Huawei is the new kid on the block in the residential solar world despite being the largest inverter manufacturer in the world. Building a decades of experience in large scale commercial and utility solar they have stormed into the market with an efficient, lightweight inverter that appears to offer all the features the leading manufacturers offer and more.
Having seen many inverter manufacturers come and go over the years I was very sceptical at first but the more I’ve learnt about Huawei, it’s products and incredible R & D capabilities the more I’m starting to think maybe this inverter is the “real game changer”.
It almost seems Huawei were patiently waiting in the sidelines, observing the industry, identifying the best features and taking notes of common problems before developing the new SUN2000L series inverters. On paper it’s a very impressive piece of technology, an inverter which can function as a basic string inverter or together with optimisers for either partial and full optimisation. On top of that it’s a true ‘battery ready’ hybrid inverter, compact, efficient (98%), lightweight, weather rated (IP65) and has a flat 10 year warranty backed by established support centres.
Huawei, pronounced “hua way’ is a massive Chinese communications and technology company known largely for it’s mobile phones and recently became the world’s second largest mobile manufacturer behind Samsung. Having grown rapidly since 2013, Huawei now has over 180,000 employees in 170 countries with over $90 billion in revenue in 2017. However the most impressive figure is the research and development capability with close around 80,000 employed in R & D making Huawei the 6th largest investor globally behind Intel.
Of course in regards to Solar Huawei is relatively unknown outside of China as they have, until now focused on the local Chinese scale utility and commercial inverters market. Interestingly they only built string solar inverters not central inverters and believe string technology is superior which is becoming the industry trend.
Residential Inverter Series SUN2000L
The first residential hybrid inverters from Huawei, the compact SUN2000L series range from 2 to 5kW output and all feature ‘dual MPPT trackers’ with a wide operating voltage range from 120 to 600V (2kW). However with the LG battery connected the upper voltage must be reduced to 495V which limits string lengths to 11-12 panels. This is coincidentally the direct opposite problem facing the main competitor SolarEdge, where optimised systems have several issues with shorter strings below 6-7 panels. In comparison the SUN2000L inverters allow very short strings of 4 panels along with the flexibility to function with or without optimisers (more about optimisers below). Oversizing PV is also rated to a modest 1.33 inverter rating depending on panel configuration.
On top the respectable specs is the slick compact lightweight design with natural convention cooling via the large rear heat sink, meaning no cooling fans. The inverters are all weather rated (IP65) which is standard for string solar inverters but not as common for battery ready hybrid inverters. There is no display screen having only 3 LED indicators. Setup and configuration is via Wifi which is becoming more common as screens can fail over time leading to warranty issues.
The SUN2000L series also feature an integrated DC isolator although this is not currently certified to Australian standards (TBA). Of course the big ticket winners are the optimisation and plug and play battery capability… see below.
One big stand out feature of the SUN2000L range is the ability to function as a standard stand-alone string inverter, with partial optimisers or with full panel optimisation. This is something no other inverter manufacture has managed to deliver and since installers like more flexibility when installing systems this gives Huawei a big advantage. However additional optimisers will only function with the add-on unit called the ‘smart PV safety box’. The ‘safety box’ for short basically works as a hub which collects data from the optimisers and relays this onto the inverter via the comms connection. Hopefully Huawei can develop a small additional plastic enclosure to house the safety box and cover the multiple terminals and connections at the base of the inverter as well.
Optimisers also known MLPE (module level power optimisation) have been available for many years from other manufacturers like SolarEdge and Tigo energy, however the Huawei smart PV optimisers ability to be partially deployed on only panels which suffer shading is something that previously only Tigo optimisers offered.
Of course one of the big advantages of panel level optimisers is the individual panel level monitoring but this in not yet available. The individual panel level monitoring capability is coming and we were told it is close to being released.
Much like micro-inverters optimisers offer a wide range of benefits over string inverters. Listed below are some common problems optimisers can help overcome and improve system performance.
- Shading – Trees, buildings, poles, wires, antennas, or rooftop structures
- Panel mismatch – manufacturing tolerances
- Panel damage – micro cracking, hot spots or water ingress
- Temperature difference – thermal mismatch at different times of the day
- Soiling – Dust, snow, bird droppings or birds
- PID – Potential voltage and current leakage issues
Additional system design benefits of optimisers
- Multiple orientations one on string
- Different panels on one string – ideal for upgrading old systems
- Maximise roof space – shading in winter less of an issue
- Can install parallel strings of unequal lengths
- Monitoring at the individual panel, string and inverter level.
