Figure 4.5: World primary energy consumption by fuel type.

Source: IEA, 2006b. Note: The IEA convention is to assume a 33% conversion efficiency when calculating the primary energy equivalent of nuclear energy from gross generation. The conversion efficiencies of a fossil fuel or nuclear power plant are typically about 33% due to heat losses whereas the energy in stored water (and other non-thermal means) is converted in turbines at efficiencies approaching 100%. Thus, for a much lower energy equivalent, hydro can produce the same amount of electricity as a thermal plant without a system to utilize the waste heat. 1000 Mtoe = 42 EJ.