Is there some site where I can calculate estimated solar panel output if I give it panel efficiency, latitude, tilt angle and panel direction/azimuth? I'm just too lazy to do the trig and also allow for movement of sun through the year.

@w_pettersson Interesting, but I doubt it. If your location is up or near a mountain, say, and is frequently clouded over, additional information would be needed to make such an estimate. Or if your location is a desert within the tropics, it might be easier to estimate.

@withaveeay Sorry if it wasn't clear, I don't want a calculator/site that takes into account anything and everything. I want something specifically to account for those things I mentioned (and ignores anything else).

@w_pettersson Perhaps one option is to ask people in the area who already have solar? Maybe there's a business / community-good opportunity here - a web site on which people can upload their solar info.

@w_pettersson PVWatts is the gold standard for grid tie (so talks about everything in terms of AC kWh, etc.) but is still useful for DC systems since you can adjust losses and they show insolation.

@w_pettersson I've been using for a while now, while we wait for our solar install, to try to get an idea of what to expect. I use it with a plug-in to Hone Assistant but you can just feed their API with a one line request too.

@w_pettersson I can't say for sure how accurate the estimate is until our hardware gets installed but I've seen other home assistant solar users with pretty close forecast and generation graphs.

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