Freight transport is measured in ton-kilometres (t-km). If one ton of
Cornish pasties are transported 580 km (figure 15.5) then we say 580 t-km
of freight transport have been achieved. The energy intensity of road trans-
port in the UK is about 1 kWh per t-km.
When the container ship in figure 15.6 transports 50 000 tons of cargo a
distance of 10 000 km, it achieves 500 million t-km of freight transport. The
energy intensity of freight transport by this container ship is 0.015 kWh per
t-km. Notice how much more efficient transport by container-ship is than
transport by road. These energy intensities are displayed in figure 15.8.
In 2006, the total amount of road transport in Britain by heavy goods vehi-
cles was 156 billion t-km. Shared between 60 million, that comes to 7 t-km
per day per person, which costs 7 kWh per day per person (assuming an
energy intensity of 1 kWh per ton-km). One quarter of this transport, by
the way, was of food, drink, and tobacco.
In 2002, 560 million tons of freight passed through British ports. The Tyn-
dall Centre calculated that Britain’s share of the energy cost of international
shipping is 4 kWh/d per person.
Water’s not a very glamorous stuff, but we use a lot of it – about 160 litres