Environmental Engineering Reference
In-Depth Information
micro-earthquakes. The advocates of EGS say this phe-
nomenon is understood and they know how to control it.
It may be that hydraulic fracturing developed for the
natural gas industry has given a new understanding of
what happens deep underground. We will have to see if
this is so.
Australia and Europe are the leaders in EGS technol-
ogy with commercial-scale projects being constructed in
both Australia and Germany. The United States, which
started the development in the
s, is now behind and
in need of a technology transfer injection. Too often in
the United States the impatience of the Administration
and Congress leads to the abandonment of science and
technology areas that do not produce results at
rst try. In
spite of the uncertainties I do agree with the main MIT
conclusion: the promise of EGS is enough to make a
large-scale try worthwhile to evaluate the technology
and the costs.
One other approach is worth mentioning: heat pumps.
These are small systems that are capable of supplying
both residential heating in winter and cooling in summer.
If you drill down only a few tens of feet in almost all
regions of the non-tropical regions of the world, the
underground temperature will be about
F(
C).
F can allow you
to heat your house, you should look at your refrigerator.
In the refrigerator heat is extracted from the inside of the
box by a refrigerant and dissipated into the room by the
cooling coils and
If you wonder how a reservoir at only
fins on the back of the standard refriger-
ator. In the heat pump, heat is extracted from the ground,
cooling the ground slightly, and dissipated in the house by
a system very much like what
is on the back of a
