What stands out at me from these results:

  1. Now, having visited Japan a couple of times, I’m impressed at Japanese mastery at whatever they set their mind to, whether it be knives, solar panels, or whisky J. But Japan’s solar market has been soaking up most of Japanese-made solar panels for quite a few years now, making it difficult to get your hands on Kyocera panels at a reasonable price.
  2. Phono Solar’s has excellent results for a panel that is very affordable – indeed it’s about half the price of Kyocera panels.
  3. The location of the manufacturer doesn’t necessarily indicate quality – Chinese manufacturers perform quite well in the list.

In DNV-GL’s words: “We find three key takeaways from the Scorecard’s test results.

  • Overall, many module vendors performed well across all tests. For example, 8 manufacturers degraded less than 3% after 4 times the IEC duration in Thermal Cycling (the IEC pass/fail criteria for 200 cycles is 5% degradation).
  • Two manufacturers performed in the top group on every test: Kyocera and Phono Solar.
  • Roughly 55 – 60% of top group modules were manufactured in China. This is roughly equivalent to the ratio of Chinese module participation in the full PV Module Reliability Scorecard. This demonstrates that manufacturing location is not a good proxy for reliability.”

Now, DNV-GL’s isn’t the only scorecard out there. BNEF’s tiering system is another product evaluation method that is often misunderstood to directly assess product quality. Indeed, BNEF’s Tier 1 List states explicitly “We strongly recommend that module purchasers and banks to do not use [BNEF’s Tier 1] list as a measure of quality, but instead consult a technical due diligence firm such as …. DNV-GL” (and others). BNEF is actually a quantitative measure of bankability, not quality. There are also ratings schemes that measure manufacturer’s environmental sustainability and financial viability, which can also be considerations for module purchasers. In Australia, we also have some local schemes operating:

  • The CEC (which manages the list of panels that meet the minimum standard) also publish which panels have met some additional independent quality measures. Look for “independent quality measures” in the list of approved solar modules.
  • The CEC has recently updated the terms and conditions of listing a solar panel, which place more stringent requirements upon panel manufacturers or importers, in particular to provide appropriate levels of customer support and meet warranty requirements. Look for “Meets new CEC T&Cs” in the list of approved solar modules
  • The CEC has also been testing independently-sourced products to ensure they meet the claims made on their international certificates, and de-listing products that produce less power than quoted, or use different materials to those originally specified.
  • There are some reference sites where in-field performance of a number of panel brands is tested and compared, in a single environment. The DKA solar centre is an example of this.
  • We also have the Positive Quality scheme (run by the Australian Solar Council), which unfortunately hasn’t reached critical mass with four manufacturers listed.

To summarise,

  1. It’s in the self-interest of a PV retailer to sell product that will perform well over a long life
  2. The only way we will know the actual performance of a solar panel over 25 years is by monitoring it for 25 years. But by that time the technology will have evolved and improved, and so the outcome will be meaningless.
  3. Highly-accelerated lifetime testing can identify which panels are more likely to survive the environmental extremes solar panels could be exposed to over their full life.
  4. BNEF’s bankability list is not a measure of panel quality.
  5. There is no universal test of panel quality, so it is up to solar retailers to do their due diligence, using tests such as DNV-GL’s.
  6. DNV-GL’s test rates Kyocera and Phono Solar panels as likely to perform best for many years of typical environmental exposure.