Environmental Engineering Reference
In-Depth Information
Figure 4.63.
Model of a helium-inflated airborne wind turbine.
Source:
James Provost
at Wikimedia Commons (modified).
Windmills in the Sky
Two-thirdsofthewindmovementonthisplanetoccursintheuppertroposphere(thelowest
leveloftheEarth'satmosphere),whereincessantwindcurrents,knownasjetstreams,swirl
around the globe. This, in wind energy terms, is the mother lode. Since it is not possible to
construct towers that rise 10,000 metres into the sky (the world's tallest building is 'just'
830 metres tall), engineers are looking at other ways to position turbines at such heights.
These typically involve various types of kites and balloons that are tethered to the ground.
The great attraction of airborne wind turbines is that they would transform wind power
from an intermittent to a base-load power source. Moreover, they would dispense with the
most expensive component of conventional wind power plants - the tower - and greatly
reducetheimpactsintermsoflanduseandbirdmortality.However,asgoodasthissounds,
there are a few major technical questions that need to be answered before airborne wind
turbines progress from the experimental to the commercial stage: how to safely suspend
devices thousands ofmetres above the ground,howhighthe maintenance costs will be,and
how to prevent collisions with aircraft (Gibbs
2009
).
Cold Water on Cold Fusion
In 1989, Stanley Pons and Martin Fleischmann made a splash. Their claim to have initiated
a fusion reaction at room temperature unleashed a frenzy of scientific and public interest.
The year 1989 was already one of extraordinary events. Starting in March, a few weeks
before Pons and Fleischmann's announcement, the Iron Curtain began to tear. The world's
media was highly receptive to stories of breakthrough, and the prospect of unlimited safe
and clean energy that this claim opened up was more than revolutionary; this was the
modern equivalent of the philosopher's stone, the legendary substance, eagerly sought
by medieval alchemists, that could turn base metals into gold. Unfortunately, unlike the
events unfolding in Eastern Europe, Pons and Fleischmann's news turned out to be too
good to be true. Under pressure from the university that had funded their research, they
had made their announcement prematurely, before submitting their findings to peer review.
After numerous scientists tried, and failed, to replicate their experiment, the claim was
discredited.
