He must know what he's talking about, eh?
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He must know what he's talking about, eh?
C
Chuck Olson
What's extra today may well be just the right amount tomorrow when you plugsteve said:
in your Prius to charge its extra battery overnight, or when you get your
electrically-heated hot tub (heating it up overnight when grid rates are
lowest). I'm loading up my south-facing garage roof with the maximum I can
put up there - - electricity is the highest form of energy you can have
since it can be converted into heat or rotational power or kinetic or
potential energy. Anyone who doesn't plan to set up all the PV generation he
can afford should re-think the situation if it isn't too late.
Chuck
W
Walt Bilofsky
Not to get lost in the math - it sounds like you ran PVWatts 1 and
pulled the hourly observations off for each azimuth? (That should be
24*365 = 8760 rows.)
That's what I did - but only for the two azimuths of interest to me,
the orientations of my roof (160 and 250).
Then I worked the spreadsheet to provide peak and off-peak kWh output
estimates month by month, and cranked that into a time-of-day billing
calculation. So I can now plug in the number of panels in each
orientation and get my estimated bill for the year.
I'm spending too much time on this stuff. Fun, tho'.
pulled the hourly observations off for each azimuth? (That should be
24*365 = 8760 rows.)
That's what I did - but only for the two azimuths of interest to me,
the orientations of my roof (160 and 250).
Then I worked the spreadsheet to provide peak and off-peak kWh output
estimates month by month, and cranked that into a time-of-day billing
calculation. So I can now plug in the number of panels in each
orientation and get my estimated bill for the year.
I'm spending too much time on this stuff. Fun, tho'.
Solar Flare said:
Did not, did not.
The hours labeled 12 13 14 15 16 17 in the PVWatts spreadsheet represent
the timespan from 12:00-17:59, the peak rate period of noon to 6pm.
Real usenet news readers display fixed pitch font.
What reader are you using? It looks okay in Google proportional, and looks
better by selecting the fixed font option.
I was able to manipulate the data manually. All that is needed is a
different front end for the PVWatts data. I would like to see the optimum
tilt angle and azimuth given to me, instead of having to put them in at
various values and manually check the results.
The 22 degree tilt and 225 degree orientation listed on my installer's
proposal are optimized for time-of-day metering, since I get more money
from PG&E that way, or, it would cost me more to buy from PG&E during those
times. I believe that closer to 180 degrees produces more watts overall,
but those aren't as dollar efficient.
How does one discover the optimum angles, other than hunt and peck with
PVWatts?
Walt Bilofsky said:
Yes. I ran PVWatts-v1 once for each azimuth.
Including the indentification at the top, 8777 rows in each sheet.
I trimmed that to 2190 rows of peak time, and found the average.
It would seem natural to select your city, and have the same data set
return the optimum tilt angle and orientation for overall watts, time of
day watts, or time of year watts. Different front end, but the data is
obviously there.
I was trying to find the optimum. The proposal says my panels are going to
be oriented at 225. I thought that was flat on the roof, and near the
optimum, but I'm not sure. Maybe the panels are going to be mounted to
225, because that is the optimum. With my $5 compass, it looks like the
house is at 215.
I want my stuff installed before winter makes it depressing to look at the
Fronius computer monitor.
W
Walt Bilofsky
Your compass is showing you 215 magnetic. In these parts, correcting
for magnetic deviation, that would be about 230 true. The way I did
it was to look at my property's parcel map. It shows the boundary
line directions to two decimal places, and the roof is parallel to the
boundary.
Y'know, it looks like I will wind up with a Fronius inverter. Is the
monitoring software as lame as it looks? It appears aimed at
controlling industrial banks of many inverters, and although you can
look at individual string outputs you can't export that data.
Is that the case?
Is there any other software that will work with the Fronius?
Do I have the right impression that Sunny Boy software is a lot more
friendly for small residential users?
Walt Bilofsky said:
I corrected for that. 15d27m here.
Good thought. Now I have to go dig through some paperwork.
I can display my parcel online, but it doesn't expose the coordinates,
which I find annoying. The data is obviously there, and I'd like to plug
it in to my GPS. Instead, I compare the county online photo with ExpertGPS
showing the same photo, and "guess" at the coordinate.
