Reviews of Grid Tie Inverters

Discussion in 'Connecting to the Grid' started by imported_admin, Oct 22, 2010.

  1. We'd like to create a resource that lists various grid tie inverters appropriate for small wind turbines or hybrid solar/wind systems. If you've had an experience with a grid tie inverter, post a review here and we'll eventually compile the postings into a single concise resource for people to learn about grid ties and where to go to buy them.

    Thanks!
     
  2. leamywind1

    leamywind1 WindyNation Engineer

    I have 3 windturbines 2 pole mount and 1 roof mount. (1) wind Blue with 5 Windy Nation blades,(I) Windmax 500w and (1) windmax (1kw) i use the Sun G 500 (10-30v) watt and the SWEA grid tie inverters. I have manufactured a control box to contains these components in an all in one enclosrure using a Turnigy meter and GFCI protection. I have forund that using a 24v wind turbine really works well with these grid tie inverters. I get power out of them(10-30 watts) in about 8-10MPH winds for low wind production. You must look at your wind charts for power and voltage to match it up with a grid tie inverter. These grid tie inverters are not UL approved but if you are not getting permits and inspections they are a great choice to reduce your electric bill. If you want to acctually get paid for the energy you make you must use a UL approved grid tie inverter. ( Aruora, Windy Boy, ect.)

    The Sun G grid tie inverter disconects at 30v for overvoltage protection and has a dump load built in, you just have to add the dump load resisstor. Please see my video's on all of this
    www.leamyelectricinc.com
     
  3. windyguru

    windyguru WindyNation Expert

    Larry, welcome to the forum and thanks for the post. - Josh
     
  4. Minnesota

    Minnesota WindyNation Engineer

  5. leamywind1

    leamywind1 WindyNation Engineer

    Hey thanks for the grid tie links. You have many decitions to make for grid tie.
    One is if you want to use batteries for battery back up and or grid tie capability or just a hobbie.
    Two is you have to understand that most UL grid tie inverters have a high voltage start input so your tubine must be able to hit that start voltage (cut in) in low wind to get the best production. Check your tubine chart or measure it yourself. I wish one of our americans would come up with a grid tie inverter for the micro turbine that is UL approved.It would shure as hell help out with these economical timesas well as promote more wind power for our home use. Not to many people I know have $60,000.00 for a 10kw Bergey these days or the space to install.

    Ther are some grid ties like the Ginlong that have a 30v start but I am not sure if it is fully UL approved.It says"UL compliant" If you have a 24v turine you would probablly need 15MPH winds or so to hit that voltage starting point even with MPPT. 48V would need a little more wind speed possibly. Outback, Aroura and I belive Windy Boy are UL approved. If you are looking to get into a lower wind grid tie inverter so you can produce power at a lower wind speed, which you can, there are no options for UL approved as far as I know. Non UL grid tie inverters will have a voltage range of 10-30v or 22-60v. They would be SWEA, Sun G-e-bay type. I only recommend the Sun G type as I have it and tested it. This is more for the micro wind turbines like Windy Nation, Windmax, Wind Blue ect. ect.ect.ect.ect. Hitting 12v in 8MPH winds is great but not if you have a grid tie inverter that starts at 30v or higher. Aagin, I am speaking of low wind and low volatges. This is why you must determine what you want to accomplish with a turbine. Charge batteries or grid tie and get paid for it or, grid tie and help out on your electric bill. Using non UL grid tie inverter does have it's pros and cons. One is if your utility finds out they could give you problems although I have never had a problem. In my opinion if you are going grid tie with a micro wind turbine, I feel it is better to get a constant 50-300 watts then to wait for 20-30MPH winds to produce 1000 or more watts. High wind is a given with any turbine, it is the low wind speed vs. power production we are looking for. This is provided your turbine is rated at 1000w or less. I beleive in more constant power through the year then 1000 watts 3 times a year. So you have to match the turbine to the inverter you are choosing. Yes, you can do transformers to up the volatge from lets say 12v to 50v ect. and relays but that gets a lot more complicated for the average DIY. I have found cost effective wise and production wise to use a 24 volt turbine and a Sun G wind turine grid tie inverter. This all works great for me as I do not live in Tornado Alley or on top of a mountain. Until the pricing gets lower and the red tape goes away I do not forsee any other way of doing it Grid tie with out batteries)unless you have the space, the wind, and the money. Your situaion might be different but for me it works GREAT. My avg. wind speed is 12MPH. and I see wind gust up to 45-70MPH in the winter. No I am not a fan of China but it is the only damn thing that works in my situation.
    Basickly I have 3 turbines hooked to 3 inverters loaded with MPPT at 10-30v and 20-60v and get 1,800 watts at 28-30MPH winds. Low wind about 10-100 watts 8-14MPH winds.
    Hope this helps
    Larry
     
