Data loggers...

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  • silent wolfsilent wolf Solar Expert Posts: 92 ✭✭✭✭
    Re: Data loggers...

    Ok, now for the main question to ask.


    I need some solar panels for this research project.

    I have everything up to this point, as in nothing to do for a solar array.

    What I need.

    Solar mounts, solar panels, wire, inverters (enphase inverters) And everything else.

    I am looking to get around a 1.2kw system, that I can add onto later if i prefer.

    The question I have is, should I let a professional do it, and get tax incentives and such, and use the electricity, or should I get everything myself and do it myself, as I can.

    I am leaning towards letting a pro do it, then when its all done, just take the panels down that I need to modify and then put them up later. And then I know for sure everything is done right.


    Can you guys recommend any solar installer that would install in my area, thanks!
  • silent wolfsilent wolf Solar Expert Posts: 92 ✭✭✭✭
    Re: Data loggers...

    What would be better? One main inverter with a MPPT's or enphase inverters?
  • mike95490mike95490 Solar Expert Posts: 8,664 ✭✭✭✭✭
    Re: Data loggers...
    What would be better? One main inverter with a MPPT's or enphase inverters?

    edit: Sorry - I didn't catch you were experimenting with stuff. So, to measure differing effects, micro-inverters are better.

    --

    Depends. If you have no shade issue, a single inverter via a high voltage DC array should be fine.

    If you have shade issues, an array of micro-inverters is a way to put a panel up, that will only work part of the time, which I think is pointless.
    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 ,

  • BB.BB. Super Moderators, Administrators Posts: 30,196 admin
    Re: Data loggers...

    I am assuming you want to test 1 panel at a time (no water, water jacket, different design water jacket, etc.).

    Then, the Enphase is better for you. This allows each panel to operate at its optimum electrical point (as determined by Enphase).

    If you put all different panels on one MPPT type controller--it would pick some average operating point and you would hardly see any differences between cooled panels and uncooled panels (cold panels jack Vmp up--Pmp=Vmp*Imp.... If you don't properly track Vmp, then your cooling is for nothing. Imp actually drops a small bit with cooler panels).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • silent wolfsilent wolf Solar Expert Posts: 92 ✭✭✭✭
    Re: Data loggers...

    Do you guys know what the smallest solar array I can buy and still get solar incentives?
  • BB.BB. Super Moderators, Administrators Posts: 30,196 admin
    Re: Data loggers...

    I don't believe I have seen a minimum for the Federal. Don't know about Arizona--but you can check through this data base for other rebates/credits:

    www.dsireusa.org

    At some point, the paper work / permits (if grid tie) / licensed Electrician costs kind of overwhelm the benefits of a small system.

    If this is a test setup--It would not be the worst thing in the world use ground racks with roof simulation behind them (adjustable air gaps / different roofing materials / colors) if you want to characterize the variables further.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • silent wolfsilent wolf Solar Expert Posts: 92 ✭✭✭✭
    Re: Data loggers...

    Just found t, its 1.2 kw.
  • silent wolfsilent wolf Solar Expert Posts: 92 ✭✭✭✭
    Re: Data loggers...

    Ok, well I got some local quotes, and found out there is a big difference in price, so I will probably just do it my self. I am just going to do a 500watt system or so, but I need mounting rails. What kind of mounting rails do you recommend? I would like it fairly simple, and also so I can adjust the angle of the panel.
  • silent wolfsilent wolf Solar Expert Posts: 92 ✭✭✭✭
    Re: Data loggers...

    Anyone? I need to order it fairly quickly.
  • BB.BB. Super Moderators, Administrators Posts: 30,196 admin
    Re: Data loggers...

    Regarding Rails... For short term use, just about any solid frame work should do OK. Long term, need to watch for aluminum corrosion against steel mounting hardware. Also, pressure treated lumber can be hard on fasteners (you can get PT Lumber rated hardware and build your frame out of wood).

    The frame work need to not have any twisting of the frame work from loading (solar panels are thin tempered glass and cannot with stand twisting).

    The panels are designed for around 50 lbs per sq. ft of wind loading... So each panel position and the framework needs to withstand the cumulative wind loading of 100's of lbs per panel.

