Hoymiles Microinverters

Speedster

Speedster

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I figure these guys deserve a thread of their own as currently the discussion about them is scattered across the various battery / inverter / generator threads.

I'm strongly considering pulling the trigger on some of these and wanted to hear the thoughts of those who have gone this route. My plan is to hook up 3 x MI-1200 (only because I can't find any MI-1500 locally) with 3 x 400W panels to each. If you have Hoymiles, would you recommend this route and, if so, whay would you change.

And, just for clarity, I know this will be grid-tied with no backup when the grid goes down and only provide power when the sun is shining.

@thehuman @vassen I'm taking the liberty of tagging you guys as I know you have some MI's in operattion.
 
Here are the datasheets for the MI-600 and MI-1200 units. These are currently the only two models available in SA.

Both have max of 60V per panel at 11.5A, with the MI-600 allowing up to 2 panels and the MI-1200 up to 4.
 

Attachments

I can give you a half-assed answer.

I bought them with the view to feed them into the generator input of the inverter to take over once my battery gets below a certain level. This was going to be as a backup backup since I was going to put panels on both MPPT controllers of the inverter

I since did a complete 180 and ditched the idea when I decided to get divorced since I have to sell the house. I have since sold everything.

I'm still going to do it when I get another house
 
The_Ogre said:
I can give you a half-assed answer.

I bought them with the view to feed them into the generator input of the inverter to take over once my battery gets below a certain level. This was going to be as a backup backup since I was going to put panels on both MPPT controllers of the inverter

I since did a complete 180 and ditched the idea when I decided to get divorced since I have to sell the house. I have since sold everything.

I'm still going to do it when I get another house
Click to expand...
Hey man. Sorry to hear that! Divorce has been a destroyer of many dreams. Hope you get back on your feet real quick - and then you'll get those Hoymiles pumping.
 
I vaguely remember looking into this a few years ago as a potential way of scaling out a solar system over time and back then I backed away from the idea purely because it would end up being stupidly complicated and expensive to go down this route.
 
ToxicBunny said:
I vaguely remember looking into this a few years ago as a potential way of scaling out a solar system over time and back then I backed away from the idea purely because it would end up being stupidly complicated and expensive to go down this route.
Click to expand...
Fair enough. Costs are obviously crucial. It does look like pricing may have shifted over the years. My initial calculation shows that this will be about on par with the sunsynk for 5kW
 
Speedster said:
Fair enough. Costs are obviously crucial. It does look like pricing may have shifted over the years. My initial calculation shows that this will be about on par with the sunsynk for 5kW
Click to expand...
I would be very surprised if costs hadn't shifted over the years :)

For me the bit that made it "unfeasible" was just the complication of the whole thing... at the time I was looking for something that I could expand over time and easily flip circuits onto whilst expanding the system bit by bit, and it just ended up being more effort than it was worth for the microinverter style.

Made way more sense then (and I would think even now) to get the right sized inverter and then expand from there with panels and batteries.
 
I am still a bit confused on how you get to blend Micro Inverter power with grid power, as almost all the material I find online looks something like this:
20190326144814_33501.jpg


The way I understand electricity is that it oscillates at 50hz and forms a sine wave similar to:

dc-vs-ac-alternating-current-sine-wave-waveform-5b74a6e146e0fb005063fb8e.png


If you have 2 or more sources that is out of sync on same line you will have interference patterns eg:

3HFnr.png


You need some sort of device/method that takes them and remove the interference pattern or you will have to physically switch between the 2 sources.

One way I see this done is to convert both to DC and then back to AC but that's just as good as installing another inverter in your house. ie: In my mind its not just as simple as joining the micro inverter to the grid power in the DB box.

Now if there is a simple "device" one install in the db that combines multiple AC input to a single output please enlighten me what + price.
 
AlphaJohn said:
I am still a bit confused on how you get to blend Micro Inverter power with grid power, as almost all the material I find online looks something like this:
20190326144814_33501.jpg


The way I understand electricity is that it oscillates at 50hz and forms a sine wave similar to:

dc-vs-ac-alternating-current-sine-wave-waveform-5b74a6e146e0fb005063fb8e.png


If you have 2 or more sources that is out of sync on same line you will have interference patterns eg:

3HFnr.png


You need some sort of device/method that takes them and remove the interference pattern or you will have to physically switch between the 2.

One way I see this done is to convert both to DC and then back to AC but that's just as good as installing another inverter in your house. ie: In my mind its not just as simple as joining the micro inverter to the grid power in the DB box.

Now if there is a simple "device" one install in the db that combines multiple AC input to a single output please enlighten me what + price.
Click to expand...
The microinverter will sync to the grid before it starts generating, just like any solar inverter.
 
AlphaJohn said:
How?

Cause Solar inverters get fed from AC so have a gauge what to sync to?
Click to expand...
Conceptually in exactly the same way as a steam power station. The only difference is that instead of a rotating mass with inertia, you have a PLL.

You are worrying about something you should not be worrying.
 
Thanks for this thread. I like the micro inverter setup but its always been quite pricey but will check these out.
The only thing I don't like is that you will need to put in a number of smaller DB's or have enough space for separate neutral bars and switch/breaker setups hence a more complicated/costly DB setup.

But it is a nice way to organically grow your solar setup.
 
ToxicBunny said:
I would be very surprised if costs hadn't shifted over the years :)

For me the bit that made it "unfeasible" was just the complication of the whole thing... at the time I was looking for something that I could expand over time and easily flip circuits onto whilst expanding the system bit by bit, and it just ended up being more effort than it was worth for the microinverter style.

Made way more sense then (and I would think even now) to get the right sized inverter and then expand from there with panels and batteries.
Click to expand...
Why do you say it's complicated? You simply connect the microinverters to your DB and that's it. The electronics will do the rest.

The only kak thing is it will shutdown when the power goes off for safety reasons. That's another reason I chose to sell mine. It is an excellent idea to save on electricity, but if you only use 5kWh per day then it's a bit of a waste - as was the case with me.
 
B-1 said:
Thanks for this thread. I like the micro inverter setup but its always been quite pricey but will check these out.
The only thing I don't like is that you will need to put in a number of smaller DB's or have enough space for separate neutral bars and switch/breaker setups hence a more complicated/costly DB setup.

But it is a nice way to organically grow your solar setup.
Click to expand...
I don't think that's necessary. You run a single connection to the dB and then the microinverters connect up in parallel via the supplied connectors.
 
The_Ogre said:
Why do you say it's complicated? You simply connect the microinverters to your DB and that's it. The electronics will do the rest.

The only kak thing is it will shutdown when the power goes off for safety reasons. That's another reason I chose to sell mine. It is an excellent idea to save on electricity, but if you only use 5kWh per day then it's a bit of a waste - as was the case with me.
Click to expand...

My end goal was to build a system that could eventually take the house "off-grid" and the micro inverters (at least at the time) made that a way more complicated thing to work towards
 
Speedster said:
I don't think that's necessary. You run a single connection to the dB and then the microinverters connect up in parallel via the supplied connectors.
Click to expand...

Had a quick look and these are not full micro inverters I was expecting and are just grid tied with no backup function. That said they open completely different options and look to be ideal for getting geysers off grid easily.
 
B-1 said:
Had a quick look and these are not full micro inverters I was expecting and are just grid tied with no backup function. That said they open completely different options and look to be ideal for getting geysers off grid easily.
Click to expand...
All micro-inverters are grid-tied inverters only.
 
How would one stop back feed into the grid if you have a meter that doesn't like it with these?
 
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