Question

Why are we looking at alternate sources of energy?

Answer 1

Hint: Renewable energy sources are those sources which replenish on their own and are readily available in nature. Like solar energy, wind energy, energy obtained from biomass.
Non-renewable energy sources are those sources which do not replenish on their own and have very limited availability in nature. For example fossil fuels which includes petroleum, coal and natural gas.

Complete answer:
The main reason why we are searching for an alternate source of energy is because fossil fuels are non-renewable sources of energy which means they are not available in abundant quantities and cannot be replenished. Fossil fuels will continue to get exhausted if their consumption is not controlled. Therefore, it is far better to switch to alternate sources of energy in order to apply the concept of sustainable development.
Geothermal energy is the energy which is obtained from the earth. This energy can be obtained from the hot spots that are formed when the molten rocks present at the core of the earth are pushed towards the earth’s crust. Hot springs are commonly used for the production of electricity in the geothermal power plants.

Additional information:
Following are the example sources of energy that are renewable:
Wind: Wind energy is obtained from the air which is blowing at a very high speed. This energy is trapped using windmills in order to generate electricity. Blowing of air is dependent on the uneven heating of the earth. Since the heating of the earth is never ending, wind availability will also be forever.
Sun: The energy obtained from the sun is called solar energy. It is produced by the fusion of hydrogen into helium atoms, fusion of helium into other heavy metals and it continues further. A considerable amount of hydrogen and helium is available on the sun which will never be exhausted. Hence, solar energy is also a renewable source of energy.
Following are the example of energy that are exhaustible:
Wood: The source of wood are generally forests. Due to growing deforestation the number of forests are reducing at a very alarming rate. We know that it takes several years to grow a forest. If this rate of deforestation increases, the availability of wood will drastically decrease. Therefore, wood is an exhaustible source of energy.
Coal: The source of coal is from the dead remains of the plants and animals which remained buried for years. Due to increased Industrialisation, the demand for coal has also increased and it cannot be replenished as it takes thousands of years. Therefore, coal is also an exhaustible source of energy.

Note:
Fossil fuels are obtained from the earth’s crust after several years as they are the remains of the dead plants and animals. They are similar to coal and petroleum and are readily available for use. These are non-renewable sources of energy i.e. cannot be replenished. Whereas solar energy or sun energy is abundant in nature and can be replenished.