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Physics
Electrical energy and power — Which appliance uses more energy?
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Set the power and usage duration of two appliances, then watch their energy meters to distinguish W, kW and kWh.
Simulated time: 0:00Press Run to watch the two meters change.
- Appliance A
- 0.0000 kWh; Used 0:00 min
- Appliance B
- 0.0000 kWh; Used 0:00 min
30 min = 0.5 h
360 min = 6 h
Constant power while on. Simulated time is accelerated.
Separate measurements · meters start at 0
So far
No energy used yet
Energy use depends on both power and usage duration.
E = P × t
A · Model heater1 kW × 0 h= 0.0000 kWh
B · Model fan0.1 kW × 0 h= 0.0000 kWh
W and kW measure power. kWh measures energy: kW multiplied by hours.
Units and meters
1,000 W = 1 kW · 1 kWh = 1 kW × 1 h = 3,600,000 J
Real meters accumulate readings. Energy during a period is the final reading minus the initial reading. Start over begins a new measurement here.
Model notes
- Each load has a stable supply and constant power while on. Energy is power multiplied by usage time. Simulated time is accelerated at the selected rate.
- The heater, fan and lamp are illustrative examples, not specifications of a product. Real appliances may change power by setting or cycle; rated power cannot always be multiplied by the entire time plugged in.
- Temperature, rotational speed, brightness, efficiency, standby consumption, current and AC waveforms are not simulated. Drawing size and fan motion do not represent wattage.
- The two meters are independent measurements starting together. Readings show energy for this run, starting at zero; real meters normally accumulate and readings must be subtracted. Pause suspends the simulation, not the physical power supply.
- The 0–3,000 W and 0–720 min ranges belong to the learning tool, not limits on real appliances. Rounded display values are never used to calculate subsequent energy.