Solar Panels and Inverters

July 12th 2016

Which solar panels perform best in Perth? We have been running a rooftop test for over two years now and the latest results have Q.Cells still out in front of ET by 0.5%.
Each panel in this comparison has a micro inverter connected to it so that we can remotely monitor individual panel power production.                                                                                  


            % Gain

12/2/2014 though to 12th July 2016

German engineering
Phone Home...brilliant
Originally German
World No.3
China's former No.1
Commercial favourite
Norway / Singaporean
Chinese No.5
Hanwha Home brand
Popular Chinese
+ 7.12%
GY Group
Excellent low cost panel
The Rest
11 other popular panels
-7% to + 2% (av 0%)

German engineered Q.Cells are quite simply the best and have been since day 1. They cost about $20 a panel more than ET, the next best Tier 1 panel. Schott, another German engineered panel are great but cost more than Q.Cells. Canadian (Chinese despite the name) have performed consistently well, Yingli and Suntech are a high risk proposition due to long standing financial problems. Not sure what's going on these days with REC panels. Jinko produce 7% less power on the roof than ET but cost about the same. SolarOne started strong on the test roof but have slipped back over the past year or two, and Renesola are only slightly better than the Tier 3 control panel GY.

Other notable panels, not on our test roof.
GCL arrived in Australia in 2016 and have started to buy market share with some heavy discounting. They also have the cheapest Lithium Ion battery system that works with Goodwe inverters.

LG panels are reportedly well made but relatively expensive as are Conergy and SolarWorld.

About this panel comparison here

For a more detailed review of all these panels click the blue link above

What is a Tier 1 solar panel?
Tier 1 solar panels are measured the same way as Blue Chip companies listed on the stock market. Well-known brands, profitable, able to withstand the ups and downs of the World economy. Bloomberg New Energy Finance provide a list of the solar manufacturers of Tier 1 panels. If a company is financially struggling, Bloomberg remove it from the list. It's a measure of financial strength more than being about the quality of products, although of course, the two are obviously closely linked. Click here for the most up to date Bloomberg Tier 1 panel list.


European made inverters, SMA, Fronius, Bosch and ABB are, despite the relatively higher price, still doing remarkably well against the huge Chinese brands. Coming in about 30% cheaper than the Europeans is the best of the Asian brands, Sungrow. For those who prefer micro inverters, SolarEdge are the best and then Enphase. If you want reliable WIFI to see your solar data online, then Fronius and Sungrow are best.

Most inverters come with a 5 year parts and labour warranty, with the option to purchase a further 5 years. Some brands give the extra 5 years away for free or at minimal extra cost. Inverter failure rates are typically in the 1 to 2% range for the first couple of years and then the chance of failure rises fairly steeply after that. Therefore, the longer your free warranty, the better.

Have you watched our two minute videos? (Click the blue links below)

1. How Solar Works
2. Choosing a Solar Panel

3. Solar Inverters

Inverter Technology
Whilst panels are so simple with no moving parts and almost never fail, inverters by contrast are expensive and work hard all day long and are packed with electronic components and software.

There are four different types of inverter technology.

1. String Inverters
2. Hybrid string inverters with battery storage
3. Micro Inverters
4. DC optimers and associated inverters

1. String Inverters

The solar panels are connected in series in a 'string' of up to 15 panels.

Inverters are either 'single tracking or dual tracking' . A dual tracking inverter is needed for installations where panels are facing in different directions (e.g. North and West) unless the number of panels on each orientation is identical (e.g. 10 panels North and 10 panels West is fine on a single tracker but 11 and 9 is not).

Most solar installations use string inverters. As they work in series, when any panel in the string is shaded then the voltage and therefore performance of the whole string is reduced until the shade has gone.

(see below for effect of shade)


2. Hybrid String Inverters with Battery Storage
You can't just connect batteries to a regular inverter. We have written a whole web page on this subject. Click here.

3. Micro Inverters connected to every solar panel

It costs about $100 extra per panel to have a micro inverter compared to most string inverters. The advantages of micros are fourfold compared to string inverters.
Each panel is a law unto itself so shading of one panel doesn't have any negative effect on an unshaded panel.

You can point the panels any which way you like too, North, West, East, it makes no difference.
The DC to AC conversion is done on the roof so the maximum voltage running through the solar conduit is 240V, not potentially 600V with a string inverter.
You don't need to find space for a large box to put on the wall.

Popular brands are Enphase (excellent for Perth heat), APS , Solarbridge and Aurora

We sell Enphase micros as well as the ET 250W with Solarbridge Pantheon II micro factory fitted.

Even better than a micro?...see next choice.

4 .DC Optimsers and associated inverter

Similar extra cost as micros, you get a 'micro' on each panel but you also get a central inverter that does the DC to AC conversion. Same advantages as micros for shade and roof orientations.

It's actually the safest (1 volt per panel open circuit), and most efficient solution with excellent WiFi  and smartphone reporting and a 25 year warranty. SolarEdge have this section of the market won hook line and sinker. Want the best of the best? This is it.

Download SolarEdge product overview
Download SolarEdge reporting software overview is the web site for Good Day Mate Pty Ltd trading as SOLAR4EVER Company registered in WA on 26th October 2008 (A.C.N.133884938)

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Telephone : (08) 6102 2527