Enphase microinverter

Microinverters: Are they right for your solar system?

by James Martin II on 18 April, 2017

in Installation advice,Solar System Products,Inverters,Microinverters & Power optimisers

As the name suggests, microinverters are small inverters for use in solar PV systems, usually installed at a ratio of one per solar panel. By contrast, most solar PV systems in Australia have a single, centralised inverter called a string inverter. What are the advantages of having a solar PV system that uses microinverters instead of a string inverter?

Advantages of microinverters over string inverters

The most important job of an inverter – micro or otherwise – is to convert DC electricity into appliance-friendly AC electricity. Considering only this functionality (and excluding the bells and whistles that can come with microinverters, depending on the manufacturer), there are a number of advantages: Read the full article →

James Martin II

James Martin II

Communications Manager at Solar Choice
James has been Solar Choice's primary writer & researcher since 2010. He lives in Newcastle in a house with a weird solar system.
James Martin II

{ 13 comments }

Garry 29 May, 2017 at 5:39 pm

Hi
How does the micro inverter arrangement deal with charging battery storage?
I take it that you have to install an ac-dc charger?

Regards
Garry

Solar Choice Staff 1 June, 2017 at 11:03 am

Hi Garry,

There are dedicated battery inverters (sometimes called ‘inverter-chargers’) that can be hooked up to a system to function independently of the solar panels. You will need some sort of communications between the two systems to make sure the batteries ‘know’ when to charge, but certainly not an insurmountable problem. (Read more: Retrofitting batteries to an existing solar system.)

Hope this helps!

Dick 28 May, 2017 at 8:36 pm

Trying to work out the best option for my situation ! Post Code 3500
Have normal house requirements including a 6Kw Heat bank and want to optimise generation hours in June, figure if I can do this the rest of the year will be a breeze. To do this I have been quoted on 6 east facing panels, 6 west facing Panels 18 North facing panels. This is slightly bigger than your Table above, comparing Micro invertor & String invertor in Brisbane. Am I correct to think Micro Invertors would be cheaper in my situation as I would need 3 string invertors !!! because of thee orientation of panels, East, West, & North. Am I dreaming ?

Solar Choice Staff 1 June, 2017 at 11:08 am

Hi Dick,

2 different panel array orientations is not a huge problem for a single inverter with two separate MPPT inputs, and 3 may even be possible in the right circumstances. Alternatively, you might even be able to get 1 central inverter with inputs from 2 arrays, and then a 3rd panel array on microinverters or a separate central inverter.

Microinverters will not necessarily be our cheapest option – while they’re indeed better with partial shading and multiple roof orientations, string inverters are generally more affordable.

Hope this helps!

lornai 11 May, 2017 at 11:30 pm

Hi, we have Sanyo Hit solar panels and sunny boy inverter (string), we are thinking of adding more panels, LG and microinverters, will the two systems work together? What is the best thing to do? Please advise.

Solar Choice Staff 15 May, 2017 at 10:05 am

Hi Lornai,

One of the easiest ways to add more panels to an existing system is to simply add more panels with microinverters. Since microinverters function independently of one another, their output and performance won’t have an impact on other panels/inverters on the house (provided of course that they’re not installed in such a way that they’re shading one another). The main downside is that if you currently use some kind of app-based monitoring system for your panels, you’d probably now need to to monitor overall system performance (one for each inverter brand).

Hope this helps! If you need quotes for a system that is at least 1.5kW in capacity, feel free to fill out our Quote Comparison Request form.

Bob Hutton 5 May, 2016 at 12:32 pm

Hi again,
Further to my previous posts, we still haven’t had our faulty panels replaced by Canadian Solar yet. We’ve exchanged over 100 emails trying to get them replaced and they finally sent out replacement panels with the wrong connectors on them and have told Green Valley Solar who are looking after my system to cut and rejoin the cables.

What do you think of that?

Solar Choice Staff 31 May, 2016 at 3:46 pm

Hi Bob,

That’s definitely a bad situation and sorry to hear you’ve had so many issues. Hoping that the system is up and running as you would ordinarily expect it to be at this point.

Valerie 25 April, 2016 at 5:15 pm

Ive been researching for our home and have come to conclusion need multiple inverters due to living close to ocean birds poo salt in air etc plus next door Greenie’s trees huge and need facing west front plus can use east back house for panels – north his trees and ocean. Had quotes but all for 3kw string – taken for granted . Phoned one in Devonport Tas along the coast form us, he said not got batteries yet but do multiple and can fit battery later when avail. Cost around $15K. Most in line round up to $5K. But we are home all day, and use off peak storage too so want storage or ability to use night cheaper power as we already pay 75% higher tariffs due to RET and only going to get worse we will pay for use of diesel due to Labor flogging off our power 2010-12 and no reserves and drought. So can only go up. So also need to know re batteries where kept and if safe some aren’t I think from forum remarks.
Anything you can tell me gratefully rec’d included how long to install and where. Just had meter box updated but would like what Bob above said ability to see if one panel failed. My last bill is for all up 1040 Kw units. Thats power and off peak combined. Dont have hot water. Use more in next 2 quarters with 2 off-peak storage heaters on. So need to be able to use these these heaters fm April to December some years.

Solar Choice Staff 31 May, 2016 at 3:51 pm

Hi Valerie,

Please give us a call if you’d like to discuss your options – 1300 78 72 73. We have lots of installers in our network who offer microinverter options.

That being said, if there are tall trees to the north of your house, it probably won’t matter if you point your panels east or west – they’re likely to still end up with some shade on them if the trees are tall enough. And yes, battery storage is still expensive – keep an eye out for costs to come doing in next year or two.

Best of luck with your system (if you get one)!

Bob Hutton 20 April, 2016 at 9:24 pm

Hi,

I have Enphase micro inverters and so far am very happy with them. The software that comes with them is brilliant, enabling you to track all that is happening with the system. So far they’ve enabled me to pinpoint 2 failed Canadian panels over the last 2 months and prove that the panels were at fault and not the inverters. My sytem was less than 12 months old at the time of these failures. The Enphase system enables you to track the performance of each panel over its lifetime. How do people with string inverters ascertain they have faulty panels and if so, which ones?

Solar Choice Staff 21 April, 2016 at 10:21 am

Hi Bob,

Glad to hear you’re happy with your system.

For systems with string inverters, there is no way to directly identify if/where there is a problem with a solar panel (unless it’s something visually obvious like a cracked or broken panel). Instead, they’d see a drop in output from their system, and it would be up to someone with technical expertise to ascertain which one (or ones) is faulty. Clearly, the ability to monitor the performance of individual panels is one of the advantages of having a microinverter system!

I should also note that Tigo and other optimisers also allow system owners to ‘see’ which panels are underperforming, as well as help to mitigate the severity of the drop in output due to the failure of a single panel.

Bob Hutton 21 April, 2016 at 3:52 pm

Thank you. That means there are probably a significant number of homes which have faulty panel/s and if they’re seeing lower output would just think it’s been extra cloudy and never realise they have a problem. Not good.
The manufacturers must hate micro inverters.

Bob

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