Useful Numbers

These numbers are the sort of things I use all the time to calculate the impact of different activities.

Contents: - Energy consumption - CO2 emissions - Fuel density and carbon intensity - Passenger travel emission factors - Freight emission factors - UK population - Water energy properties - Greenhouse gases GWP

Energy consumption

 PWh/yearMWh/person/yearkWh/person/daycontinuous kWpopulation
World primary energy14120.9572.46.8 billion
UK primary energy2.4739.61094.562.3 million
UK final energy 1.85 29.7 81 3.4

World data from IEA Key World Energy Statistics (data for 2009)
UK data from DUKES, data for 2010

Primary energy consumption counts fuel used to generate and transmit electricity rather than the electricity itself. The final energy consumption is what is actually delivered.

This data is unadjusted for the weather - In 2010 the UK was rather cold.

CO2 emissions

Emissions due to energy


From IEA Key World Energy Statistics (data for 2009)

Total CO2 emissions


World data from WRI World Greenhouse Gas Emissions 2005
UK from UK Greenhouse gas inventory, data for 2010

Fuel density and carbon intensity

Electricity*462gCO2/kWh (for 2015)
Electricity** (DUKES)332gCO2/kWh (for 2015)
Electricity (DUKES)400gCO2/kWh (for 2014)
Gas (HHV)185gCO2/kWh
Heating oil (HHV)268gCO2/kWh
Coal (HHV)340gCO2/kWh
Petrol (biofuel blend)2194gCO2/litre
Petrol (LHV)9.4kWh/litre
Petrol (LHV)233gCO2/kWh
Diesel (biofuel blend)2584gCO2/litre
Diesel (LHV)10.6kWh/litre
Diesel (LHV)244gCO2/kWh

From Government conversion factors for company reporting (2016):

From Digest of UK Energy Statistics:

* CO2 emissions due to electricity vary from year to year depending on which power stations are used.

Passenger travel emission factors

Average diesel car182
Average petrol car191
Average hybrid car129
Bus (local)100
Bus (London)79
National rail45
Airline domestic298Includes non-CO2 radiative forcing
Airline short haul (economy)166
Airline long haul (economy)152

Souce as above. This data varies from year to year, for example as vehicles become more efficient.

Your car may be more efficient than the average:

mpgl/100kmpetrol gCO2/milediesel gCO2/mile

NB These are UK gallons

To convert between l/100km and mpg - use 283/x

Freight emission factors

Freight by tonnage (100% laden)

HGV Articulated86
HGV Rigid212
Light van530
Ship general13
Ship bulk3.5
Ship container16
Ship refrigerated13
Air short haul2313
Air long haul1279

Freight by distance

HGV Articulated752
HGV Rigid666
Light van250

From DeFRA as above

UK population

64,600,000people (2014)
27,000,000households (2015)

Population and households from the ONS for 2012

Water energy properties

specific heat4.2kJ/kg/K
specific heat0.00117kWh/kg/K
latent heat vaporisation2260kJ/kg
latent heat vaporisation0.628kWh/kg

Greenhouse gases - global warming potential

 20 year100 year
Nitrous oxide289298

From IPCC Fourth Assessment Report

The GWP is a measure of the global warming impact of a gas relative to CO2 (by mass, comparing 1 kg of the gas with 1 kg of CO2). This depends on the timescale as well because different gases have different lifetimes in the atmosphere. For example methane has a half life of about 12 years and over a longer timescale it has less effect.