    Right now, metal is expensive (pretty high recycling value) and at least one yard around here has a contract to export all scrap metal and cannot even sell material out their front door.

    Unirac has some pretty nice online documentation that may help you with your design.

    -Bill

    One alternative would be to construct a "wood foundation" and then use RV mounts (or replicate their design from local material) to hold your panels.
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • AntronXAntronX Solar Expert Posts: 462 ✭✭
    Re: Data loggers...
    Ok, well I got some local quotes, and found out there is a big difference in price, so I will probably just do it my self. I am just going to do a 500watt system or so, but I need mounting rails. What kind of mounting rails do you recommend? I would like it fairly simple, and also so I can adjust the angle of the panel.

    Go buy some Unistrut or Superstrut hardware and get creative. It is like giant Erector set. My system is 520W STC, and I don't think it cost me more than $200 for materials to make very simple frame.
  • silent wolfsilent wolf Solar Expert Posts: 92 ✭✭✭✭
    Re: Data loggers...

    I thought I would just buy from a normal dealer. I only need this for about 3 panels, that can be mounted permanently.
  • BB.BB. Super Moderators, Administrators Posts: 30,196 admin
    Re: Data loggers...

    Our host, NAWS is in Flagstaff--if you ever get up there--and they have (or can order) panel mounting hardware for you (and ship, if needed).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • silent wolfsilent wolf Solar Expert Posts: 92 ✭✭✭✭
    Re: Data loggers...

    Is it ok to use a 100-150 watt solar panel on a enphase inverter?
  • BB.BB. Super Moderators, Administrators Posts: 30,196 admin
    Re: Data loggers...

    I believe so... For a 200 watt inverter you will probably have something (very roughly) around 5 watts fixed load and another 5 watts variable load (like 2.5% of actual output current).

    If you want, take a look at the enphase site and watch one of the public systems graphs and see if you can identify a cutoff point. My Xantrex unit will operate down to 0 watt output power while still drawing power from the panels (operating internal electronics/switches).

    Since you are measuring the DC power into the Enphase, you might never even see the "loses"--for you, the solar panel power output is what is most important. Although, your data maybe "noisy" until the inverter gets enough energy to operate its MPPT circuits.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • silent wolfsilent wolf Solar Expert Posts: 92 ✭✭✭✭
    Re: Data loggers...

    Ok, thanks for responding, I also have another question, what can you do with the 208Vac enphase inverter? Can you split it to 115 vac? because I found the 208 Vac for $135 and the 240Vac for $180.
  • BB.BB. Super Moderators, Administrators Posts: 30,196 admin
    Re: Data loggers...

    The 208 VAC unit is intended for "Y" connected three phase power.

    You could use one but you would have to get a transformer to convert 208 to 240 VAC.

    From the Enphase website:
    Nominal voltage/range
    208V/183V-229V
    240V/211V-264V

    I did not find the installation instructions (quick look on the website)--so I do not know if the 208 (or even 240) VAC installation is Hot/Hot or Hot/Hot/Neutral.

    If you have to connect the neutral of a 208 Volt unit--then your need a center tapped transformer design (if they make one that converts from 208 to 240 vac).

    The cost of the conversion transformer may be more than the savings of the inverter.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • dreesdrees Solar Expert Posts: 481 ✭✭✭
    Re: Data loggers...
    BB. wrote: »
    I believe so... For a 200 watt inverter you will probably have something (very roughly) around 5 watts fixed load and another 5 watts variable load (like 2.5% of actual output current).
    The Enphase inverters are over 93% efficient down to 10% (19W) so I suspect that their fixed load is much lower than 5 watts. At 93.3% efficient at 19W output, that's only 1.4W for fixed and conversion losses.

    Test results here:
    http://gosolarcalifornia.ca.gov/equipment/inverter_tests/summaries/

    Wow - compared to central inverters, the micro-inverters do a very good job down below 20% rated output.
  • BB.BB. Super Moderators, Administrators Posts: 30,196 admin
    Re: Data loggers...

    Cool information---Yes those Enphase are surprisingly (to me anyway) efficient at 10% loads...

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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