Switzerland Nov 23, 2012: Zero-energy snow
cannon uses hydropower from reservoir upstream
from: Basler Zeitung online: Lots of snow, little energy
(orig. German: Viel Schnee, wenig Energie)
http://bazonline.ch/wissen/technik/Viel-Schnee-wenig-Energie/story/28451939
Translation from Deepl:
<By Walter Jäggi
The snowmakers' recipes are getting better all the time.
Already, snow lances are being developed that do not
require a power supply.
Since the first accidental discoveries in the 1950s, the
artificial production of snow has been based on the
principle of trial and error. Water was sprayed into the
cold winter air and snow was produced - or not.
Since artificial snow consists not of flakes but of frozen
water droplets, the snow masters - the experts at the snow
cannons - over time made use of a finding by meteorologists
on the formation of rain: a fine mist of tiny droplets, only
a thousandth of a millimeter in size, provides nuclei to
which the water particles attach, which are ejected by a
second nozzle. Droplets up to two millimeters in size are
formed, which ice up on their short flight through the air
from the outside to the inside. The quality of the snow
depends above all on the humidity and the temperature.
Efficient snow cannons wanted
Snow can be made with mobile propeller machines or with
stationary snow lances. Since more and more slopes are being
sprayed with artificial snow, slope makers are very
interested in efficient snow cannons. The physical processes
involved in the transition from water to ice grain were
studied for the first time in the world using scientific
methods at the University of Applied Sciences Northwestern
(Fachhochschule Nordwestschweiz) in Switzerland in Windisch.
Kurt Heiniger, professor of thermal and fluid
engineering, an expert in waterjet technology, together
with experts from the WSL Institute for Snow and Avalanche
Research (SLF), developed a snow lance that uses only a
fifth of the compressed air and thus electricity compared
to conventional models. Marketed under the name Nessy by
the small Swiss manufacturer Bächler, it is selling quite
well, according to Bruno Koch, one of the managing
directors.
Harnessing the energy of water
Kurt Heiniger was not yet satisfied with Nessy. In his
laboratory, the economical snow lance was further
developed to a zero-energy type that requires no power
supply at all. "We use the energy that is in the water,"
Heiniger explains. If the water comes from a reservoir or
storage basin several hundred meters higher up, there is
enough pressure to operate the snow lance without
electricity. This saves operating costs, but above all it
eliminates the need for costly pipelines for compressed
air and electricity. However, the second generation of
snow lances is not yet in use.
The development of artificial snow systems is not only of
interest in Switzerland. Leitner, the major South Tyrolean
ropeway and snow machine manufacturer, is involved in the
European EcoArtiSnow research project, in which a
Fraunhofer Institute and the Toggenburg mountain railroads
are also collaborating. The first prototypes have already
been run in Toggenburg, and the project will last until
2014.
Energy storage
The pipe networks for water, compressed air and
electricity are the most expensive part of any snowmaking
system. For each kilometer of snow-covered slope,
investments of around one million Swiss francs can be
expected. The expensive storage lakes, reservoirs, pumps
and water pipes could also be used in summer. Small
hydropower plants or even small pumped storage systems
could be integrated into the existing infrastructure.
Unfortunately, says Roland Zegg, head of the consulting
firm Grischconsulta, these opportunities are still hardly
used in Switzerland. This is in stark contrast to Austria,
where some ski resorts are already producing more
electricity than they need themselves, and can use it to
bolster their balance sheet, which is heavily dependent on
winter weather.
Water is stored temporarily
The provision of water is the bigger problem in snow
production than power supply. Without wells, reservoirs,
pumping stations and pipelines, it is not possible. Two to
two-and-a-half cubic meters of snow require one cubic
meter of water, and all the technology in the world can't
change that, says Bruno Koch of snow lance manufacturer
Bächler, but he also emphasizes: "The water is not
consumed, it's stored temporarily, so to speak, until the
snow melts." Geographically, ski areas would be
predestined for the use of renewable energies: Slopes for
hydroelectric power, sunshine for photovoltaics, wind for
wind turbines, and electrical installations are available.
The obstacles are political, not technical, says Zegg.
There are some Swiss examples, however, such as the hydro
grids in Flims and Samnaun, the small solar ski lift in
Tenna in the canton of Grisons, and the Little Matterhorn
mountain restaurant in Zermatt, which is powered by solar
cells. "Much more would be possible," Zegg says.
Besides propeller machines and snow lances, there are
other methods for snow production, but they are too
expensive. An Israeli company, for example, is building
the Snowmaker, which is used in individual ski resorts. It
can produce snow even at high temperatures. In Zermatt, it
is needed to extend the slope on the receding Theodul
glacier to the Dry Bridge (Trockener Steg) station before
the onset of winter. (Tages-Anzeiger)>
