ÜDS-Fen 2003-1 Soru=64

We understand from the passage that, since many of the coal-fired power stations in the US have almost completed their economic lives, they ----.

Can coal ever become a friend of the environment?
Coal-fired power stations supply half the electricity
used in America, and a similar amount in many other
industrial countries, but are responsible for 80% of
the power industry's emissions of carbon dioxide the
most worrisome of the so-called "greenhouse
gases". Because of special exemptions, much of the
country's coal-derived electricity comes from plants
that are more than 30 years old. Many of these
plants are approaching the end of their commercial
lives, and the thought of having to replace a lot of
dirty old power stations, with new ones that will have
to comply with the Clean Air Act, is causing a
nightmare in the power industry. Suddenly, energy
engineers are talking about "clean coal" technology.
That message has been heard before. There was
similar excitement over clean coal in the mid-1980s
and early 1990s. Large sums of taxpayers' money
were handed out to firms developing clean coal. The
difference this time, say energy engineers, is that a
number of electricity suppliers have actually started
building facilities that use clean coal.