A solar water heater consists of a collector to collect solar energy and an insulated storage tank to store hot water. One of the popular devices that utilize solar energy is the solar water heater manufacturers.
The water passing through the risers gets heated up and is delivered to the storage tank. The circulation of that water through the collector's absorber panel raises the temperature to 80 C on a good sunny day. The total system with solar collector, storage tank, and pipelines is called solar hot water systems.
TYPES OF SOLAR WATER HEATING SYSTEMS
They are of two types:
• Closed-loop systems
In this, heat exchangers are installed to protect the systems from hard water obtained from borewells from freezing temperatures in the cold regions.
• Open-loop systems
In this either thermosyphon or forced circulation system, the water in the plans is open to the atmosphere at one point or another. They are suitable for domestic and small institutional systems, provided the water is treated and portable in quality. The forced circulation systems use electrical pumps to circulate the water through collectors and storage tanks.
FEATURES OF SOLAR WATER HEATER
As evident by the name, a solar hot water heater turns cold water into hot water with sun rays.
1. Around 60 deg – 80 can attain 1-deg c temp efficiently depending on solar radiation, weather conditions, and solar collector systems.
2. Hot water for homes, hostels, hotels, hospitals, industries, etc.
3. Can install on rooftops, building terrace, and open ground where there is no shading.
4. Solar water heater generates hot water on clear sunny days, partially clouded bot, not on a rainy or heavy overcast day.
5. Only soft and potable water can be used.
6. Stainless steel is used for small tanks, whereas Mild Steel tanks with anti-corrosion coating are used for large tanks.
7. Solar water heaters of 100-300 liters capacity are suited for domestic application.
8. Can use larger systems in restaurants, guest houses, hotels, hospitals, industries, etc.
FUEL SAVINGS
A 100 liters capacity solar water heater can replace an electric geyser for residential use. Solar water heating systems capacity and saves 1500 units of electricity annually.
AVOIDED UTILITY COST ON GENERATION
The use of 1000 solar water heaters of 100 liters capacity can contribute to a peak load shaving of 1 MW.
ENVIRONMENTAL BENEFITS
A solar water heater of 100 liters can prevent the harmful emission of 1.5 tonnes of carbon dioxide per year.
PRICE
Its output concerns Rs 15000-20000 for 100 liters capacity systems and Rs 110-150 per installed liter for more extensive capacity systems.
The solar radiation is absorbed by the flat plate collector, which consists of an insulated outer metallic box covered on the top with a glass sheet. Inside there are blackened metallic absorber sheets with built-in channels or riser tubes to carry water. There are 60 BIS-approved manufacturers of Solar Flat Plate Collectors.