Observing the world of renewable energy and sustainable living

Energy related conversion factors

Conversion factors.

1 horsepower = 736 watts

1 kilocalorie = 4190 joules
1 kilowatthour (kwh) = 3600 kilojoules = 859 kilocalories
1 m3 natural gas = 10 kwh (9,769 kWh)
1 barrel of oil = 1700 kwh
1 calorie (cal) = 4.184 J
1 British Thermal Unit (BTU) = 1055 J

Energy content of some fuels

1 kilogram of dry wood 5,3 kwh 19,0 mJ
1 kilogram of coal 8,1 kwh 29,3 mJ
1 cubic metre of natural gas 8,8 kwh 31,7 mJ
1 litre of petrol 9,1 kwh 32,6 mJ
1 litre of diesel-oil 10,0 kwh 35,9 mJ
1 kilogram of hydrogen 33,6 kwh 120,8 mJ
1 kilogram of Uranium 235 22,2 million kwh 80,0 million mJ

mJ = mega-Joules

Thermal energy content of 1 liter of petrol = 7800 kcal
Enough energy to bring more than 8 buckets of water of 10 liter from room temperature to boiling point.

Mechanical energy in 1 litre of petrol = 9.1 kwh
It takes 1 m3 of petrol to lift a Boeing of 334 ton from ground to 10 km altitude (ignoring horizontal speed, friction, efficiency engines)
1 kilo-calorie (kcal) is enough to lift a cow 1 meter.

Energy conversion
Maximum efficiency of transforming heat into mechanical energy is about 50% (Carnot formula: efficiency = (Thigh – Tlow) / Thigh )
A steam-turbine in a power plant has an efficiency of 45%

Maximum efficiency conversion of mechanical energy into electricity is up to 100%
A generator in a power plant has an efficiency of 95%

Maximum efficiency conversion of electricity into mechanical energy is up to 100%
The electric motor of the “Solar car” has an efficiency of 97%

Energy prices (Netherlands, 2012):

energy source

  price per unit  

  price per kwh  

 1 litre of petrol =  9,1 kwh

€   1,81

€   0,20

 1 m3 of natural gas =  8,8 kwh  

€   0,65

€   0,07

 1 kwh electricity from the grid

€   0,22

€   0,22

1 adult male human is a chemical process that generates in rest on average 100 Watt surplus heat.
1 human can produce 100 Watt of useful labour during a longer period of time.
1 wildly dancing human can produce 400 watt of thermal energy.
During short periods of time human athletes can generate up to 800-1000 Watt.

Personal note: man, in his fifties in reasonable physical condition, on a hometrainer, can produce 120 Watt for 30 minutes at pulse 120. Sweating but not exhausted

1 barrel of oil = 8 years of human physical labor
1 kwh = 1 day of hard physical labor

Energy consumption average Dutch household (2.28 persons in 2008):

electricity 3560 kwh
natural gas 1625 m3
car 1444 liter petrol

Average distance car: 17400 km
Primary energy in power plant: 8900 kwh (efficiency 40%)

Converted into liter gasoline equivalent:

lighting 0.4
Fridge, tv, washing, ironing, vacuum cleaning 2.3
heating, warm water, cooking 4.3
car 4.0

Total 11.0 liter gasoline equivalent

These four categories in pie diagram:

Solar Energy


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12 thoughts on “Energy related conversion factors

  1. Ragnar Arnason on said:

    Excellent and I gor what I was looking for. Thanks

  2. Pingback: Energi: bensin – kcal – watt | homo ludens

  3. Pingback: Klimapilegrim | homo ludens

  4. Two small nit picky errors. When using SI prefixes lower case m is for milli, upper case M is for mega so 1kg of dry wood should be 19,0MJ. Also unit that are named after someone should be uppercase, so a kilo Watt hour is kWh not kwh.

  5. Mechanical energy in 1 litre of petrol = 9.1 kwh
    It takes 1 m3 of petrol to lift a Boeing of 334 ton

    here, it goes from referring to 1 litre of petrol, and then 1 cubic metre of petrol, which makes me wonder which one is correct?

  6. I THINK I WORKED IT OUT, 1000l of petrol to a cubic metre!

  7. Martin Winlow on said:

    Please sort out your units and metric prefixes!
    Generally any metric prefix greater than 1 uses a capital letter and any unit named after someone does the same – so, eg MWh (megga watt hour). The only common exception is ‘k’ for kilo (1000). Thank you!

  8. エラー硬貨を売却して現金化をしようと考えた場合に、そもそもエラーコインをどこで売却すればいいのだろうか。エラーコインのような特殊な硬貨を買取してくれるショップや業者についてもわかっておくべきです。


  9. No situação das proteínas puras, ocorre avesso,
    pois se consumirmos CEM calorias desde proteínas puras
    que nem a aberta de bagos, a título de exemplo, isso trabalho se dará de aparência em grau superior demorada, obrigando nosso
    corpo humano a adestrar em grau superior com o objetivo de
    abrir esse comida.

  10. peter e braham on said:

    when you give equivalencies – eg lighting in .4 l gasoline, what is the time period you use?

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