📖 Chapter 1 of 8 · Green Energy - Basic 2 · Class 7
Chapter 1: Where Does Our Power Come From?
Quick Recap of Basic 1. This chapter helps you remember what you learnt in Green Energy — Basic 1, and adds a little more.
In this chapter
- Remember: what energy is and why we need it every day.
- Power from the Sun, the wind and flowing water.
- How electricity travels from nature all the way to our homes.
- Meet Anaya from Rajasthan and Ravi from Tamil Nadu.
The Big Idea
Energy is the power to make things move, glow, heat up or work. Most of our electricity is made in big power plants far away, and it travels to us through wires. Green energy is electricity made from nature’s gifts that will not run out — sunshine, wind and flowing water.
Did You Know?
Bhadla Solar Park in Jodhpur district, Rajasthan, is one of the biggest solar parks in the world. It spreads over about 14,000 acres of desert — more than 7,000 football fields could fit inside it!
Story Time — Anaya and the Sea of Blue
Anaya, age 10 · Jodhpur, Rajasthan
Anaya lives in Jodhpur, the famous Blue City of Rajasthan. During the summer holidays, her Mama (uncle) took her on a long drive into the Thar Desert. He works as a technician at the Bhadla Solar Park.
As the jeep climbed a sand dune, Anaya gasped. In front of her was a shining “sea” of blue that went on and on until it touched the sky. “Mama, why has someone put so many mirrors in the desert?” she asked.
Mama laughed. “They are not mirrors, beta. They are solar panels. Each one catches sunlight and turns it into electricity. Lakhs of them work together here.”
“But why build them in the desert?” Anaya asked, wiping the sweat from her face. “Because the desert has what solar panels love most,” said Mama. “Bright sunshine on most days of the year, and lots of open land. We only have to keep the panels clean. Dusty panels make less power, so workers and cleaning machines wipe the sand off.”
A camel walked slowly past the long rows. Anaya thought for a moment. “So the same Sun that makes this sand so hot can also run the fan in our house?” Mama nodded proudly. “Exactly! Nature gives us the energy. We just need clever machines to catch it.”
Story Time — Ravi Counts the Giant Fans
Ravi, age 9 · Muppandal, near Kanyakumari, Tamil Nadu
Ravi lives in a small village near Kanyakumari, at the southern tip of India. From his rooftop he can see tall white towers with three long blades standing on the hills. His friend Selvi from Chennai came to visit and pointed at them. “Why does your village need such giant fans? Is it very hot here?”
Ravi giggled. “Those are not fans, Selvi. Fans use electricity to make wind. These do the opposite! The wind turns their blades, and they make electricity. They are called wind turbines.”
Ravi’s Appa explained more. “Our village is near a gap in the Western Ghats hills. Strong winds from the sea rush through this gap, especially from June to September. That is why Muppandal became one of the biggest wind farms in India.”
Just then, a gust of wind flapped the colourful clothes on Paati’s drying line. Selvi laughed. “The same wind that dries Paati’s saris is making electricity for Chennai!”
That evening the two friends tried to count the turbines on the hills. They reached 64 before the sun set. “Every one of them is working without smoke,” said Ravi. “That is why we call it clean energy.”
Things to Remember from Basic 1
In your first Green Energy book, you learnt where power comes from. Let us quickly remember the big ideas.
- Energy makes things move, glow, heat up and work — our fans, lights, pumps and phones need it.
- The Sun gives light and heat. Solar panels turn sunlight into electricity.
- The wind spins the blades of wind turbines to make electricity.
- Flowing water in rivers and dams spins turbines to make electricity too.
- Green energy comes from nature’s gifts that do not run out, and it keeps our air clean.
- Electricity travels through wires. It is powerful — never touch open wires, switches with wet hands, or electric poles.
Safety first! Never fly kites near power lines and never climb electric poles or transformer fences. If you see a fallen wire, stay far away and tell an adult at once.
Solved Examples
Think first, then read the answer.
1. What is energy? Give two examples of using energy at home.
Show answer
Answer: Energy is the power to make things move, glow, heat up or work. At home we use it when a fan moves the air and when a bulb glows at night.
2. Why are big solar parks often built in deserts like the Thar?
Show answer
Answer: Deserts get bright sunshine on most days and have wide, open land. More sunlight means more electricity from each panel.
3. Do wind turbines make wind?
Show answer
Answer: No. Fans use electricity to make wind, but turbines work the other way round — the wind turns their blades and they make electricity.
4. How can electricity made at Bhadla reach a home in a faraway city?
Show answer
Answer: It travels through very long, thick power lines held up by tall steel towers, and then through smaller wires into our homes.
5. Name three sources of green energy and the machine that catches each one.
Show answer
Answer: Sunlight → solar panel; wind → wind turbine; flowing water → water turbine at a dam.
✎ Now You Try!
Your school can put up either a solar panel or a wind turbine. Your town is very sunny but not very windy. Which should it choose, and why?
Check Your Understanding
A. Fill in the blanks
- Energy is the power to make things , glow, heat up or work.
- Bhadla Solar Park is in the state of .
- Muppandal wind farm is near in Tamil Nadu.
- Solar panels turn into electricity.
- Electricity reaches our homes through .
B. True or False
- Wind turbines make wind for the village. ( ___ )
- Deserts are good places for solar parks. ( ___ )
- Sunlight will run out in a few years. ( ___ )
- We should never touch open electric wires. ( ___ )
C. Choose the correct option
- Which of these is a green energy source? (a) coal (b) wind (c) diesel
- In a dam, the turbine is turned by (a) smoke (b) falling water (c) sand
- Anaya first thought the solar panels were (a) mirrors (b) kites (c) windows
D. Answer in two or three sentences
- Why did Muppandal become a big wind farm?
- Write the energy chain for wind power in four steps.
- Name two machines in your home that use electricity.
Brain Buster
Look out of your window for five minutes. Can you spot anything that uses energy from the Sun or the wind? List it!
Check your understanding
Tap an answer to see if it is correct. This is just for fun — nothing is saved.
1. What is energy?
- The power to make things move, glow, heat up or work
- A kind of food only
- A type of wire
Show answer
A. The power to make things move, glow, heat up or work
2. Why are big solar parks built in deserts like the Thar?
- Deserts are cool and cloudy
- Deserts get bright sunshine and have open land
- Deserts have many rivers
Show answer
B. Deserts get bright sunshine and have open land
3. Do wind turbines make wind?
- Yes, like fans
- No — the wind turns them and they make electricity
Show answer
B. No — the wind turns them and they make electricity
4. How does electricity reach our homes?
- Through wires and power lines
- Through water pipes
- Through the air as smoke
Show answer
A. Through wires and power lines