http://www.ck12.org Chapter 3. Making A Difference
Figure 20.34:Nine out of ten vehicles in London are G-Wizes. (And 95% of statistics are made up.)
Notes and further reading
A widely quoted statistic says “Only 1% of fuel energy in a car goes into moving the driver.”In fact the percentage
in this myth varies in size as it commutes around the urban community. Some people say “5% of the energy goes
into moving the driver.” Others say “A merethree tenths of 1 percentof fuel energy goes into moving the driver.”
[4qgg8q] My take, by the way, is that none of these statistics is correct or helpful.
The bicycle’s performance is about the same as the eco-car’s.Cycling on a single-person bike costs about 1.6 kWh
per 100 km, assuming a speed of 20 km/h. For details and references, see Chapter Cars II.
The 8-carriage stopping train from Cambridge to London(figure 20.4) weighs 275 tonnes, and can carry 584
passengers seated. Its maximum speed is 100mph (161 km/h), and the power output is 1.5 MW. If all the seats
are occupied, this train at top speed consumes at most1.6 kWh per 100 passenger-km.
London Underground. A Victoria-line train consists of four 30.5-ton and four 20.5-ton cars (the former carrying the
motors). Laden, an average train weighs 228 tons. The maximum speed is 45 mile/h. The average speed is 31 mph.
A train with most seats occupied carries about 350 passengers; crush-loaded, the train takes about 620. The energy
consumption at peak times is about4.4 kWh per 100 passenger-km(Catling, 1966).
High-speed train.
A diesel-powered intercity 125 train (on the right in figure 20.5) weighs 410 tons. When travelling at 125mph, the
power delivered “at the rail” is 2.6 MW. The number of passengers in a full train is about 500. The average fuel
consumption is about 0.84 litres of diesel per 100 seat-km [5o5x5m], which is a transport cost of about9 kWh per
100 seat-km. The Class 91 electric train (on the left in figure 20.5) travels at 140 mph (225 km/h) and uses 4.5
MW. According to Roger Kemp, this train’s average energy consumption is3 kWh per 100 seat-km[5o5x5m]. The
government document [5fbeg9] says that east-coast mainline and west-coast mainline trains both consume about 15
kWh per km (whole train). The number of seats in each train is 526 or 470 respectively. So that’s2.9–3.2 kWh per
100 seat-km.