World power consumption

World power consumption is 15 TW. World electricity consumption is
2 TW.

Useful conversion factors

To change TWh per year to GW, divide by 9.

1 kWh/d per person is the same as 2.5 GW per UK, or 22 TWh/y per UK

To change mpg (miles per UK gallon) to km per litre, divide by 3.

At room temperature, 1 kT = ¹⁄₄₀eV

At room temperature, 1 kT per molecule = 2.5 kJ/mol.

Meter reading

How to convert your gas-meter reading into kilowatt-hours:

• If the meter reads 100s of cubic feet, take the number of units used,
  and multiply by 32.32 to get the number of kWh.
• If the meter reads cubic metres, take the number of units used, and
  multiply by 11.42 to get the number of kWh.
  

Calorific values of fuels

Crude oil: 37 MJ/l; 10.3 kWh/l.
Natural gas: 38 MJ/m³. (Methane has a density of 1.819 kg/m³.)
1 ton of coal: 29.3 GJ; 8000 kWh.
Fusion energy of ordinary water: 1800 kWh per litre.
See also table 26.14, p199, and table D.3, p284.

Heat capacities

The heat capacity of air is 1 kJ/kg/°C, or 29 J/mol/°C. The density of air
is 1.2 kg/m³. So the heat capacity of air per unit volume is 1.2 kJ/m³/°C.

Latent heat of vaporization of water: 2257.92 kJ/kg. Water vapour’s
heat capacity: 1.87 kJ/kg/°C. Water’s heat capacity is 4.2 kJ/l/°C.

Steam’s density is 0.590 kg/m³.

Pressure

Atmospheric pressure: 1 bar ≅ 10⁵ Pa (pascal). Pressure under 1000 m of
water: 100 bar. Pressure under 3000 m of water: 300 bar.