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Huawei inverter testingIt’s time to do the Huawei Solar inverter review. This is a bit exciting! Inspired by the hype at trade shows, I went out and bought a Huawei inverter a few months ago and set it up at my warehouse to test.

This post will introduce this “new player” called Huawei. I’ll then explain what the Huawei inverter specification has promised and you’ll understand why I got excited – but Solaredge, Fronius, Tigo and many more manufacturers got nervous. We’ll then look to see if Huawei Solar has delivered on their many game-changing promises.


Who is Huawei anyway?

Huawei is based in Cantonese-speaking China, and in Cantonese, it is pronounced “Wah way”. However, when translating to English, the company chose to write it in pinyin with the Mandarin pronunciation “Hwa way”, so I think we should run with that.

Huawei is pronounced “Hwa way”

The name literally means “Chinese Achievement”. And achieve they have:

  •  In 2017, Huawei overtook Apple to become the second largest mobile phone manufacturer in the world. (The largest is Samsung.)
  • They boast a presence in more than 170 countries. There are only 195 countries in the world.
  • Huawei employs 180 000 people globally. Apple have 123 000 and Samsung have 275 000.
  • 80 000 of their employees work in Research and Development. They have 15 Research and Development institutes.
  • Huawei have 800 employees in Australia.
  • They supply the 4g network for Vodafone, Optus and TPG in Australia.

I could go on and on but… “whatever”. That’s in telecommunications and other industries. What do they know about solar? In 2015, 2016 and 2017, Huawei shipped more solar inverters worldwide than any other manufacturer. (Measured by total inverter output capacity). Drop the mic Huawei!


Huawei inverter shipments


I only heard the name “Huawei” for the first time last year, but last year they shipped the same capacity as SMA and ABB put together. That’s humungous!


The apparent game changer

The reason this new Huawei Solar SUN-20005KTL is creating so much hype is that at first glance at the Huawei inverter specification (see it here), it does everything we ever wanted an inverter to do.

  • It’s a “battery ready” inverter at an affordable price.
  • It can connect to the reputable LG Chem battery – like SolarEdge.
  • We can install it without optimisers for affordability as a standard string inverter – like Fronius.
  • We can selectively install optimisers on shaded panels only – like Tigo
  • Or, we can optimise all panels – like SolarEdge.
  • It’s got an inbuilt IV curve tester – like nothing before!

But before you rush out and buy on Huawei’s promise like I did, read on. For the last three months, I’ve had a Huawei Solar SUN-20005KTL inverter on my wall testing. This is my review.


The Huawei Solar inverter reviewed


Huawei optimiser

Inside a Huawei Solar optimiser

There are three things I like about the Huawei Solar optimiser solution. Its electrical simplicity, its selective deployment and its flexible string voltage.

Electrical simplicity

The job of an optimiser is to adjust the panel voltage depending on the sunshine and shading so that the current in each panel is equal. This allows us to achieve maximum power from the system. In the case of SolarEdge, the voltage continuously decreases and increases, or “boosts and bucks”. The Huawei Solar optimiser only bucks the voltage of poorer performing panels in order to increase to the current of the higher performing panels. The Huawei inverter then boosts the voltage as appropriate. In theory, this means simplicity and reliability on the roof.

Selective deployment

A term that I borrowed from Tigo, “selective deployment”, allows us to save on cost by only installing optimisers on the panels that are going to be affected by shade.  The optimisers cost around $80 each. So if you had ten panels that were not affected by shade, you could easily leave ten optimisers off and save $800.

Flexible string voltage

The Huawei Solar optimiser solution has another significant advantage over Solaredge. The SolarEdge HD wave inverter works on a fixed voltage of 380V. This means that the string of panels must add up to 380 volts in every situation, however, each optimiser has a boost voltage limit, which is usually 60 volts. In some situations, this means the SolarEdge optimiser is not capable of boosting high enough to compensate the current of the lower performing panels. This results in the lower performing panel actually dragging down the other panels in that string. The Huawei inverter, by contrast, has a variable input voltage and can work as low as 90 volts. In theory, this means the optimiser doesn’t have to work as much, and we avoid the losses that can happen with SolarEdge installations.

However, I didn’t test if this actually happens. I’m just assuming this is the case after reading the Huawei inverter specifications.


The Huawei inverter Safety Box

It’s not because I didn’t get around to testing it. It’s because I can’t monitor the panels individually. Ignore what the Huawei website says, The Huawei optimisers do not yet have panel level monitoring or safety shut down. Actually, they do, and a solar wholesaler has it testing on their system nearby my office. But it doesn’t work so they won’t release it. No kidding.

Let’s just rewind to the part about Huawei having 800 000 R&D employees and 15 R&D institutes. Then they released the optimisers to solar wholesalers who bothered to test it. I guess at least someone caught the problem at the eleventh hour.

