http://www.ck12.org Chapter 3. Making A Difference
3.2 Better transport
Modern vehicle technology can reduce climate change emissions without changing the look, feel or performance
that owners have come to expect.
California Air Resources Board
Roughly one third of our energy goes into transportation. Cantechnologydeliver a reduction in consumption? In this
chapter we explore options for achieving two goals: to deliver the biggest possible reduction in transport’s energy
use,andto eliminate fossil fuel use in transport.
Transport featured in three of our consumption chapters: Chapter Cars (cars), Chapter Planes (planes), and Chapter
Stuff (road freight and sea freight). So there are two sorts of transport to address: passenger transport, and freight.
Our unit of passenger transport is the passenger-kilometre (p-km). If a car carries one person a distance of 100 km, it
delivers 100 p-km of transportation. If it carries four people the same distance, it has delivered 400 p-km. Similarly
our unit of freight transport is the ton-km (t-km). If a truck carries 5 t of cargo a distance of 100 km then it has
delivered 500 t-km of freight-transport. We’ll measure the energy consumption of passenger transport in “kWh per
100 passenger-kilometres,” and the energy consumption of freight in “kWh per ton-km.” Notice that these measures
are the other way up compared to “miles per gallon”: whereas we like vehicles to delivermanymiles per gallon, we
want energy-consumption to befewkWh per 100 p-km.