Energy is power times time; household energy is billed in kWh.
Energy E=Pt in joules, or in kWh for billing (1 kWh=3.6 MJ). Cost is kWh × tariff. Energy efficiency reduces consumption: LED lamps give the same light at around 1/6 of the power of incandescent lamps.
A 2 kW heater running 3 hours uses 6 kWh.
Energy bills and battery capacity use energy rather than power, so this unit links how long something runs to how much it costs.
Energy is power times time; household energy is billed in kWh.
Energy bills and battery capacity use energy rather than power, so this unit links how long something runs to how much it costs.
Multiply the power in kilowatts by the hours of use to get kWh, then multiply by the tariff in currency per kWh.
No. A kilowatt-hour is a unit of energy, the power of one kilowatt sustained for one hour.
Typical applications include estimating the monthly cost of running a fridge, predicting how long a phone battery lasts at a given power and comparing the energy use of two lighting options.
Study "Electric power" first (topic 6 of 106 in Electrical Engineering). It covers the groundwork this topic builds on.
Standby loads add up. Demand charges for industry. Energy meters integrate power.
A 2 kW heater running 3 hours uses 6 kWh.
The next topic is "Series circuits", which builds directly on this one.
It is classed as Beginner in Electrical Engineering (topic 7 of 106). It is an entry-level topic. It relies only on basic school mathematics and the ideas introduced earlier in this discipline.
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