A kilowatt hour is equal to the amount of electrical energy consumed at a rate of one kilowatt. 1 kilowatt hour is the same as 1000 watt-hours.
So using that principle. A 500 watt microwave will consume 500 watt-hours in an hour, or 0.5 kilowatt-hour.
Comment
In practice, it's difficult to determine an answer to your question, because microwaves don't operate continuously but, rather, in short bursts. Without knowing the cycle rate of each burst of energy, it's impossible to come up with a definitive answer.
To calculate the wasted energy in a TV, you would multiply the power consumption of the TV (in watts) by the time the TV is left on (in hours). This will give you the energy consumed in watt-hours (Wh). To convert watt-hours to joules, multiply by 3600 (since 1 Wh = 3600 joules).
75W means bulb which give 75W power when connected to domestic light. Power is nothing but energy per second. Thus energy consumed by bulb can be calculated as follows. E = 75*60*60*4J = 1080kJ
A 100 watt light bulb uses 2.4 kilowatt-hours of energy if it is left on for 24 hours straight (100 watts x 24 hours = 2400 watt-hours = 2.4 kilowatt-hours).
60 days is 24x60 hours, so the energy used is 60x24x60 watt-hours, 86400 watt-hours or 86.4 kilowatt-hours or units. If it is a 60-watt incandescent bulb it could be replaced by a 12 watt low-energy bulb, and in the same time that would use only 17.3 units, saving 69 units costing about £10.
Power = Energy/time 100W=Energy/360 Seconds Energy = 100/360 Energy ≈ 0.27 Joules
Watt hours means energy or work and watts means power. You can never convert this. However, if you mean kilowatt hours, simply move the decimal 3 places to the left: .16075 kwh.
To calculate the wasted energy in a TV, you would multiply the power consumption of the TV (in watts) by the time the TV is left on (in hours). This will give you the energy consumed in watt-hours (Wh). To convert watt-hours to joules, multiply by 3600 (since 1 Wh = 3600 joules).
Watts is the product of amps times volts. As you can see this combination could have lots of variables depending on the different voltages that are in use and the variable amperage's of multiply loads. To find watts per year you would first have to find the wattage of the device, then extend it to watts per hour if the device is continually on. Then take this figure times 24 hours in a day and then finally times 365 for the days in a year. This will give you the answer that you are looking for.Alternate answer: The question is fundamentally meaningless. A watt is a measure of energy per unit time. An appliance that uses 60 watts, will use 60 watts in a second, 60 watts in a minute, 60 watts in an hour, or 60 watts in a century. Total energy can be expressed in units like "kilowatt-hours" (equal to 1,000 watts for one hour, or 100 watts for 10 hours, etc.). Our 60-watt appliance, left on continuously, will use about 525 kWh per year.
The energy consumed by a 100-Watt light bulb left burning continuously for two weeks is calculated by multiplying the power rating (100 Watts) by the time (2 weeks = 14 days = 336 hours). Therefore, the energy consumed would be 33600 Watt-hours or 33.6 kilowatt-hours (kWh).
75W means bulb which give 75W power when connected to domestic light. Power is nothing but energy per second. Thus energy consumed by bulb can be calculated as follows. E = 75*60*60*4J = 1080kJ
A 100 watt light bulb uses 2.4 kilowatt-hours of energy if it is left on for 24 hours straight (100 watts x 24 hours = 2400 watt-hours = 2.4 kilowatt-hours).
To calculate the energy usage of the light bulb, we first convert the power in watts to kilowatts (60.0 W = 0.06 kW). Then, we multiply the power by the time (0.06 kW * 60 days) to get the total energy consumed in kilowatt-hours. Therefore, the light bulb would use 3.6 kWh of electrical energy if left on steadily for 60 days.
There are zero amps in a 300 watt bulb. Watts are the product of amps times volts. W = A x V. To find amperage use the equation A = W/V. If you find the voltage of the 300 watt bulb uses, divide the wattage by the voltage and it will give you the amps of a 300 watt bulb.
Power use of an electrical appliance is calculated by finding its rating in watts. The formula is W = I x E. Watts = Amps x Volts. <<>> Power is a general term. If you want to know how much you pay to power a certain appliance you need to figure out the amperage of the appliance, (usually located on the appliance itself or in the instructions). Power companies use kilowatt hours to charge you for electricity, to figure out how many kilowatt hours your appliance uses you would need to multiply the amperage your appliance uses by .115 and that would give you the kilowatts it is using. Then you would multiply that by how many hours you use said appliance and then multiply by your cost per kilowatt hour, (found on your electric bill).
60 days is 24x60 hours, so the energy used is 60x24x60 watt-hours, 86400 watt-hours or 86.4 kilowatt-hours or units. If it is a 60-watt incandescent bulb it could be replaced by a 12 watt low-energy bulb, and in the same time that would use only 17.3 units, saving 69 units costing about £10.
The one with a high number of Watts left on for a long time.(Your neighbour's 500W garden floodlight that's left on all night.)The energy a lightbulb uses is it's power multiplied by the amount of time it is used for. A lightbulb's power is measured in Watts (W).The old fashioned incandesant bulbs are often 40W, 60W or 100W, but much of the energy they use produces heat not light - not very efficient.Mains or 12Volt halogen bulbs are usually 50W, 35W or 20W - these still produce wasted heat but are more efficient than incandescent bulbs.Low energy bulbs are only 7W, 9W or 11W and are very efficient hardly any energy wasted as heat.LEDs are low power e.g. 3W and also very efficient - but often less bright.So the lightbulb that uses the most energy is one with a high number of watts left on for a long time.
If no, or few, applications are left up and running a computer will not consume much power when left on. Computers in general consume less power then a single light bulb when running. At idle they may go down to as little as 30 watts depending on age, speed and configuration of the computer.