Energy Units and Conversion Factors

METRIC PREFIXES

kilo(k) = 103

mega (M) = 106

giga (G) = 109

tera (T) = 1012

peta (P) = 1015

exa (E) = 1018

VOLUME

1 m3 = 1,000 litres (l)

1 U.S.gallon = 3.78 l

1 Imperial gallon = 4.55 l

Example: 1 TJ = 1,000 GJ = 1,000,000 MJ = 1,000,000,000 kJ = 1,000,000,000,000 J = 1012 J

1 J = 0.001 MJ = 0.000001 GJ = 0.000000001 TJ

ENERGY UNIT CONVERSION

Toe = tonnes oil equivalent

1 Mtoe = 41.9 PJ

Example: 1 MWh x 3.600 = 3.6 GJ

HEAT OF COMBUSTION (HIGH HEAT VALUES)

1 l gasoline = 47.0 MJ/kg = 35.2 MJ/l (density 0.75 kg/l)

1 l ethanol = 29.7 MJ/kg = 23.4 MJ/l (density 0.79 kg/l)

1 l diesel = 45.0 MJ/kg = 37.3 MJ/l (density 0.83 kg/l)

1 l biodiesel = 40.0 MJ/kg = 35.2 MJ/l (density 0.88 kg/l)

SOLAR THERMAL HEAT SYSTEMS

1 million m2 = 0.7 GWth

Used where solar thermal heat data have been converted from square metres (m2) into gigawatts thermal (GWth), by accepted convention.

Note: 1) These values can vary with fuel and temperature.

2) Around 1.5 litres of ethanol is required to equate to 1 litre of gasoline.