Do you have solar?
There will be fireworks!
Is there a signature??
Independence = Off-Grid?
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Did you start 4th of July festivities a day early? 
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One town near us did their fireworks last weekend and many are this weekend, so “Fourth of July” seems pretty flexible. Unfortunately, we’re way out in the country and only see subdued flashes on the clouds from here.
Actually, now I am curious if solar arrays can register (a bit) of generation from near-by fireworks (or lightning perhaps?). Anyone know the answer???
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I was really, really hoping that somehow your fireworks were registering as solar and you were seeing flashes of solar production in Sense.
But I agree with @andy. My curiosity is piqued…
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Calling @kevin1: We’re going to need a pretty scatter chart here for proof and astronomical object (moon?) comparisons. You don’t have plans for the 4th do you?
Careful people: Don’t want to be reading about freak ladder + sparkler accidents tomorrow. Stay safe!
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I have, out of curiosity, looked at our 8.3kw solar panel array using both Sense and the Enlighten monitoring, with a clear sky and full moon directly above. Both show zero watts. I’ve never checked during a really good thunderstorm, but I will the next time we have a doozy.
So, moon-power doesn’t do it…perhaps a really great fireworks display would, but not up here in the mountains of NH for sure.
Don’t hold your breath …
It’s not exactly an easy calculation to do precisely, there are things like the lunar spectral irradiance. Roughly speaking the relative power potential at the Earth’s surface of Solar vs Lunar light is about 1,000,000 to 1.
8.3kW/1,000,000 = nix + nada.
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I would imagine that there’s some production happening, but not enough to register within the bounds of the system. Maybe more sensitive measurement equipment could display the .03 or whatever watts produced. But I’m just guessing…this is a fun topic. Maybe I’ll take it to the expert minds on Reddit…
I’m with @RyanAtSense, it produces some, but not enough to register or not consistent enough to be worth it…
an example of this, I have a 2-story apartment complex just south of me… their building doesn’t shade my panels, but they have this parking lot light that is high on the building and that light hits my panels… as it happens, my Sense reports solar production: -4w on one leg and +7~+9w on the other leg… my sunpower monitor doesn’t register anything, but Sense and my smart meter (monitoring smart meter directly through EAGLE-200) both register a constant 5w power generation through the night…
is it worth anything? well, the motion security light on the garage is 10w when it comes on, so yea, its worth something… but not enough to write home about…
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I would bet that any non-zero solar production at night is a measurement error. Mine shows 1W generated all night. My inverter actually turns off at night, and I believe that includes a relay physically disconnecting it. It turns on once a sufficient voltage is reached (I think ~150-200V in my system), and off once it goes below the threshold voltage for several minutes continuously. That means that it actually is a power draw for about 10 minutes in the morning (10W to 0) and 30 minutes at night (0 to 20W).
Fireworks, the moon, and streetlights aren’t sufficiently bright to get enough voltage to turn the inverter back on, so they generate nothing. Potentially, you could measure some power directly off the panel with sensitive enough equipment, but it would never exceed the losses of an inverter.
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My Enphase micro-inverter system has a central controller that draws a bit of power while monitoring the system and reporting it to Enphase and our installer. Even during the night that draws 1-2 watt.
Definitely nothing generated by moonlight, and we haven’t had a chance to check lightning…or fireworks. Peak daytime power on our system is 8,350 watts, which only happens for a few hours during mid day.
Classic bell curve on perfectly clear days otherwise, which forms a nice picture on Sense (and our welserver). Even high fluffy clouds generate all sorts of dips and valleys, which Sense solar monitors very very accurately. It’s always within less than 1% (usually a within 0.1-0.3%) of the power companies revenue grade metering, which is excellent. Shows what one device on one CT transformer set can do with excellent electronics backing it up.
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Indeed @kynan, I would bet you are right. Any given inverter should have a fairly straightforward correlation between “startup time” (threshold) and total bus capacitance.
@andy, this relates to thoughts I’ve been having during a conversation with @kevin1 about the rate of change of inverter anomalies (potential failures) vs panel & inverter degradation (slow) vs the speed of clouds==>maximum possible rate of change in solar waveform due to clouds/weather. This points to the disaggregation potential of the solar wave.
BTW - @ixu, I didn’t even try to do the analysis of the night of the 4th, despite your encouragement for 2 reasons.
- A rough back of envelope calculation showed that solar power generated by fireworks or even a full moon wouldn’t even register, given the precision of the Sense and SolarCity measurements. Plus the inverter has a fairly high threshold of voltage generation from the panels before it event starts to sync with the grid.
- There’s no line of site from fireworks to my panels !
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