SOLAR TRACKING SYSTEMS

Good Lord, you're an idiot, AlwaysWrong.

I've seen thousands with a "moving chain" and *none* with a fixed chain. AlwaysWrong earns his name once again.

Erica -

On a clear, sunny day, connect your solar panel such that you can measure the current. A load other than your amp meter is not needed.

Adjust the tilt in all directions while observing the current. Record your observations of current vs angle in both planes . Analyze the data.

Tell us if you learn anything.

Usually you use two identical panels on both sides of the polar axis, perfect balance.

The world does not revolve around your inadequacies.

I have two garage doors which both open via a chain drive on both sides of the door driven with a single motor where the two chains are connected via a drive shaft.

Your little enclosed world does not allow you to see beyond the Sears and Roebuck toy door openers.

And don't come back with a twisted backpeddling answer in an attempt to redeem what you never had. We all know your "Always Wrong"

Jamie

On Sun, 25 Oct 2015 09:46:37 -0400, krw Gave us:

Ever heard of direct drive, dumbfuck?

The link I posted describes it. Popular mechanics describes old technology.

And I read the page long before you posted it, twit.

Go back to your post about panel control. You actually got that one right about how it does not need to be accurate.

But then again... damn, aren't you dead yet?

On Sun, 25 Oct 2015 09:47:43 -0400, krw Gave us:

I posted a link, dumbfuck.

Considered one of the best made, Direct Drive uses a fixed chain and the motor is in the trolley.

You lose again, alzheimer boy.

On Sun, 25 Oct 2015 09:51:16 -0500, M Philbrook Gave us:

The opener I posted a link to and described tops the list on quality and function, and is German made, you retarded, presumptuous piece of shit.

Yes, it depends on how the OP construct the frames and panels, whether the panels are moved individually or tied together.

There is no need to move anywhere close to the speed of the sun. We want t o move it instantaneously, even if we suffer a few percentages of errors. EPS (Electric Power Steering) can run in couple of seconds. If you need to make a turn in 1.6 minutes, you could be dead.

If we move it in 10 seconds, we can run it for 1% duty cycle or 50 watt-hou r. Even 10 seconds are much more than what we need to pulse the motor.

GPS is *not* a two way communications medium. It is one way and only provides location and time info. It is way over kill for a project like this where the location never changes and you really only need to know the time to some fraction of an hour.

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Rick

Sorry, Sir Newton, rotational speed of the Earth, not the Sun.

50% right. Most single axis trackers are fairly well balanced. Dual axis trackers are not well balanced.

See drawing in lower left of data sheet. This is a rather large 16 panel single axis monster. Notice that the elevation tilt range is limited by the placement of the elevation pivot being located directly over the mounting pipe. The specs above show that array tilt is fixed at 45 degrees, which is the balance point. It is not adjustable and will not suffice for a tracker that requires manual elevation adjustments. If one tries to tilt such a device, the side loading will jam the bearings in the 8" pipe.

One the other hand, dual axis trackers require that the elevation pivot be somewhat cantilevered off the mounting post, so that elevation can be adjusted. Compare the location of elevation pivot on this dual axis tracker, with the single axis tracker above:

5 to 60 degrees elevation. However, this type of construction is NOT well balanced above the mounting pipe, and will need to deal with the side loading and associated increased friction.

The dual axis trackers which are split down the middle to clear the mounting pipe are a good solution. They're not very common because this type of construction ruins the structural rigidity and stength. Here's what a real bearing and pivot assembly looks like: Note the gap between panels (actually mirrors) for clearance:

Problems begin when a typically tiny azimuth motor tries to turn 200 sq-ft of panels in a stiff wind. I'll assume a single axis tracker that is well balanced. Guesstimating: Force = Area x Wind-Pressure x Drag-coeff Assuming someone cleverly mounts the tracker with half the panels blocked by buildings or trees, a 40 mph wind, an a guess at the drag coefficient = 1, I get: Wind-Pressure = 0.00256 * mph^2 * 1 = 0.00256 * 40^2 * 1 = 4 lbs/sq-ft Half the area of a 12 panel array is about 100 sq-ft at 45 degrees: F = 100 sq-ft * 4 lbs/sq-ft * 0.5 = 200 lbs The force acts on the center of the exposed part of the array, which is about 3.5 ft from the rotational axis producing: 200 lbs * 3.5ft = 700 ft-lbs of torque. With a well lubricated high ratio worm gear drive, a small motor can probably produce that much torque. However, I don't have numbers on the motors used and can't offer any calcs.

