simple rotating panel

sbslider

New Member
Joined
Sep 27, 2020
Messages
6
I have a very small simple system. A single 12V 0.5A panel charging a set of old electric lawnmower lead acid batteries. I use this to power a single night light. i recently added another item to the circuit which consumes power 24 hrs/day, and my little panel doesn't keep up. I'm not super concerned about "fixing" that problem, I'm more interested in seeing how simply I can improve the system I have. My idea is to have a simple circuit driving a motor to rotate the panel from east to west over the course of 12 hours. I know there are TONS of sensor based systems running with arduino or such. Great for folks that want that. I'm theorizing for my simple system I could get a decent boost in energy collected if I could have the panel pointed east in the morning, and at the appropriate time have it start rotating toward the south, then the west. If I understand the data I saw correctly, for where I live (maybe the same for everyone?) the time of day that the sun is due south in the sky varies only +/- 15 minutes over the year. If I have the panel pointing due south in the middle of that spread, the loss of energy collection over the course of the year would be small. I would need to manually change the elevation over the course of the year, but this is fairly simple and not very time consuming. I would plan on optimizing that angle for when the sun is higher in the sky, to make the most of the high irradiance radiation hitting the panel.

So, is my hypothesis close to right, and if so are there simple setups (DIY or otherwise) that would rotate 180 degrees in 12 hours, then reset back to the start each day?
 

sbslider

New Member
Joined
Sep 27, 2020
Messages
6
thanks for the response JoeHam.

I have seen that video, but never actually watched it, as it first glance the setup seemed fairly complex. But it is a pretty clever setup. He claimed its less than $10 in parts, but that is not at all accurate based on the affiliate links. Nonetheless, some food for thought. My panel is inside a skylight in my carport, so I couldn't really implement something like his without a lot of design effort. But I may glean some ideas from this, we'll see. My small space is part of my reason for just wanting a simple vertical shaft rotation from east, to south, to west, then reset. I may be able to use one motor and two small panels to accomplish that. still a bit hung up on the reset part, I'll need to read the comments from the video more.
 

JoeHam

Photon Sorcerer
Joined
Dec 30, 2019
Messages
2,668
For only azimuth rotation wouldn’t just two small drive panels and one motor on a vertical shaft work?

Then put the cardboard divider as he shows and in the morning the one panel should pull it back around to morning sun??

I have no experience here but the simplicity is beautiful IMHO.
 

sbslider

New Member
Joined
Sep 27, 2020
Messages
6
For only azimuth rotation wouldn’t just two small drive panels and one motor on a vertical shaft work?

Then put the cardboard divider as he shows and in the morning the one panel should pull it back around to morning sun??

I have no experience here but the simplicity is beautiful IMHO.
I agree the simplicity is really nice. But I'm skeptical of the 2nd panel receiving sun through 180 degrees of movement back to the original position. I also wonder what happens when a storm front moves in overnight, and there's not sufficient sun to move the motor for several hours, then the sun is present later in the day and the angle is too oblique, or behind the panel, to drive the motor.
I think the simple 12 hours one way, 12 hours back to start is really simple, at least in concept. I'm just not sure yet how to implement it yet. It may be a combination of the Parker Solar Probe and something else for reversing direction.
 

sbslider

New Member
Joined
Sep 27, 2020
Messages
6
Guess how cube sats orient their solar panels?
Put panels on all sides.

http://cubesats.wdfiles.com/local--files/start/Solar Panels - Cubesat Structure - Aluminum housing - education_ksc_nasa_gov.jpg

Make a passive "tracker" with no moving parts. Get three panels and join the to form 3 sides of a cube. That will present a good area to the sun throughout the day and the seasons.
Interesting idea, but I wonder if the combination of the panels is efficient enough to be equivalent to one panel that somewhat closely tracks the sun.
 

Hedges

I See Electromagnetic Fields!
Joined
Mar 28, 2020
Messages
9,208
I agree the simplicity is really nice. But I'm skeptical of the 2nd panel receiving sun through 180 degrees of movement back to the original position. I also wonder what happens when a storm front moves in overnight, and there's not sufficient sun to move the motor for several hours, then the sun is present later in the day and the angle is too oblique, or behind the panel, to drive the motor.
I think the simple 12 hours one way, 12 hours back to start is really simple, at least in concept. I'm just not sure yet how to implement it yet. It may be a combination of the Parker Solar Probe and something else for reversing direction.

Don't oscillate, rotate:


Now you need slip-rings, or else have enough wire to wind up for a week or month, then unwind by hand.
 

Hedges

I See Electromagnetic Fields!
Joined
Mar 28, 2020
Messages
9,208
Interesting idea, but I wonder if the combination of the panels is efficient enough to be equivalent to one panel that somewhat closely tracks the sun.

To the first order, similar to one 2-axis tracker of same presented area. There is a difference in how much light enters vs. reflecting when striking at an angle, however.

Panels have become so cheap that multiple orientations is the way to go.
Unless the objective is to study trackers, useful for concentrator systems, communication, lasers.
 

sbslider

New Member
Joined
Sep 27, 2020
Messages
6
Don't oscillate, rotate:


Now you need slip-rings, or else have enough wire to wind up for a week or month, then unwind by hand.
Yeah, I've thought of that too. Definitely would need slip rings, which might not be bad with my only 1/2Amp. I've tried imagining somehow to make a 24 hour clock drive the panel in an oscillation using an arm of some sort.
 

sbslider

New Member
Joined
Sep 27, 2020
Messages
6
To the first order, similar to one 2-axis tracker of same presented area. There is a difference in how much light enters vs. reflecting when striking at an angle, however.

Panels have become so cheap that multiple orientations is the way to go.
Unless the objective is to study trackers, useful for concentrator systems, communication, lasers.
First, thanks for the multiple responses, I do appreciate all the inputs.

I think 2 (or more) panels could be a decent idea, I just have a small space where my one panel is located, not sure I can get a second panel in an appropriate orientation or not. I do like not having moving parts, less to go wrong. So I wonder if I was able to fit multiples, the simple cube doesn't seem to be the way to go, seems like something that focuses more on the sun when its high in the sky and at maximum output would be a better approach. Just not sure yet what the angles would be, and how much changing them over the year would help. That's why I went mentally down the simple 12 hour rotating panel thought train.
 
Top