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Many people violate the definitions of power and energy. Some people do it publicly, thereby misleading unfortunate readers. Below is a short list of some of these violators. If you know another site, book, journal, etc. please add it to this list. If you want someone to check out a dubious definition or comment about power and energy, or if your site is on this list and you rebuke the claim of violation, please add your comment to the discussion tab. If your site is on this list and you have fixed it, congratulations and thank you, please feel free to move your site to the removed site list or just ask on the discussion tab. Remember, in short, Energy equals Power multiplied by Time, where:

  • Energy is a measurable quantity, an ability to do work. In electricity it is measured with the unit kilowatt-hour (kWh).
  • Power is the rate at which work is performed. In electricity it is measured with the unit watt (W).

See Electricity basics and Power and energy for more information.

Dishonorable Mention

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Oasis Montana Inc. Renewable Energy Supply and Design
A 300 watt per hour load for ten minutes equals 50 watt-hours total
Xtra Light Ltd - Suppliers of BLT Lighting
divide this by 1000 to get the cents per Watt per hour.
TurboCat Lighting Systems
Please note that when viewed in "ounces per watt per hour"
ECS Solar Energy Systems, Inc.
PV panel on the fan can deliver about 11 watt per hour
Iowa General Assembly Amendment
The kilowatt per hour competitive bid rate shall not be less than the annual average rate of off-peak kilowatt per hour rates and peak kilowatt per hour rates at which an electric utility would have had to purchase the power.
Bureau of Land Management - Wind Energy
This trend is continuing as evidenced by a recent application to place 1,500 kilowatt per hour machines on public lands that would, if authorized, become the largest turbines to be installed in the San Gorgonio Pass area.
World Nuclear Association and The Spectator
It calculated the cost in pence per kilowatt per hour of five sources of electricity generation
Education and Manpower Bureau of Hong Kong
Electricity is measured in kilowatt per hours (kWh)
WRAL North Carolina News
"The average increase would be about $7.70 for a customer that uses a thousand kilowatts per hours," said Garrick Francis, a spokesman for Progress Energy. (hopefully a misquote --Lonny 22:27, 15 July 2006 (PDT))
The Dollar Stretcher website
So at 0.135 kilowatts per hour that would cost $6.80 per month if used continuously.
Caspian Energy Investor Magazine
So, at adjustment-free mode of the pump units, electric energy unit discharge for pumping 1 ton of oil makes 1.85 kilowatts per hour, and at the adjustment mode - 0.73 kilowatts per hour.
US EPA Natural Gas STAR Program
‹‹Wet seals require 50 to 100 kiloWatt per hour (kW/hr) for ancillary equipment while dry seals need only 5 kW/hr ancillary equipment while dry seals need only 5 kW/hr
North Dakota Legislative Council - Minutes of the Electric Industry Competition Committee
Mr. Fuglesten said the bill draft proposes two kilowatt per hour tax rates
P3 International P4400 Kill A Watt Electricity Usage Monitor product description
Plug whatever item you want into the device and it will tell you the efficiency of that item by displaying the kilowatt per hour.

And the Winner Is...

The top entry in the hall of shame goes to Their error is on the first page of how hydropower plants work. I have emailed them about this, as well as other errors, to no avail. Now they have become the winner of the Hall of Shame - Power vs. Energy.

A violation of Power and Energy from along with a logically and mathematically equivalent sentence in everyday analogous units.
What says. The equivalent sentence.
The world's hydropower plants output a combined total of 675,000 megawatts, the energy equivalent of 3.6 billion barrels of oil, according to the National Renewable Energy Laboratory. According to Seaworldtm the average cruising speed of a hammerhead shark is 2.85 miles/hour the equivalent to the distance around the earth at the equator.

Removed from the Hall of Shame for Honorable Behavior

Currently no Hall of Shame sites have fixed their erroneous content. Please feel free to email the sites about their deeds.

TreeHugger Magazine - LiveWork Article
Thank you for the quick changes, removing kW/h greatly improves the readability and accuracy of your article.

Explanation of the Error

HowStuffWorks says the world's hydropower output is approximately 675,000 MW. This is consistent with data published by, and is roughly equivalent to 340 dams of 2,000 MW each. Hoover Dams. (Note HowStuffWorks referred to the term "output" which is sometimes used interchangeably in industry as "capacity".) Total hydro generation according to world energy is about 2,633 TWh in 1999, resulting in a respectable average capacity factor of 43% (2,633 TWh / (675,000 MW * 8760 hrs/yr) ).

Assuming one MWh is the energy equivalent of 1.7 barrels of oil, then hydro generation is equivalent to roughly 1.5 billion barrels of oil. Looks like where they went wrong with the calculation is they assumed hydro plants run 100% of the time. If hydro plants did run all the time, that would be 3.5 billion barrels of oil however. ~lori g. Hydro plants can only run when there is water behnd them. If the generation capacity of the dam was equal to the average flow of the river then it could run at 100% capacity all the time. In practice the generation capacity of most dams is higher so they can generate more electricty when demand is higher (during the day) and balance this by running at part load when demand is low (e.g. at night).

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