Talk:Orders of magnitude (power)

How small?

Anyone have a good idea how small this should go? It seems to me that most of the really small powers are better expressed as energy, when you have reactions of individual molecules and such. I know some LEDs and such go at least down to microwatts, and there's the now-infamous (there's that word again!) antpower, albeit badly calculated. Anybody know any nanowatts or smaller that have any use? Perhaps the average power output of a single human cell, or something like that? -- John Owens 10:34 19 May 2003 (UTC)

Multiple of three powers instead of decades

Also, I'm open to suggestions as to when we should start grouping by thousands instead of decades. I'm thinking around 1 E24 W, and around 1 E-6 W if we go any smaller than that. Comment? -- John Owens 13:26 19 May 2003 (UTC)

Should the examples be in "engineering" scientific notation? in other words, multiple of three exponents. for instance, in the kilowatts section was a 1.1x10^4. i changed it to 11x10^3, so that it is in kilowatts. This is certainly the way I would prefer units, but I am an engineer and others may not like it. - Omegatron 15:30, Jun 18, 2004 (UTC)

I would like the numbers include a non-three-power notation i.e. write 1x10^4 W as 10 kW; 1.4x10^5 W as 140 kW and so forth. I think this will make the sections more readable for people not familiar with this notation, and greatly increase readability. --Deelkar 04:00, 3 Nov 2004 (UTC)

Conversion corrected

I corrected the conversion from 1MW to horsepowers. I used g = 9.80665m/s^2, which should be common average, after calculation it came slightly less than 1360.

Put these all in one page

I really, really think this should all be one one page. It will make it a lot more usable, and easier to maintain into the bargain. Onebyone 03:12, 9 Dec 2003 (UTC)

Done, and since even on one page the list still doesn't look at all cramped, I think the result is the right thing. There are now 48 redirects to this page... Onebyone 01:25, 13 Dec 2003 (UTC)

which world

"average total power consumption of the world"

this just means human activities, right? - Omegatron 03:00, Aug 17, 2004 (UTC)

total power consumption

the issue isn't with the words "power consumption", but with the word "total", implying the amount of power consumed in one year, which is silly, since power is a rate per unit time. i think the "total" just means "total for all of the united states", not "total for the entire year", but we should rephrase and get a reference. - Omegatron 17:02, Dec 9, 2004 (UTC)

Maybe I misunderstood. Is "total power consumption" meant to include non-electrical power? If so, that's my mistake, and it should probably be restored to the way it was before I removed it. --Doradus 23:23, Dec 9, 2004 (UTC)

Oh yeah, you're probably right. Either way, it should be verified and explicitly phrased. - Omegatron 14:45, Dec 10, 2004 (UTC)

I came here looking for an explination of this ... I figured someon had asked. SO does this mean Total ELECTRICAL power consumption vs. Totoal power of all types consumption. Is is an avrage? a peak? im so confused %-) Dalf | Talk 05:05, 22 Apr 2005 (UTC)

"...3.34 TW – geo: average total (gas, electricity, etc.) power consumption of the U.S. in 2005[14] ...." [1]

This entry is ambiuous in terminology. TW is Power NOT Consumption- TW-year [8760 TWh]is Energy(Consumption).

From the source[14] this is 100.4 "quadrillion Btu" PER YEAR - taking quadrillion to be 10^15 Btu this would be 1.15 x 10^13 Btu/hr = 3.35 X 10^9 KW = 3.35 TW??

The entry might read better as: "Rate of Energy consumption in the USA averaged over the year 2005"

BTW the units for Power are often ambiguous: Watts are units of Mechanical Power, Btuh are units of Heat Transfer -actually there does not appear to be any units for "Electrical" Power - the Volt-Ampere is actually Joule/Coulomb X Coulombs/sec = Joules/sec = watts.

What, not watt, would be a good unit of electrical power? And the famous person named for it - DeGraff, Franklin? Any takers?

Pete318 (talk) 17:49, 22 November 2010 (UTC)

categories?

What is the point of all the tags (Biomed, tech, etc.) on this page? Is it not obvious that something related to lasers is technological and something related to blue whales is biological? I just don't really see the point of these at all. --Deglr6328 03:44, 10 August 2005 (UTC)

Yeah, that's silly. If it's not clear what a particular example is, it should be clarified in prose. — Omegatron 14:55, 7 December 2006 (UTC)

Moreover, many example, in particular Sci-Fi ones, are just totally irrelevant and non-representative. The power consumption of the StarTreck enterprise is just a random number picked by the scenarist. --137.194.3.137 14:47, 7 December 2006 (UTC)

I don't see anything wrong with sci-fi entries. We don't want them to overwhelm everything else, but a few notable ones (estimated power the Death Star would require to explode a planet, etc.) are fine. — Omegatron 14:55, 7 December 2006 (UTC)

