The concept of Watt-hours was messing me up. I think I get it now.
Energy is the potential to do some work, measured in Joules.
Power is the rate at which work is done and is measured in Joules per seconds, i.e., Watts.
If you want to know how much energy something “uses”, multiply it’s power by how long it has been running.
e.g., something with a power of 100 J/s (i.e., 100 Watts) running for 10 s will use 1,000 Joules of energy.
For household use, Joules is not a very convenient unit, so we use Watt-hours (W•h) or kW•h, which is the number of Watts an appliance uses times the number of hours it runs. Watt-hours and Joules are both units of energy.
Watt-hours is not Watts-per-hour, i.e., it is not a rate. It means Watts-times-hours. If we break it down, we can convert back to Joules: W•h = (3600s•J) / s = 3600J.
I hope I summarized it properly and didn’t make any math mistakes!
The concept of Watt-hours was messing me up. I think I get it now.
W•h = (3600s•J) / s = 3600J.I hope I summarized it properly and didn’t make any math mistakes!