GoodWe Inverters: An Insight

A deep dive into the Suzhou-Based inverter brand used widely by Australian Solar companies, including Sunflex.

Company History

Jiangsu GoodWe Power Supply Technology Co Ltd was founded in 2010 in Suzhou, China. In 2012, GoodWe established itself in the Australian market, setting up an office in Melbourne. GoodWe designs and manufactures inverters for the residential, commercial, and energy storage markets. GoodWe manufactures inverter sizes ranging from 0.7kW to 250kW of both single and three-phase types.

GoodWe quickly grew to be an internationally renowned inverter manufacturer, with more than 1200 employees situated in 15 different countries. By the end of 2019, GoodWe had distributed inverters to more than 100 countries totaling a global PV installation of 15GW.

GoodWe in 2019 was considered the largest storage hybrid inverter supplier, and a top 5 single-phase string inverter supplier worldwide by Global energy research consultancy group Wood Mackenzie. In 2020, EUPD Research awarded GoodWe the Top Brand PV seal in Australia for the second consecutive year. In February 2020, GoodWe became the world’s first non-European inverter manufacturer to obtain the prestigious VDE-AR-N 4110-2018 compliance certificate by TÜV Rheinland Industrie Service. Also in September 2020, GoodWe was listed on the Shanghai Stock Exchange. Following a scrutinous selection process, GoodWe has been awarded an exclusive licensing contract for global sales by General Electric (GE).

What are Solar Inverters?

A solar system’s inverter is the point at which the DC electricity produced by solar panels is turned into grid-compatible AC electricity. Typically there are 2 approaches to inverters – either string inverters or micro-inverters

String inverters (such as most of GoodWe’s product range) have traditionally been the standard in the solar industry. They send the power produced by solar panels to a central inverter that changes it from DC electricity to the usable AC electricity that powers homes. GoodWe also specializes in hybrid string inverters which provide the ability to charge a battery as well as use solar power immediately as its created.

Micro-inverters, generally a more expensive solution, provide a small inverter for each solar panel that is installed. This means that each panel operates individually which creates more visibility over performance and can offer some advantages in partly shaded conditions.

GoodWe Inverters: Points of Difference

Range of Hybrid Inverter Options

GoodWe has the largest range of storage inverters on the market including single-phase LV hybrid solutions (ES, EM), single-phase AC coupled retrofit solutions (SBP), single-phase HV hybrid (EH) and three-phase HV hybrids (ET). This makes GoodWe a good option if you are installing a battery that requires a hybrid inverter or if you plan to keep your options open to installing batteries in the future.

Multiple MPP Trackers

Maximum Power Point Trackers (MPPTs) dictate how many different roof orientations a string inverter can handle. If panels on the same MPPT are tilted differently they will only perform as well as the lower-performing panel which will impact output throughout the day. GoodWe’s inverters are often selected as they offer more MPPTs than their competitors across different inverter sizes. GoodWe’s MS series is the only 3 MPPT single-phase inverter in the Australian market. This means if, for example, you were hoping to install panels on the North, West and East sides of your house, your options would be to use a GoodWe MS or use a more expensive micro-inverter or power optimizer solution.

DC Oversizing

DC oversizing refers to installing more solar panel capacity than the output potential of the inverter. At face value, this seems like a design like this could be wasting some power, but after factoring in efficiency losses and acknowledging that solar panels will never output their nameplate watt rating, oversizing by 33% can be a cost-effective design and is permitted by the Clean Energy Council’s guidelines. Oversizing beyond 33% can be advantageous if you have a battery installed and can store surplus DC energy.

GoodWe Inverter Efficiency

An important aspect of getting the most value out of a solar inverter is choosing an appropriately sized inverter to optimize the solar panel system efficiency.

Residential inverter efficiency standards are generally 95 to 98 per cent, GoodWe inverters meet these standards. The least efficient GoodWe inverter is the NS Series 1kW which still records a 96.5% max efficiency. Asides from this one inverter all GoodWe inverters have at least 97% max efficiency.

Several GoodWe models have over a 98% max efficiency, one of these models is the SDT Series 10kW. This Three-Phase Dual-MPTT string inverter has a 98.3% max efficiency, making it one of the industry’s more efficient inverters.

GoodWe Inverter: An Insight into Warranties

In Australia, all CEC-approved GoodWe inverters come with a standard 5-year manufacturer’s warranty. For the DNS and MS series, Goodwe offers an additional 5 years where they will replace the ‘parts-only’. In years 5 to 10 the customers would receive the replacement parts for free, but would still be required to pay for delivery, all labor costs and any taxes/duties.

In 2019 Goodwe launched an online warranty extension service. Customers can conveniently extend their warranty periods up to 25 years depending on the model of the inverter, simply by entering the serial number via their online portal and following the prompts. This needs to be done within 6 months for inverters above 25kW in capacity and within 2 years if below 25kW in capacity.

The Limitations of GoodWe’s Inverters

GoodWe inverters won’t perform as well as micro-inverters or power optimizer solutions in partly shaded conditions. If there are trees above your roofline on the North, East or West side of your house then it would be worth discussing the pros and cons of alternatives with Solar Choice before deciding on technology.

Additionally, the 5 year full warranty offered by GoodWe is rapidly becoming one of the shortest inverter warranties offered in Australia with many of the growing Chinese companies offering a standard 10-year warranty. As we’ve discussed previously, a warranty is only worth something if the company providing it is still around and there is an accessible route to claiming it if your Solar Installer is no longer around – by all available measures GoodWe looks to be a good bet.

Is GoodWe the Right Option?

In some cases, GoodWe may be the only string inverter option that can be used for houses with multiple roof aspects. Technically speaking, GoodWe’s inverters are able to offer similar characteristics to some of the premium options in the market.

We consider GoodWe to be one of the Chinese inverter manufacturers with a better reputation with a good history in the Australian residential solar market. Their inverters are price more competitively that the European or micro-inverter options so can offer some savings for customers looking to maximize value under a particular budget.

By Hugh Speck for Sunflex Solar.