February 5, 2020

Adjusting Our Solar Panels

My "Solar Power Day" blog post was lengthy long enough as it was. However, there was one more thing I wanted to show you—one last thing we did when we finally got our system up and running—how we adjust the angle of our solar panels to take advantage of the seasonal position of the sun.

Photo from "The Solar Panels Are Up."

Originally, we talked about putting our solar panels on the roof. Now I'm glad we didn't. Rooftop panels are fixed, but by putting the panels on a rack on the ground, they can be made adjustable. High-tech tracking systems are available, or adjustments can be made manually, like ours.

You may recall that Dan made the rack for our solar panel array.


He spent a lot of time thinking how to make it adjustable. Here's what he did.

The panel frame is attached to the stand with hinges at the top.

The bottom is supported by slotted strut channels
and a steel dowel pin pounded into the frame.

These are also hinged at the frame.

How do we know what angle to adjust the panel array to? With a nifty idea we got from Prepper's Total Grid Failure Handbook; simply glue a nail to one of the solar panels. In our case, we glued it to the 50-watt panel we use for our portable battery recharging station. We didn't glue it to an array panel because we didn't want it sticking out where it might accidentally scratch someone.

On a sunny day at noon, tilt the panel until the nail's shadow disappears.

I tilted the panel just enough so that you can see the shadow. The panel is
turned until the shadow disappears, then the array is adjusted to that angle.

The array angle is changed by simply moving the channel struts to another slot.

Done.

Angel adjusted for late January.

That's my kind of technology.

Adjusting Our Solar Panels © February 2020

25 comments:

Boud said...

This is the kind of simple looking idea that when someone else thinks of it, you go, well yes of course. But you didn't think of it! It's great. I hadn't realized that you needed to tilt the panels seasonally.

Leigh said...

Boud, thanks! Not everyone worries about it. Most panels are on roofs, so the roof angle is it. Considering that the sun's angle changes about 47° between summer and winter solstices, there's a lot of potential energy lost. It only makes sense to capture as much as we can!

Sandi said...

Wow!

Ed said...

While you are at it, you should add some roman numerals in a circle around the nail, say I to XII.

Do you have a device where you can see how much current is being generated as you adjust the panels? I would suppose that is how automatic systems work by tying into that. I ask because I would be curious at how the current varies by angle of the sun to the panels.

Mama Pea said...

What a smart, great idea for adjustment! This is the first I've heard of ground mounted panels being adjustable, but, of course, it makes a lot of sense. Can't tell you how many times (a million?) we've wished we had gone with a ground mounted array rather than ours on the tall pole. Hindsight, eh?

Cockeyed Jo said...

I'm definitely stealing this idea from y'all for our system. LL

Sam I Am...... said...

That Dan is so talented! If either of my husbands had been 1/2 as talented and hardworking as Dan...I might still be married! LOL!
I love the nail/shadow technique! Brilliant!

Leigh said...

Sandi, it is to me! ;)

Ed, that's a good idea! What I thought this morning, is that I should mark the holes in the struts by month, so that next year we can adjust by the marks.

You could see the difference in angle adjustment from the charge controller. It should real-time input and output. We didn't think to check that out though.

And here's a video for a DIY solar tracking system that looks very doable - https://youtu.be/offXMebQTIc. He claims he gets the same power with tracking as stationary panels twice the size. Cheap too.

Mama Pea, I wonder why they came up with pole mounting for panels. To emulate roof-mounted? To get them above shade from bushes or ground objects? Dan nixed poles because our wind gets so strong he was afraid they'd blow off and away! I am glad we went with ground mounted rather than putting them on the roof.

Jo, be my guest!

Sam, Dan sometimes doubts he can figure something out, but he always does in the end. :)

Mama Pea said...

Leigh, we're in the middle of a heavily forested area so the pole mounting was to get the panels up above the tree line for maximum sunlight. The other option would have been to clear cut the trees for more area than we wanted. But you're absolutely correct in that the high winds wreak havoc on those panels way up in the air. If we were to do it again, we'd find a way to go with ground mounted panels as you have. Hindsight? Experience is the best teacher? Yep.

Leigh said...

Mama Pea, trees are always a challenge when it comes to harvesting sunlight. Our panel location is good, but not perfect, so we sometimes discuss if we should cut down a few more trees to lengthen the sun hours. On the other hand, some of those trees shade the house, which means 10-15° cooler temps than if we got direct sun all day. That's a lot since we don't use air conditioning! It's a dilemma, but when we have choices to make, we just do the best that we can at the time. But we always learn a lot after the fact! Don't we?

Helen said...

Very clever and 'doable' ideas. High tech meets lo tech.

Hill Top Post said...

Our little town has rows and rows of solar panels which provides power for the town, plus more. I am sure they adjust automatically, but I kind of like the nail method.

Retired Knitter said...

Well done!!

Leigh said...

Helen, the lower the better! So much easier to keep up with. :)

Mary, that's fantastic! Some adjust, some don't. If it had been too complicated or too expensive, we probably wouldn't have done it.

RT, thanks!

Cathy Kennedy said...

Leigh,

Your Dan sounds really clever. This story reminds me of my late FIL. He was a great with his hands and honestly I believe he could build just about anything he wanted - very smart! It sounds like the adjustable rake for the solar panels are is going to work out well. Way to go!

Leigh said...

Cathy, people like that always amaze me. I tell Dan he should have gone into engineering, but he didn't enjoy college so he joined the military instead. Still, that's the kind of mind it takes to come up with things like this!

wyomingheart said...

Really awesome job, Dan! I have been reading my new copy of “ Prepper’s Total Grid Failure Handbook”, and haven’t got to the nail test yet. Very informative post today, which gives much thought to our future project. We are going to make the new barn on solar, and don’t have trees to factor into that equation. I really love the comment you made on marking the month positions. That, my friend, is brilliant! Gotta use that idea, depending on the placement of the 5 panels we have. Thanks, Leigh!

Leigh said...

Wyomingheart, isn't that a great book? It gave me the confidence to do what we've got now! It does take a lot of thought and planning though. You need a blog so we can see what you decide and how you do it!

Nancy @ Little Homestead In Boise said...

Cool!

Rain said...

That's SO smart about the nail! Your panels look great Leigh. I loved reading about this project!

Leigh said...

Nancy, we think so!!

Rain, thank you! We were fortunate to have good resources to help us out.

Florida Farm Girl said...

That's just plain brilliant. You and Dan figure out so many things. I am just amazed.

Powell River Books said...

Our panels are on the roof (and one is on the roof of our boat that is a floating shed). They face the right direction but can't be adjusted up and down. This time of year it doesn't make too much difference with very little sun and lots of clouds. - Margy

Chris said...

So the nail is positioned, just like a stationary sundial, reads the time of day. Oh, now that's clever! Once again, thanks for sharing all these nifty details.

Leigh said...

FFG, thanks! It helps to have good reference resources! It also helps to not have much money, lol. That's a sure kick-start for creative thinking. :)

Margy, considering your location, it makes sense to count on solar mostly at certain times of the year. All the adjusting in the world doesn't matter much if the panels aren't getting sun!

Chris, exactly. At noon, there's no shadow when the sun is directly overhead. I plan to number the slots in the struts according to the months, so we'll know where to move them in the future without the nail shadow.