SunPower (US) Questions

[Walt Bilofsky]

Anyone use inverters from SunPower (the one in California)?

Their web site is pretty sparse. The data sheets say "display with
data logging capabilities as standard". Does that mean you can get
logged data off the unit into your PC? Or just read it off the
display?

Any other experience to share with either their inverters or panels?
Thanks in advance.

 

[Solar Guppy]

Sunpower is just a re-branded PVPowered unit

http://www.consumerenergycenter.org/cgi-bin/eligible_inverters.cgi the
information is noted in the listing

PVPowered has a 2 line vacuum florescent display and a RS232 port you can
connect to a PC for basic data logging.

www.solar-guppy.com/forum for more information on Gridtie inverters

 

[[email protected]]

Anyone use inverters from SunPower (the one in California)?

http://www.sunpowergeo.com ?

Their web site is pretty sparse. The data sheets say "display with
data logging capabilities as standard". Does that mean you can get
logged data off the unit into your PC? Or just read it off the
display?

They are selling me a system with Kyocera panels and a Fronius inverter.
There is a display on the inverter, but Fronius also has an optional data
package that I bought. As soon as I get it installed (within 30 days(?),
I'll put the results up on the web on a daily basis.

http://www.kyocerasolar.com/products/ksimodule.html KC125G x 48
<http://www.fronius.com/worldwide/usa.solarelectronics/products/ig_4000_5100.htm>
<http://www.fronius.com/worldwide/usa.solarelectronics/products/monitoring.htm>

 

[Walt Bilofsky]

PVPowered has a 2 line vacuum florescent display and a RS232 port you can
connect to a PC for basic data logging.

Thanks - it sure does. Interesting - my SunPower vendor said it did
not. Well, either the SunPower labeled ones don't, or he doesn't
know.

 

[Walt Bilofsky]

my inverter is a sunpower - "PV" inverter.

How long has it been working for you? Have you had any problems? Have
you heard of any problems with them?

Is it a SunPower labeled inverter, or a PV label?

 

[Walt Bilofsky]

Thanks for the details. What make and model of panel do you have, and
how many panels?

Did you have a contractor install your system? Your contractor (or
you) should really look into time-of-use billing. It leverages your
panels because you put energy back during a much higher rate period.

For example, I use 6900 KWH a year, but I project that generating just
5600 KWH will zero out my bill.

Walt

 

[[email protected]]

This system is oriented WSW, so not ideal anyway. In Germany, there's a

Another poster referred to time of day metering.

In California, if you opt for time of day metering, rates are higher during
periods of peak usage, Noon-6pm, Monday-Friday.

Rates Summer Winter
Peak $0.2937 $0.1147
OffPeak $0.0866 $0.0896

The local utility credits back power at retail rates, so you want to
generate the most power between 12 and 6pm. This makes a WSW orientation
ideal. You want your peak to be at 2:00pm. My house is at 225 degrees. I
recall that the ideal would be 218 degrees.

 

[[email protected]]

How do you do this? Manually?

My Fronius software can not do such a task...

I don't have the system yet. Once I get it, I will figure out how to do
it. That's the sort of work that I do ;-)

(I take it that the original poster was not interested in my installer,
sunpowergeo.com, in California ;-)

 

[[email protected]]

i'll check on the time of use billing. i might accidently have the
capability now. the electric company installed a digital meter & the
meter installer said it can send readings back to the office. it must
have a clock in there somewhere...

Do you get a PG&E bill once a year, or every month?
Is your "rate schedule" E1 (fixed) or E7 (time of day).
A special meter would have to be installed for grid-tie in California, but
the time of day scheduling is optional, although I would expect any
installer to take care of that.

 

[Walt Bilofsky]

Actually Steve is in Southern California Edison territory. I glanced
at their web site - their peak period is 10 am to 6 pm weekdays. I
didn't check out their actual rates, but I assume they are different.

I am in PG&E and have the same rates as you.

I am looking at 160 and 250 degrees for the two sides of my roof, and
160 turns out to be just a touch better than 250 - at least if my
spreadsheet and the hourly data I got from PVWatts version 1 are all
correct, which is a big if. 160 is further from your ideal of
218, but I guess it generates enough more off-peak KWH to make up for
losing those late afternoon peak KWH.

A quibble, but 218 degrees is SW, not WSW.

 

[Walt Bilofsky]

walt - i have 18 Sharp panels,

Can you tell me the model number and/or the wattage of the panels?

Thanks,

Walt

 

[Walt Bilofsky]

(I take it that the original poster was not interested in my installer,
sunpowergeo.com, in California ;-)

Actually I got a bid from them, but they proposed different hardware.
They are a contractor in San Rafael, and not related (as far as I
know) to Sunpower Corp., a manufacturer in Sunnyvale and a subsidiary
of Cypress Semiconductor.

