Solar Trackers

[Paul 55,116]

I was reading another topic just a moment ago. It was one from earlier this year where members were discussing solar arrays. I happened over a post I made at the time. It reminded me of some information I have been seeking. I don't recall where I found the video. Perhaps posted by another member? I don't know. I search so frequently for things, I tend to forget where I started anyway, once I have found them. 

 

Anyway, here is the video: 

 

 

The guy sells these complete systems (eBay homecsp YouTube: HomeCSP) for what I would consider reasonable costs. However, while the trackers can take power direct from the panels, typically, the savings you get with a single tracker may not be worth the added cost. Not 100% sure of the savings using a dual axis tracker. But, I am pretty sure it would be considerably higher.

 

Either way, to make up for the "loss" you would have using a static array, as apposed to a tracking system, you may as well add another 20% to 30% more panels to make up for the difference. After all, you will not only have the cost of the tracker(s). You will also have the cost of the mount, the brackets, the installation costs, the maintenance of the tracking system over time, etc. I am just not sure the cost justifies the difference in the watt hours gained throughout the day, by using a tracking system. But, they are neat as hell to watch, especially large array trackers!

 

With that said, I still want to try this down the road, at least using single axis tracker. It would be neat to watch it follow the sun across the sky, as well as calculating the actual watt hours gained. 

[Knowdafish 1,772]

 

 

I am just not sure the cost justifies the difference in the watt hours gained throughout the day, by using a tracking system.

 

You are correct. It is cheaper to make up for any perceived or actual loss by just adding more panels if space allows. The panels are safer in a high wind situation mounted to a flat roof too than a tracker that usually sits on a pole. The solar panels will act like a sail and the pole will act like the mast of a boat especially in high winds. 

[SkyMan 26,673]

 

 

It would be neat to watch it follow the sun across the sky, as well as calculating the actual watt hours gained.

You do lead an exciting life Paul.    j/k

 

I think if I were to do solar and wanted to get more out of it with something like this, I'd mount the panels on a pivoting bracket on the ridge of my roof and go adjust it a few times a day by pulling a clothes line on a pulley.  It wouldn't get maximum sun but most of it.

[thebob 18,260]

Instead of the linear actuators I think I'd be using car window winder motors and scissor jacks!

 

The electronics can be much simpler. For example like a line follower robot. He is using LED's as Light Dependent Resistors (LDR's) and a microcontroler, but you only need to control an H- Bridge to power the motor. His limit switches are all points of failure and aren't necessary with good mechanical design of the movable axis. I would be tempted to not even bother tracking the altitude. It could be done with a simple mechanical ramp as at our latitude it doesn't change that much year round and a simple adjustment every quarter would be enough.

 

So a simple polar mount, an old car axle for example. Maybe a car flywheel for the large circular toothed drive and some bike chain and sprockets to get some reasonable gearing. That should be enough to track east to west. You could probably even drive that with a falling weight, instead of an electric motor, and adjust the weight/gearing to get the timing right through the day.

 

If you included a pivot for the altitude it could simply be attached to a jockey wheel that runs on a ramped track to control altitude as the panel rotates. It would need to be manually reset each morning, and just left in a good position if unattended for trips away.

 

Electric motor drive could be as simple as a fixed speed motor with the right gearing, or some led's or LDR's as position sensors and either a discrete or microprocessor controller.

 

The mount and pivots are going to be the expensive part, the electronics not much at all.