SOLAR TRACKING SYSTEMS

^^^^^^^^^^^^^^

Holy low energy density, Batman!

As long as strange things are on the table...

I wonder if it pencils out to have no generator up in the windmill tower - just the blades, some bearings, some gears, and a cable that winches a big concrete block up in the air when the wind is blowing. Put the generator on the ground and let the concrete pull on a cable connected to its shaft when the wind isn't blowing. Guy named Otis figured out how to make this safe if one of the cables fails.

Supply power to run the generator as a motor. The turbine blades will act as a propeller to drive it towards the land. When it gets close, switch off the motor, and drive a crane out into the surf to flip it back over.

Matt Roberds

On a sunny day (Wed, 28 Oct 2015 16:09:35 -0700 (PDT)) it happened snipped-for-privacy@gmail.com wrote in :

Those are RC servos, I have something like that, it CANNOT carry a solar anal of any normal size. The system requires 1-2 mS width pulses several times per second. the width sets the angle. Wnen no pulses the system free wheels (you can move it by hand).

PIC driver code (good enough for a small camara):

On Thu, 29 Oct 2015 06:43:03 +0000 (UTC), snipped-for-privacy@att.net Gave us:

I am pretty certain they are tethered to the sea floor.

But we all saw how good tethering works.

You obviously didn't try to work out how big your concrete block needs to be.

Jeroen Belleman

The one with a vertical axis follows azimuth and the other follows elevation - pretty much like a tank gun turret or altaz scope drive.

Unknown so you move them back to the origin and then count steps or have shaft encoders of some sort so that you know absolute position.

I think you need to find a basic reference book rather than asking questions here. Your lack of knowledge makes answering very hard.

You would probably be better off with a kit from the likes of

Hi,

So, its the motor at the bottom that controls the Azimuth (just like the turret moves in the tanks) the motor at the top will be the elevation control motor(like the Gun in control by the motor at the top).

Can you recommend any reference book?

Let's say that the vertical axis motor is at zero Azimuth which means it is at South and the motor increments 50 degree each time it receives the pulse. Now, in- order to move it to 294, the motor needs about 5 pulses.

Am I right?

Is it possible that I can calculate Azimuth using the HMC6352 Digital Compass? the link is as follows. If yes, then how

Is it possible that I can calculate Elevation using ADXL345 Digital accelerometer? The link of the part is as follows. If yes, then how

Not necessary unless you have mobile panels mounted on trucks. If the panels are fixed on ground. Earth's position relative to the Sun is fixed as a function of time.

I wonder if it pencils out to have no generator up in the windmill tower - just the blades, some bearings, some gears, and a cable that winches a big concrete block up in the air when the wind is blowing. Put the generator on the ground and let the concrete pull on a cable connected to its shaft when the wind isn't blowing. Guy named Otis figured out how to make this safe if one of the cables fails. [/quote]

My brilliant idea to smooth out the power drops from windmills was to mount a windmill on top of a water tower and use it to pump the water up, with a water turbine at ground level to generate electricity at a constant rate and an underground tank to store the used water until it was pumped back up to the top to go around again, until I calculated that a small city-sized water tower would only provide a few MW for a few minutes, sigh.

This one is easy, you make the windmill double-ended, with a tower going up and a tower going down into the water, so one set of blades is in the air and the other is submerged, driven by water currents. If it flips over, no problem, they just reverse roles :-).

----- Regards, Carl Ijames

On a sunny day (Thu, 29 Oct 2015 07:26:48 -0700 (PDT)) it happened snipped-for-privacy@gmail.com wrote in :

No,

Just point it south or north for 1.5 ms pulse.

Many things are possible, but only if you try. Else you can onanate about it for the rest of your life and nothing(tm) happens.

Set the g*d*m*** first step try something then come back here. There is no substitude for hands on experince as Mr brown shows he has not with these servos.

Here:

With counter weight, not very stable now is it?

Sounds grim:

That's what they do at Niagara Falls, there is a big reservoir (google Lewiston Reservoir) They fill it up every night and drain it during the day.

George H.

