Getting a 5.72kW system installed.

jschner
jschner Registered Users Posts: 22 ✭✭
I tried to get a grid-tie system installed last year but the local rebates ran out just as I filed. We are talking I missed it by minutes which was a bummer. But this year I got in on it. Here are some of the details:

22 - Suniva:OPT260-60-4-1B0
1 - Power-One:PVI-5000-OUTD-US (240 V) mounted in insulated garage.
2 strings of 11 panels.
Roof mount S. 174deg.
26 deg tilt.
Minimal shading Nov. to Jan. from a telephone pole before 10am and after 2pm, otherwise clear views.

GoSolar CA CSI-EPBB calculator figures annual 8432kWh production. Not sure how realistic that is?

Installed out the door for $3.25kW. Installer will buy everything and will get the local rebate so my out of pocket will be $10,390 at completion - Fed rebate.

Install to be completed by Dec. 15th. Just in time too as the city to raise electric rates from $0.134 to $0.148 Jan 1st. Then to $0.156 Jan 2013. If everything goes as planned I figure a payback time of around 5 years assuming no rate increases after 2013.

I bought a RS485 to USB adapter for the PVI-5000 and looking for a <$150 Craigslist netbook for Aurora Mon., monitoring locally and uploading to PV Output.

Anyway, that will be my setup. Can't wait to get it in and operating.

Comments

  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: Getting a 5.72kW system installed.

    Have you tried PV Watts for a city near your installation (just use defaults and enter your array as 5.72 kW and the tilt of your roof). There is an output power as hourly numbers you can enter into a spread sheet, and knock out the times when you will have shading.

    No matter what anyone says--Pretty much any shading will knock 50% or more of your array's output. Installation, shading, equipment configurations are all over the map... There are some cases where you might get less than 50% degradation of output power for small sections of array shading--But for a decision like this, don't assume that shading will not make a difference.

    The good thing is you still have no shade in the middle of the day, and winter production is usually much less than summer, so a bit less of a smaller amount is not a huge issue (and in California, most of the major power companies force use of Time of Day, Winter/Summer net metering... For me, summer afternoons I get ~$0.30 per kWH for generated power, in winter is is something like ~$0.12 per kWH--again, making lost winter production much less of an issue of costs/lost output).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: Getting a 5.72kW system installed.

    I should also add--If the shading is the result of things you cannot control (trees, trees not on your property, shading from buildings next to your installation, etc.)... Take that into account too. If the array will be shaded a few years down the road by something that you cannot control--Take that into account too.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • LucMan
    LucMan Solar Expert Posts: 223 ✭✭✭
    Re: Getting a 5.72kW system installed.

    Talk your installer into using a different inverter than the Aurora. The total output from your system will be much less than if using an SMA or equivalent inverter. I've been there!
  • jschner
    jschner Registered Users Posts: 22 ✭✭
    Re: Getting a 5.72kW system installed.

    Thanks for the info Bill.

    The utility is a very small city non-profit electric system. The electric rates are straight rates winter or summer, day or night for now. They do tier up about $0.08 after 750kW of usage but I should be well under that with this setup.

    On PV Watts there is not a location close to me, 2 hours away at best, but it does say 5.42 avg sun hours per day in my area. The annual figures are slightly less than what the contractor had calculated. $1183 vs $1220 first year.

    I did retry the GoSolar site and set Nov. and Jan at 70% production and Dec to 50% production and it gave me 7975kWh of yearly production. About a 6% yearly loss. Bummer but I guess that is not too bad over all as you mentioned. If I get my 2 strings setup in a way that only one is being impacted at a time, I wonder how much that will help? 50% of a single string? So only a 75% impact overall?

    It will be interesting to see how real life compares to all this on-paper stuff this next year.

    The very top of that pole is it for uncontrollable things. Being close to winter solstice is really helping to verifying the controllable things are handled.
  • jschner
    jschner Registered Users Posts: 22 ✭✭
    Re: Getting a 5.72kW system installed.
    LucMan wrote: »
    Talk your installer into using a different inverter than the Aurora. The total output from your system will be much less than if using an SMA or equivalent inverter. I've been there!

    Probably too late now but I can ask. But I'm curious why? The Power-One spec is 96.5% eff. and a 200V startup voltage. PVI-5000US Datasheet

    Are you saying my panels may peak over the 5K limit of the inverter and the power is clipped or just plain less efficient output?

    Ok I found one thread, http://forum.solar-electric.com/showthread.php?9311-power-one-aurora-inverter-questions&highlight=aurora

    That is interesting. It's a different model number but I'll watch carefully to see if I can tell if this problem happens with my setup.

