Newbie neeeds some input

System
System Posts: 2,511 admin
in Grid Tie and Grid Interactive Systems #1
I live in So Cal, near SD and am planning on having a solar system installed before year end on my home. The basics - I consume 11625kW a year (12250 max over past 4 years) - have a home facing South (192 degrees), 21 degree slope on roof. Two proposals - one for 5.1 kW system rated at 4.423 kWh AC using 22 Kyocera 235 multi-crystalline panels and an SMA Sunnyboy inverter; and the second one, a 4.3 kW system rated at 3.667 kW AC using 18 Samsung 241 mono-crystalline panels and a Fronius inverter. I don't want to add problems with company names but they are both licensed in CA and seem to have lots of experience. Costs in CA seem to be in the $6.40 to $7.30 per kW for systems. Net of the credits (CA and Federal) the cost of these two systems is within a few hundred dollars of one another and they both appear like they'll get me into Tier One on the utility's tiered rate plan. I can also switch to TOU rates and probably save more as the Tier one rate will be lower. I am retired, expect to live in home another 10 years and don't expect consumption to go up much. Past 4 years usage has been within a few hundred kW hours of average but my rates have gone up by 9+ percent in past years due to Tiered billing. I have tons of questions and have tried to search and/or research info - but at risk of being buried in opinions - does anyone have some input for me here in making a decision

Thanks in advance for your hep. :D
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Comments

  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    #2
    Re: Newbie neeeds some input

    that's a tough one for us to decide for you. i'm not sure of samsung's warranty, but they are a well know company. kyocera is also well known and has a good reputation for solar and honoring warranties already in place. the higher output system may help you in those peak usages and any expanded needs for electrical energy. that brings the point up of expandability on the smaller system, just in case you would need or want more power.
    you should ask how high off of the roof each pv system will be as 6 inches or more will allow for better cooling of the pvs and hence a better performance during hot periods. keep in mind pvs super heat and quickly even under somewhat modest temps and heat is detrimental to your output performance. this needs addressed regardless of which system you elect to get.
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  • System2
    System2 Posts: 6,290 admin
    #3
    Re: Newbie neeeds some input

    Niel - thanks. The higher output system only has a 4000 series inverter (SMA) and the CA State Solar web site estimates that it could produce as much as 4400+ kWh which is in excess of the capacity of the inverter. This sounds like a problem to me but the salesman says it will rarely if ever produce at peak efficiency so I shouldn't be concerned. Is this true? Also, both installers want to mount this 3-6 inches above the roof but I have a semi-circle, fire proof cement tile and that means it ill only be an inch or two above the high part of each tile. I'd prefer to have the PV panels at least 6 inches above the low point and preferably 8" above the low points. Sound reasonable?
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  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    #4
    Re: Newbie neeeds some input
    temeculawineguy wrote: »
    Niel - thanks. The higher output system only has a 4000 series inverter (SMA) and the CA State Solar web site estimates that it could produce as much as 4400+ kWh which is in excess of the capacity of the inverter. This sounds like a problem to me but the salesman says it will rarely if ever produce at peak efficiency so I shouldn't be concerned. Is this true? Also, both installers want to mount this 3-6 inches above the roof but I have a semi-circle, fire proof cement tile and that means it ill only be an inch or two above the high part of each tile. I'd prefer to have the PV panels at least 6 inches above the low point and preferably 8" above the low points. Sound reasonable?

    it's true that the pvs will rarely hit their rated power. you can see it from this list put out by your home state.
    http://www.gosolarcalifornia.ca.gov/equipment/pv_modules.php
    you are more likely to hit that 4400w rating though being in a southern state that gets a great deal of unimpeded sun. this is greater than 1000w/m2^. maybe some of your fellow socal members would like to chime in on their systems and what it is they see from them. when it exceeds the power that the inverter can accommodate then it is held back to that inverter's limit and the rest just doesn't get sent out. there is also no room for expanding if you would like to, but you could just add another solar setup separate from your present one if need be.

    the height is achievable with longer roof jacks and adds a very small few extra $ to the overall system. you can look up the prices and see it is small and is not unreasonable to ask for. don't let them tell you that they aren't available, for they are.
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  • TickTock
    TickTock Registered Users Posts: 16 ✭
    #5
    Re: Newbie neeeds some input

