Solution

Conventional or non-renewable energy sources: • The energy sources which once consumed and cannot be restored are called Nonrenewable source of energy. • These sources either cannot be renewed at all or cannot be renewed at least in the near future. • Fossil fuels (coal and crude oil) are the best example of conventional energy sources. • The coal reserves, also known as buried sunshine, are the fossilised terrestrial plants which got transformed coal as a result of high temperature and pressure. • Petroleum is also known as liquid gold and was formed from dead marine plants and animals. • In contrast, the energy sources which can be renewed again after use are called non- conventional or renewable sources of energy. • Hydropower, solar energy, wind energy and geothermal energy are examples of non- conventional or renewable energy sources.