Microinverters + snow = pretty good

roof-snowSo we had a nice snowpocalypse this weekend – about 17″ of snow in 24 hours.  It covered up the solar panels pretty well, but thanks to a long pole and a squeegee, I knocked quite a lot off, as you can see above.*  How are we doing for power output now?

One thing about solar PV; shading kills output, but as you can see I’ve still got decent performance:


Shading a whole row of cells on a panel pretty much kills all production for that panel.  And, in a traditional string of panels with a single inverter, the entire array of panels drops to the output of the lowest panel.  However, I have a setup with micro-inverters, with 1 inverter under each panel, so that they can operate independently.

This is a really good thing; rather than each panel being at about 1W, the clear ones are sailing along while the snow-covered ones are still limping.  It’s a sunny day, so hopefully they’ll pick up a little heat and the snow will start sliding off.  It’s -3F (-20C) so  it’ll be an uphill battle to melt the snow!

You can keep an eye on how it’s going this week on the public monitoring site.

* I could only reach the lowest row with my 23′ pole, but the left array came tumbling down in an avalanche.  It was quite impressive!

4 thoughts on “Microinverters + snow = pretty good

  1. Great picture, and nice job on clearing the snow. Wish we had a microinverter system — of course, we haven’t had much snow yet. 10 of 14 days in December have had a high of 50 or above. Three days in the 60s..

  2. Nice! If it were a warmer, just a bit of sun hitting a panel would be need to quickly melt the snow enough to slide off.

    Have you check inverter temps to see how much warmer the inverters that are getting full sun are compared to the others?

  3. That sun-melting theory doesn’t work quite as well as you’d hope ;) Eventually yes, but this time we got ice on top of the snow. Sigh. Doesn’t the earth WANT my help?

    The clearer panels got to 12C vs 5C for the mostly-covered ones – some of that is sun heat, but I’m sure some of it is “we’re making juice so the inverter heats up” so it’s a little chicken-and-eggy.

  4. Pingback: Hanlon’s Razor and Online Comments | Eric's Blog

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.