The part in question is called the “safety box”, but I prefer to call it Henry after our Octopus friend from The Wiggles. It might be hard for you to picture what it looks like installed, but it’s about 150mm square with eight legs. Four connectors plug into the DC isolator and four that plug into the inverter. Once it is installed, it looks more like Henry break dancing below the elegantly designed Huawei inverter.

To recap, we have learned two things about the safety box. It doesn’t work, and it’s octopus ugly.


The Huawei Solar Battery Solution

One of the biggest attention grabbers about the Huawei inverter is that it is a hybrid inverter. This just effectively means that it has a battery charger inside the inverter. What is even more interesting is that they chose to couple with one of the most reputable batteries on the market – LG. However, there is another tiny weeny problem that the R&D team overlooked. It does not have Emergency Power Supply mode (EPS). Your lights will not stay on in a blackout.


“Whoop dee do dah!” say Huawei Solar.
“How often do most people lose power anyway?”

But that’s not the point – at least it’s not the point in Queensland. In Queensland, we need three reasons to justify to ourselves why we would waste ten grand of our hard earned money on a battery.

  1. Return on investment. Without mainstream “time of use” charges in QLDand with feed-in tariffs up to 16 cents, a $10000 battery will take you about ten years to pay off. So we need more reason.
  2. Blackout insurance. Imagine you lost power in the middle of Friday night footy. Let’s say that happened twice in the next ten years. Most blokes could justify a couple of grand a game to know they would still get to watch the footy while the neighbours brought around the beers.
  3. Bragging rights at the pub. You could probably justify another grand just there – until you tell them you didn’t get the Friday night football blackout insurance package.

Seriously, if a customer is going to make a discretionary spend of $10 000 on a battery in Qld, it’s not purely a financial decision. The battery needs to have the ability to run in a blackout.


IV Curve Diagnosis

Last year I went to a solar trade show in Munich. The real WOW factor for nerds visiting the Huawei Solar stand was that their upcoming 5kW inverter had an inbuilt IV Curve tester. An IV tester can accurately find a degradation fault within a panel. To put this in perspective, about five years ago I geeked and bought an IV Curve tester for fun. It cost me about $10 000, and it was a pain in the neck to set up and use.

Now the Huawei SUN-20005KTL can apparently generate an IV curve with just “one click”? Geek me out!  Sadly, I couldn’t find the button for this “one-click remote IV curve diagnosis”, so I emailed Huawei Solar tech support.

I finally was advised that the IV curve testing will only be available when (and if) the safety box is released.

I want my money back.


Huawei Inverter Monitoring Platform

Online monitoring is an important tool for fault finding and system maintenance. The Huawei inverter monitoring platform is not to bad for the customer, but for the installer who may want to fault find, it’s blatantly lacking historical data. Historical figures we often refer to are DC voltages, DC current per tracker, AC voltages at the inverter and the kWh meter. None of this is available with Huawei inverter.


The Huawei inverter specifications

What we want from a  hybrid inverter

CEC guidelines limit us to installing no more than 6.6kW of solar panels on a 5kW inverter for systems without batteries. However, when we install solar with batteries, we can install as many panels as the inverter manufacturer allows. In the case of the Solaredge, we can install 11.6kW of panels on a 5kW StorEdge inverter. This means that even when solar production is low, or household consumption is high, you are likely to fully charge your battery. It also means you can get bang for buck with the STC “rebate”.

What we get from the Huawei Hybrid

Let’s see how the Huawei inverter stacks up to SolarEdge. From the Huawei inverter specification:

  • The input current restriction on the Huawei 5kW inverter is 11 amps; so we can’t parallel into one input.
  • If a battery is installed, the maximum voltage is 500V. This means a maximum of 11 standard solar panels in a string.
  • The Huawei is a hybrid inverter. If you don’t get a battery now but you want your system to be “battery ready”, then we’ll have to string your panels to suit: in strings of 11.

So when we are installing a mid-range Korean made 300W Qcell panel on the Huawei hybrid inverter, and you want to max out your panels, you are limited to 2 strings of 11 panels, or 6.6kW. We cannot oversize the panels on the inverter like we would with SolarEdge or any half-decent hybrid inverter. Not only that, unless you pay extra for optimisers (with no monitoring or safety shutdown or IV curve testing) we are restricted to a solar panel design of:

  • 11 panels one direction, 11 in the other (6.6kW) or,
  • 22 panels in one direction.

You effectively can’t use Sunpower, the worlds best panel. If you buy a cheap 270W Chinese panel to go with your cheap Chinese Huawei hybrid inverter, It’s even worse. You are limited to 5.94kW.

The Huawei inverter build

If it is any consolation, the Huawei inverter is a smart looking unit. When you look under the hood, it appears solid – I would suggest it appears better built than the new SMA.

This statement from the user manual is just a tad concerning

Do not install the SUN2000L outdoors in salt areas. A salt area refers to the region within 500 meters from the coast or prone to sea breeze.

I guess the logic is: if you can afford to live on the beach, you can probably afford a Fronius anyway.