Yeah, but it's cheap and starts quickly. (Yes 14 minutes is considered quick when you're playing with megawatts). If you're building a utility backup system, cheap and fast startup are good things to have.

CAES (compressed air energy storage) is nothing new and has been in use for many years. Would you believe 100 MegaWatts?

Efficiency sucks because much of the stored energy is in the form of heat produced as a side effect of compression. If the heat isn't stored by insulation and leaks into the surroundings, when the pressure is released in the turbine-generator, the exhaust might easily be spitting ice cubes.

Drivel: I'll be gone for a few more days. Too much work, too many problems, irate customer, and insuffient luck are making me rather scarce.

Hi,

What enclosure should I use for holding the control circuitry of the tracker?

I am looking for an enclosure that can hold 5 x 5 inch PCB, UL approved and can survive lighting, extreme cold and hot weather.

erica

Might as well ask for one that comes with a unicorn.

But seriously, if you're concerned about UL approval, you really need some serious help understanding the quagmire that is the approval system...and the expense involved.

Your electronics will fry long before the lightning hurts the box it's in.

Sounds like you're early in the process. Make the box bigger than you think you need...stuff happens.

ok mike you scared me. I know what can be involved working with UL. Can you direct me to the enclosure?

That depends on the local weather and environment. If you're located in the middle of a tropical jungle, your enclosure will be very different from one designed to survive in Antarctica. Some details as to the intended environment or general location would be helpful.

Does this PCB have a height? Any space occupied by I/O connectors, cabling, switches, lights, fuses, emergency shutoff, heater, desiccant, GPS antenna, or mounting hardware? I would get a box about twice as big as your 5x5x??? PCB to take care of everything you forgot to mention.

There are far more approvals required than just UL. UL is primarily concerned whether your device can present a fire, shock, or safety hazard. The actual enclosure has little to do with UL approval, unless you decide to make it out of wood or cardboard, which might catch fire. You may want to look at what existing tracker products use for controller enclosures, and which regulatory approvals they display on their packages and literature.

For enclosures, I usually end up with a NEMA rated electrical enclosure from: etc.

No electronics can survive a lightning hit. The best you can do is provide a path for the extremely high currents to travel, on the OUTSIDE of a metal enclosure, to ground. The enclosure will probably be destroyed or trashed, but the inside circuitry just might continue to operate. There are also a substantial number of lightning protective devices that will need to be added to all I/O wires if you want your circuitry to survive. Even a nearby lightning hit can induce substantial currents in wires (that act like part of a transformer) which will then destroy circuitry. Whether all this protection is worthwhile is dubious. It might just be cheaper to make the PCB easy to replace, and off the customer spare boards.

Look into ESD (electro static discharge) testing: It's nothing compared to a lightning hit, but if you can survive the major ESD tests, you have a fair chance of also surviving a nearby lightning hit (but not a direct hit).

How extreme or over what temperature range? Humidity? Condensing moisture? Immersion? Salt fog? Sand and dust? Thermal shock? Bullet proof? Bird droppings? The list of environmental tests is rather extensive. I suggest you start with MIL-STD-810: and decide which of these you need to pass and how your so far unspecified circuit will be protected.

There are some tests that are unique to power devices. For example, what happens when you short the leads to the drive motor? Does a fuse blow? Or does everything get hot, melt, or catch fire? Got any protection against the installer with sunstroke that reverses the inputs and outputs, or connects the wiring backwards? It happens far too often to ignore.

Incidentally, don't forget about EMC (electromagnetic compatibility) and FCC incidentally radiation (Part 15) tests. Solar inverters already generate quite a bit of RFI (radio frequency interference) and the FCC wants to be sure that your device doesn't add to the problem.

Thanks Jeff , the links are really helpful. DO you have any experience with solar panel's back tracking with tilt-meter? erica

On Mon, 2 Nov 2015 19:53:45 -0800 (PST), snipped-for-privacy@gmail.com Gave us:

Search for a "NEMA" enclosure.

On Mon, 02 Nov 2015 20:51:34 -0800, mike Gave us:

UL doesn't approve a simple mechanical box. They approve completed products.

mike is dumb and should not be relied upon for intelligent responses.