Solar Tracker

Recently designed and built a solar tracker in my backyard. It captures the sun from sunrise and follows it all the way till sunset. This maximizes the electrical output from the PV panels, thereby improving conversion efficiency. My design can also be controlled manually form softkeys on the control panel as well as wirelessly from a remote control software on my laptop.

Category:

Science & Technology

Tags:

• solar
• tracker
• mechatronics
• automation
• embedded

[tsbrownie]

Seems like all these trackers with their computer controls and all, use more electricity than they put out. It's more practical just to put up more panels at different angles.

[aaqilkhan]

@tsbrownie - i installed a 2kW system using my tracker. The system controller along with the drive system consumes a very small percentage of the power it produces. The surplus is stored in battery bank and converted to AC power. By the way, where did you get your statistics that it consumes more power than it puts out? Have you actually calculated/measure or just "baseless assumption"?

[enticed2zeitgeist]

@tsbrownie I've heard solar panel trackers gain between 15-50% efficiency when they face the sun directly. It takes surprisingly very little to power to rotate the panel in most cases because they are usually balanced evenly. Also, just because the sun moves all day long at a very slow rate doesn't mean the panel is. The panels probably only move once every 5-15 minutes. I have tried to build a solar tracker with Arduino, the photo diodes aren't as sensitive as you might think.

[aaqilkhan]

@enticed2zeitgeist Using photo diodes isn't very efficient, as the failure of one diode can render the whole apparatus useless. My system uses embedded PIC controller programmed to compute the astronomical position of the sun and corrects the position when the error between current and calculated position varies by a certain angle (programmable value). Its more efficient than using photo diodes - which also have problem of shadows etc.

[arikz22]

HEY

I AM ARIK FROM ISRAEL

CAN U PLS SHARE WITH ME HOW DO U TRACK THE SUN

I WILL PAY FOR UR ADVICE

ARIKZISK@GMAIL.COM

ISRAEL

[aaqilkhan]

@arikz22 - send me an email with details on what exactly you need help with?

[tsbrownie]

@jhs5150 Talking about electricity to run the computer / motors. Maintenance includes bearings, motors, etc.

[tsbrownie]

@jhs5150 Yes you get more power from the panels, BUT the net increase from the system is small or loss. You have to include energy to run the computer/motors, ... Trackers are also limited to the number of panels they can turn because of wind/weight.

With panels at $0.91 / watt or less a fixed 2KW system with 30% more panels would cost $546 extra. Cheaper than a computer, motors, frame, maintenance, ... A simple manual adjustment for season would add significantly at very low cost.

[jhs5150]

@chiunang You can use a 36 or 24 volt actuator and run it at 12 volts. It'll work, but slower. Also some of the trackers, such as the Redrok let you adjust the duty cycle from 0-100%.

[jhs5150]

@tsbrownie

Here is the quote from his site.

"Many have said that it makes no sense to use a solar tracker with PV systems as it is cheaper to just add an extra panel for every three. To this I say bunk." Using the NREL data:

I find that in Minnesota a single axis tracking PV panel will have a 40% increase in output in December and a 100% increase in June."

Of course your location will have different results.

[jhs5150]

@tsbrownie I'll find it and post the link here. If you're talking about computer programmed tracking, yes you'd have to factor that in but you know as well as I, once a program is written to do it, you only have to modify it to use on another system. You're not going to write a new program.

[tsbrownie]

@jhs5150 Went to look and can't find anything specific in that hodgepodge of stuff. I have a bit of experience designing and building solar stuff (enought that people have paid me to do it) and if you look at the total energy cost to track it's high. You have to include *everything*: energy to write the programs on the computer, the computer to track, the downtime to maintain, the electricity to build & operate, etc. It's way a lot of new solar farms are "fixed".

[jhs5150]

@tsbrownie That's actually not true. If you go to redrok.com he explains why.

[tsbrownie]

@enticed2zeitgeist I admire him for doing the work & not just talking. Other ways to get results are static inverted V's, dynamic V's, more batteries, etc. Trade lower tech for reliability. Uses up front $'s rather than on-going tech/maintenance. I did the battery option almost 20 years ago, want to try the inverted V's one of these days. It's just time & money.

[enticed2zeitgeist]

@tsbrownie I don't think traditional solar panels are a wise solution at all for the same reasons you have just stated. I think Solar Stirling generators or heat differential methods are much more direct and do require expensive equipment to produce. Also the chances of them breaking down are much less as well, easier to clean etc.

[tsbrownie]

@enticed2zeitgeist You are correct, they gain a lot when they are accurately pointed from my personal tests. I am really thinking KISS (keep it simple / smart). All that stuff will make it more efficient on short time scales, but in the long run one must count all the power used to aim as well as in production and maintenance (and power lost from tracking failures) on the total system to determine if it's worthwhile. I'm "guesstimating" it's close / not worthwhile.