Editing Mechanization (section)

==Mechanical vs human labour==
When we compare the efficiency of a labourer, we see that he has an efficiency of about 1%–5.5% (depending on whether he uses arms, or a combination of arms and legs).<ref>{{Cite report
 | last1 = Ayres
 | last2 = Ayres
| last3 =Warr
 | first1 = R. U.
 | first2 = L. W.
 | first3 =B.
 | title = Exergy, Power and Work in the U. S. Economy 1900–1998, Insead's Center For the Management of Environmental Resources, 2002/52/EPS/CMER
 | year = 2002
 | url =http://flora.insead.edu/fichiersti_wp/inseadwp2002/2002-52.pdf
}}</ref>  Internal combustion engines mostly have an efficiency of about 20%,<ref>[http://ffden-2.phys.uaf.edu/102spring2002_Web_projects/Z.Yates/Zach%27s%20Web%20Project%20Folder/EICE%20-%20Main.htm IC Engine 20% efficient]</ref> although [[Wärtsilä-Sulzer RTA96-C|large diesel engines]], such as those used to power ships, may have efficiencies of nearly 50%. Industrial electric motors have efficiencies up to the low 90% range, before correcting for the conversion efficiency of fuel to electricity of about 35%.<ref>{{Cite web |url=http://www.e-traction.eu/content_thewheel_advantages.php |title=Electrical engines with combined power converter / motor at 86% efficiency |access-date=2011-03-22 |archive-url=https://web.archive.org/web/20160305103841/http://e-traction.eu/content_thewheel_advantages.php |archive-date=2016-03-05 |url-status=dead }}</ref>

When we compare the costs of using an internal combustion engine to a worker to perform work, we notice that an engine can perform more work at a comparative cost. 1 liter of fossil fuel burnt with an IC engine equals about 50 hands of workers operating for 24 hours or 275 arms and legs for 24 hours.<ref>[http://www.manicore.com/anglais/documentation_a/slaves.html 1 liter of fuel yielding 100 arms for 24 hours, when efficiency is 40% which is never]</ref><ref>Home documentary by Yann Arthus Bertrand too stating that 1 liter of fuel yields 100 arms for 24 hours; probably from same calculation</ref>

In addition, the combined work capability of a human is also much lower than that of a machine. An average human worker can provide work good for around 0,9&nbsp;hp (2.3 MJ per hour) <ref>{{Cite journal |last=Ozkan |first=Burhan |year=2004 |title=Energy input–output analysis in Turkish agriculture |journal=Renewable Energy |volume=29 |issue=1 |page=39 |doi=10.1016/s0960-1481(03)00135-6 |bibcode=2004REne...29...39O |url=http://www.econturk.org/Turkisheconomy/energyinput.pdf |access-date=2018-04-20 |archive-date=2022-05-25 |archive-url=https://web.archive.org/web/20220525140642/http://www.econturk.org/Turkisheconomy/energyinput.pdf |url-status=dead }}</ref> while a machine (depending on the type and size) can provide for far greater amounts of work. For example, it takes more than one and a half hour of hard labour to deliver only one kWh – which a small engine could deliver in less than one hour while burning less than one litre of petroleum fuel.   This implies that a gang of 20 to 40 men will require a financial compensation for their work at least equal to the  required expended food calories (which is at least 4 to 20 times higher). In most situations, the worker will also want compensation for the lost time, which is easily 96 times greater per day.  Even if we assume the real wage cost for the human labour to be at US $1.00/day, an energy cost is generated of about $4.00/kWh. Despite this being a low wage for hard labour, even in some of the  countries with the lowest wages, it represents an energy cost that is significantly more expensive than even exotic power sources such as solar photovoltaic panels (and thus even more expensive when compared to wind energy harvesters or luminescent solar concentrators).<ref>[http://www.fao.org/docrep/010/ah810e/AH810E08.htm Combined work capability of human vs machines]</ref>

{{See also|Economic growth#Energy and energy efficiency theories|l1=Energy and energy efficiency theories}}