    Thanks for the heads up!
  • jschner
    jschner Registered Users Posts: 22 ✭✭
    Re: Getting a 5.72kW system installed.

    Holidays, city permit delays, rain/snow, and a few time consuming mistakes by installers, I was able to finally get this system up and running on Dec. 31st.
    http://pvoutput.org/list.jsp?userid=15767

    Ended up using an RS485 to USB I got off ebay for $9 and found an HP Mini laptop for $60 on Craigslist to do all the data gathering using Aurora Monitor and use wireless to upload to PV Output. USB was plug and play and the whole setup with HP Mini uses about 8watts with the lid closed doing it's thing.

    So far it seems like it is all working well. Overcast today but both strings track nearly identical when there is like shading or full sun on both strings.
  • jschner
    jschner Registered Users Posts: 22 ✭✭
    Re: Getting a 5.72kW system installed.

    A little update - No issues to date with this grid-tie system, inverter has been working well. According to the monitoring software I have been getting around 95.5% efficiency from the inverter. Both strings are tracking within 20watts of each other when not shaded. The Suniva Panels seem to work well but the pollen really likes these black panels. I'm hosing them off about once a week right now until things calm down.

    Had a good clear cool day yesterday. Peaked the inverter for a short while and produced 37.7kWh. It would be nice to hit 40kWh or 7.0 eff. but I'm not sure if that is possible due late afternoon shading and temps. So far it has been working better than expected. Can't ask for any more than that.

    04/08/13
    Energy Generation: 37.743kWh (6.598kWh/kW)
    Exported: 37.743kWh
    System: 5.720kW
    Panels: 22x260W Suniva OPT-260-60-4-1B0
    Inverter: Aurora PVI-5000-OUTD-US
    Orientation: South - Low Shade
    Location: United States 96019 - N. California
    Array Tilt: 26.0 Degrees
    Weather: Fine
    Comments: Updated 19:35 UTC-7:00
    Graph & Stats: http://pvoutput.org/list.jsp?id=15767&sid=13640
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: Getting a 5.72kW system installed.

    Glad to read that all is well. Very happy when a plan comes together.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • SkiDoo55
    SkiDoo55 Solar Expert Posts: 414 ✭✭✭
    Re: Getting a 5.72kW system installed.

    Pollen really doesn't care it like my panels also, here in the valley. Have the same problem, they turn yellow often and have to be rinsed off frequently. Dust blowing is a problem too, since we don't get rain much during the summer. Can see about a 4-5% improvement after cleaning.
    Great to hear your system is up and working.
    GT3.8 w/4600W Trina 230W, TX5000 w/5000W ET-250W, XW4024 w/1500W ET-250W, 4 L16, 5500W Gen. (never had to use) Yet!!
  • solar_dave
    solar_dave Solar Expert Posts: 2,397 ✭✭✭✭
    Re: Getting a 5.72kW system installed.

    DUST! Heck it rained mud here last night. You should see the cars on the roads today. This happens when a front pushes through stirring up the desert dust and then it "trys" to rain but is just virga. Basically it is raining out of the cloud but most of the water just evaporates do to low humidity near the ground until only mud is all that is left. What a mess today on the panels I just cleaned over the weekend.
  • Blackcherry04
    Blackcherry04 Solar Expert Posts: 2,490 ✭✭✭
    Re: Getting a 5.72kW system installed.

    Mine had some dust and dirt on them from over the winter, I chose to do them in the evening and I got about half done. I figured that I would do the others the next evening. You could tell such a difference in the half I cleaned, they sparkled. They are all on Enphase inverters , so I can tell down to the panel level the exact production for day and the watt production by the minute. There was not one bit of difference between the clean and dirty side, NOT one bit. So I have to question the value of even doing it, I was disappointed.
  • inetdog
    inetdog Solar Expert Posts: 3,123 ✭✭✭✭
    Re: Getting a 5.72kW system installed.
    They are all on Enphase inverters , so I can tell down to the panel level the exact production for day and the watt production by the minute. There was not one bit of difference between the clean and dirty side, NOT one bit. So I have to question the value of even doing it, I was disappointed.
    Are you sure that you did not have the Enphase inverters over-paneled so that all were clipping?
    If they stayed the same during lower light before noon and the output of all of them increased above that point, then yes, that is disappointing, but will save you the trouble of cleaning more than just one next time to test. :-)
    SMA SB 3000, old BP panels.
  • Blackcherry04
    Blackcherry04 Solar Expert Posts: 2,490 ✭✭✭
    Re: Getting a 5.72kW system installed.
    inetdog wrote: »
    Are you sure that you did not have the Enphase inverters over-paneled so that all were clipping?
    If they stayed the same during lower light before noon and the output of all of them increased above that point, then yes, that is disappointing, but will save you the trouble of cleaning more than just one next time to test. :-)
    Yeah, I am sure they weren't clipping, I do see it every once in awhile it's very evident when they are putting out 199 watts and you get a flat top graph, doesn't look like it's going to happen this year, so far anyway. My March was 352 KWH behind last year, April doesn't look much better. I saw absolutely no difference. I really expected to see some difference it's a pain to drag the hose up there, bought a fancy brush, new garden sprayer for my soap.
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: Getting a 5.72kW system installed.

