kw to kwh

[BHORTON]

:?: I need to convert "KW" to "KWH".

[shill]

If I understand correctly, you need to convert kW to kWh. There is no such conversion, since kW is a measure of power, whereas kWh is a measure of energy. You can, however, convert between joules (J) and kWh by dividing J by 3 600 000, or multiplying kWh by the same number. To get a kWh value from a kW value, you would need two values; the power in kW, and the number of hours (h) that the power has been used. Then you would simply multiply the kW by the h, thus getting kWh.

[thedude]

I also have this problem of converting kW to kWH as I'm trying to figure out how much it will cost me to run certain equipment. I understand what you said, but if a freezer mfg tells me that the freezer will use 12 kW per day, then is that the same as 0.5 kWH (12 kW/24 hours)? That doesn't seem like much when we pay about $0.12 per kWH. But using this rate, is the cost per month then = $0.12/kWH * 0.5 kWH * 24hrs/day * 30 days/mth?

[Guest]

I think there is some confusion here. The number of kw is the amount of power it is using when it is on. A light bulb turns on and off with a switch. A freezer turns itself on and off as needed according to a thermostat.

Kilowatt-hours are a measure of the total energy used (usually over a longer period of time). It is the amount of power times the number of hours.

Lets look at a 100 W light bulb (which is 0.1 kW). If it is on one hour per day, that is 0.1 kWh per day, and 3 kWh per month (assuming a 30 day month). The same bulb running 10 hours per day, would consume 1 kWh per day, 30 kWh per month, and if it ran 24/7, 2.4 kWh per day, 72 kWh per month.

I think your freezer manufacturer is estimating 12 kWh per day, assuming some on/off cycle to keep it at temperature. It would use about 360 kWh per month.