Some Elementary Science  Power  work per unit time  is measured
in watts (joules per second).
Work (or energy) can be represented as power multiplied by time. In the international system of units (SI ), energy is in wattseconds, or joules. However, for measuring energy consumption, the utilities use the kilowatthour, which is the power in kilowatts multiplied by the time in hours. (1 kWh = 3.6 million joules.) It would be nice if influential people knew this information from juniorhigh science. They might not be tempted to spew  worse yet, to teach  such confused garbage as given below. But, what can you expect from people who think leverage and science are verbs. (Don't believe it? Look up sciencing with your favorite web browser!) 
Ignorance at
Business Week 
"The drain from such devices in
U.S. homes alone adds up to 5 billion watts
per year
…" [emphasis added]
Andy Reinhardt

Ignorance in
6th grade textbook 
"How Much Power is Used in a Home
Monthly? Use is figured in kWh or kilowatthours. What is a
kilowatt? A 100 watt light bulb uses 100 watts
per hour
of use.It
will use 1,000 watts if burned for 10 hours.A
kilowatt is 1,000 watts."
Chapter 3, Why is it Happening?
of

Ignorance in
"educational" website 
"A. If the wattage is given,
divide
the wattage by 1000 to get kWh. Then
multiply by the cost of a kWh, approximately 71/2¢ ($.075), to get
cost of operation per hour."
"
100 watts/hr. x 10 hrs. = 1000 watts"
[Editor's note: True, but meaningless
arithmetic. If these energy experts knew their subject, they might
write: 100 watts x 10 hours = 1000 watthours.]