If the figures are canon, and can be traced to an official source, then it could be interesting to compare them with real world examples. The power generated by the Death Star is around 3 x 10^33 watts, going by a number of technical commentaries, but has never been stated in a canonical source. —Preceding unsigned comment added by 86.147.150.62 (talk) 02:51, 2 January 2010 (UTC)

Photosynthesis

I corrected the power (by about 10 x) based on total primary production of fixed carbon, calculated as if in the form of carbohydrates. Harold f 22:55, 28 June 2006 (UTC)

Better power calculation based on Science article on primary production (PDF).Harold f 02:33, 23 August 2006 (UTC)

Let me add another 100fold to the "average photosynthetic power output per square kilometer of land": It is not specified what kind of land. All land, desert, tropics, northern Europe, tundra? Also, I doubt that 16-23 kW is correct for either of them. In the cited source FAO I couldn't find any such figure. The only information in that source that seems to be closer related is "The net result being an overall photosynthetic efficiency of between 3 and 6% of total solar radiation."(FAO). Even if we only assume 1% efficiency and combine that with another source that says "average irradiance over the year is [...] roughly [...] 100 W/m^2 or 2.4 kWh/m^2/day in northern Europe, e.g. the UK" (Energy Balance: Photosynthesis and Peak Oil) we get

100 * 0.01 W / m^2 = 1 W / m^2
1 square kilometer of land is 10^6 m^2 or 100 ha
=> 10^6 W / km^2 = 1 MW / km^2

or 10 kW / ha (northern Europe at 1% photosynthetic efficiency).

Energy Balance: Photosynthesis and Peak Oil says the average irradiance over the year in the tropics is 208 W / m^2. Considering the maximum photosynthetic efficiency of 6% (FAO), we'd have: 208 * 0.06 W / m^2 = 12.48 W / m^2 1 ha is 10,000 m^2

=> 124.8 kW / ha (tropics at 6% photosynthetic efficiency)

0 kW / ha (desert)

I'd suggest:

"0 - 125 kW - average photosynthetic power output per hectare of land"

... and be happy if somebody with more knowledge on this topic could help out. Zico75 (talk) 13:02, 11 February 2009 (UTC) —Preceding unsigned comment added by Zico75 (talk • contribs) 11:55, 11 February 2009 (UTC)

Io's flux tube

Io's flux tube carries about 10^12, not 10^18. I'll try look for something around 10^18.

Thric3 20:27, 9 March 2007 (UTC)

3 GW - Tech: approximate peak power generation of the world's largest nuclear reactor?

Which nuclear reactor is the world's largest? TerraFrost 17:27, 18 April 2007 (UTC)

This is wrong, as the largest Nuclear powerplant is the Kashizaraki plant in Japan, with a 8.212 Gigawatt output. —Preceding unsigned comment added by 92.1.135.191 (talk) 18:34, 5 October 2009 (UTC)

Citation needed?

Was looking for the average power output of cars, and got really confused when I ran into "GEN H-4 one-man helicopter" at 30kW (less than the power output range cited for typical automobiles). There doesn't seem to be a wikipedia page on this helicopter, or any citation on this 30kW claim. Is there seriously a helicopter that takes less gas than the most efficient car? Because if so then I want one!

This thing is essentially a backpack with rotors, which very brave (or stupid) individuals strap on their backs as the best available iteration of a helicopter hat. By the way, 30kW is a lot of power even in general aviation, e.g. in the 1929 a hungarian flew an 18hp (13kW) ultralight airplane from the Balkans up to Sweden and back, a total of 5000km in seven days, including to detours via Germany. We are totally spoiled by 100+ kw cars and 65 kilo hp powerful jet airliners nowadays. 91.83.2.152 (talk) 21:03, 19 June 2009 (UTC)

Wrong decimal point

> 10 MW - tech: highest ERP allowed for an UHF television station

This is clearly impossible. A very large AM band radio station with a 300 meter tall tower emits maximum 2MW and can be heard up to 1000 kilometers away (for example I was able to listen to MR1 Radio Kossuth of Budapest, Hungary during the late evenings when I visited Turin in North Italy in 2000).

A radio emitter tower with 2MW power output has water-cooled vacuum tubes the size of a schoolkid, which need replacement every few hundred hours due to the excessive wear caused by such high power.

There is absolutely no way an FM emitter (TV station) will produce 10MW of radio frequency, it would just melt the surroundings away and jam the military radar crew to madness. Obviously the article has the decimal dot in the wrong position, and it should be 1MW or maybe 0.1MW i.e. 100kW! —Preceding unsigned comment added by 91.83.2.152 (talk) 20:57, 19 June 2009 (UTC)

Figures hard to reconcile

On the one hand, the article says that the point at which signal power is overwhelmed by thermal fluctuations is around 10⁻¹⁸ watts. On the other hand, the power of the Galileo space probe's radio signal as received on earth is said to be 10⁻²⁰ watts – some 100 times smaller. How can that be? 86.179.2.205 (talk) 20:14, 11 February 2011 (UTC)