{"id":40405,"date":"2020-06-22T13:01:04","date_gmt":"2020-06-22T02:31:04","guid":{"rendered":"https:\/\/www.solarquotes.com.au\/blog\/?p=40405"},"modified":"2020-06-22T13:44:39","modified_gmt":"2020-06-22T03:14:39","slug":"solar-panel-letid-update","status":"publish","type":"post","link":"https:\/\/www.solarquotes.com.au\/blog\/solar-panel-letid-update\/","title":{"rendered":"LeTID Update: Unlikely To Become The Problem Many Feared"},"content":{"rendered":"
\"Solar

LeTID: Limited in new PERC panels from reputable manufacturers and probably not a disaster for old ones.<\/p><\/div>\n

Fourteen months ago I wrote about a type of solar panel degradation called LeTID.\u00a0 This is short for Light and elevated Temperature Induced Deterioration.\u00a0 It’s also Norwegian for “laugh time” which is what I think they called the Joker movie over there.<\/p>\n

LeTID loss is experienced by PERC panels, which are now the most commonly produced kind on the planet.\u00a0 A lot of installed panels have the potential to suffer from it.<\/p>\n

While first discovered back in 2012, LeTID mostly took the solar industry by surprise and only became a well-known issue around two years ago.\u00a0 Manufacturers weren’t happy to discover PERC technology introduced to increase efficiency at low cost could end up costing CEOs their Lamborghinis — or Hyundais in the case of leaner operators.1<\/a><\/sup><\/p>\n

The LeTID problem was first really brought to Australian attention by Ben Neville of MC Electrical<\/a> in this article<\/a>.\u00a0 Five months later I wrote about it here<\/a> and concluded that — while it was a serious problem — we probably didn’t need to panic because major solar panel manufacturers were working hard to fix the problem.\u00a0 But I’m concerned corporate PR departments would say that even if it was a surging tsunami of disaster. So I’m revisiting the issue to see if — 14 months after my original article — I was right that there was no real need to panic. \u00a0Or if I should upgrade my recommendation to full-blown hysterical panicking<\/a>.<\/p>\n

In this article I will tell you:<\/p>\n

    \n
  1. \u00a0What LeTID is and how it differs from its degrading brother LID.<\/li>\n
  2. \u00a0The kind of panels that suffer it and why LG Neon and SunPower Maxeon panels don’t.<\/li>\n
  3. \u00a0How bad LeTID is and why it’s probably not a disaster if panels on your roof suffer from it.<\/li>\n
  4. \u00a0How to minimise your chances of getting solar panels that suffer LeTID or avoid it entirely.<\/li>\n<\/ol>\n

    By the time you’ve finished reading you should be able to decide for yourself whether PERC solar panels are the best thing since sliced bread or the worst thing since bread that gets sliced after you’ve eaten it.<\/p>\n

    \"\"<\/p>\n

    LeTID Is Not LID<\/h2>\n

    One form of PV degradation known about for decades is Light-Induced Degradation or LID.\u00a0 This affects most panels, including all PERC ones, and causes around a 2%\u00a0 decline in output in the first couple of days of exposure to sunlight.\u00a0 It’s quite different from LeTID that takes years to reach its full extent and can result in much greater deterioration.\u00a0 A quick summary of the differences are:<\/p>\n

      \n
    • LID:<\/strong>\u00a0 Around 2% deterioration.\u00a0 Takes days to occur.\u00a0 Worse in monosilicon solar panels.<\/li>\n
    • LeTID:<\/strong>\u00a0 Can cause over 10% deterioration in severe cases.\u00a0 Takes years to reach full extent.\u00a0 Worse in polysilicon panels.<\/li>\n<\/ul>\n

      All panels that suffer from LID account for it in their performance warranties which generally allow a 2.5% deterioration in the first year.\u00a0 Because LeTID more or less took the PV industry by surprise, warranties contain no special provisions for it.<\/p>\n

      Percentage Deterioration — Not Percentage Points<\/h2>\n

      Just to be clear, if I say a solar panel degrades by 2% I mean it will produce 2% less energy.\u00a0 It doesn’t mean a 2 percentage point decrease in panel efficiency.\u00a0 A 20% efficient panel that degrades 2% will become a 19.6% efficient panel, not an 18% efficient one.<\/p>\n

      What Is LeTID?<\/h2>\n

      No one knows what LeTID is caused by.\u00a0 Not when you get down to the nitty-gritty level of atoms and molecules.2<\/a><\/sup>\u00a0 But researchers working it are pretty sure hydrogen is involved.\u00a0 This is a pity because other researchers are trying to put more hydrogen in solar cells to fix other problems.<\/p>\n

      While we don’t know all the chemical details of what’s going on inside solar cells, we don’t have to understand what’s going on to describe LeTID, as I am about to do.\u00a0 Here it goes… I’m getting ready to describe it…\u00a0 Any keystroke now…\u00a0 Here it comes…<\/p>\n

      Light and elevated Temperature Induced Deterioration is deterioration induced by light and elevated temperature<\/strong>.<\/p><\/blockquote>\n

      Gee… that turned out to be easier than I thought it would be.<\/p>\n

      If you want some details, if you want me to go into the nitty-gritty specifics of just what kind of light and what kind of temperatures are required, I can do that.<\/p>\n

      The type of light that is bright enough to cause LeTID is sunlight.\u00a0 While you could install panels in the shade, indoors, or upside down to prevent them from being exposed to sunlight, I can’t recommend this.\u00a0 You’ll lose far more output than you ever will from LeTID and exposure to sunlight is sort of the whole point of solar <\/em>panels.\u00a0 Sure, they still work when it’s cloudy, but they work a lot better when them blue skies are smiling down.<\/p>\n