German magazine tests 10 solar panels

In September 2006, respected solar power magazine, Photon International, bolted 10 different solar panel manufacturers panels to a test rig in Germany and measured the performance of those panels over 12 months.

The panels they tested were:

  • Photwatt
  • Solarworld
  • Shell Solar
  • BP Solar
  • Solar Fabrik
  • Isofoton
  • Kyocera
  • Sunways
  • Sanyo
  • Sharp

The results of the testing were that the difference in power produced across all the solar panel brands was 9.85%.

The results are shown here:

Solar Panel test

From Photon International Magazine September 2007

As you can see Photwatt panels came top.

Interestingly the Sanyo panels which many vendors claim are the “best of the best”, came second last. Apparently Sanyo’s excuse was that the magazine were supplied with defective panels, oh and the dog ate their homework too I imagine.

The well known brand “Sharp” came a surprising last place.

Of course this test was 3 years ago. I imagine that the losers of this test have upped their game in recent years. The latest issue of the magazine has some more recent results in it as soon as it arrives in the mail from sunny Germany, I’ll let you know the latest winners.

Wouldn’t it be great to put the top 10 most popular Australia panels through a similar test (including the many ‘own-brand’ panels). Let me know if you think that is a good idea in the comments. If I get enough interest I may organise such a test myself. Watch this space…

About Finn Peacock

I'm a Chartered Electrical Engineer, Solar and Energy Efficiency nut, dad, and founder of My last "real job" was working for the CSIRO in their renewable energy division.


  1. The Desert Knowledge Centre in Alice Springs, has a both real-time and historical comparison of a wide range of panels.

    It is possibly a better indication of how panels perform in higher temperature conditions than those in Germany.

    There is a graphical interface where it is easy to compare the overall performance and match it up with local sunlight, temperature, wind and other recorded values.

    When looking at the Normalised Data graphs kWh/kW installed, the Sanyo HIT panels are generally the best performing.

    An interesting contrast with the German data, which as you mention, is some years out of date.

  2. Nevile Taylor says

    Hi Finn. I have signed up to have an 8 WINAICO Panel with a Growatt Sungold 2000 inverter giving a 2 Kw system installed. Reading the reports of all makes of panels and inverters makes one wonder why the results vary so much between different agencies leaving a person wondering if his selection will produce good results. Every manufacturer reckons their eqipment is the best but tests show otherwise. I hope I have made the right decission

  3. I would love to learn more about solar. What’s best to read, and can one buy individual cells and do something creative. Thankyou.

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