1.Solar Water Heater

A Solar Water Heater (SWH) is a system that uses sunlight to heat water. It reduces the use of electricity or other fuels for heating water.

Main parts

  • Solar collector: Absorbs heat from sunlight.
  • Water tank: Stores the heated water.
  • Insulation: Reduces heat loss from the tank and pipes.
  • Pipes: Carry water between the collector and tank.
  • Frame/support: Holds the collector at a suitable angle.

Working process

  1. Sunlight falls on the solar collector.
  2. The collector absorbs solar radiation and converts it into heat.
  3. Water passing through the collector gets heated.
  4. Hot water moves toward the storage tank.
  5. Cooler water moves toward the collector again.
  6. This circulation continues and gradually increases the temperature of the stored water.
  7. The hot water can then be used for bathing, cleaning, and other purposes.

Main benefit: It uses renewable solar energy and can reduce electricity consumption.

2.Solar Dryer

A Solar Dryer is a device that uses solar energy to remove moisture from food or agricultural products. It is commonly used for drying fruits, vegetables, grains, herbs, spices, and other products.

Main parts

  • Solar collector/heating area: Heats the air.
  • Drying chamber: Holds the material being dried.
  • Trays: Keep the food/product in a thin layer.
  • Air inlet: Allows fresh air to enter.
  • Air outlet: Allows moist air to escape.
  • Transparent cover: Allows sunlight to enter and helps retain heat.

Working process

  1. Sunlight enters the solar dryer.
  2. Solar energy heats the air inside the collector or drying chamber.
  3. Warm air moves around the food/product.
  4. Heat causes the moisture in the product to evaporate.
  5. Moist air moves out through the outlet.
  6. Continuous airflow removes moisture and gradually dries the product.
  7. The dried product is collected and stored properly.

Advantages

  • Uses free solar energy.
  • Reduces dependence on electricity or fuel.
  • Provides more controlled drying than open-sun drying.
  • Helps protect products from dust, insects, and some contamination.
  • Can improve storage life by reducing moisture.