kWh

• A watt is a common unit of measure for electrical power
• Power is a measure of the instantaneous electricity being used when you turn on any electrical appliance
• Power requirements are called out in watts on labeling for everything, from light bulbs to microwaves
• Kilo means one thousand, so a kilowatt is 1,000 watts
• Energy is the accumulated amount of power being used over some period of time
• Energy is expressed in kilowatt-hours
• An analogy to understand energy is driving a car, where speed is equivalent to power and distance is equivalent to energy
• In small amounts, energy is measured in watt-hours, while for households, it is measured in kilowatt-hours
• 1 kilowatt-hour is 1,000 watts used over one hour
• Example: Burning 10 100-watt bulbs for one hour uses 1 kilowatt-hour of energy
• Example: Leaving a single 100-watt bulb on for 10 hours uses 1 kilowatt-hour of electricity
• Leaving a 100-watt bulb on every workday while away would cost $65 per year at 25 cents per kilowatt-hour
• It is important to turn off lights before leaving the house and switch to low-wattage LED bulbs
• Kilowatt hour (kWh) is the amount of power demanded over a specific amount of time
• Power multiplied by time equals energy
• Kilowatt (kW) is a unit of power, where 1 kilowatt equals 1,000 watts
• Watt (W) is a unit of power, named after the engineer James Watt
• Joule is a unit of energy, where 1 watt equals 1 Joule per second
• Kilowatt hour (kWh) is equivalent to 3.6 megajoules
• Energy formula: energy equals power multiplied by time
• To convert kilowatts to watts, multiply by 1,000
• To convert watts to kilowatts, divide by 1,000
• To calculate electricity consumption, use the formula energy equals power multiplied by time
• To calculate the cost of electricity consumption, multiply the kilowatt hour consumption by the electricity tariff per kilowatt hour
• To calculate monthly electricity consumption, create a table of electrical items, note down their power in kilowatts, calculate the hours per month they will be switched on for, and use the energy formula to find the consumption for each item
• Add up the values in the energy column to find the total kilowatt hour consumption per month
• Consider additional costs like tax when calculating the total cost
• Power is the rate at which an appliance uses electricity, indicating how much energy it uses every second
• Power is measured in watts, with a kilowatt being equal to a thousand watts
• A 20-watt light bulb uses less energy than a 100-watt light bulb, with the 20-watt bulb being dimmer
• In terms of electricity and a wire analogy, pushing electricity slowly into a 20-watt light bulb is like water dribbling out of a hose pipe slowly
• Pushing electricity five times faster into a 100-watt light bulb makes it five times brighter
• Solar systems are sized based on power measured in kilowatts, indicating how much electricity they produce at midday on a sunny day
• Energy is measured in kilowatt hours, representing how much electricity has been used over a period of time
• Kilowatt hours measure the amount of electrical energy used or generated over time