SuomeksiEnergy Values and Conversion Factors
Comparing Energy Contents
What makes comparing different energy forms and energy gains somewhat challenging, is the wide variety of different units of measurement. Some energy forms are given in tonnes, some in loose cubic metres, stacked cubic metres or solid cubic metres, some in kilos and so on. Also moisture content greatly affects the energy gain.
At http://muunnin.com you will find counters (in Finnish) which can be used to convert between different units of measurement. For example, to convert kilowatts into megawatts, go to http://muunnin.com/teho/.
Fuel Oil as the Baseline
If we wish to compare renewable energy sources according to their energy content, the easiest way is to compare them with fossil fuels, and with the one that we are most familiar with: fuel oil. This way we can better understand the huge potential that bioenergy in its different forms has. Given in different units of measurement, fuel oil has approximately 10 kWh/litre or 11,8 kWh/kg or 42,7 MJ/kg.
In the table below, fuel oil’s energy contents is compared with those of wood chip, pellet, briquette, peat and oat.
| Feature | Chips from lopped poles | Wood pellet | Wood briquette | Sod peat | Oat | Fuel oil |
| Moisure content % | 25-30 | 8-10 | 8-10 | 25-40 | 14 | |
| Bulk density (kg/m³ᶩ ͮ) | 250-320 | 600-650 | 600-650 | 350-400 | 520-590 | 0,845 |
| The energy density (kWh/m³ᶩ ͮ) | 700-900 | 2 900-3 900 | 2 900-3 400 | 1 400 | 2 200-2 500 | 10 000 (kWh/m³) |
| Ash content | 0,5-2,0 | 0,5 | 0,5 | 4,0-6,0 | 5,0-7,0 | +/-0 |
Conversion Factors
A conversion factor is a ratio which is used to convert a measured quantity into a different unit.
| toe | MWh | GJ | Gcal | |
| toe | 1 | 11,630 | 41,868 | 10,0 |
| MWh | 0,08598 | 1 | 3,6 | 0,86 |
| GJ | 0,02388 | 0,2778 | 1 | 0,2388 |
| Gcal | 0,1 | 1,1630 | 4,1868 | 1 |
Typical Heat Values and Densities of Certain Fuels
| Fuel | Unit of Measurement | GJ | MWh | toe | t/m3 (or t/ m³ᶩͮ ) |
| Crude oil | tonne | 41,868 | 11,63 | 1,00 | 0,855 |
| Heavy fuel oil normal/low sulphur | tonne | 40,60/41,10 | 11,278/11,417 | 0,970/0,0982 | 0,955 |
| Light fuel oil | tonne | 42,50 | 11,806 | 1,015 | 0,845 |
| Diesel oil | tonne | 41,50 | 11,528 | 0,991 | 0,845 |
| Liquid oils | tonne | 46,30 | 12,861 | 1,106 | 0,580 |
| Coal | tonne | 25,211 | 7,003 | 0,602 | 0,800 |
| Coke | tonne | 29,30 | 8,139 | 0,700 | 0,750 |
| Natural gas (OoC) | 1 000 m³ | 36,00 | 10,00 | 0,860 | 0,732 |
| Blast furnace gas | 1 000 m³ | 3,79 | 1,053 | 0,091 | |
| Coke oven gas | 1 000 m³ | 16,70 | 4,639 | 0,399 | |
| Black liquor | DT | 11,70 | 3,250 | 0,279 | 1,415 |
| Birch chip (log) | m³ˢᵗ | 5,40 | 1,50 | 0,129 | 0,400 |
| Mixed chip (log) | m³ˢᵗ | 4,51 | 1,25 | 0,107 | 0,350 |
| Fuel chip | m³ᶩ ͮ | 2,88 | 0,80 | 0,069 | 0,300 |
| Saw dust | m³ᶩ ͮ | 2,16 | 0,60 | 0,052 | 0,300 |
| Wood shavings | m³ᶩ ͮ | 1,80 | 0,50 | 0,043 | 0,100 |
| Conifer bark | m³ᶩ ͮ | 2,16 | 0,60 | 0,052 | 0,300 |
| Birch bark | m³ᶩ ͮ | 2,52 | 0,70 | 0,060 | 0,350 |
| Wood pellet | tonne | 16,92 | 4,70 | 0,404 | 0,690 |
| Sod peat | m³ᶩ ͮ | 5,04 | 1,40 | 0,120 | 0,380 |
| Milled peat | m³ᶩ ͮ | 3,24 | 0,90 | 0,077 | 0,320 |
| Biogas | m³ gas | 14,4 – 28,8 | 4 - 8 | 0,344 – 0,688 |
Source: Energy statistics (KTM) and VTT Energia.
