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I'm in my 5th year of my DIY, on grid, solar system and have decided this year I would try an figure out how to install a tilt system for my panels to increase productivity. I have a 3500w system and two months out of the year the system pays for itself, My panels are mounted on a 20 degree inclined canopy roof. I figured if I could install a manual tilt system, it would increase the output of my panels and depending on the tilt system I could have at least two times a year, maybe more depending on the system, where the system would product enough power to pay for all my power needs. Has anyone here ever built their own tilt system or is my only hope to buy a premade tilt system? Thanks for any help.
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My photovoltaic panels are hung on a freestanding array. They are hinged at the top. I have boards cut to different lengths, to act to prop each panel at a specific angle. I have three angles. One which I calculated for my Latitude to present the panels at 90-degrees from direct sunlight at Summer Solstice [which is very near horizontal]. I have one angle for both the Spring Equinox and the Autumn Equinox, and I have a third angle for the Winter Solstice [which is very near to being vertical].
As we pass through the Winter Solstice I want my panels to be at the perfect angle as the sun passes on that arc. So I have marked on my desk calendar the mid-point days between each of these solar events, that is when I walk out and re-adjust my panels.
It may gain me 5%.
4400w, Midnite Classic 150 charge-controller. -
I did. It allowed 3 fixed tilt adjustments, one @ latitude and the other 2 @ +/- 20 degrees for 4 tilt adjustments/yr. with the seasons. Worked great as long as I kept the snow off it and cleared the snow from behind it for the winter tilt, but it looked a bit funky.
It was built long ago in a land far away for a small (64 ft.^2) domestic water heating system in Buffalo, NY on a sunspace roof tilted at local latitude, but there's no reason it couldn't have been scaled up if roof space was adequate or ground mount possible.
I used galvanized chain link fence components after I quickly learned that wood is not a good material for solar framing/supports.
Just make sure you check the wind loading not only on the fixed anchorage points but on any hinges or moveable joints.
Also make sure the panels will not move due to snow or other external static loading(s).
Allow for movement of wiring and check local codes for such things as well as exposure when the array orientation is changed.
Have you checked out the possible increases in production from different panel orientations ? If you're at latitude tilt now, if you're located at a relatively low latitude you may not see a large annual production increase by changing orientations.Comment
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It will certainly be easier to build an adaptable array, with a ground mount.
Here is one you get when an electrical type tries to design something
mechanical. Tilt range is 90 degrees, of 6061 aluminum and 18-8 stainless bolts.
This 24 panel 6KW array has been up with no damage for 5 years,
including the just past storms that took down one tree and countless
branches on my property. One ice storm, one wind storm. The invisible
foundation has 77 bags of concrete and 240 feet of rebar.
The upper pivoting section weighs around a ton, the same for the fixed base.
The weight is on 6 roller bearings attached just above the center of gravity,
nearly balanced so changing the tilt is a onehand job (only when the wind is
not blowing). 6 lower braces stiffen it up, have 6 bolts removed while the tilt
is changing. That little red boat winch hardley works, but has convenient
locking in position while the braces are re attached.
This array is designed to require absolute minimum snow removal efforts.
Note 40 in ground clearance, piling up snow will not block panels. It also
allows a lot of grass to grow under it. The 8 in center gap means snow need
slide only the minimum distance to fall clear. A steep angle lets most snow
just slide off by itself as in the last 2 snow storms. Otherwise just a few taps
along the bottom often bring snow down. Bruce Roe
18ArrayR.JPGLast edited by bcroe; 04-05-2023, 10:12 AM.Comment
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Thanks for the great replies guys. I wish I had the room some of you have but being a city dweller my space is very limited. I did not want to put it on my house roof because of the chance of damaging it, so I put it on my boat canopy and that has worked out great because it allows me to clear the snow off after each storm, which there have been a lot this Winter and now into Spring. We do get some high winds here, so whatever I do I will need to make sure the panels are really solid. I like the idea of a 3 position tilt adjustment, not sure I would need 4 considering the incline of my setup starts at 20 degrees and the max tilt I would need here is 54 degrees. To start off I plan on just doing a single row of panels, to see how that works out, it will be my upper row but considering this row is almost 17 ft long, I'm not sure how to build a frame that will allow me to tilt the entire length of it at the same time, I'm thinking it might be best to break that down into smaller sections, maybe two that are 8 ft long. I'll take a pic later today, after I get the snow off yet again, so you guys can see what I'm dealing with.Comment
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I analyzed doing this years ago and concluded that any mechanism easily operated by a single person for a typical (>24 panel) residential array would be far more expensive than the additional solar gain achieved. Better to just add a few more PV panels and have a nice, strong, simple, easy to permit system....BSEE, R11, NABCEP, Chevy BoltEV, >3000kW installedComment
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Even if DIY with zero value for labor, I have no doubt the extra cost for most variable tilt systems that will hold up in most climates most likely exceeds the value of the increased production, but it can be a fun exercise.
I'd reiterate that before doing it one gets reasonably reliable estimates of long term production enhancement as well as a reasonable SWAG of the present value of any long term savings.Comment
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It isn't the panels that you need to worry about.
It's the racking and equally importantly the attachment points and also whatever the whole array/assembly is attached to.
Tilted arrays can and easily do act like big sails. A canopy may well not be designed to take the applied loads from wind which are also considered variable for design purposes.
Try carrying a 4 X 8 sheet of CDX in a breeze for a good learning example, but do it in an open area.Comment
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It's funny but a local POCO called TECO just installed a 74MW array that can track the sun from East to West close to me and most of those panels are frozen in place (some pointed E , W and straight up) so IMO even a large corporation can't build or maintain a system that can move the panels to track the sun. But maybe a homeowner can find a way to do it cheaply and have it pay for itself.Comment
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Q: How can fixed panels - which means a fixed array, track the sun ?
Reads to me that maybe one design idea might have been to have a flatter output curve by multiple panel orientations for the array or some other than non-standard output curve for a specific need or purpose.Comment
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I have built a couple of manual tilt systems but noneon the roof due to potential snow and wind loading issues. Panels mounted at roof angle a few inches off the roof are not major contributors to wind uplift but tilt them up in the air and they become, a "sail". If someone was building a new roof they could incorporate the extra structure and supports but not very easy to retrofit. WIth respect to snow, a tilted panel tends to be a problem as the snow will build up at the base of the array cutting into some of the extra output.
My pole mount is balanced around an axis, I can change the tilt in about 5 minutes with a couple of wrenches. The other array requires a pole and hydraulic floor jack. It takes me longer to adjust the tilt. If you dont make it easy, its likely you will not make the adjustments.Comment
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All Earth in VT makes tracking arrays with both vertical and horizontal tilt. They look quite robust but of the 4 that I am aware of, one is permanently facing south (no tracking), One is mounted too low and it stalls in the snow (usually facing north) and the two others run most of the time. They only make some financial sense in VT as the incentives were written around them but I see them in Maine and NH on occasion. The dealer that installed them in my area went bellyup so I expect warrany repairs are now a problem.Comment
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Solar arary pic 4-4-23.jpg
It's been snowing for three straight days, finally got enough snow of the panels to take a pic. It's a mess with all my stuff stored for the Winter but you guys can at least get an idea what I'm dealing with. I use that long white PVC pipe with a broom on the end to get the snow off after a storm but it really piles up at the bottom, almost 4 ft right now. After all your comments I think I've decided to just tilt that bottom one and add two more onto my array, that will max out my inverter but will made the wind issue less of a problem and with only three panels to tilt, it will be much easier to build a design that can be manually tilted. Thanks everyone for your thoughts.Comment
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