Household electrical appliances – energy consumption and tiered electricity bills
Design & TechnologyElectrical Engineering & SafetyAges 11–12
Use it with your class: students open it from a link or a QR code, with no account needed.
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The house has nine familiar electrical appliances with realistic power ratings: a 9 W LED bulb, a 60 W fan, a 100 W TV, a fridge, a 700 W rice cooker, a 500 W washing machine, a 1000 W iron, an 1800 W electric kettle, and a 900 W air conditioner. Students click to switch each appliance on or off, click the arrows to raise or lower its daily hours of use, then watch the energy E = P(kW) × t(h) for each device, the total kWh for the month, and the bill calculated under California's (USA) tiered electricity rates.
Lesson: Introduction to household electrical appliances: rated power, energy consumption, and safe, efficient electricity use
What it shows
The electrical energy an appliance uses is its power multiplied by the time it runs: E = P × t, with P in kilowatts and t in hours giving kilowatt-hours (kWh). The simulated house has nine appliances with realistic power ratings, from a 9 W LED bulb to an 1800 W kettle. High power alone does not make an appliance costly: a kettle used for a few minutes a day uses less energy than a fridge that runs around the clock. Under a tiered tariff, energy above a base allowance is charged at a higher price per kWh.
How to use
Start with Turn All Off and switch on one appliance at a time, reading its daily and monthly kWh. Change running hours with the ▲▼ arrows on each tile, and raise the Hours of air conditioner use per day to see which device dominates the total. Switch the Electricity pricing method between the tiered and flat rates and compare the bill for the same consumption. Finally adjust the Number of 9 W LED bulbs and the Number of billing days.
Parameters you can change
- Number of 9 W LED bulbs 1–12 bulbs
- Hours of air conditioner use per day 0–12 h
- Number of billing days 1–31 days
- Electricity pricing method California (USA) tiered rate (PG&E), Flat rate 0.43 $/kWh
Questions to explore
- Which appliance uses the most energy in a month, and is it the one with the highest power rating?
- How much energy is saved in 30 days by using the 60 W fan instead of the 900 W air conditioner, 6 hours daily?
- Under the tiered rate, why does each extra hour of air conditioning cost more once total use passes the base allowance?
