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Because energy is routinely priced by the watt-hour.
by kemiller 9y ago
Because energy is routinely priced by the watt-hour.
- aqme28 9y agoI'm still curious why it's priced by the watt-hour instead of the Joule
- 6nf 9y agoIt's easier for a consumer running a 100 watt appliance for 2 hours to calculate the cost.
- badosu 9y agoProbably because power consumption of utilities are measured by watt, so watt/h gives more intuition on how much energy was consumed.
- deleted 9y ago[deleted]
- em3rgent0rdr 9y agoI think because consumer devices are rated in watts, and consumers can easily guess how many hours they use a particular device.
- BurningFrog 9y agoWithout knowing anything specific about this, but knowing a lot about how the world works, I'm fairly confident this convention predates the wide acceptance of the Joule unit.
- Someone 9y agoLooking at https://en.wikipedia.org/wiki/General_Conference_on_Weights_and_Measures#CGPM_meetings https://en.wikipedia.org/wiki/General_Conference_on_Weights_..., the Watt and the Joule were formalized at the sa,e conference (in 1948). Of course, that doesn’t rule out that your claim is true, but it does make me wonder whether it does. I would guess kWh is used because it makes it easier for customers to verify that they aren’t scammed, given that appliances are tagged with Watts. I guess appliances are tagged with Watts and not Joule/s because it is easier to use a single unit than two.
- BurningFrog 9y agoYes, but note my "wide acceptance of" weasel phrase. My impression is that the Joule only started being used widely in the 70s. I did try to find out when it was defined but failed, so thanks for digging that fact up!
- Someone 9y agoThere’s also https://books.google.com/ngrams/graph?content=Watt%2CJoule&year_start=1800&year_end=2000&corpus=15&smoothing=3 https://books.google.com/ngrams/graph?content=Watt%2CJoule&y.... That is for books and must cover mentions of both Watt’s and Joule’s name and of the unit (and, likely, way more of the names. The units typically are abbreviated), so I don’t think that proves or disproves much about wide use of the units. The difference before 1860 probably is there because James Prescott Joule was less than a year old when James Watt died in 1819 (at the age of 83) Edit: https://books.google.com/ngrams/graph?content=kJ%2CkWh%2Ccalorie&year_start=1800&year_end=2000&corpus=15&smoothing=3 https://books.google.com/ngrams/graph?content=kJ%2CkWh%2Ccal... seems to support the claim that “Joule” came up relatively late.