    I tried that a couple times on my array (after a lot of pollen)--And I could not see any difference either just reading my Central inverter LCD.

    My panels are on a 2nd story roof and I have to drag out a big ladder to get up there and clean--Have not done that a few years.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • inetdog
    inetdog Solar Expert Posts: 3,123 ✭✭✭✭
    Re: Getting a 5.72kW system installed.
    BB. wrote: »
    --And I could not see any difference either just reading my Central inverter LCD.

    I tried hosing off my very dusty looking panels, and the only effect I saw was the short term improvement from cooling the panels. :-)

    The eye can see changes in the amount of light scattered at the surface of the panel, but although that may double from .1% to .2% it will only produce tiny change in the amount of light which is getting through to the panel.
    SMA SB 3000, old BP panels.
  • Blackcherry04
    Blackcherry04 Solar Expert Posts: 2,490 ✭✭✭
    Re: Getting a 5.72kW system installed.

    Here is the peak from today, there has always been a disparity in output on a couple panels, it's always been less that 10 w. I also have a couple vent stacks that will effect it at some point in the day and one tall heater stack that takes out one panel after 4:00 in the afternoon. They will clip at 199w as I said, but not often. The half I cleaned were the half on the right side, best I can say. That 5th panel from the right , top row has always been a lagger.

    Dang, after looking close the ones I cleaned are putting out LESS, that sux's.

    Attachment not found.
    .
  • SkiDoo55
    SkiDoo55 Solar Expert Posts: 414 ✭✭✭
    Re: Getting a 5.72kW system installed.

    4% is only about 126 watts on 3KW of panels. Is does add up at the end of a full summer day.
    On a 200 watt Enphase would only be @ 7 watts at full power.
    If mine were on a two story house it would be only rain cleaned unless I saw a huge drop in production.
    My numbers are up over the last couple of years to date.
    My modest system has produced 17.5 MWh since 08/2010. 1430 KWh for this year as of yesterday.
    Still want to put op the other system on my south/east facing roof, will double my system from current. That would be max I could do without doing service panel upgrade, and I would be producing lots more than I consume. Might upset PG&E
    Beside on cleaning being semi retired (out of work) have lots of time to clean them when they look very brown.
    GT3.8 w/4600W Trina 230W, TX5000 w/5000W ET-250W, XW4024 w/1500W ET-250W, 4 L16, 5500W Gen. (never had to use) Yet!!
  • jschner
    jschner Registered Users Posts: 22 ✭✭
    Re: Getting a 5.72kW system installed.

    I had a few 38kWh production days since my last post and thought that was it for the peak due to warming temps but a nice cold front moved in and boosted things a bit.

    05/21/13
    Energy Generation: 40.102kWh (7.011kWh/kW)
    Exported: 40.102kWh
    System: 5.720kW
    Panels: 22x260W Suniva OPT-260-60-4-1B0
    Inverter: Aurora PVI-5000-OUTD-US
    Orientation: South - Low Shade
    Location: United States 96019
    Array Tilt: 28.0 Degrees
    Weather: Fine
    Comments: NM=99770
    Graph & Stats: http://pvoutput.org/list.jsp?id=15767&sid=13640

    I'm fairly pleased with this system producing 40kWh in a day and getting 7 on efficiency. That despite peaking the invertor for over an hour and getting some late afternoon shading.

    The Aurora inverter and Suniva panels are performing better than what I had expected. And yes I'm still hosing the panels off at the end of the day about once a week for bird crap and pollen.

    I talked a friend down the street from me into installing a system with the same equipment but he has a 6k inverter and two more panels with a South and West orientation. He is hitting 44kWh and 7 eff. and a very happy camper as well.
    http://pvoutput.org/comparelive.jsp?sid=16698&sid1=13640&dt=20130521