Solar Energy Conversion

SOLAR ENERGY CONVERSION

Solar energy conversion is the process of conversion of direct sunlight into more useful forms. This solar energy conversion occurs by the following two mechanisms.

1. Thermal conversion.

2. Photoconversion.

1. Thermal conversion

Thermal conversion involves absorption of thermal energy in the form of IR radiation. Solar energy is an important source for low-temperature heat (temperature below 100°C), which is useful for heating buildings, water and refrigeration.

Methods of thermal conversion

1. Solar heat collectors.

2. Solar water heater.

1. Solar heat collectors

Solar heat collectors consist of natural materials like stones, bricks (or) materials like glass, which can absorb heat during the day time and release it slowly at night.

Uses

It is generally used in cold places, where houses are kept in hot condition using solar heat collectors.

2. Solar water heater

Fig 7.6 Solar Water Heater

It consists of an insulated box inside of which is painted with black paint. It is also provided with a glass lid to receive and store solar heat. Inside the box it has black painted copper coil, through which cold water is allowed to flow in, which gets heated up and flows out into a storage tank. From the storage tank water is then supplied through pipes.

2. Photoconversion

Photoconversion involves conversion of light energy directly into electrical energy by the photoelectric effect.

When the energy of solar radiation falls on the surface of a metal, it is absorbed and used to excite and eject electrons from the surface. This ejected electrons move in a circuit and generate electric current.

Methods of photoconversion

Photo conversion can be made by the following method. Photogalvanic cell (or) Solar cell