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Micro Inverter Setup - Thoughts please

  • 06-04-2023 7:47pm
    Registered Users Posts: 1,425 ✭✭✭

    Think of putting this inverter in the shed

    • I have one 380w solar panel here left over where the glass has shattered so I am thinking to coat it with resin and use it for one input on the inverter - I dont want to put it back into the string as I fear it will reduce power on all panels.
    • Also have 3 phase 24v 300w turbine that I was going to make a bridge rectifier for and connect that to the other side of the inverter, as the inverter has an 18v startup

    Was going to monitor the setup with a Shelly PM.

    I would imagine that there would always be a load on the turbine so would I go with resistor for the dump load or could I just configure a Normally Closed relay to short out the turbine in the event a power outage when they will be no load ?


  • Registered Users Posts: 65,058 ✭✭✭✭unkel

    The inverter is grid tied and the turbine will never output more power than the inverter can handle. So why would you need a dump load? The grid is your dump load 😁

  • Registered Users Posts: 1,425 ✭✭✭Big Lar

    @unkel Aware of that, but what if the power goes off I was thinking ?

  • Registered Users Posts: 65,058 ✭✭✭✭unkel

    Oh aye, that would be a problem alright if the power went off during strong winds 😁

    Also not sure how suitable those micro inverters are for turbines.

  • Registered Users Posts: 190 ✭✭oaklands

    Have a look around Youtube for video on this unit/family also verify the IP rating, if any.

    I am using Hoymiles micro inverters (HM-x00) and eevblog did a tear-down recently on YT with a positive conclusion. They come in single, dual & quad pv panel config. Some of the quads only have 2 trackers. Single have 1 and the dual have 2 trackers/MPPTs.

    The only thing is that they use a DTU to communicate with them (=very $$$).

    The inverters can be sourced on and some of the sellers apply 0% VAT.

    I am using OpenDTU on an ESP32 + NRF24L01, which is working very well for data logging. Also supports MQTT.

    (AhoyDTU runs on ESP8266 + NRF24L01.)

    Note: I am only using them for 1 month.

    Edit: My understanding is that micro-inverters need the Grid/mains to operate....but please verify.

  • Registered Users Posts: 2,474 ✭✭✭bullit_dodger

    Correct - the Hoymiles are powered from the AC side, so if the AC side fails they don't produce any output. So no "backfeeding" issues.

    Also running two 2 panel & two 1 panel Hoymiles micro-inverters along with the Hoymiles DTU. Working fairly well (after I had to open a support ticket with Hoymiles to bump the firmware which they were able to do remotely) Other than that, I'd recommend.

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  • Registered Users Posts: 190 ✭✭oaklands

    What was the issue you needed to resolve with the HM firmware?

    Also, what version is your latest firmware?

    Unfortunately, AFAIK the original DTU is required to update the firmware????

  • Registered Users Posts: 2,474 ✭✭✭bullit_dodger

    I was able to get the DTU on my Wifi easy enough, but while it could "see" the Microinverters it just _would not_ attach the devices to the account. I should say that I'm a software engineer, so while "user error" it's always possible, it's unlikely. Anyway, opened a ticket and since it was on the Wifi, the lad updated the firmware remotely and that solved that. It was a case that the firmware on the inverters were higher than the DTU firmware.

    The microcode package (hidden very well on their website) couldn't be downloaded. It would seem that while they do make it "available".....they do a good job in hiding it :-)

    No idea of the firmware version now. it's not visible in the front end app. So I'd ahve to attach to the http gateway, and then look up the password etc. Been in and working very solid for the last year, but a bit of a faff on to be fair to get initially setup

  • Registered Users Posts: 6,824 ✭✭✭10-10-20

    I'm evaluating a small solar setup on a shed using microinverters. Can't go down the string inverter route as I can only fit two panels.

    Who's still supplying to the DIY trade in Ireland currently, I think Solartricity went full-wholesale only recently?

  • Registered Users Posts: 65,058 ✭✭✭✭unkel

    Rexel / Kelliher's and

    Or you could pick up a few second hand panels from the likes of DoneDeal or adverts. And get a microinverter from AlieExpress (if there isn't one to be found locally)

  • Registered Users Posts: 6,824 ✭✭✭10-10-20

    Thanks! Yes, Hoymiles are out-of-stock locally it seems.

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  • Registered Users Posts: 2,474 ✭✭✭bullit_dodger

    Have been very limited stock there on midsummer, I got 2x of them June last and then had to get 2x two panel via ...

    Search results for "hoymiles" (

    Belgium website, but were fairly quick and responsive. Also have Enphase. I've been happy with the Hoymiles, but apparently Enphase has the slight (slight) advantage in software monitoring. I can't quantitively confirm that as I only have seen Hoymiles (which has been ok)

  • Registered Users Posts: 6,824 ✭✭✭10-10-20

  • Registered Users Posts: 190 ✭✭oaklands

    FYI: pricing seems to be a lot better on ebay (from Gemany) including VAT & shipping.

    Whichever one you chose, check out several YT reviews first.