Solar planning service with shading info?

[badutahboy]

Hi all,

I'm working on designing my DIY install solar setup. I have all my numbers and know what I'm working with, and have figured out my ideal panel placement, etc. However, I have some big trees to the south of my house which are going to impact the system (definitely in the winter months, minimally if at all in the summer months).

I'm curious if anyone knows of a service I could hire freelance to do a system design in Aurora or other similar software which would include a shading analysis. Alternatively, is buying a solar pathfinder a better option?

I'm leaning toward a computerized design, simply because I don't have a south facing roof. The west slope of my roof is far more usable and less impacted by the trees, but it's azimuth is about 285 degrees, so it's slightly north facing. East will give me better production by about 10%, theoretically speaking. However, as I mentioned, the shading issues are probably a bit harder, and I also have most of my vent lines on the east side, so layout may be more complicated.

I'm hoping a computerized design would handle the math to determine if the real world performance would match that scenario, and make it worth the additional hurdles in order to save upfront cost.

Any help for me?

Thanks in advance.

[J.P.M.]

What software are you using for output estimates ?

[badutahboy]

Pvwatts calculator. Adjusting just for azimuth only: east (105 degrees) vs west (285 degrees). It consistently showed the east (slightly south) facing system producing 10% better than West.

[J.P.M.]

Pvwatts calculator. Adjusting just for azimuth east (105

If you're technically inclined try SAM == PVWatts on steroids. has some shading capability. Rent a solar pathfinder for backup/confirmation.

[badutahboy]

If you're technically inclined try SAM == PVWatts on steroids. has some shading capability. Rent a solar pathfinder for backup/confirmation.

What is SAM?

Edit: I'm assuming you mean this: https://sam.nrel.gov/download , right? I'll play with it a bit tomorrow and see what I can figure out with it.

Also, see my edited previous post for it to make sense. For some reason, on mobile it kept cutting it off.

[J.P.M.]

What is SAM?

Edit: I'm assuming you mean this: https://sam.nrel.gov/download , right? I'll play with it a bit tomorrow and see what I can figure out with it.

Also, see my edited previous post for it to make sense. For some reason, on mobile it kept cutting it off.

SAM is indeed from NREL. It's about the best for the money at this time. It seems to give pretty reasonable comparisons with other stuff like TRNSYS, but needs more input than PVWatts. If you're familiar with solar design, it's a reasonably quick learn - 10 - 20 hrs. est. if you're familiar w/ solar modeling ins/outs. If you're not, don't bother until you're up to speed. What you don't know can hurt you.

[badutahboy]

SAM is indeed from NREL. It's about the best for the money at this time. It seems to give pretty reasonable comparisons with other stuff like TRNSYS, but needs more input than PVWatts. If you're familiar with solar design, it's a reasonably quick learn - 10 - 20 hrs. est. if you're familiar w/ solar modeling ins/outs. If you're not, don't bother until you're up to speed. What you don't know can hurt you.

Got it. I played with it a bit last night and this morning, and I think it's way over my head. I think I could do better with a solar pathfinder, but I'd have to manually calculate just how much of a hit I'd take from shading. Most of the installers I talked to swear by Aurora and their LIDAR shading mapping, so I'm really hoping I can find someone who has that capability who could set up a scenario in Aurora for me.

I talked to the owners of bright harvest solar, but they wouldn't give me info on how they get their info to calculate shading, and then told me they don't have good info for my area. So far, that's the only online service I've found that offers a similar solution.

If I can't find someone who can help me out, I'll probably buy/rent a solar pathfinder, and will likely go with my current west-facing plan. The east side has the potenial for better production, but I suspect that a good portion of the gains PVwatts showed would be lost to shading issues year round. It could still be a higher producing system, but if the gains are under 5%, the added hassles of keeping a fast growing tree cut back and installing around vents, etc just isn't worth it.

Simple observation has shown me that I will likely have next to no shading issues on the west facing install from Feb-Oct, but will get very little production through the winter months. I'm not sure that's entirely bad, since those are the worst production months anyway, and I live in an area that gets snow. If I can't count on production due to trees, that ultimately means I don't need to worry about figuring out how to clear snow from my panels to get them producing again sooner.

[adoublee]

Trying to set up a solar pathfinder on a roof kind of sucks. If your renting, rent a SunEye.

[bcroe]

Trying to set up a solar pathfinder on a roof kind of sucks. If your renting, rent a SunEye.

That makes advantage #30 of a ground mount. Bruce Roe