Understanding KWh and appliance rating

[sma92878]

Hello all,

I'm very new to solar, and I don't like to take things for granted. When you see the watt rating on an appliance, for example this induction cook top below:

https://www.amazon.com/Rosewill-Induction-Electric-Independent-Lightweight/dp/B09RNDX5H2?th=1

If it states it's 1800w, that's 1800w used if it's powered on for 1 hour, is this correct? From what I'm reading all w rating on appliances is effectively a KWh.

Kind regards

 

[sunshine_eggo]

Sorta.

1800W is an instantaneous power.

1800W used for an hour consumes 1800Wh of energy.
1800W used for 30 minutes consumes 900Wh of energy.

An appliance like that cook top or a fridge cycles on and off, so while it's on, it may only use "X" Watts, but how often it runs determines how much energy (kWh) it uses in a day.

The yellow/black Energy Guide labels often give an annual cost or kWh usage. Simply divide the annual kWh value by 365 to get daily kWh.

 

[rmaddy]

No, the watt rating is how many watts it is using at any given moment.

Watt hours is the energy it uses over time. So an 1800W load over one hour is 1800W x 1h = 1800Wh. If you used it for 10 minutes it would be 1800W x 1/6h = 300Wh.

 

[timselectric]

Hello all,

I'm very new to solar, and I don't like to take things for granted. When you see the watt rating on an appliance, for example this induction cook top below:

https://www.amazon.com/Rosewill-Induction-Electric-Independent-Lightweight/dp/B09RNDX5H2?th=1

If it states it's 1800w, that's 1800w used if it's powered on for 1 hour, is this correct? From what I'm reading all w rating on appliances is effectively a KWh.

Kind regards

No
That's 1800w continuous, at max power setting.
It would use 1800 watt hours, in 1 hour. (AKA 1.8 kwh per hour)

Edit:
Minus any off cycling, as stated above.

 

[Jim Burrow]

Just to make it clear, 1800 watts is 1.8kw
1800 watts for one hour is 1800-watt hours (1800 wh) or 1.8 kwh