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Electronics => Power & Renewable Energy => Topic started by: antonmi97 on April 25, 2019, 09:48:49 pm

Title: Sun tracking panels
Post by: antonmi97 on April 25, 2019, 09:48:49 pm
Hello everyone!

I want to make a test setup at my parent's house where I want to install a few (3-4) poly panels but not flat on the roof but on a system that'll move the panels a few times a day so that they get as much sun as possible. The rest of the system would be a MPPT, batteries, DC lines for LED lights and a pure sine wave mains phase matched inverter so that I can use it on-grid.

Now, my question is what do you guys think about the sun tracking and what configuration would you recommend for it (there is a LOT of wind in my area, so that is my biggest concern). Any help is highly appreciated
Title: Re: Sun tracking panels
Post by: fourtytwo42 on April 25, 2019, 11:42:41 pm
Here is just the site for you http://re.jrc.ec.europa.eu/pvgis/apps4/pvest.php (http://re.jrc.ec.europa.eu/pvgis/apps4/pvest.php) this allows you to compare static vs tracking in any location in Europe.

Personally I found the incremental gain small compared with the cost of installing a tracker AND here in the UK we have very strict planning regulations that prevent the use of a tracker on roof mounted panels anyway.
Title: Re: Sun tracking panels
Post by: Flenser on April 26, 2019, 12:02:34 am
+1 for fortytwo42's advice to compare static vs tracking.
Figuring out how much extra power you can expect to harvest would also allow you to work out the pay back period to expect on the extra money you will spend on the tracker hardware & electronics.
Title: Re: Sun tracking panels
Post by: wraper on April 26, 2019, 12:17:09 am
Yeah, it likely will be more economical to just install more panels at the same cost as less panels + tracker.
Title: Re: Sun tracking panels
Post by: antonmi97 on April 26, 2019, 04:19:11 am
wow, what an amazing resource, thank you!

what about mounting the panel in a FIXED position such that it has the best light income angle at the peak time of production, let's say from 1pm till 5pm? No moving parts, easy to bolt really tight to the roof and so on.
do you guys have any info about best general practice of mounting the panels?
Title: Re: Sun tracking panels
Post by: fourtytwo42 on April 26, 2019, 07:08:58 pm
My pleasure :) This site should give you some ideas for roof mounting systems https://www.solarchoice.net.au/blog/how-to-install-a-solar-panel-mounting-system-on-your-roof/ (https://www.solarchoice.net.au/blog/how-to-install-a-solar-panel-mounting-system-on-your-roof/)
The actual type and availability I think is somewhat country specific.
Also beware the clips to mount the panels to the rails are usually specific to a given thickness of panel and that is NOT standard so you have to have your panels selected already before buying the mounting system.

As for your question about angles again use the site, in my case I am lucky my roof is angled ~52degrees that is good for winter when the sun is low on the horizon, I am also lucky to face SSW!
Title: Re: Sun tracking panels
Post by: The Soulman on April 26, 2019, 08:21:27 pm
Yeah, tracking is not a thing anymore, fifteen years ago it was because of very high solar panel prices
these have now dropped considerably.
Absolute perfect orientation of fixed panels isn't that necessary as well, but beware of any partial shading (from trees or even a small chimney) that might occur during the day when using series connected panels.

Your plan is: parallel panels -> mppt charger -> battery's -> loads -> surplus energy via inverter to the grid??
Title: Re: Sun tracking panels
Post by: Seekonk on April 26, 2019, 11:47:15 pm
Out of necessity I have my panels almost flat. That gives consistent bad performance all day.  I am quite happy with that as I use the power real time and have minuscule storage. I run an entire camp on a car battery. Plenty of PV hot water and even have a dishwasher with heated dry. Panels are cheap compared to replacing batteries. I don't understand why more people don't do it this way.
Title: Re: Sun tracking panels
Post by: fourtytwo42 on April 26, 2019, 11:52:41 pm
I was going to mention the battery thing but each to there own, IMOP they are very expensive and poor performance hence I use the grid as my battery and store energy as hot water :)
Title: Re: Sun tracking panels
Post by: antonmi97 on April 30, 2019, 08:20:21 pm
Again, wow. I have so much questions now about energy storage. But the main question for now is what about the phase matched inverter? Can I sell back energy to the grid with it? Any personal experiences with that?
Title: Re: Sun tracking panels
Post by: fourtytwo42 on April 30, 2019, 08:37:04 pm
Again, wow. I have so much questions now about energy storage. But the main question for now is what about the phase matched inverter? Can I sell back energy to the grid with it? Any personal experiences with that?
I think what you call a phase matched inverter we would call a grid tie inverter. Such an inverter synchronizes with the grid but also must meet strict safety criteria, the most important being that it is not able to deliver energy to the grid if the grid voltage is not present due to power failure (this is called ant-islanding).
In the UK to be able to sell energy to the grid the installation must be installed by someone certified to do such work, a DIY installation does not qualify. To answer your question you would have to find out what the local rules in Croatia are, usually you would ask the company that supplies your electricity.
Title: Re: Sun tracking panels
Post by: antonmi97 on June 12, 2019, 06:40:51 am
Hello everyone!

I just wanted to update you guys on what I've built for my solar system.

I choose a Sole UNI 5000 (5kVA MPPT hybrid charger+inverter), got myself 4 huge 12V batteries for free that were barely used in a backup power system (just about 50-100 cycles on them) and 6 310W poly panels. (DIAGRAM -> http://www.deviantpics.com/images/2019/06/11/Capture.png (http://www.deviantpics.com/images/2019/06/11/Capture.png))

For the tracking I've built a dual axis solar tracker from scratch (3D renders and concept photos HERE -> http://www.deviantpics.com/image/wNR (http://www.deviantpics.com/image/wNR)
http://www.deviantpics.com/image/wNK (http://www.deviantpics.com/image/wNK)
http://www.deviantpics.com/image/wNZ (http://www.deviantpics.com/image/wNZ)
http://www.deviantpics.com/image/wNa (http://www.deviantpics.com/image/wNa)
http://www.deviantpics.com/image/wNo (http://www.deviantpics.com/image/wNo)
http://www.deviantpics.com/images/2019/06/11/fig1.png (http://www.deviantpics.com/images/2019/06/11/fig1.png))

I'm controlling it with a Arduino and ESP8266, I've added an anemometer, 4 quadrant light exposure sensor (made with LDR's), I control the actuators with relays (for now, I'm thinking of doing it with mosfets) and all the tubes and bars are huge overkill steal ones (cheaper and my actuators can handle it + probable expansion in the future).
All the work was done by me and my dad so all in all, the whole system cost us LESS THAN 2800$!!!!
And that includes every bolt, cable, MCU, sensor, the inverter, the panels, EVERYTHING EXCEPT THE BATTERIES (THEY WERE FOR FREE). I've even multiplied the cost by 1.1 just to be sure in case I missed something.

I would love to hear your opinion about this project and if you can recommend any improvements