    I have 10.88 KW of panels on my south-facing 5:12 pitch roof. The highest peak I ever logged was 9.9kW on May 11. Most days I don't break 9kW. Temperature plays a big role - May 11 was a cool day (for Pheonix :-). Array temp peaked at 115F and ambient peaked at 86F.
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  • System2
    System2 Posts: 6,290 admin
    #6
    Re: Newbie neeeds some input

    Update - for what its worth - we are in final stage of selecting a company to do this and the one we favor has agreed to engineer the system with "deep track" rails and be sure the height is at least a minimum of 4" above the highest point of the Spanish tile roof we have - they have also asked to go up to a 4.0 Fronius inverter (vs. 3.8 originally proposed) as they say it will work better with two strings of 9 panels each (at their expense) and include the $750 monitoring option at no cost to us. They also came down about $.50 per kW installed price. So, I believe we are getting a good system that should keep us close to all Tier 1 power rates from SCE. I expect to offset all our Tier 3 and 4 power use.

    I am still open to suggestions as we haven't signed anything - but time is short as we want to get this up before year-end in order to use the credit on our 2010 tax return. Thanks for help so far and additional comments/input. (This is the second option I outlined in my original post - Samsung LPC241 panels, Fronius inverter - 18 panels).
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  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    #7
    Re: Newbie neeeds some input

    it all sounds good so far. i can't think of anything more unless the guys think of something else.
    oops, i just remembered there were some issues going on with the fronius inverters that were addressed on the forum. try a search on the forum for that info and then confront the installer if he knows of it and if a solution was reached?
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,637 admin
    #8
    Re: Newbie neeeds some input

    I think this is the thread that Niel was typing about:

    Fronius MPP Hunting

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • System2
    System2 Posts: 6,290 admin
    #9
    Re: Newbie neeeds some input

    It is, thanks. I read all the posts and will ask the installer about this when I se him tomorrow. Sounds like I should ask him to use a different inverter if cost is the same.
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  • Solar Guppy
    Solar Guppy Solar Expert Posts: 1,989 ✭✭✭
    #10
    Re: Newbie neeeds some input

    Use a SMA or Xantrex unit, there is no reason to select a know problematic manufacture, I doubt the installers have any knowledge about what brands have issues
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  • TickTock
    TickTock Registered Users Posts: 16 ✭
    #11
    Re: Newbie neeeds some input

    The only other thing I would say to consider is the rated temperature of the inverter. This is ultimately why I picked Fronius - it is rated to operate from -4F to 122F. None of the others I looked at went that high and we do see days nearing 120 here in Phoenix. I didn't want to risk voiding the warrantee. I have never encountererd any problems with the inverter. Just works. But it is only 1 year old now...
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  • nvyseal
    nvyseal Solar Expert Posts: 108 ✭✭✭✭
    #12
    Re: Newbie neeeds some input

    I also have a Fronius 5.1. It is working flawlessly. On this forum we may have has A report of hunting/clipping, but mine is working great. 2 years come November. Only thing i regret is that it's not web connected, but can be. I elected to go with a TED device, but thats not really for prime time also.
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  • Solar Guppy
    Solar Guppy Solar Expert Posts: 1,989 ✭✭✭
    #13
    Re: Newbie neeeds some input

    Xantrex GT series is specified for -25C to 65C ambient , desn't need a fan like the Fronius units do


    http://www.schneider-electric.com/sites/corporate/en/products-services/renewable-energies/products-offer/range-presentation.page?c_filepath=/templatedata/Offer_Presentation/3_Range_Datasheet/data/en/shared/renewable_energies/xantrex.xml&f=F13%3ARenewable%20Energies~!NNM1:Solar+Grid+Tie+Systems~!NNM2:Single+Phase+Solar~!NNM3:Xantrex
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  • autoxsteve
    autoxsteve Solar Expert Posts: 114 ✭✭✭✭
    #14
    Re: Newbie neeeds some input

    Sounds interesting and all I can say is I have had a great experience with my system (Fronius inverter). If you want more info on the company that installed my system and the equipment, email me at: stevenleslie@yahoo.com
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