One- and two-axis solar trackers

zimny8 wrote:

Kolego wizard1968, well nice among the carrots and others you have grown .

Back to the already famous picture:




Can someone describe how it is possible, when from simple geometry it follows that the plane on which the sun's rays fall at an angle of 90st is 100%, and already, for example, at 45st is 50% of its visibility.
Because, after all, that's the point, how much surface is illuminated.
Take a sheet of paper twist and experience, so what if the sheet appears to be illuminated all the time, when the amount of incident "rays" of sunlight at, say, 45st will be half as much.

So how does it relate to this graphic?

At an angle of 45 degrees, the incident area of the sun is almost half as much. Given that we have in theory 1000W/m2, half will be 500W. On top of that, there is reflection of rays, as the panel is not perpendicular to the rays. Hence much lower efficiency already at 10-20 degrees, even though the sun shines the same. This is what no installer will tell you, because they either don't know and don't understand, or don't want to tell you because they don't have a cheap turntable on offer.

I found something like this

The truss mast has three advantages:
- it is easier and cheaper to get 4 60x3 steel pipes than one 320x8,
- the mast can be made taller, e.g. at 5 m, and I intend to do so, since I do not live on a hill,
- it will be much lighter, precisely because of the truss structure, and at the same time rigid and tall, as if it were a 320x8 mm pipe.

bachin wrote:

marik_te wrote:

Let me insert a photo of a design I had the pleasure of creating some time ago.
Two tables on separate trackers with 15 340W panels each.

Can I get more data:
-dimensions,
-bearings,
-drives, etc.?
I'm planning to make something similar from scrap metal, because cost is important.

Unfortunately, I can't say much, because as soon as I did the electrical part.
Each tracker, and there were two is for 15 panels, 5 each in 3 rows. Which, with 340W panels, gives some 5mx5m table dimensions. The turntable was at a height of about 3m from the ground, which made it possible to mount the table inclined in the middle and maintain a safe distance from the ground even when vertically inclined. The drives came from disassembly ( some obtained from the dismantled tonsil factory), they were drives on a double reducer with a motor of about 50-100W three-phase. The slewing reducer directly drove the slewing through a permanently mounted pinion at the bottom of the base. I know it would have been simpler if it had been the motor at the bottom and the pinion rotated with the top; but that was not my idea. The inclination was made based on a threaded rod put through something like a nut directly in the reducer. This gave the possibility to adjust the tilt from horizontal to vertical.
On the electronic side, a solar tracker controller of the Reivision project rebuilt by the manufacturer to work with the inverter was used. The control was a simple "0" to one input ran the motor one way, and a "0" given to the other input of the inverter ran the motor the other way. The controller had a light probe connected to it, which resembled 4 small panels of about 1x2cm arranged in a square and at an angle of about 80 degrees to the table. It worked by comparing the voltages from these 4 panels and sought to drive the motors in such a way as to get the same voltage from the detectors.

From what I know the installation has been in operation for approx. 2 years and, with the exception of a problem with one of the controllers, where it was damaged, most likely by a discharge, everything works flawlessly. The yields are more than two times higher compared to a similar installation installed stationary.
[video:01e0805fc2]https://filmy.elektroda.pl/53_1699736786.mp4[/film:01e0805fc2].

With these inverters and motors and gearmotors, it's a very cool idea. The whole thing will last forever as the inverters are oversized. I have to make a taller tracer, because there is a high building around and a very cool solution on YT suggested (above). It is much cheaper and easier to make a 5m mast from a truss. It comes out a little more welding and fun, but I think this is the best solution.