Renewable and Non-renewable Resources
ICSE Class 7 · Geography · Chapter 11
What this chapter covers
- Energy: meaning and importance
- Renewable and non-renewable resources
- Renewable sources: solar, hydro and wind
- Non-renewable sources: coal and petroleum
- Major hydroelectric projects of India
- Conservation of energy and power resources
Key points
- Energy is the ability to do work; it lights, heats, moves and runs everything around you.
- Energy decides how far a region can develop, but it is not shared equally between rich and poor or between cities and villages.
- Renewable resources such as sunlight, flowing water and wind are replaced by nature; non-renewable resources such as coal and petroleum are a fixed stock.
- Solar power uses solar cookers, water heaters and solar cells; it is clean and free but stops at night.
- Hydroelectricity uses falling water stored behind a dam to spin turbines; it is clean but large dams displace people and harm rivers.
- Wind power comes from wind farms on coasts and plateaus; the supply rises and falls with the wind.
- Coal is formed from ancient plants and is burned in thermal power stations and steel plants; major coalfields lie in Jharkhand, West Bengal, Odisha and Chhattisgarh.
- Petroleum is refined into LPG, petrol, diesel, kerosene and bitumen; Digboi, Mumbai High, Ankleshwar and Barmer are important oil areas.
- Major hydroelectric projects include Bhakra Nangal (Sutlej), Hirakud (Mahanadi), Tehri (Bhagirathi), Sardar Sarovar (Narmada), Nagarjuna Sagar (Krishna) and Idukki (Periyar).
- Conservation of energy resources means using energy wisely and avoiding waste, at home, in school and across the country.
Questions answered
What is energy? Give two examples of sources of energy used in your home.
Energy is the ability to do work, such as moving, heating or lighting something. Examples from a home include electricity for lights and fans, and LPG for cooking.
Distinguish between a renewable resource and a non-renewable resource, with two examples of each.
A renewable resource is replaced by nature again and again and does not run out, such as sunlight and wind. A non-renewable resource took millions of years to form and cannot be replaced once used up, such as coal and petroleum.
Why are coal and petroleum called fossil fuels?
They formed from the buried remains of plants and animals that lived millions of years ago, so they are fuels made from ancient life, like fossils.
Give two advantages and two limitations of solar power.
Advantages: sunlight is free and never runs out, and panels make no smoke or noise. Limitations: there is no power at night and less on cloudy days, and panels and batteries are costly to set up.
Explain in simple steps how electricity is produced at a hydroelectric power station.
A dam stores river water in a reservoir at a height. The water falls through large pipes and spins a turbine. The turbine turns a generator, where coils spin near magnets and produce electricity. The water then flows back into the river.
What is rural electrification? Give one reason why a home in a remote village may still have less energy than a city home.
Rural electrification is the work of taking electricity to villages through power lines, small power stations and local solar systems. A village home may still have less energy because the family cannot afford much electricity, or because supply comes for only a few hours a day.
Name two coalfields of India and the state in which each is found.
Jharia in Jharkhand and Raniganj in West Bengal. Other correct answers include Korba in Chhattisgarh and Talcher in Odisha.
Name the river and the state of: (a) Bhakra Nangal Project, (b) Hirakud Dam, (c) Nagarjuna Sagar Project, (d) Idukki Project.
(a) Sutlej; Himachal Pradesh and Punjab. (b) Mahanadi; Odisha. (c) Krishna; Telangana and Andhra Pradesh. (d) Periyar; Kerala.