  6. murray2paddles

    murray2paddles WindyNation Engineer

    I have three turbines, two that feed grid tie inverters.
    750 Windy Nation with furling mount system, this feeds an SWEA system of 4 * 250 watt inverters.
    SWEA is a company situated in Holland.
    Input V rating is 20 - 55
    Should only require three but having the fourth inverter , just use it as a back up.
    Have had lots of trial an error, mostly in the set up / tuning of the chips to match the power curve of the 750
    This system does not have MPPT. It is the tuning of the chips that match the turbines capability.
    I am challenged when it comes to understanding electronics so to tune my own chips or to understand the formulas that are required in knowing what settings to use, this is difficult for me. It also requires a computer, then to take out the chips and alter those settings.
    If you understand electronics, then it should not be an issue other than the time involved of dismantling each unit to make the changes.

    Lately it has been running excellent and even during tremendously high winds. No down time due to over voltage.
    SWEA has been doing my tuning for me and they have been sending replacement chips with different tuning to test on the Windy 750 to discover the best match.

    The only weakness so far has been as mentioned above, no MPPT and the issue on tuning the chips.
    What I will give a rating on will be the after sales care by SWEA.. It is excellent , you could not ask for better and there is no language barrier.

    The 2nd turbine is a Windy 500 feeding a 1200 watt grid tie " Power Jack "
    The input V rating is 28 - 55
    This unit is produced and sold from China.
    The recommendations are not to use a turbine rated higher than 600 watt
    First time I hooked it up to a Windy 500, I melted it in less than 2 min.
    Good sales care, they replaced it immediately. A word of caution on international sales, even though a replacement will be offered you will have to send back the damaged unit at your own postal cost and this is not cheap.
    Replaced the Windy 500 with a Windblue and then a Presto to try out. Ran well, no problems but not much power produced.
    2nd recommendation was to use a battery bank to buffer the volts. Tried it but did not like it at all
    SWEA provided me with one of their dumploads, on AP box that would control the Volt input and back on went the Windy 500
    Since then this unit has worked well and is handling all the wind (even very large storms ) with out a furling system.
    On its own, no it was not operating or matching my turbines. With add ons it became a decent unit.

    Next project will be putting up a Windy Nation 2 kw and so far the plan is to use a Ginlong grid tie inverter system. We have a few reasons to choose the Ginlong, one is no language barrier as they have British offices and person to communicate with. 2nd has been their offer to construct their inverter to match our turbine. It will also have the MPPT .
    3rd is their record of producing good products.
    This turbine will require 12 Ft blades which I am finishing up the construction of .
    If there are any changes to these plans we will post them.

    As stated before in other posts the single greatest advantage / disadvantage about these grid tie systems is the involvement of computer systems controlling them. They are developing so quickly that as soon as you have made a purchase it is outdated due to a more evolved unit being produced.

    murray
     
  7. leamywind1

    leamywind1 WindyNation Engineer

    Hey Murray,
    Great article. Yes, that is why I am a fan of the Sun G no major chips to be programed. Just set it and forget it. I am going to get ride of the SWEA inverters and just use the AP box for a dump lodad control and beef up with some more Sun G's

    Larry
     
  8. Minnesota

    Minnesota WindyNation Engineer

    Larry, with just the SUNs what will happen above 30V? What is the SUN-G model number (the one that cuts off at 30V but does not fry).
     
  9. murray2paddles

    murray2paddles WindyNation Engineer

    Larry, I was asking similar questions as Minnesota on the V over on one of the other forum threads. ?
    Also where have you found the best price to purchase the Sun D from ?

    Hey Josh, guess we have transformed your thread of Grid Tie Reviews into an extension of just grid ties... :oops:

    murray
     
  10. dlmcbm

    dlmcbm WindyNation Engineer

    my 300w Grid Tie Inverter with dump load

    [attachment=0:28dsj63j]inverter 300w.jpg[/attachment:28dsj63j]
    Model
    LT-S300G-WDL

    Normal AC Output Power
    250W

    Maximum AC Output Power
    300W

    AC Output Voltage Range
    Switch is at 230V Position
    190V ~ 250V

    Switch is at 115V Position
    90V ~ 130V

    AC Output Frequency Range
    46Hz ~ 65Hz

    Total Harmonic Distortion(THD)
    <5%

    Power Factor
    0.99

    DC Input Voltage Range
    10.8V -30V DC (not AC)


    Peak Inverter Efficiency
    92%

    Standby Power consumption
    <0.5W

    Output Current Waveform
    Pure Sine-wave

    MPPT Function
    Yes

    Over Current Protection
    Yes

    Over Temperature Protection
    Yes

    Reverse Polarity Protection
    Yes

    Island Protection
    Yes

    Stackable
    Yes

    The pros---
    The dump load is very nice. if it goes over volts it will flip to the dump load.

