What is meant by conventional sources of energy? Write the names of two conventional sources of energy.

Conventional sources of energy, also known as non-renewable sources of energy as we cannot reuse after using them once and these are being used extensively for a long time due to which their known reserves have been depleted to a great extent. Now, they are available in limited quantity.

Coal, petroleum and natural gas are the most widely used conventional sources of energy.  All these three accounts for about 90% of the world’s production of commercial energy.