Non Conventional sources of energy are generally renewable sources of energy. This type of energy sources include anything, which provides power that can be replenished with increasing demand for energy and with fast depleting conventional sources of energy such as coal, petroleum, 'natural gas etc.

The non- conventional sources of energy such as energy from sun, wind, biomass, tidal energy, geo thermal energy and even energy from waste material are gaining importance. This energy is abundant, renewable, pollution free and eco-friendly. It can also be more conveniently supplied to urban, rural and even remote areas. Thus, it is also capable of solving the twin problems of energy supply in a decentralized manner and helping in sustaining cleaner environment. However, the importance of the renewable energy or non-conventional sources of energy was recognised in the early 1970s. But now, it has been accepted that renewable energy resources can provide the basis for sustainable development.

During the past quarter century, a variety of renewable energy technologies have been developed and deployed in villages and cities. In India, a separate Ministry of Non-conventional source of energy has been created for planning, promoting and coordinating relating to all aspects of renewable energy resources. India today has one of the largest programmes for non- conventional sources of energy. According to energy experts, India's non-conventional energy potential is estimated at about 1, 95000 mw. Can you handle it instrumental usher. An estimate of 31 percent of this potential comes from the Sun, 30% from ocean thermal, 26% from bio-fuel and 13% from wind. During the last two decades, several renewable energy technologies have been developed and deployed in villages and cities.

However, the major non-conventional energy sources that are being used for power generation are: (i) Solar Energy: Sun is the source of ail energy on the earth and most parts of our country have bright sun throughout the years except a brief monsoon period. According to an estimate, India receives solar energy equivalent to-over 5000 trillion kHz per year which is far more that the total energy consumption of the country. The exploitation of this vast solar energy can be done through both the thermal and photovoltaic routes for a variety of applications like cooking, water heating, drying of farm produce, water pumping, home and street lighting, power generation for meeting requirements in villages, schools, hospitals etc.

For this purpose, various solar water heaters and dryers, solar cooker and solar photovoltaic cell have been developed. Solar photovoltaic technology enables direct conversion of sun light into electricity without causing pollution. (ii) Wind Energy: Wind is another important source of non-conventional energy.