I think not. That seems consistent in postings.
W
Walt Bilofsky
Did you imply that you might cook up some?
A
Antipodean Bucket Farmer
Wasn't that the name of the Secretary Of The Interior
during the Carter administration?
Antipodean Bucket Farmer said:
Sounds right, now that you mention it, but this guy probably couldn't vote
during the Carter era.
Walt Bilofsky said:
Did you imply that you might cook up some?
I might do some things for my own edification.
I would not do anything to arouse their ire for public use.
I haven't seen it yet, but I will be posting something to the internet on a
regular basis, even if it is transcribed by hand.
I make a business out of avoiding hand transcription, automating interfaces
between systems, so I doubt if that will be the end result, unless Fronius
says it has to be.
Once I get the software, I might approach them professionally.
Walt Bilofsky said:
That wasn't helpful. I looked at the parcel map. My property lines are
N 38 24' 51" E (Solar 218)
S 52 36' 01" E (Solar 212)
N 46 28' 45" E (Solar 215)
The line at the street has no degrees, just feet, which looks like it is
parallel to the back line. S 52 36' 01" E (Solar 212)
Looking at the blurry photo on the county GIS web site, I would say the
house is square with the first line listed above, which is handy, since
that agrees with my compass.
It's too far to the property lines for me to measure with my Stanley
Strait-Line, and I'm too lazy to actually measure it.
I tried sighting along all four sides of the house (which is irregular) and
setting GPS waypoints for each corner. That wasn't helpful either. My
eTrex doesn't seem accurate enough for survey work ;-)
J
Jemmy Ducks
Watt was Secretary of the Interior during the first Reagan
administration. He is most famous for suggesting that since Jesus was
coming soon, there really wasn't much point in preserving natural
resources: everything's going to burn up in the apocalypse anyway.
W
Walt Bilofsky
Clarence -
Fronius' software is downloadable from their web site, and they have
some sample data. My system isn't in yet but I took a look at the
program. (It wouldn't start up unless I had a free serial port.)
See
http://www.fronius.com/worldwide/usa.solarelectronics/downloads/software.htm
..
I'm a software person myself, and would like my PV system to be
well-metered on my PC. Could you please send me an email or say how
to demystify your email address? I'd like to exchange ideas.
Regards,
Walt Bilofsky
www.toolworks.com/bilofsky
Walt Bilofsky said:
You don't like my email address? Just "reply". It's legit ;-)
Jemmy Ducks said:
After I posted, I realized that my recollection of James Watt didn't fit
with my recollections of Jimmy Carter ;-)
Like this?
From MAILER-DAEMON Mon Oct 17 10:58:11 2005
Return-Path: <MAILER-DAEMON>...
----- The following addresses had permanent fatal errors -----
<[email protected]>
(reason: 550 error: mail failed; try re-sending it to ...)
Nick
Like this?
----- The following addresses had permanent fatal errors -----
<[email protected]>
(reason: 550 error: mail failed; try re-sending it to ...)
Darn. Supposed to work. Used to work.
Maybe I'll have to fix that ;-)
D
daestrom
This would be, quite literally 38 degrees, 24 minutes 51 seconds from 'true
north'. The reciprocal would be 218/24/51
S 52 36' 01" would be 127 23' 59". How did you get 212?? The reciprical
would be 307 23' 59"
Shouldn't this last one be just 46/28/45, the reciprocal being 226/28/45 ??
I don't understand your (Solar ???) numbers.
There's always celestial navigation. Worked for hundreds of years before
GPS ;-)
If you can find Polaris on a clear night, line it up with a point over your
roof with some point in the yard and drive a stake. Next day, come out and
take all the readings you like. (beware, Polaris isn't *exactly* north all
the time, it makes a very tiny circle around true north).
daestrom
daestrom said:
This is a line that I think is parallel with the end of the house. It
would be the direction that the solar panel would face, 218.
I don't understand that. Why is 52 = 127?
Yes ;-) A little bad math there. I don't know where that came from.
I could do that. I can spot Polaris easily from the driveway.
I'll have to find it over the house.
I plotted south using the moving sun, and a series of points.
