Renewable Journal

A month of solar electricity – Renewable Journal for 11/27/2014

My home’s SolarCity solar panels have been up and running for nearly a month now and while there haven’t been bumps along the way, there have been some interesting discoveries.

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On this Thanksgiving day, I’m thankful that the solar panels are up and running. In fact, they’ve been up and running since October 30, nearly a month at this point. While I’m still very satisfied with my solar lease, I’ve discovered a few things about the panels in that month.

The inverters (the electronics that convert the DC output of the panels to 240 V AC to connect to the house and the grid) have communication modules on them. Apparently the inverters need both AC power from the house and DC power from the panels before they’ll turn on and communicate with the SolarCity monitoring gateway. As an electrical engineer, I think this is bonkers. Sure, it saves a teeny tiny amount of energy, but it also make electrical engineers who know a thing or four about designing electronics go “WTF?” and waste time digging into the inverter user guides on the web to understand why the the inverters stopped communicating when the sun went down. And yes, I discovered this at the end of Day 1.

Speaking of crazy design decisions, the inverter manufacturer made another one (or were forced to by utilities and/or regulators who are being idiots) with respect to the communication status LED. On every piece of wireless internet equipment I’ve used in the last 15 years, solid green means that you’ve established connection (sometimes flashing as data is passed) while blinking green once per second means that communications is still being established. The inverter communication modules work the exact opposite. News flash, inverter folks – FIX THIS. If you’ve got a piece of wi-fi equipment that connects to an internet gateway for monitoring, it needs to conform to standard internet/wi-fi equipment interfaces. You wasted 15 minutes of my time, but multiply my time by the number of installs and we’re talking one hell of a lot of customers’ time wasted. I discovered this the morning of Day 2.

Have you ever had a woodpecker (a common flicker in my case) pecking a hole in the side of your attic? Did you know that the solar panels, rattling in high winds, sounds almost identical to a woodpecker attacking the side of the house? Now you do.

As expected, clouds affect solar panel production, but I was surprised to discover that even small amounts of snow affect the panels WAY more than clouds. I’ve even had days when the right kind of cloud cover seems to have increased production somewhat (I’ll have more to say about this another time), but not snow. Any snow thick enough to cover the panels entirely and the production plummets until the snow melts, blows, or slides off. I expected an effect, just not as big an effect as there is.

And speaking of snow sliding off, after the first major storm in Colorado a couple of weeks ago, I noticed a pile of dropped snow below the west roofline. Given the chunks of ice in it, It would have sucked to have been under it when it fell. Important safety tip for those of us with solar panels on high roofs over walkways – scan the roofline for teetering snow.

Finally, when I was winterizing the swamp cooler for the season, I walked around the roof looking at the panels for the first time. It was interesting to see them and how they’d been attached, but I made a small, unpleasant discovery too. There’s not enough room for me to safely put up my holiday lights on my upper roof. I usually sit hang the lights from sitting on the roof, but if I tried that this year I’d either break the solar panels that go up to within inches of the edge in some places, or I’d fall 25 feet onto concrete. Or both. I guess it’s time to reassess whether lights on that section of the roof is important enough to pay someone with a scissor lift (or more than just my one tall ladder) to come out and hang them for me.