    I did get to test this with a battery to get steady reading. the input was at 13.2V @ about 8amps 106watts Output was 91 watts for a rating of 86% of its max 92% rating. Not to bad for a $130 inverter.

    the cons---
    It is rated at less the 0.5watts @ idle. per my Kill-A-Watt meter it takes 3 watts @ idle. Still not real bad.

    The dump load is nice but in the event that the grid goes down it DOES NOT divert to the dump load. It seems that it needs power to trip the relay to the dump load so any power would be lost if the grid goes down.



    I am trying running into a small battery bank parallel to the inverter to control over voltage so I can use it all. It will drain the batteries down to 10.8V that will eventually kill the batteries but I work at an auto repair shop so I can get OK ones for free to use.
    Overall I am very satisfied with this GT inverter. looking at specs and all it seems to be just like the SUNs. They also make these in 500w and for AC or DC.
    Hope this helps you all out. now I just need to get rid of this delco generator and get a windy up on my tower.
     

    Attached Files:

  11. murray2paddles

    murray2paddles WindyNation Engineer

    good post !
    Is the dump load internal or external ?
    When the home grd goes down, is their a braking system or does the turbine free wheel ?
    does it have it's own rectifier ?

    Check out the relay we have tested on the forum thread gri tie inverters .
    I think that would take care of your battery issue and not lose potential power when your inverter is not working.

    After reading your report & Larrys, I think the two of you have shown us how to take advantage of low to high volts !
    Thanks guys.

    Murray
     
  12. dlmcbm

    dlmcbm WindyNation Engineer

    Hey Murry,
    I should have stated that it has connections for a dump load. It does not have a dump load in itself but you can hook whatever one you want up to it.
    There is no braking system. I would have thought that they would have made it connect to the dump load in the event the grid goes down but they did not.(at least mine dont work that way) I have kinda taken care of that with the batteries. If the grid goes down it will continue to charge the batteries then when it comes back up it will take the power from them.
    Mine is a DC version so there is no rectifier but they make an AC version that has one built in.
     
  13. murray2paddles

    murray2paddles WindyNation Engineer

    Well between you and Larry I have an interest in what you fellows have posted, so much that I might try my hand at a low Volt inverter set up also.

    I am thinking of purchasing one or two 360 watt 14 - 30 Volt inverters. They will be tied in too the same system as my 1200 watt 28-55 Volt inverter. ( see my earlier report on this set up.
    I had melted this one before using a WN 500 but I have an SWEA,  AP box that controls my V in at 56 and one of their dump loads .
    This has worked very well other than losing out on the low Volts. I will still use a Windy 500 on this set up.
    So my plan would be communing in to one rectifier to the AP box. This box accommodates 4 inverters outlets so both low V inverters and the 1200 would be wired up from this. Now from one turbine it will be feeding 3 inverters covering Volts in from 14-55.
    The 14-30 V inverter also have MPPT so because it is just one turbine I am using their is a good chance the MPPT will still be functioning.
    On the down side, if I do this It will require I get a job for a few days to pay for it. :roll:

    mur

    Sent from m
     
  14. leamywind1

    leamywind1 WindyNation Engineer

    Hi Guy,s Great post's on The Sun G
    [attachment=0:36tun7jc]wind turbine controller 2.jpg[/attachment:36tun7jc]

    Yes the Sun G needs A/C power to work the dump load. Here is what I did.
    In the upper right of my control box you can see a contactor just to the left of the A/C breakers. That is a N/O 50 amp 120v 3 phase contactor with an aux. contactor N/C attached to the main contactor in white on the right side. The red leads on the left are to connect the A/C turbines wires.When the A/C power goes off the main contactor opens and the aux. one closes shunting the two a/c turbine wires to slow the tubine down and stoping power from going to the inverter-system. Once A/C power is restored then the main contactor closes and the system restores power to the inverter-system. This can be done on the d/c side of the rectifier as well. Shunting the positive of the turbine to a battery, dump load ressistor, hot water element, ect. The same dump load ressistor can be used off of the one you put in for the inverter t begin with. So this has an electric A/C brake. For the D/C side or the aw A/C side. Depends on how you want it wired. It has all the meters and connections to hook to the grid.

