what is a solar tracker?

greg_kr

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Jun 27, 2008, 8:10:06 AM6/27/08

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Hi,

What exactly is a solar tracker? I read this page :

http://www.redrok.com/led3xassm.htm#fitch

I think it is a device which senses light, and then outputs a control
signal. What is it typically attached to? Some kind of motor which can
receive the control signal and rotate accordingly?

I just build a simple solar power generator. I am interested in
improving it. If I could somehow make the panel follow the sun, this
would be a HUGE improvement.

Thanks,

Greg

Duane C. Johnson

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Jun 27, 2008, 10:16:05 AM6/27/08

to greg_kr

Hi Greg;

greg_kr <gkr...@gmail.com> wrote:

> What exactly is a solar tracker?

A "Solar Tracker" is the device or components that are
used to sense and acquire the Sun. It is generally used
to control motors on the "Tracking Mount" to implement
movement.

The Zomeworks tracker is based on weight transfer and
pressure changes to implement moment in their tracking
mount. See:
http://www.redrok.com/main.htm#zomeworks
http://www.redrok.com/elcheapo.htm

Computer, or "Clockwork", controllers such Timothy
Leonard's Enhancement Electronics trackers
http://www.redrok.com/main.htm#trak:

> I read this page:
> http://www.redrok.com/led3xassm.htm#fitch

> I think it is a device which senses light, and then
> outputs a control signal.

But the LED3X is more than just a sensor it contains
the power driver circuitry to directly drive permanent
magnet gear motors.

> What is it typically attached to? Some kind of motor
> which can receive the control signal and rotate
> accordingly?

Most use old C-Band satellite dish actuators or movers.
These are radially available, generate large movement
forces, move relatively slowly, and have built in limit
switches. All good qualities when tracking the slow
speed of the sun across the sky.

Or better yet because an even slower movement can be
attained is to use high gear ratio DC motors such as
Graingers 2L003
http://www.grainger.com/Grainger/wwg/itemDetailsRender.shtml?ItemKey=2L003
along with a large final gear reduction.

> I just build a simple solar power generator.

What is it like?

> I am interested in improving it. If I could somehow
> make the panel follow the sun, this would be a HUGE
> improvement.

> Thanks,

> Greg

Duane

greg_kr

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Jul 1, 2008, 8:56:53 AM7/1/08

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Hi,

Thanks for the reply, the information helped me out alot.

My Solar Power Generator is very simple. it is one 12V Solar Panel
feeding a Deep Cycle 12V marine battery going out to a 400Watt
Inverter. I use it to power a fan or my laptop or cellphone charger.

I live in a apartment, and I cannot post anything on the roof So I am
in the process of building some kind of swing arm scaffold to stick
out my window so I can get the panel more sun.

This was my first little project, but my real goal is to collect
enough solar energy to power a Air Conditioner. The Air Conditioner I
have in mind draws 490 Watts using 4.5 Amps. I want enough solar
panels to feed a system of 12V batteries connected in parralel (I
think, because I will still connect this to a 12V battery which will
feed a 1000W.

So right now I think I should connect the batteries in parallel and
the solar panels in parallel. Does that sound right?

How would I calculate how many panels and the size of the panels given
my power requirements for the Air Conditioner?

Thanks alot!

Greg

renewabl...@hotmail.com

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Jul 1, 2008, 10:00:02 AM7/1/08

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The power requirements need to include the average number of hours
your PV panel will be in full sun. You may need to guesstimate this
based on the average number of cloudy days in your area & the total
potential number of hours your panel is exposed to full sun.

Adding PV or batteries in parallel will increase the amps output.

Connecting them in series will increase the voltage.

Load=(running watts+(start up watts-running watts)Xnumber of hours you
need to run the A/C answer is in watt hours.
Most A/C units have a "Locked rotor" load rating use it to calculate
start up watts.
This will give you the wattage of inverter you need. (always use a
larger inverter than the expected peak load to prevent burn out, don't
expect its peak load rating to cover the start up load most won't for
long)
Charge ability of PV panel is found by: (It seems some panel MFG's
like to rate their panels output in full sun in orbit (no atmosphere)
so measure the panel.)

Measured panel output in watts X average number of hours PV panel is
exposed to full sun.
answer is in watt hours.

Battery output rating is in amphours X voltage to get watthours.
the inverter you select should tell you the wattage or amp draw at
full load. they are not 100% efficient so include the loss in your
calculations.
It is recommended tat you use a charge controller between the PV array
and the batteries to prevent over charging. (over charging shortens
battery life)
I've attached a JPEG of ohms law formulas that should help you do the
math.
Hope this info helps you out.
Bob
Every bit of green effort we make helps the planet!

On Tue, 1 Jul 2008 05:56:53 -0700 (PDT), greg_kr <gkr...@gmail.com>
wrote:

Duane C. Johnson

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Jul 2, 2008, 12:04:10 AM7/2/08

to greg_kr

Hi Greg;

greg_kr <gkr...@gmail.com> wrote:

> Thanks for the reply, the information helped me out a lot.

> My Solar Power Generator is very simple. It is one 12V

> Solar Panel feeding a Deep Cycle 12V marine battery going
> out to a 400Watt Inverter. I use it to power a fan or my

> laptop or cell phone charger.

> I live in a apartment, and I cannot post anything on the

> roof So I'm in the process of building some kind of swing

> arm scaffold to stick out my window so I can get the
> panel more sun.

Take a look at this drsign:
http://www.redrok.com/led3xassm.htm#dg240
It's small and can support about 11 square feet of panel.
This might fit the bill.

> This was my first little project, but my real goal is to
> collect enough solar energy to power a Air Conditioner.
> The Air Conditioner I have in mind draws 490 Watts using
> 4.5 Amps. I want enough solar panels to feed a system of

> 12V batteries connected in parallel (I think, because I

> will still connect this to a 12V battery which will feed
> a 1000W.

I doubt you can run an air conditioner from a small setup.

> So right now I think I should connect the batteries in
> parallel and the solar panels in parallel. Does that
> sound right?

> How would I calculate how many panels and the size of
> the panels given my power requirements for the Air
> Conditioner?

You will need a lot of panels to do this.

> Thanks a lot!

greg_kr

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Jul 2, 2008, 8:57:59 AM7/2/08

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Awesome! That was the information I was looking for! Thank you very
much.

Greg