Posted by DJ on April 29, 2004, 12:06 pm
William P.N. Smith <> wrote in message
William, yes, they are available very shortly; Menova Engineering of
Ottawa (the parent company) is currently arranging manufacturing
contracts with local sheet-metal companies (a very simple,
easy-to-assemble design,quite elegant, really, from a engineering and
assembly point of view; the result of hundreds of thousands of dollars
in R&D), interviewing potential sales and consulting staff, and
surveying local renewable energy installation companies (where I came
in ;-) for their product network. They expect to do the first major
install in a few weeks, actually, at a local Ottawa home that will be
using Power-Spars for SDHW and home heating. I will definitely be
As I have not gotten my formal information package, I can't give you
exact prices, but, dollar for dollar, they seem to be priced
equivalent to quality conventional flat plate collectors, ie, retail
for a single collector seems to be about $000 CAN.
It's hard to compare them, though, as there are some very interesting
differences in the engineering, "seasonally different from flat plate"
performance curves, the addition of photovoltaics, the parabolic
Like I said, it is a very interesting product...
Posted by Ecnerwal on April 29, 2004, 1:21 pm
Skeptical and wary of sales-pitches am I...
It's notable that they compare the thermal output to "single glazed flat
plate", "unglazed plastic pool", and "vacuum tubes" - but not to a
common double-glazed flat plate. Remember, concentrators only work on
clear days, while flat plates can get some heat on cloudy days.
Depending where you live (cloudiness-wise) that can make a significant
The PV output component strikes me as low. The illustration appears to
have PV showing on the face, which would mean that the PV is not
concentrated - at which point there's really no benefit to combining the
two. Many folks on the solar concentrator mailing list use fluid cooling
of PV concentrators, but find practical difficulties with integrating it
with water heating, since you need controls/systems to extract heat when
you need it and dump it when you don't need it, so that the return fluid
is still cool enough to keep the PV happy - and hot water is far more
difficult to efficiently move from a location far from the dwelling [if
the wall or roof is not a suitable location] than electricity is.
They also base their output for comparison purposes on 5.5 sun hours per
day, but if you download the brochure, their own map indicates how few
areas (especially of Canada) that applies to...
Still, nice to see some work on commercializing concentrators. I am
hard-pressed to see where hundreds of thousands of research &
development dollars went, on what looks like a pretty typical (albeit
neat and clean, as befits a commercially produced product) parabolic
Cats, Coffee, Chocolate...vices to live by
Posted by John W. Hall on April 29, 2004, 2:56 pm
On Thu, 29 Apr 2004 13:21:57 GMT, Ecnerwal
I wondered about that also. I assume it is primarily intended to
provide sufficient electrical energy to run the pumps & controls,
without which it would be useless in a major power outage.
I note also that a future version has four times the electrical
energy, but it does not indicate how they do that.
Cochrane, Alberta, Canada.
"Helping People Prosper in the Information Age"
Posted by DJ on April 30, 2004, 1:29 am
Yeah, imagine that. Four times. What a coincidence. That's rather
similar to the calculated sun multiplication in the focal area of the
parabolic dish ;-).
Posted by DJ on April 30, 2004, 1:26 am
And well you should be ;-). However, the Canadian Government's own
guys at NRCAN are also very excited about the results they've
personally seen from this device.
This is certainly no philosopher's stone; it doesn't do everything
well, but it does do some things very well, like it's efficiency in
Not yet, no. The PV on the front is for running the instrumentation
and tracking motors. I'm not letting any cats out of the bag by saying
that photovoltaics in the focal point are being tested for durability
at the government testing lab up here right now, actually.
Much like the stuff coming out of Iogen right now in Ottawa
(amusingly, one of Iogen's labs is just a couple of blocks from
Menova's offices), this does bear watching...