I'd welcome a post or email of your experience with them.

 

[[email protected]]

I am in PG&E and have the same rates as you.

I am looking at 160 and 250 degrees for the two sides of my roof, and
160 turns out to be just a touch better than 250 - at least if my
spreadsheet and the hourly data I got from PVWatts version 1 are all
correct, which is a big if. 160 is further from your ideal of
218, but I guess it generates enough more off-peak KWH to make up for
losing those late afternoon peak KWH.

I don't know if 218 is specific to me, or if it might also need to be
adjusted for your location.

A quibble, but 218 degrees is SW, not WSW.

I really need to have a compass in front of me when I say things like that.
I was leaning toward the "south isn't perfect" theme. I only said WSW
because that was what the poster said. I really didn't think of my 225 as
WSW... blurred writing on that one from me.

Trying to plug this in at PVWatts is difficult.
I know my panels are going to be at 22 degrees. If I put in various
orientations, I can see the effect on the noon-6pm output.

There must be a better calculator out there for this purpose. I would
think, at least in California, it would be a standard tool.

Here's my summary:
PVWATTS: Hourly PV Performance Data
http://rredc.nrel.gov/solar/calculators/PVWATTS/version1/
City: SAN_FRANCISCO State: CA
Lat (deg N): 37.62 Long (deg W): 122.38
Array Tilt (deg): 22

Array power from 12:00 to 18:00
Azimuth Average Peak
180 2200 4047
200 2293 4065
210 2319 4054
220 2329 4029
225 2328 4029
230 2323 4030
240 2302 4019
270 2152 3885

 

[[email protected]]

The Fronius system is very complicated, as it supports a multitude of
stations. ....
The fact that the data cannot be accessed will be remarked as
"user-unfriendly" on my web pages of the PV system when I finished them...
maybe some day they will re-think it.

I have read about their proprietary protocol that they don't choose to
share in other posts.

I want to share my PV experience on the web. If the only way I can do that
is with an occasional screen print, I would do that. If they store in a
Jet database, that might be simple enough to view. It might be
deliberately obscured, though.

I would like to automate it so that it runs at least once a day without
intervention. If I can't do that, I can't; but I will try.

 

[[email protected]]

[email protected] wrote:

Actually I got a bid from them, but they proposed different hardware.
They are a contractor in San Rafael, and not related (as far as I
know) to Sunpower Corp., a manufacturer in Sunnyvale and a subsidiary
of Cypress Semiconductor.

I'd welcome a post or email of your experience with them.

I don't have an installation yet, although I think it is grinding along
slowly. I spoke to them first in April of 2005. I don't recall when James
Watt came out to the house. I am fairly remote, so I am used to having
difficulty getting contractors lined up to come out, and then actually
having them show up. SunPowerGeo seems to be in the middle of that pack.

I am supposed to be installed sometime in the next thirty days.

 

[[email protected]]

i get a monthly bill. that was my choice when i filled out the
paperwork. i could have gone with monthly, quarterly, or yearly
billings.

What do your bills look like each month?
Do they show a credit during the summer, and a charge during the winter?
I suppose that could be like anyone with the balanced payment plan.
Do you have to pay any particular amount month to month?

My understanding is that on the day the meter is turned on, I begin an
annual billing cycle. I will receive no bills from PG&E until one year
later, when I should get a small bill. It can't go negative, as PG&E is
not required to ever pay me for solar power.

 

[[email protected]]

Too many rows for 12-18:00

The raw data is a few thousand rows representing several years of
daily*hourly reporting. What I put here is the average of those lines for
each of some different azimuths in the first column, and then a peak for
each of those azimuths.

 

[[email protected]]

Is there an annual cutoff for your credit or can it be carried
indefinitely or perhaps a sliding credit?

It trues up on the anniversary date each year. You lose the credit, or pay
the balance.

 

[Steve Spence]

I don't have an installation yet, although I think it is grinding along
slowly. I spoke to them first in April of 2005. I don't recall when James
Watt came out to the house. I am fairly remote, so I am used to having
difficulty getting contractors lined up to come out, and then actually
having them show up. SunPowerGeo seems to be in the middle of that pack.

I am supposed to be installed sometime in the next thirty days.

James Watt .....

 

[[email protected]]

Count the rows. There are too many for the times spec'd

Count what rows?
There is one row that is the average of 8920 entries 12:00 through 17:00
with a panel oriented at 180 degrees.
There is one row that is the average of 8920 entries 12:00 through 17:00
with a panel oriented at 200 degrees.

A total of 8 rows for 8 different azimuths.