Panel Oscillation (Follow the sun)

[weldme]

I am looking to install a PV array on my property to reduce my power use and eventually produce more than I use. Being that I am an engineer and typically over think things I was investigating weather I oscillate the array to follow the sun using a single small motor and linkage system. This would only be approx 20 -30 degrees each way from centre.
Being that the sun approximately moves 15 degrees every hour it should give me 3-4 hours extra peak power per sunny day.

Question: Has anyone done this before and is there value in going to this length, rather than installing them flat North facing as I am in New Zealand.

[SeanB]

There is a benefit in doing so as you get both a longer usable power time as well as the peak power period is larger. Biggest issue is the linkages are more complex than a fixed mount, and require regular maintenance and lubrication, as opposed to the panels which just need a regular wiping down to keep them clean.

[weldme]

Hi Sean

Thanks for the feedback, The linkages are the easy part for me as I work in the material handling industry and we constantly use links, cylinders and motors to automate our cheese handling plants www.hadencustance.com
I plan to use a sliding bar and simple links. One concern I do have is the shading effect it may have on the panel next door and from what Martin was saying on his videos this can bring down the performance of the whole panel.
I guess I need to way up what the gain in power V's the time it may be shaded and how far I need to increase the panel mounting centres to offset the shade effect.

I tried to paste a screen shot image of the drawing I have but this forum will not work for some reason. I will keep trying unless some one can tell me what I doing wrong all it comes up with is this -->

[SeanB]

Picture format is probably wrong. Try making a zip file of the drawing and attaching it.

As to the linkages you will need to have a larger spacing between the panels to allow the linkages to work, the distance will have to be enough so that the full lock at each end does not shade the adjacent panel until the sun is way off the mid line of the panel.

[weldme]

Hi Sean

Thanks I have attache the photo instead of inserting it, As you can see the blue lines would be the potential sun lines and I will need to spread this out a bit further to avoid shading.

Thanks

Simon

[warlock]

Hey WeldMe,

I have recently completed a 2KW install and at the time of the install I had the same discussion with my supplier as to why don't I follow the sun for extra performance. Basically his argument was if I have extra roof space "which I do" I would do better by just adding an additional panel or 2 to compensate for the difference in losses. The cost of implementing a system which would follow the sun is far more expensive than just adding the additional 2 panels. This he said was due to the mounting system had to be stronger as now you have a potential wind problem were the panel is higher on 1 side, also the mounting system is far more complex than just securing it to your roof and, then all the maintenance and up keep.

None the less I did some investigation into costs of a tracking system and basically for the same cost as the tracking system I could have added 50% more watts to the roof. Granted I am no engineer and would need to purchase these this and can't just make my own.

So I would so if space is a big problem and you need more power then maybe yes a sun tracking system might help, but the general consensus is don't bother just add 20% more power.

[weldme]

Thanks Warlock

You raise some very valid points. I had thought the cost maybe  offset by the cost of an extra panel.  Basically this is where I am at. Roof space is not too limited and an possibly get up to 6-7 KW laid flat on the roof so could be the best way to go. I have worked out that I could gain 2-3 hours peak per sunny day so this equates to an extra panel cost. If I can do the tracking system for close to the cost of a panel I should be break even. the extra spacing required would equate to approx 1 panel size, again break even roof space requirement.

The tracking system will not cost me a lot as I have accumulated a lot of old spare parts from the business I work in when they had a big clean out, PLC, small motor gear unit. You are correct and I would need to make the frames stronger, I guess the main problem would be to stop the panel twisting under wind and as you said maintenance, this would not be a lot unless something went wrong and parts needed replacement.

Lots to think about Mmmmmm!!!

Thanks for your thoughts>>

Weldme

[SeanB]

You would ned a frame the panel sits in, as the regular panel sides are not really strong enough for any load other than a flat lay. As well there is extra load on the glass and seals. Probably best to do a fixed positioning of the panels to either have more early exposure or more late exposure and add extra panels to add power. Otherwise spacing them off the roof slightly to allow air flow around them for cooling adds more power from dropping panel temperature.

[weldme]

Thanks for all the info, It seams there is no great benefit and could just be trouble in the long run.

It may be a little while before I get to test these theories but will definitely post some details when I get access to the gear.

[OrangePower]

Hi weldme, very interested to know if you completed your oscillating frame.