I think the idea is great except
that it is surely better to lock out a lagoon that is mostly drained in the fall
during low water. What is left is then
allowed to freeze solid and water is then allowed in from the river in small
surges to provide another inch or so every few hours. It will also be easier to keep a flowing pipe
open than to use start and stop procedures.
At worst one creates a mountain of ice instead of a nice clear sheet.
Then as spring approaches, the
same ice can be covered with a thick mat of sawdust and wood chips and then
protected with canvass. It is thus well
insulated.
Recall that in the nineteenth
century that Boston winter ice was packed in
sawdust and shipped to India !
The ice then provides a natural coolant
during the summer and can hardly be cheaper.
I cannot think of any place in Canada
were it may be worth the trouble to do this ourselves as no none wants to
actually haul the ice at all. Montreal or Ottawa
have the river but may not have quite enough of a hard cold to do it all
properly. The prairie cities certainly
could use it easily though but then the necessary infrastructure will dissuade.
However in a green field build
out like Ulan Bator
this could work very well.
From the
Guardian
http://environmentalresearchweb.org/cws/article/news/47803
Mongolia is to launch one of the world's biggest ice-making experiments later this month in an attempt to combat the adverse affects of global warming and the urban heat island effect.
Mongolia is to launch one of the world's biggest ice-making experiments later this month in an attempt to combat the adverse affects of global warming and the urban heat island effect.
The geoengineering trial,
that is being funded by the Ulan Bator
government, aims to "store" freezing winter temperatures in a giant
block of ice that will help to cool and water the city as it slowly
melts during the summer.
The scientists behind the 1 bn tugrik (£460,000) project hope the
process will reduce energy demand from air conditioners and regulate drinking
water and irrigation supplies. If successful, the model could be applied to
other cities in the far north.
The project aims to artificially create "naleds" –
ultra-thick slabs of ice that occur naturally in far northern climes when
rivers or springs push through cracks in the surface to seep outwards during
the day and then add an extra layer of ice during the night. Unlike regular ice
formation on lakes – which only gets to a metre in thickness before it
insulates the water below – naleds continue expanding for as long as there is
enough water pressure to penetrate the surface. Many are more than seven metres
thick, which means they melt much later than regular ice.
A Mongolian engineering firm ECOS & EMI will try to recreate this
process by drilling bore holes into the ice that has started to form on the
Tuul river. The water will be discharged across the surface, where it will
freeze. This process – effectively adding layers of ice rinks – will be
repeated at regular intervals throughout the winter.
The qualities of naleds (also known as Aufeis, German for "ice on top") have
been known for hundreds of years. The North Korean military used them to build
river crossings for tanks during the winter and Russia has used them as drilling
platforms. But engineers usually see them in negative terms as a threat to
railways and bridges.
The Anglo–Mongolian company believe their proposed use in Ulan Bator could set a
positive example that allows northern cities around the world to save on summer
air conditioning costs, regulate drinking supplies, and create cool
microclimates.
"Everyone is panicking about melting glaciers and icecaps, but
nobody has yet found a cheap, environmentally friendly alternative," said Robin Grayson,
a Mongolian-based geologist. "If you know how to manipulate them, naled
ice shields can repair permafrost and building cool parks in cities." He
said the process will work in cities where the summer is intolerably hot and
winters have at least a couple of months with temperatures of –5 °C to
–20 °C.
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