- Remote troubleshooting via the monitoring portal
At present there is only one optimiser on offer, the SUN2000P with max input power rating of 375W, max input current of 12A and a good voltage range of 10 – 80V. As previously mentioned this means very short strings of 4 panels can be used with full optimisation, something I’m interested in as it gives an impressive flexibility in designing systems with shading issues. Huawei have chosen to use ‘Powerline’ communications much like SolarEdge which transmit via the DC cables connected to the solar panels.
The Huawei SUN2000L inverters have a built in 'high voltage' DC coupling battery interface which is compatible with the popular LG chem RESUH batteries. The high voltage batteries from LG are a high performance cost effective battery solution and will soon have the capability to be expanded with multiple 9.2kWh units up to a total of 19.2kWh total storage capacity. The inverter is a true plug and play hybrid inverter with no additional combiner boxes required to function with the LG battery.
However there is no back-up power supply function available so like some hybrid inverters there battery power will be unable in the event of a blackout. Although not surprisingly we were told by Huawei that this is in development and an additional add-on back-up box will be available in 2019. More battery options are also in development and due to be released in 2019 including compatibility with the BYD high voltage modular battery system.
To use the battery function, like all hybrid inverters an additional ‘energy meter’ is required to monitor energy flow to and from the grid and household circuits. This will be available soon with CT clamp meters for both single and three phase systems. See energy meter spec's.
Quality and reliability is the most important criteria in the world of solar, especially now with many inverter companies either having recalls or multiple failures. We are yet to test the Huawei inverter in the harsh Australian summer/s but from the outset it seems Huawei have done some serious engineering to ensure this inverter will go the distance.
The build quality looks impressive with well built weather rated connectors but more importantly Huawei have done some extremely rigorous testing of their own at the Huawei global compliance and testing centre carrying out some of the most extreme tests I have ever heard of including hitting the inverter with lightening! Yes that’s correct, they attached the inverter to a steel pole and shot a rocket with a cable into a thunderstorm to induce a lightening strike… Impressive and in some ways just insane! Apparently it was still functional afterwards so they blew it up with an explosive test as well. Seriously, but it wasn’t clear if it was still functional.
The Huawei EMC lab and testing facility is recognised by several leading international testing verification organisations including TUV, UL and FCC. They perform many extreme durability tests including thermal cycling, extreme humidity, salt-mist corrosion and even submerge the inverters underwater.
Service and Warranty
Much like in North America and Europe Huawei have already established themselves in Australia with around 700 employees based in service, sales and distribution centres in most capital cities. Huawei are keen to engage with the solar community and have already setup a training centre in Sydney along with a research and development centre in Melbourne.
The new SUN2000L inverter series will come with a flat 10 year warranty which is becoming more of an industry standard as opposed to 5 years plus paying for an additional 5 years. This is backed by an claims response time which Huawei are reporting will be less than 3 working days. See the Huawei online service portal here.
Commercial String Inverters
Considering Huawei built their reputation on larger scale 3 phase string inverters it is not surprise that they offer a huge range of very efficient commercial and utility scale string inverters from 8kW to 90kW 3 phase. With 3 MPPT trackers on the smaller residential and up to 6 MPPT on the 50 to 90KW units they offer a high level of design flexibility.
Huawei have also developed some extremely sophisticated monitoring and tracking capabilities into the larger commercial inverters with powerline communication and smart I-V curve diagnosis. This is something that would normally require expensive equipment and testing so having this I-V power curve analysis built in is a huge plus.
Another extremely advanced feature is the integrated PID (potential induced degradation) recovery system which is claimed to reduce the PID effect by up to 75%. This is an impressive feature and something large scale installers will be more than happy to see with many having suffered PID issues in the past causing all sorts of problems.
Wrap up - Summary
Huawei have engineered an impressive residential inverter which on paper appears to be a dream come true for anyone wanting a flexible 'battery ready' grid-tie system. It also promises many benefits to installers in regards to monitoring and efficient remote system trouble shooting. Once panel level monitoring is available this will be a great option for grid tie installations but until the back-up capability is available I don’t believe it will become a popular hybrid option.
The SUN200L inverters still have to prove their performance in the harsh Australian conditions but with the long list of features, good local support, Wi-fi software and smart ‘load’ control capability also in the pipeline, Huawei look to give some of the well established inverter manufacturers like Fronius, SMA and SolarEdge a run for their money.