Sea breeze or not, the Huawei inverter specifications claims the inverter has “natural cooling”. I’ve shown in other blogs, that when SMA and ABB say “natural cooling” they are just kidding. The SMA and ABB have internal fans. But it was nice to see that when Huawei say “natural cooling” they mean “no fan”. An internal fan in an inverter is considered a weak spot – another moving part. But if you don’t install a fan, the concern is high temperatures will shorten the life of the capacitors.

Solaredge heat testingSo, how hot does the Huawei inverter get? I ran an internal temperature test and compared the Huawei inverter to the SolarEdge HD wave, both running with 2kW of panels. I’ve explained why the Solaredge inverter runs comparatively cool even without an internal fan (Check out my SolarEdge heat test). It turns out that internally, Huawei inverter runs even cooler. The reason for the low temperature is that casing is completely metal, which works as a heat sink.

This is why the Huawei inverter specification states:

“Burn Warning. Do not touch a running SUN2000L because the shell is hot when the SUN2000L is running”.

Don’t say you weren’t warned.

Huawei smoke test

Huawei Solar inverter thermal imageOut of curiosity, I ran 6.6kW of panels into the Huawei inverter and even paralleled a string just to see if I could make it smoke. I got it up to 55° internal. What is concerning is the inverter derates when it gets to 45°.

The hottest the case got to was 43.4°, which is just warm to touch. While it was winter, and the inverter is mounted indoors, the casing certainly wasn’t hotter than I would expect in that situation. If this inverter was mounted outside in summer and was charging and discharging a battery, you may want to heed their “burn warning”.


Huawei is an impressive company and has lived up to its name “Chinese Achievement” by not only gaining a huge share of the telecommunication industry but by dominating the solar inverter market internationally. However, when it comes to their new residential Hybrid inverter, the Huawei SUN-20005KTL is severely lacking.

Huawei’s strong point is the simplicity of the optimiser, however, until we see the safety box, panel level monitoring, safety shutdown, and IV curve testing is just a theory. When installed with a battery, the system won’t run in a blackout. If you even plan to install a battery in the future, your solar panel design options are stupidly limited unless you buy the optimisers with limited functions. The monitoring platform is lacking and the inverter parameters make it ridiculously inflexible, You can’t use it if you live near the beach, and you may need to make sure your kids don’t touch it when it’s running.

If you want to buy a Huawei inverter, I have one for sale a at a bargain price.

If you want a better option and you are in South East Queensland, contact us.

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6 Comments on "Huawei Inverter Review – the good, the bad, the ugly."

6 Comments on Huawei Inverter Review – the good, the bad, the ugly.

Mark C said : administrator Report 5 days ago

Hi Will, Thanks! The Sungrow Hybrid can also only take 1 string per MPPT, but the voltage input is 600v, so we can string 13 or 14 panels into one input (depending on the panel.) How do you work it out? I'm taking a long flight to Israel next week, and on the plane, I'll be writing a blog to answer that question :) My impression of the solax is that it is junk, but haven't looked at it for a long time. It's on the "to Blog" list.

Will said : Guest Report 6 days ago

Hi Mark, thanks for the very informative review. I also read/watched your review on Sungrow hybrid inverter SH5K+. I would like to know how many standard panels can you put on each string/MPPT on the Sungrow SH5KT or Fronius Primo 5kw (international version)? How do you work it out? Also can you parallel into one input (MPPT?) if using the Fronius or Sungrow? What do you think about the Solex x-hybrid gen3? Many thanks.

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Mark Cavanagh said : administrator Report 3 weeks ago

Hi Stephen. I wrote a blog a while ago now on Redback. I had a lot to do with it back then, working with them on battery warranties and giving feedback on their product etc. Redback was flawed from the beginning. In Phil Livingstone's own words, they "are a software company - not a hardware company". They are trying to create all these futuristic head in the sky type things, but they have missed the fundamentals of having an inverter that actually works.

Stephen said : Guest Report 3 weeks ago

Hi, What do you think of Redback smart hybrid inverter? Regards

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Mark Cavanagh said : administrator Report 3 weeks ago

Hi Terry, no, it is available now as their website says ..... .....(The image with the house says the safety box was available in q1 2018.) ..... ........ I've talked with 2 wholesalers who are selling them and have heard others in the industry who have installed them too.

Terry said : Guest Report 3 weeks ago

Hi Mark, Seeing as you've had this inverter for three months is it possible you were testing a very early release as I understand it's not being released until Q1 2019.

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Hi Mark, Seeing as you’ve had this inverter for three months is it possible you were testing a very early release as I understand it’s not being released until Q1 2019.


Hi, What do you think of Redback smart hybrid inverter? Regards


Hi Mark, thanks for the very informative review. I also read/watched your review on Sungrow hybrid inverter SH5K+. I would like to know how many standard panels can you put on each string/MPPT on the Sungrow SH5KT or Fronius Primo 5kw (international version)? How do you work it out? Also can you parallel into one input (MPPT?) if using the Fronius or Sungrow? What do you think about the Solex x-hybrid gen3? Many thanks.

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