purposes.

10. Different types of SWH: Active SWH direct circulation system. Pumps circulate water through the collector. Indirect circulation. pumps circulate non freezing heat transfer fluid through the collectors . Passive SWH. Integral collector storage . Works best for areas where temperature rarely falls below freezing. Thermosymphon systems. Where differential pressure of hot and cold water and gravity is used.

11. Cloudy / rainy day effect: On cloudy days also, if it is for a day or two, you still get warm water as water gets heated due to diffused radiation available in the atmosphere. The system, however, is either connected to an electric geyser in the house or an electrical back-up is provided in the storage tank of the system which is switched on when water is not sufficiently hot So, you get hot water all the time even on rainy days.

12. Applications: Residential House. Textile Industries. Hospitals and Nursing Home. Dairies and Food processing Factories. Hotels and Restaurants. Boiler House,etc .

13. Savings : Solar Water Heater is proven to be actually cost effective in the long run. A 100 litres capacity SWH can replace an electric geyser for residential use and saves 1500 units of electricity.

14. Environmental benefits: Solar thermal is one of the best ways to lower a building's carbon footprint and help protect the environment. Reduced greenhouse gas emissions: A 50-collector solar hot water system can offset over 50 tons of CO 2  per year, or 5,000 tons over the life of the system. A 100-collector pool-heating system can offset over 80 tons of CO 2  per year. A SWH of 100 litres capacity can prevent emission of 1.5 tonnes of carbon- dioxide per year.

15. Advantages: Simple to construct and install. No or negligible running cost. Low maintenance . Cost is low and economically competitive with electric water heating system. It saves time and high grade form of electric energy. T emperature up to 100C can be achieved by simple flat plate collector.

16. Disadvantages: Freezing problem Over heating problem Solar thermal panels can only heat water. There are few parts of the system like the pump and antifreeze which need to be checked to ensure that they are performing optimally.