Need some basic advise on panel urgently

WandaFletcher
WandaFletcher Registered Users Posts: 5 ✭
in Solar Beginners Corner #1
Hey guys, I am not total noob to solar but don't have enough knowledge to decide on anything. So here is what I need to know asap; I plan to switch on 100% solar for my guest house. My requirement is approx 300-350 units a month. Considering this, I think 3 KW should be sufficient to meet the requirement. I have many things to understand; First Point is, how it matters if I go for 30 Panels of 100Watt or 12 Panel of 250 Watt? Does it make any difference in performance.
2nd point is: some people are advising me to buy from local guy, but they have given much higher quote than compared with walmart/amazon etc. For example, the local guy has quoted around $15K, while it cost me significantly less if I buy online

AIMS (250WX12) https://www.walmart.com/ip/AIMS-Power-PV250POLY-250W-Solar-Panel-Pack-of-6/354293383 ($7500+Shipping)
Aleko (250WX12) http://www.sears.com/aleko-gdt-spu250w12v-ap-aleko-spu250w12v-monocrystalline-modules/p-SPM14914267515  $5600+Shipping)
HQST (100WX30) https://magesolar.com/best-solar-panel/ ($4900+Free Shipping)
Mighty Max (100WX30) https://www.amazon.com/100-Watts-100W-Solar-Panel/dp/B01HHDC6NQ ($3300+Free Shipping)

So I plan to buy online and use the local installer only for installation and support. Another advantage is the local guy is also going to do paperwork for 30% tax credit which I am not sure if it will be easy to do on my own if I buy online.

and last important point is; should i look only for branded panel or I should go with affordable one (I personally would prefer to go with low cost)
Please suggest asap (I have less than 2 days to make a decision). Thanks a ton in advance
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Comments

  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    #2
    Does your guest house currently have grid power ? 
    Anything you take OFF-GRID will cost you at least 5x as much as grid power
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

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  • Photowhit
    Photowhit Solar Expert Posts: 6,006 ✭✭✭✭✭
    #3
    WandaFletcher said:
    Please suggest asap (I have less than 2 days to make a decision). Thanks a ton in advance
    Solar is NOT something to rush into!

    You need to know what type of system you are setting up. A grid tied system (no batteries, electric fed back into the grid) a hybrid system (back feeding the grid with backup batteries in case the grid goes down) or an off grid system just solar array and batteries often with a generator for backup power.

    I would stay away from Sears and Walmart, and look for solar specific store. neither of those even said basic info, like if the panels are UL listed.

    WandaFletcher said:
    I think 3 KW should be sufficient to meet the requirement. 
    How did you calculate usage? How will you heat and air condition your guest house? How will you heat water?

    WandaFletcher said:
    My requirement is approx 300-350 units a month. 
    What is a unit? Are you talking about Kwhs here?

    WandaFletcher said:
    First Point is, how it matters if I go for 30 Panels of 100Watt or 12 Panel of 250 Watt? Does it make any difference in performance.
    Not really in general. Smaller panels require more connections and more mounting hardware so are harder/more expensive to install. For home installation everything should be tested to UL safety specs. 


    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Magnum MS4024, Prosine 1800(now backup) and Exeltech 1100(former backup...lol), 660 ah 24v Forklift battery(now 10 years old). Off grid for 20 years (if I include 8 months on a bicycle).
    - Assorted other systems, pieces and to many panels in the closet to not do more projects.
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  • mcgivor
    mcgivor Solar Expert Posts: 3,854 ✭✭✭✭✭✭
    #4
    Generally the ~250W 60 cell panels are the cheapest per watt, due to supply and demand,  because they're used for grid tied systems, watch out for shipping costs on larger panels. By 100% solar are you proposing off grid? because that's a loosing battle financially if grid is available and contrary to popular belief it's not as green as it painted.
    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery with Battery Bodyguard BMS 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
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  • Estragon
    Estragon Registered Users Posts: 4,496 ✭✭✭✭✭
    #5
    Also, guests can be idiots left to their own devices. I'd include idiot-proofing capability in the overall system.
    Off-grid.  
    Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
    Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
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  • WandaFletcher
    WandaFletcher Registered Users Posts: 5 ✭
    #6
    mike95490 said:
    Does your guest house currently have grid power ?  
    Yes, it does have but I was planning to go for standalone. I think I need to do homework now
    Photowhit said:

