Worldwatch Institute

A Convenient Truth
from power plants is equivalent to all of the
energy consumed in Japan. 28 By integrating
power generation with factories and buildings,
high-temperature waste heat can be used to
produce electricity, or, in another configuration,
the waste heat from power generation can
be used for industrial and building heat,
increasing total energy efficiency from 33 percent
to as high as 80–90 percent. 29
Some of the world’s first power plants
employed CHP, and while it has since fallen
out of favor in most nations, some have pursued
it aggressively since the early 1980s. Finland
and Denmark obtain 40 and 50 percent
respectively of their electricity from CHP, far
above the levels found in countries such as the
United States (8 percent) and Germany and
China (12 percent each). 30
It is estimated that CHP in Europe reduced
annual CO 2 emissions by 57 million tons
between 1990 and 2005, accounting for 15 percent
of European emissions reductions. 31 If
most industrial countries were to aggressively
pursue CHP, it would eliminate the need for
new coal plants and allow many older plants to
be gradually shut down. At today’s energy
prices, much of the investment can be justified
in energy savings alone. The United States
could get 150 gigawatts, or 15 percent of its
power, from the unused waste heat from heavy
industry as well as from manure, food industry
waste, landfill gas, wastewater, steam, gas
pipeline pressure differentials, fuel pipeline
leakages, and flaring. This is as much power as
the entire U.S. nuclear industry produces. 32
A global assessment by the McKinsey Global
Institute of the potential to improve energy
productivity concluded that the rate of annual
improvement between now and 2020 could be
increased from 1 percent to 2 percent, which
would slow the rate of global energy demand
growth to just 1 percent a year. 33 If these gains
are extended to 2050, the growth in world
energy use could be held to roughly 50 percent
above current levels, rather than the doubling
that is projected under most business-as-usual
scenarios. This large difference is equivalent to
the combined current energy consumption of
the European Union, Japan, and North America.
34 By fully exploiting all of the opportunities
described above, the world could likely do
even better than that.
Future increases in energy productivity
will not only reduce consumption of fossil
fuels, they will make it easier and more affordable
to rapidly increase the use of carbon-free
energy. And additional gains can be made by
altering the design of cities—for example, by
increasing the role of public transport, walking,
and cycling while reducing dependence
on automobiles.
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