Posted by Morris Dovey on July 20, 2008, 4:33 pm
Ron Rosenfeld wrote:
You've pointed to a really important issue that I haven't given enough
attention: that of designing systems so as to deal with worst case
scenarios. (I should have known better, since my part of Iowa has seen
two "five hundred year" floods in 15 years.)
I have a collection of average monthly insolation data, which seems to
provide a reasonable basis for calculating fuel savings when a solar
system is added to a conventional system, but isn't adequate for
I'm not sure about the "enough data available" assumption, because
what's needed is at least hourly insolation data for an extended period
of time for (I'm guessing here) at least 250 well-placed sites in the
If anyone has a link to this kind of data, I'd appreciate if you'd post
True. The fluidyne pump has only two moving parts that can wear out, a
pair of check valves - and at this point I still don't have a strong
sense of how long they can be built to last.
One percent presents an interesting challenge. With this technology, the
challenge shifts to analysis of weather patterns, storage sizing,
collector sizing, and pump capacity planning - rather than equipment MTBF.
DeSoto, Iowa USA
Posted by Ron Rosenfeld on July 20, 2008, 5:12 pm
That information (and more) is all available from NREL.
They have Typical Meteorological Year data from 237 sites in the US, Guam
and Puerto Rico for 1961-1990 (TMY2) and also, from 1,454 sites in the US
and territories for 1991-2005 (TMY3)
The raw data is also available so you can construct a "worst-case" scenario
using your own algorithms.
Posted by Morris Dovey on July 20, 2008, 6:17 pm
Ron Rosenfeld wrote:
A look at http://rredc.nrel.gov/solar/pubs/NSRDB/3-1F.html was enough to
convince me that there's plenty enough data to work with.
Lucky me - I have a ready-to-format 160GB drive sitting in my machine
just waiting for this kind of feast. This is exactly the kind of
situation that makes me wish I'd had internet access 50 years ago.
Tell your friend to not hold his breath - this may take a while. :-)
DeSoto, Iowa USA
Posted by bealiba on July 21, 2008, 12:56 pm
Well it has been a couple of days and Tweedledee has runaway. Now he
is trying to look knowledgeable and hoping no one will notice that he
has failed to tell us what the the 20% system losses are. Let alone
prove that the formula for system sizing is incorrect. He has invoked
Peukert's law, STC, PTC, and any other thing he can, and still has
can't come up with a convincing mathematical argument to support his
fanciful claims. Still what can one expect from a trugabelly.
The spreadsheet of the Sizing Formula is free, correct and allows for
worst case scenarios and playing "what if" with different numbers at
no cost with help with any questions via email. Which is a lot more
than you will ever get out of Tweedledee.
Posted by wmbjkREMOVE on July 21, 2008, 2:30 pm
On Mon, 21 Jul 2008 05:56:43 -0700 (PDT), email@example.com wrote:
Good to see that it's sensibly priced.
It's a 9th-grade level sub-par offering with worse-than-average
potential for GIGO, and your over-reliance on it is one reason you're
so accomplished at posting hideously-wrong calculations, such as the
154 panel recommendation earlier in this thread. Why not consider the
obvious? If "the spreadsheet of the Sizing Formula" <snorf> was half
as good as you keep telling us, then others would be recommending it
and you wouldn't have to work so hard at selling it here. The fact
that you have nothing better to do than pursue a
catastrophically-failed promotion strategy is also telling.
Bad advice tends to cost, even if the perpetrator gets nothing from
If you want pen pals, you'd probably do better on Facebook or some
such where the participants don't know your history. You'll need an
alias, something like "Lonely Bungles" should attract like-minded