Energy Management
Primary 6 · Science and Elementary Technology
Energy Management
Lesson 3 of 6
15 min
Let's begin
In Musanze, Umutoni types a Cash Power token into the meter, and the bulb in the sitting room lights up. "But where does this electricity come from?" she asks her father.
"From many places," he says. "From rivers, from the sun, and even from gas under Lake Kivu." Let us follow the electricity back to where it begins.
A source of energy is anything that stores energy we can use to make something happen. For example, energy stored in petrol makes a moto move, and energy in firewood cooks food.
Plants store the sun's energy as they grow, which gives us food, wood and biomass. The sun's heat lifts water into the sky as clouds, which fall as rain to fill rivers for hydropower. The sun also warms the air unevenly and makes wind. Even petroleum and peat come from plants and animals that got their energy from the sun long ago. Geothermal and nuclear energy are the only big sources that do not come from the sun.
Tip
Trace it back to the sun
Food, wood, rain for hydropower, wind, and even petrol all started with sunlight. Only geothermal heat and nuclear energy come from somewhere else.
Try each one on your own first, then tap Show answer to check.
Which source of energy does the KivuWatt plant in Karongi use?
Answer: Methane gas from Lake Kivu.
Explain in two or three steps how a hydropower station makes electricity.
Answer: Water stored behind a dam falls through a pipe, it spins a turbine, and the turbine turns a generator that makes electricity.
Name two things biogas can be made from.
Answer: Any two: cow dung, food waste, toilet waste, crop waste.
Which source does Rwanda import completely?
Answer: Petroleum (petrol, diesel, kerosene).
Why do most Rwandan families cook with firewood or charcoal, and what problem does this cause?
Answer: It is easy to find and cheaper for many families, but cutting too many trees causes deforestation, and the smoke harms health.
What you learned today
Sources and credits
Quick check
Match each power plant or place in Rwanda to its source of energy.
Tap one on the left, then its partner on the right.
