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Carbon emissions of different fuels
Fuels for heating, power and transport
Fuels for heating and power

These represent figures for the carbon or carbon dioxide emitted by full combustion of each fuel, per unit of energy. Note that life cycle CO2 emissions depend strongly upon details of supply chains, production techniques, forestry or agricultural practice, transport distances, etc.

Fuel Net calorific value (MJ/kg) Carbon content (%) Approx. life cycle CO2 emissions (including production)
See note 1
Annual total CO2 emissions to heat a typical house
(20,000 kWh/yr)
kg/GJ kg/MWh kg kg saved compared with oil kg saved compared with gas
Hard coal 29 75 115 414 8,280 -2,000 -3,740
Oil 42 85 87 314 6,280 0 -1,740
Natural gas 38 75 63 227 4,540 1,740 0
LPG 46 82 72 259 5,180 1,100 -640
Electricity
(UK grid - delivered)
- - 164 590 11,800 -5,520 -7,260
Electricity
(large scale wood chip combustion)
- - 16 58 1160 5,120 3,380
Electricity
large scale wood chip gasification)
- - 7 25 500 5,780 4,040
Wood chips
(25% MC) Fuel only
14 37.5 2 7 140 6,140 4,400
Wood chips
(25% MC) Including boiler
14 37.5 5 18 360 5,920 4,180
Wood pellets
(10% MC starting from dry wood waste)
See note 3
17 45 4 15 300 5,980 4,240
Wood pellets
(10% MC drying from green wood using gas)
17 45 22 80 1,600 4,680 2,940
Wood pellets
(10% MC) Including boiler
See note 3
17 45 7 26 520 5,760 4,020
Wood pellets
(10% MC - dried from green using gas) Including boiler
17 45 25 91 1,820 4,460 2,720
Grasses/straw
(15% MC)
14.5 38 1.5 to 4 5.4 to 15 108 to 300 5,920 to 6,172 4,240 to 4,432

Notes:

  1. Life cycle analysis data from: Carbon and energy balances for a range of biofuels options Elsayed, MA, Matthews, R, Mortimer, ND. Study for DTI URN 03/836, 2012 Guidelines to Defra / DECC's GHG Conversion Factors for Company Reporting, and: Comparison of energy systems using life cycle assessment A special report for the World Energy Council July 2004
  2. www.electricity-guide.org.uk/fuel-mix.html
  3. These figures for wood pellets include the hammer mill and pelleting process, however do not include sourcing the feedstock and any pre-processing such as drying. If starting from green wood then drying could be a very major component, however pellets are often made from dry waste wood that has been dried for another purpose, such as joinery. These figures also do not include transport (which is included in the figures for wod chips).
Fuels for transport

Note that life cycle CO2 emissions depend strongly upon details of supply chains, production techniques, forestry or agricultural practice, transport distances, etc.

Fuel Net calorific value (MJ/kg) Density (kg/m3) Energy density (MJ/l) Carbon content (%) Carbon emission on combustion CO2 emission on combustion Approx. life cycle GHG CO2 eq. emissions
(see note 2)
Land use implications
g/litre kg/gal g/litre kg/gal g/MJ g/mile at 4.5 MJ/mile
(see note 1)
g/litre kg/gal g/MJ g/mile at 4.5 MJ/mile
(see note 1)
miles/ha at 4.5 MJ/mile
(see note 1)
ha/yr at 10,000 miles pa
Petrol 44 730 32 87 635 2.89 2328 10.6 72.8 328 2600 11.8 81 366 - -
Diesel 42.8 830 36 86 713 3.24 2614 11.9 72.6 327 3128 14.2 87 391 - -
LPG
(mainly propane)
46 510 24 82 418 1.90 1533 7.0 65.0 292 - - - - - -
Bioethanol
(from sugar beet)
27 789 21 52 410 1.87 1503 6.8 71.6 322 724 3.3 34 155 26400 0.38
Bioethanol
(from wheat)
27 789 21 52 410 1.87 1503 6.8 71.6 322 511 2.3 24 109 13800 0.72
Biodiesel
(from rapeseed oil)
37 880 33 77 678 3.08 2486 11.3 75.3 338 1334 6.1 41 183 9100 1.1
Biodiesel
(from waste vegetable oil)
37 880 33 77 678 3.08 2486 11.3 75.3 338 437 2.0 13 60 - -

Notes:

  1. 4.5 MJ/mile is equivalent to 32.5 mpg for a petrol car or 36.4 mpg for a diesel car.  However, this makes no allowance for differences in combustion efficiency between different engine designs.  For example, diesel engines run at higher compression ratio than petrol engines and therefore are typically more efficient (fewer MJ per mile)
  2. Life cycle analysis data from: "Carbon and energy balances for a range of biofuels options" Elsayed, MA, Matthews, R, Mortimer, ND.  Study for DTI  URN 03/836
  3. To convert miles per gallon of a particular fuel to grammes of CO2 per km divide the figure for g/litre of CO2 (either directly from combustion or lifecycle) by the mpg figure multiplied by 0.354 (to convert to km/litre):
    g/km = (g/l)/(mpg x 0.354) = (g/l x 2.825)/mpg

CO2 emisions vs. fuel consumption

Including UK and international forestry in BEAT2

This report calculates the greenhouse gas emission savings (taking account of changes in forest carbon) resulting from using a range of forestry products (roundwood, wood chips and wood pellets) from UK and overseas forests to generate electricity. Downloadable from here.


Other facts and figuresOther facts and figures