Tower of
Power
No, we're not alking about the
classic soul band, so
we won't be "Diggin'
on James Brown."
We're focusing on
Solar Wind Energy,
Inc., which is offering
"a bold new approach
to overcome the
current limitations of
conventional wind energy sources." The company has announced
the acquisition of a 600 acre chunk of real estate in San Luis, AZ,
for the first US installation of its patented Solar Wind Energy
Tower (SWET). The SWET is what is generically referred to as a
solar wind downdraft tower. In operation, a mist of water is
injected into the hot dry air at the top of the tower. The air
absorbs the water, and thereby becomes cooler and denser. As a
result, it drops downward at speeds up to 50 mph and is diverted
into wind tunnels at the bottom where turbines are projected to
generate up to 1,250 MW per hour.
It may be bold, but the concept isn't entirely new; it's really a
twist on the solar updraft tower first proposed in 1903 by Isidoro
Cabanyes, a Spanish army colonel. This design sucks hot air up
through the tower using the chimney effect and generates power
in pretty much the same way. An experimental model was in
operation south of Madrid from 1982 to 1989, when its guy
wires corroded and it fell over. The 33 ft ( 10 m) dia chimney rose
to a height of 640 ft (195 m) and used a collection area
(greenhouse) that covered 110 acres. The maximum output came
in at about 50 k W. Several others have been built or proposed.
The downdraft version requires less land, and it has the
advantage of operating 24 hours a day. However, pumping water
to the top eats up an estimated 50 percent of the turbine’s
output, so it isn't an unmixed blessing. The concept has been
promoted for 15 years or so by Prof. Dan Zaslavsky of Iowa State
University. He estimates that — depending on construction costs
and other variables — an energy tower should be able to offer
power at a cost of between one and four cents per kilowatt
which puts the price below other alternatives, except for
hydroelectric. How well the San Luis facility will operate won't be
known until it (maybe) begins operation in 2018, but it all sounds
good. In the meantime, you can see a video on the company
website ( www.solarwindenergytower.com) and even invest if
you are so disposed. As of this writing, the stock is moving at
$0.03 per share. ▲
ADVANCED TECHNOLOGY
Laser Deployment Imminent
The US Navy has been seriously interested in laser weapons since 2010, when it awarded $11
million to Kratos Defense & Security Solutions
( www.kratosdefense.com) to develop the Laser
Weapon System (a.k.a., La WS). By the time you
read this, the first prototype should be installed on
the USS Ponce for a 12 month at-sea test. The
Ponce — a half century old Austin-class amphibious
transport dock — isn't the most glamorous ship in
the Navy, but it has been used as a test bed for
several new technologies, including service as a
"lilypad" for MH- 53 mine-clearing helicopters.
The Navy has made directed-energy weapons a
major priority to counter "asymmetric threats,"
including unmanned and small aircraft, and small
attack boats. In a 2011 demonstration, a destroyer-based laser made short work of multiple small boat
threats, and in 2012 La WS downed several
unmanned aircraft (You Tube videos are accessible
by searching "navy laws laser”). As noted by Rear
Adm. Matthew Klunder, "Spending about $1 per
shot of a directed-energy source that never runs out
gives us an alternative to firing costly munitions at
inexpensive threats."
The news release from the Office of Naval
Research was light on specifics, but it was revealed
that "using a video game-like controller, a sailor will
be able to manage the laser's power to accomplish
a range of effects against a threat, from disabling to
complete destruction." Its power level has been
estimated at between 10 k W and 50 k W with an
effective range of about a mile. More info is
available at www.onr.navy.mil. ▲
■ The Navy's LaWS laser weapon, soon to be
tested in the Persian Gulf.
■ BY JEFF ECKERT TECHKNOWLEDGEY 2014
8 July 2014
■ The solar wind downdraft
tower, scheduled to begin
operation in 2018.