As a unit of volume, 1 US cup (half a US pint) is officially 0.24 l; but
a cup of tea or coffee is usually about 0.18 l. To raise 50 cups of water, at
0.18 l per cup, from 15 °C to 100 °C requires 1 kWh.

So “nine million cups of tea per year” is another way of saying “20 kW.”

Double-decker buses, Albert Halls and Wembley stadiums

“If everyone in the UK that could, installed cavity wall insulation, we could
cut carbon dioxide emissions by a huge 7 million tons. That’s enough
carbon dioxide to fill nearly 40 million double-decker buses or fill the new
Wembley stadium 900 times!”

From which we learn the helpful fact that one Wembley is 44 000 double
decker buses. Actually, Wembley’s bowl has a volume of 1 140 000 m3.

“If every household installed just one energy saving light bulb, there
would be enough carbon dioxide saved to fill the Royal Albert Hall 1,980
times!” (An Albert Hall is 100 000 m3.)

Expressing amounts of CO2 by volume rather than mass is a great way
to make them sound big. Should “1 kg of CO2 per day” sound too small,
just say “200 000 litres of CO2 per year”!

More volumes

A container is 2.4 m wide by 2.6 m high by (6.1 or 12.2) metres long (for
the TEU and FEU respectively).

One TEU is the size of a small 20-foot container – an interior volume
of about 33 m3. Most containers you see today are 40-foot containers with
a size of 2 TEU. A 40-foot container weighs 4 tons and can carry 26 tons of
stuff; its volume is 67.5 m3.

A swimming pool has a volume of about 3000 m3.

One double decker bus has a volume of 100 m3.

One hot air balloon is 2500 m3.

The great pyramid at Giza has a volume of 2 500 000 cubic metres.


The area of the earth’s surface is 500 × 106 km2; the land area is 150 ×
106 km2.

My typical British 3-bedroom house has a floor area of 88 m2. In the
USA, the average size of a single-family house is 2330 square feet (216 m2).


If we add the suffix “e” to a power, this means that we’re explicitly talking
about electrical power. So, for example, a power station’s output might be
1 GW(e), while it uses chemical power at a rate of 2.5 GW. Similarly the

mass of CO2 volume
2 kg CO2 1 m3
1 kg CO2 500 litres
44 g CO2 2 litres
2 g CO2 1 litre
Table I.3. Volume-to-mass conversion.
Figure I.4. A twenty-foot container (1 TEU).
hectare = 104 m2
acre = 4050 m2
square mile = 2.6 km2
square foot = 0.093 m2
square yard = 0.84 m2
Table I.5. Areas.