In article , Rob
wrote:


Er, it was! Have I misunderstood something - wouldn't be the first/last
time :-)

I mean he consumes 400 Watts of electricity in one hour. Stand corrected
awaits ...

The nominal unit of energy is the Joule.

Power is the *rate* of energy transfer/creation/loss.

1 Watt (power) is 1 Joule per second (energy per time period).

Thus saying "watts per hour" implies "1 Joule per second, per hour", which
may be gibberish as it is neither a power nor an energy.

Thus the Watt-hour is also a unit of energy since it is the number of
joules transferred/created/used if you use power at the rate of 1 joule per
second for 1 hour. The common unit is the kWh.

Hence it isn't clear what something like, "he consumes 400 Watts of
electricity in one hour" actually means.

Slainte,

Jim

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