    Solar is NOT something to rush into!
    The more I am reading, I am finding myself more layman. You are right in saying so

    Photowhit said:
    What is a unit? Are you talking about Kwhs here?
    Thats right. I meant Kwhs

    mcgivor said:
    Generally the ~250W 60 cell panels are the cheapest per watt, due to supply and demand,  because they're used for grid tied systems, watch out for shipping costs on larger panels. By 100% solar are you proposing off grid? because that's a loosing battle financially if grid is available and contrary to popular belief it's not as green as it painted.
    I thought of off grid but I think its better to go with hybrid. I need to rethink everything from start now
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  • westbranch
    westbranch Solar Expert Posts: 5,183 ✭✭✭✭
    #7
    If by Hybrid you mean Panels on the Guest House and you will NOT have batteries you should be calling that GRID TIED.

    Hybrid means a combo of Grid Tied and also having batteries     for times when the grid goes down, ie
    Hurricane  or snow/ice storm.

     These systems use altogether different equipment like Sunny Island by SMA..  .. https://www.sma-america.com/products/overview.html


     
    KID #51B  4s 140W to 24V 900Ah C&D AGM
    CL#29032 FW 2126/ 2073/ 2133 175A E-Panel WBjr, 3 x 4s 140W to 24V 900Ah C&D AGM 
    Cotek ST1500W 24V Inverter,OmniCharge 3024,
    2 x Cisco WRT54GL i/c DD-WRT Rtr & Bridge,
    Eu3/2/1000i Gens, 1680W & E-Panel/WBjr to come, CL #647 asleep
    West Chilcotin, BC, Canada
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  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    edited March 2018 #8
    once you add batteries to a PV solar system, it will consume $ and never produce a profit or break-even.
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

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  • WandaFletcher
    WandaFletcher Registered Users Posts: 5 ✭
    #9
    westbranch said:
    If by Hybrid you mean Panels on the Guest House and you will NOT have batteries you should be calling that GRID TIED.Hybrid means a combo of Grid Tied and also having batteries for times when the grid goes down, ie


    Hurricane  or snow/ice storm.


    mike95490 said:
    once you add batteries to a PV solar system, it will consume $ and never produce a profit or break-even.
    The idea was to have battery back up as well in case of emergency but if it does not break even, then i would probably be skipping battery setup and tie to the grid.

    Now i got the basics to rework on my plan from fresh. Thanks a lot
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  • westbranch
    westbranch Solar Expert Posts: 5,183 ✭✭✭✭
    #10
     First you need an accurate, as possible, inventory of the things you want to cover with the GT array, and compare that to the largest array you will allowed to have GRID TIED... depending on where you at the regulations may restrict the max array size...

     
    KID #51B  4s 140W to 24V 900Ah C&D AGM
    CL#29032 FW 2126/ 2073/ 2133 175A E-Panel WBjr, 3 x 4s 140W to 24V 900Ah C&D AGM 
    Cotek ST1500W 24V Inverter,OmniCharge 3024,
    2 x Cisco WRT54GL i/c DD-WRT Rtr & Bridge,
    Eu3/2/1000i Gens, 1680W & E-Panel/WBjr to come, CL #647 asleep
    West Chilcotin, BC, Canada
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  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    #11
    Generally, if your site is not plagued with frequent blackouts and only have an occasional outage, a backup generator & Transfer Switch (auto or manual) is the most cost efficient. Fuel it with propane or city gas, and you eliminate the stale gas problem. And you save $8,000 in battery replacement costs every 5-8 years. 
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

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  • WandaFletcher
    WandaFletcher Registered Users Posts: 5 ✭
    edited March 2018 #12
    mike95490 said:
    Generally, if your site is not plagued with frequent blackouts and only have an occasional outage, a backup generator & Transfer Switch (auto or manual) is the most cost efficient. Fuel it with propane or city gas, and you eliminate the stale gas problem. And you save $8,000 in battery replacement costs every 5-8 years. 
    Thanks a lot, that makes sense. It would save me big
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  • mryimmers
    mryimmers Solar Expert Posts: 117 ✭✭✭
    #13
    What Mike said
    510 watt pv, TS-MPPT 60, Exeltech XP1100, XP600 & XP250 @ 24V, 4x Trojan 105RE, Trimetric 2030, Yamaha EF2400i gen.
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