    It is best to use a 24v turbine vs. a 12v. Better production in a low wind start up. Using the sun G you should see about 10-20watts in 7-8 MPH winds with a wind max. I recommend using two Sun G's for a 1000w turbine 24 v. Posibly even 3 considering effciancy factors. Maybe two for a 500 watt turbine. Loading the turbine down on the front end will work fine as it will work great in low wind, as the wind increases so will the volts and amps. It is a trial and error thing because you have to find a happy med. with you own personal turbine. Your power curve may not be the same as my Windmax tubines. I have found that happy med. for what I have. I have it loaded with 1 500w inverter 10-30v and 22-60v SWEA inverters. plan on just loading it all with 10-30v 1500 watts as I have 3 turbines. Seen 985 watts two days ago.
    Theroy is low voltage but double the amps, but hopeing for a good power curve at the same time where volts and amps give you your turbine rating of 500watts or 1000 watts ect. would buy one and test it to start to get a good feel for what the actual power curve would be for your turbine.
    Larry

    Larry
     

    Attached Files:

  15. murray2paddles

    murray2paddles WindyNation Engineer

    Thanks Larry,

    If your estimates for your turbine are 10 - 20 watt in 7 - 8 mph.
    What is your estimate in mph to achieve the 500 advertised watts ?

    When you have the time please let me know your thoughts on the letter I sent to you on using the SWEA , AP box, etc.

    Murray
     
  16. leamywind1

    leamywind1 WindyNation Engineer

    Hi Murry, I did not get the letter-PM ASAP. Please resend. I would guess 500w around 20-25MPH winds. In my case I get more since I now have 4 connected.
     
  17. murray2paddles

    murray2paddles WindyNation Engineer

    Ok, has been resent. On your private messages on the windy site.
    Probably under your spam filters :D

    Thanks on the mph info



    Murray
     
  18. Minnesota

    Minnesota WindyNation Engineer

    Larry,

    Thanks for all the info an vids too.

    Question - The Sun-500 G w/DL; does the dump load port activate at 30V and could it be used to then drive a higher voltage GTI like the Sun 24-52 or a power jack 1200 (28-52)? - or is it best to just parallel the Sun-500 G with a higher input voltage GTI and not worry about the dump load port.

    Minnesota
     
  19. leamywind1

    leamywind1 WindyNation Engineer

    Yes it does activate at 30v. I would try hookng them all in paraelle first. See what you get. If you are using the second inverter at the lower 20v level this might help you combine power on the front end. By keeping them in paraelle the second inverter at 20v or 28v also will get a chance to catch up right away where it might take a few more seconds if it is on the dump load side to see the input voltage. So all in all I would just keep them in paraelle. I do not use the dump load control at all in my set up. (Just on the end from the SWEA) This way the all have a chance to draw power right away when needed. Depending on your turbine yuou should see 300-400watt before iit even needs to go to the other inverter. This is where you have to see when the turbine will max out with the Sun G as far as amps and voltage before it disconnects. Remeber when the Sun G disconnects and if you are using a 28v invertrer your power levels will start at zero or about 10-20w again until the 28v inveter starts to put a load on it and the voltge and amps get up to it's power curve. This is why I said you may end up using two 500 watt Sun G 10-30v on the fron end.I know hey make a 250-300 for wind as well so that also might be an option to tie into the front end but I am not sure if it comes without the rectifier.
    Aagin, it is all trial and error but this set up is pretty easy to do and only a few things to figure out to get it right then you are done. Please let me know how you make out.
    Larry
     
  20. murray2paddles

    murray2paddles WindyNation Engineer

    Thanks again Larry,

    Minnesota, after a conversation last night with Larry which included questions similar to yours I have ordered a Sun 500 to run parallel with my Power Jack 1200 = 28-55 V.
    I will be feeding them with one turbine, a Windy 500 ( with no furling ) This will come from the rectifier to an SWEA , AP box where they will be wired parallel. The AP box and the SWEA dump load will continue to protect the Power Jack on Volt overload !
    My thoughts also, that the cut in of 28 v would replace the need of the dump load for the Sun 500
    This way I will also benefit from being able to keep the MPPT active by only hooking up one turbine.
    So now the waiting game until the inverter arrives.
    If this works out ok I already see the potential of using these low Volt inverters before my battery bank. I can already keep maintenance on the bank due to the relay system that Mark developed.
    Any who, thanks Guys for all the info and creative ideas, this is what makes it exciting about a sharing forum.
    Have a good weekend.

    Murray
     

Share This Page