Environmental Engineering Reference
In-Depth Information
reductions without nuclear and hydro power. Even with
them, I would feel much more con
dent if CCS was made
to work. CCS received much
financial support about
years ago in a poorly designed program and needs to
be rethought to have a chance to become a winner. It is
a maybe.
Natural gas: Substituting natural gas for coal is a
winner as a transitional fuel to help give time to solve
the long-term problems. A modern gas-generating plant
has only about one-third the emission of the average coal
plant. In the United States, natural gas as fuel produces
electricity at lower cost than coal. If the rest of the world
has shale gas as well, this could bene
t all. The opposition
to fracking is misguided. A new study published February
leaks from gas
production are larger than previously thought, but still
small enough that there is a great bene
in Science magazine
nds that CH
t in switching
from coal to gas for electricity [
]. Fracking is not the
major source of the leaks which mainly come from hand-
ling the gas once it is above ground. Gas production does
need better regulation; the bene
ts of the shale-gas revo-
lution are so great that banning fracking will slow the
reduction in overall emissions by stopping the move away
from coal.
Renewables: This category usually includes only wind,
solar, geothermal, small hydro, and ocean systems that
produce electricity. Of them, wind is by far the largest,
though still a small part of TPES. The problem for wind
is its intermittent nature. The average output as a fraction
of installed capacity ranges from a low of
% in India to
a high of
% in the United States (somewhat higher for
offshore systems). I will use a capacity factor of
%asan
