Integrated Solar Info for Location

It would be interesting and helpful if there was an integrated app that provided daily information about the Sun based on your location; hours of sunlight, rise/set times, altitude and azimuth. There is already an app called SunCalc, maybe you could partner with them?


That would be great. Nest does something like that with AC usage spikes due to weather. Weather data might be good to add for this application as well to consider cloud cover as a cause for lower output.

Solar + Sun (location + let’s say “Space Weather”) is a fairly straightforward calculation that a clean panel or array will confirm minute-by-minute as you monitor the generation. Yes, SunCalc is handy but integration with Sun position and weather is not as easy as it may first seem.

The tricky thing comes with Solar + Sun + terrestrial weather … which tends to be hyper-local … and then things like tree and building shading. For the most part you can ignore planes and helicopters (!) but birds, bird poop, locusts, insects in general and dust (is that “weather”?) are real factors for many arrays. And then there’s rain and snow … the instantaneous weather may be fine but if your panels are covered in snow then …

All this by way of saying: Non-trivial exercise.

There have been a number of good (deep) threads on this

What would you want to come out of the solar information portion ? Sense essentially has enough geo information to run a PVWatt simulation to predict hourly and daily solar output from your location.

The challenge is as @ixu described - weather, aging/dust and shading will all cause the results to diverge from your real production. Even the NREL simulator itself applies “statistical weather” to the results so when aggregated over months or a year, the results are accurate, but not so much on an hourly or daily basis. And if you want to overlay simulated solar production vs. Sense, there are pretty straightforward ways to compare Sense export data against PVWatts already.

Again, the real question is what you would want to see come out ?

The semi-practical method to impose an optimized solar metric into your system (“to integrate the weather”) is:

Isolate a representative panel that you can get to and maintain easily (i.e. clean) and put a dedicated Sense on that one panel (tricky if you don’t have micro inverters per panel). Now that one panel becomes your reference and is essentially tracking the weather … through the limited eye of a PV panel at least.

Stick a PurpleAir or similar near the panel and throw in an anemometer for good measure.

Correlate the dedicated Sense with your hyper-local weather station and extrapolate to the array. Problems should pop right out. My guess is that’s what you really want?

Add a BloomSky for additional data and redundancy. And rainbow watching.

Of course, what you really may desire is forecasting for such wonders as preemptive load-shifting. The more data (dimensions) the better in that case. Like Sense’s disaggregation, it matters less that it works immediately and more that you can grab and archive data for future analysis.

I remind myself of @kevin1’s awesome TOU obsession, which led me to an unofficial challenge to port pricing to a spare Sense CT!. Weather is significantly more multi-dimensional so we’re gonna need a whole bunch of porting for that.

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