Electricity in Our Lives — and Staying Safe: Concept Map

Concept Map

Organise the vocabulary, quantities and relationships into a connected model.

This extension applies that lens specifically to Electricity in Our Lives — and Staying Safe.

Electricity reaches us in two very different ways.

Cells and batteries are small, portable and weak. They run torches, remotes, cellphones and radios. They are safe enough to build circuits with in a classroom.

Mains electricity comes from power stations through cables to the plug points in a building. In South Africa most of it is generated by burning coal in Mpumalanga, with a growing share from wind farms in the Eastern Cape, solar farms in the Northern Cape and one nuclear station at Koeberg. Mains electricity is enormously powerful — powerful enough to kill.

When the country cannot generate enough for everyone at once, supply is switched off area by area in turn. That planned switching-off is load-shedding.

Using less electricity saves money and eases the strain on the grid. The biggest savings at home come from heat:

• Boil only as much water as you actually need in the kettle.
• Switch the geyser off when it is not needed, or fit a geyser blanket.
• Switch lights and appliances off in empty rooms; unplug chargers.
• Cook with a lid on the pot so the heat stays in.

Safety rules that are not negotiable:

1. Only build circuits with cells — never with plug points or mains cables.
2. Never touch a switch, plug or appliance with wet hands, and never near a bath or sink.
3. Never poke anything into a plug point.
4. Report frayed cords and cracked plugs to an adult, and stay far away from fallen power lines and illegal connections.