{"id":37681,"date":"2020-03-05T11:12:17","date_gmt":"2020-03-05T00:42:17","guid":{"rendered":"https:\/\/www.solarquotes.com.au\/blog\/?p=37681"},"modified":"2024-01-25T09:01:03","modified_gmt":"2024-01-24T23:31:03","slug":"sma-shadefix","status":"publish","type":"post","link":"https:\/\/www.solarquotes.com.au\/blog\/sma-shadefix\/","title":{"rendered":"SMA Says Their Inverter’s ShadeFix Software Reduces Effects Of Shade"},"content":{"rendered":"
\"SMA

SMA’s ShadeFix doesn’t fix shade but reduces some of its secondary effects.<\/p><\/div>\n

A couple of weeks go a reader asked me to write about ShadeFix.\u00a0 ShadeFix is the software German manufacturer SMA include in their solar inverters.\u00a0 This request made me feel a bit stupid because I had no idea what ShadeFix was. After a quick search I’d opened a dozen dozen browser windows about and decided there was plenty of information and it would be easy to write a quick, descriptive article about it.<\/p>\n

I have come to rue this decision, as I neglected to check if there was any clear information on how well it performed.\u00a0 SMA gives the impression that it works very well without giving any information I could find clearly showing it does.<\/p>\n

I asked SMA for help and was told they are publishing a paper on it later this month.\u00a0 But that could be over 3 weeks away which is too late for me.\u00a0 All the information I’ve researched so far will have dribbled out of my ears by then.\u00a0 Because I’m in a race against the memory leakage, I’ll tell you what I’ve learned so far and if new information turns up I’ll either update this article or write a whole new one.<\/p>\n

ShadeFix Is SMA Inverter Software<\/h2>\n

ShadeFix is software inside all SMA inverters<\/a> that operates automatically when in use. \u00a0For the more technically minded, it is the algorithm that drives their Multi Power Point Tracker (MPPT). If you are interested in the details, Finn has previously written about how MPPTs work<\/a> and why we need them.<\/p>\n

If you have a mind as cunning as a fox, you’ve probably already guessed ShadeFix software is for fixing problems caused by shade. If you instead have a mind as cunning as a log, I’ll clue you in and tell you that it is for fixing problems caused by shade.<\/p>\n

While SMA says ShadeFix is good at its job, I haven’t found any independent evidence indicating it performs as well as their videos or the information on their site suggests.\u00a0 German engineering has a pretty good reputation, so its easy for me to believe their ShadeFix software can the reduce secondary losses caused by shade.\u00a0 But I’m 100% certain it doesn’t do anything for the direct losses caused by shade, because nothing does.<\/p>\n

Unfortunately, the SMA site doesn’t make this clear and anyone unfamiliar with how solar power systems work could easily come away with the impression they don’t need to worry about shade on their solar panels if they have an SMA solar inverter.<\/p>\n

This has caused my opinion of SMA to decline.\u00a0 This is a pity because, if you can’t trust Germans, who can you trust?\u00a0 The<\/a> Dutch<\/a>?<\/p>\n

Direct & Secondary Effects Of Shade<\/h2>\n

Shade on solar panels directly reduces power output because it directly reduces the amount of light falling on them — that’s what shade is.\u00a0 There are also secondary effects that can reduce output from unshaded solar cells in the shaded panel or from unshaded panels that are connected to the shaded panel.<\/p>\n

The five options for reducing the secondary effects of shade are generally:<\/p>\n

    \n
  1. Microinverters<\/a> (Little inverters on the back of each solar panel that let them operate independently.)<\/li>\n
  2. Optimisers<\/a> (Little boxes of electronics on the back of solar panels that also let them operate independently.)<\/li>\n
  3. Maxim optimised<\/a> panels (Like having a built in optimizer but, hopefully, even better.)<\/li>\n
  4. Shade tolerant panels such as SunPower’s P-series<\/a>.<\/li>\n
  5. Clever MPPT software in the solar inverter such as SMA’s ShadeFix.<\/li>\n<\/ol>\n

    But these only reduce losses from the secondary, additional, effects of shade.<\/p>\n

    Five options for dealing with the direct effects of shade are:<\/p>\n

      \n
    1. Nothing<\/li>\n
    2. Nada<\/li>\n
    3. Zilch<\/li>\n
    4. Zip<\/li>\n
    5. Bugger all<\/li>\n<\/ol>\n

      There is nothing that can be done about the loss of electricity caused by less light falling on the solar panels.\u00a0 It doesn’t matter what fancy electronics are used, how advanced your software is, or if it was built by Montgomery Scott from the Starship Enterprise, you can’t change the laws of physics.<\/p>\n

      \"\"<\/p>\n

       <\/p>\n

      If shade reduces the amount of light falling on a solar panel by 50%, the reduction in its output will be at least 50%.\u00a0 All that can be done is get the losses as close to 50% as possible.<\/p>\n

      Because the makers of microinverters, optimisers, and solar inverter solutions like ShadeFix often don’t come clear about their products’ inability to do anything about direct losses from shade, many homeowners mistakenly think these products can solve their shade problems.\u00a0 But shade is solar panel kryptonite and there is nothing that stops it reducing solar energy output, apart from getting rid of the actual source of shade.\u00a0 As this may involve knocking down your neighbour’s home, cutting down local trees, or blowing the top off a mountain; it’s often frowned upon.<\/p>\n

      \"\"

      Kryptonite is the weakness of both Superman and Mulletman.<\/p><\/div>\n

      ShadeFix Is Not New<\/h2>\n

      ShadeFix is not a new development.\u00a0 It’s been in SMA’s MPPTs since 2009.\u00a0 SMA just called it a different name — OptiTrac Global Peak Shade Mitigation.\u00a0 They recently changed it to ShadeFix, possibly because it’s less of a mouthful, or possibly because a dude with a ponytail in the Marketing Department though it was a good name.\u00a0 Their site says they have…<\/p>\n

      “…decided to reposition the feature in the market and give it the attention it deserves.”<\/p><\/blockquote>\n

      So that might explain the name change.<\/p>\n

      How ShadeFix Works<\/h2>\n

      SMA has a ShadeFix video<\/a> that gives an explanation of how it works using gates and toy cars<\/a>, but I don’t understand it at all.\u00a0 How does an inverter put gates inside a solar panel?\u00a0 Does it do it with a little robot arm?\u00a0 I simply don’t see how it can electronically affect what’s going on inside an individual shaded panel on a string.<\/p>\n

      \"SMA

      And who is driving the little cars? (Screenshots from SMA video)<\/p><\/div>\n

      Because the ShadeFix video is pretty useless and there isn’t much information on the main SMA site, I had to go looking for more information.\u00a0 Fortunately, I found this SMA document<\/a> that gives an explanation of how OptiTrac\/ShadeFix works.\u00a0 It has the following diagram showing 2 curves for a solar array:<\/p>\n