It's unlikely that a real tracker will be expected to handle such forces because they're usually pole mounted on the ground, where the wind is MUCH less than at elevation. Note that the specs say that it will survive a 90 mph 3 second gust, but doesn't say whether it will actually track or move in such a wind.

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Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
Santa Cruz CA 95060 http://802.11junk.com 
Skype: JeffLiebermann     AE6KS    831-336-2558

GPS satellites are bi-directional, but restricted. If you send a signal strong enough to reach the satellites. FCC wants to talk to you.

Uummm... yes, I do know. You've answered your own question. If the elevation of the sun is 20 degrees above the horizon, then the panels will need to pointed 20 degrees above the horizon. If the azimuth of the sun is at 282 degrees, then the panels will need to be pointed at 282 degrees azimuth.

If your tracker is not moving, you don't need GPS. If you are moving, GPS will give you a location, from which you can calculate the sun's position.

Communicating 2 miles can be done license free in the US. There are all kinds of 900 and 2400 Mhz narrow band (not Wi-Fi) spread spectrum radios that will work. You do not need a license, but you do need to have your equipment type certified by the manufacturer. Start here: I use FreeWave boards for low speed (serial) data for DGPS (differential GPS) correction systems: With a decent Yagi antenna, 15 miles is easy. There are cheaper RF datacomm systems available if you want to build your own.

My guess(tm) is that you're not in the USA and therefore subject to other rules and limitations. If that's the case, look into similar

2.4GHz equipment, which is legal in most (not all) jurisdictions.

Again, these are all low speed (serial) data. If you use higher speed Wi-Fi, you will loose range. For GPS, all you need is 4800 baud.

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
Santa Cruz CA 95060 http://802.11junk.com 
Skype: JeffLiebermann     AE6KS    831-336-2558

These *are* the angles you should use.

This is a little different. The panel may be on the ground, but you will want to tilt the axis of rotation so the panel is aimed at the mid elevation of the range over the year. But how will you measure the angle of the panel? Rather than try to measure the angle the panel faces, why not measure the angle of the sun? Then you don't need to think about angles at all, you just track the sun.

Back to the angles you have.

Adjust the frame to level the platform the panel is on.

There are many. What do you have available? Get an Internet connection and send an email.

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Rick

My greatest problem with this kind of trackers is the price of around $6,000 to track an array of 3 kW.:

Currently PV modules cost about $1/W or less. This tracker would roughly add $2/W to that. I think it would be better then to just add 40% more array at an additional cost of $0.40/W.

joe

Buried gas pipelines move a lot more energy per dollar than buried electric cables. And one can store methane molecules a lot easier than storing electrons; less mutual repulsion.

(Barges full of liquified natural electrons?)

Why not let the market select the best way to generate and distribute power?

In the USA, fracking has already driven the shift from coal to cleaner NG.

Totally wrong. GPS is one way, receive only. You're probably thinking of the 406 MHz EPIRB (maritime), ELT (aviation), or PLB (land based) emergency locators, which use GPS to find your position, transmit it to various satellites listening on 406 MHz, which eventually goes to an international rescue service, which dispatches some entity to rescue your posterior, which then sends you a huge bill for the honor of being rescued:

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
Santa Cruz CA 95060 http://802.11junk.com 
Skype: JeffLiebermann     AE6KS    831-336-2558

Might a fixed mirror improve the power-vs-angle curve?