Environmental Engineering Reference
In-Depth Information
developing the resource. The earliest plants simply mined
the steam from underground and then let the cooled
waste water out. It can be loaded with gases and minerals
that are harmful. Also, the underground water itself is a
limited resource and the early plants found that their
output was decreasing as the underground water was
depleted. It was economics more than environmental
concerns that led to the development of closed cycles
where the condensed steam, after use in the generators,
is pumped back into the heat reservoir.
According to the REN
group [
], there are about
GW of hydrothermal electricity generated worldwide
in over
countries. The United States has been the
largest producer, but is being overtaken by the Philippines
where there are large unexploited hydrothermal
fields.
Any place where there is signi
cant volcanic action is a
candidate; for example Iceland, New Zealand, or Japan.
This resource will grow, but it represents only a minute
fraction of TPES and will have to grow much larger to
have a signi
cant impact on emissions of greenhouse gases.
I was for a while involved with a proposal to produce
large amounts of geothermal electricity from the volca-
noes on the Island of Hawaii (known also as the Big
Island). My laboratory in California and our sister lab in
Japan were working on the design of a new kind of
particle accelerator that needed a long tunnel and a lot
of electric power. We looked at conditions there and
found that on the Big Island tunneling conditions were
very good for an underground accelerator some
miles
long. What was lacking was power to run it. When we
approached the governor
ce we found a surprisingly
warm reception. They had been looking at making
'
sof
