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SUSTAINABLE ELECTRICITY SUPPLY IN THE WORLD BY 2050 FOR ECONOMIC GROWTH AND AUTOMOTIVE FUEL
Table 6: Energy resources for a world electricity supply of 36 PWh by 2050
Energy resource
Electricity supply
(PWh/a) (%)
Number of installations
Solar conversion 25
Residential PV 3 300 million
Structure PV 3 10 million
Thermal 3 17 000
Wind turbines 9 25 600 000
Nuclear reactors 18 50 1 800
for an average installation of 5 kW(AC) per building producing an average of 2 000 kWh/a per installed
kW. At 10 000 kWh per building housing 30 inhabitants, the number of installations could reach
300 million residential buildings. For larger structures, such as large office buildings and industrial
structures, with large surface areas, the number of installations can be approximated by the Pearl River
tower being built in China (Hansen, 2007). The data for the PV installation of 3 000 m 2 area, a power
capacity of 240 kWp, providing an annual electric energy supply of 296 MWh (Boyer, 2008), used as a
model of current technology for large structures indicates that 10 million such installations could
produce 3 PWh/a. For solar thermal concentrated power, 3 PWh/a of electricity could be achieved with
trough, power tower and dish/engine conversion technologies. On the basis of installing sufficient
areas with collectors to produce 100 MWe at an average capacity factor of 20%, the number of
installation sites would be about 17 000.
The potential of wind energy to produce large-scale electric power is focused on the development
of wind-turbine tower technology from current sizes of 1 to 3 MWe to turbines that will produce 3 to
5 MWe. The number of 5 MW wind turbines that could produce 9 PWh/a by 2050, estimated for an
average electricity generating ratio of 3 GWh per installed MW (American Wind Association, 2007),
would be about 600 000. These would be located in areas of sufficient mean annual wind speeds for
commercial operation and as an auxiliary resource in other locations.
The lingering national concerns about the safety of commercial nuclear power have resulted in
very low forecasted growth in use of nuclear energy. Several governments with nuclear plants have
legislated for the closing of existing nuclear plants and many other governments have forbidden the
construction of nuclear power plants. However, the growing need for nuclear energy is becoming
increasingly apparent in the world. The world currently has more than 400 operating nuclear power
plants and many more are planned or under construction. The large specific energy of the fissionable
low-enriched nuclear fuel makes it an efficient choice as an appropriate technology. A 1 350 MWe
nuclear reactor operating above an 80% plant factor generates about 10 TWh of electricity per year. The
number of such nuclear power plants in the world that could supply 18 PWh/a would be about 1 800.
Conclusions
It is very likely that the current rate of growth of electricity supply cannot be sustained as the costs of
energy and environmental concerns escalate. The model results, based on a reduced business-as-usual
growth rate in world consumption of electricity over the next 40 years, show a strong need to plan for
a larger sustainable electricity supply, especially if the world converts to electric battery and/or
hydrogen fuel-cell vehicles to reduce dependence on petroleum-based fuels for transportation.
The most appropriate technology for achieving a sustainable electricity supply, as the replacement
of fossil-fuel combustion increases exponentially in time, must be the use of an optimum combination
of renewable and nuclear energy according to their specific energy and the distribution and scale
of their application. The million-fold difference in specific energy emphasises their appropriate
applications. Renewable energy should be used for electricity generation in the very large number of
distributed structures, such as individual buildings. It could also be used for large numbers of
distributed battery recharging and hydrogen refuelling stations. The integrated demand for electricity
by location could be very small to very large. Nuclear energy should be used for electricity generation
in the smaller numbers of centralised large-scale applications, such as electricity supply for
metropolitan cities, large airports, industrial parks, and central recharging and refuelling facilities
where the electricity consumption must be large.
324 NUCLEAR PRODUCTION OF HYDROGEN – © OECD/NEA 2010