Interesting site on solar trackers

[Joe Rich]

When poking around the web looking for information on solar trackers,
I came across this interesting site of interest to home brewers. Lots
of pictures and schematics. Maybe some good ideas. Recommends using
C-band satellite tracking systems.

http://www.redrok.com/led3xassm.htm#led3xc3

Joe

[Timothy]

Joe- I remember there used to be a passive, gas charged independent
tracking sysem that was sold back in the 80's. Have you any info on
these type of drives? t

[Joe Rich]

Timothy - There is one working here at the Solar Living Institute and
I could find out more while I am here. It uses two chambers with
amonia. Apparently when one chamber gets warmer than the other, the
amonia boils off to the other chamber and rebalances the system. BTW,
it is the only system working right now, all of the electronic
trackers are down. Says something for simplicity.

Joe

> > Joe- Hide quoted text -
>
> - Show quoted text -

[John Allen]

I am very keen to learn about trackers. Seems to me like they may resurface as energy becomes more valuable. For a little while I did some manual racking and I noticed that I could pick up a couple extra hours that way but I needed to be able to track in two dimensions to get that early morning sun.

I've been off line for a week but I'm back now.

ja

[Joe Rich]

I have my software working and, although I have not totally checked
the numbers, it looks reasonable. The software updates sun
declination every ten minutes and uses an algorithm from the
Astronomical Almanac. It also uses an atmospheric attenuation
algorithm from Kreider and Kreith. So the numbers are probably
reasonable theoretical energy estimates.

I am able to compare two scenarios right now, one for a tracker with
perfect pointing toward the sun, and the other for a fixed panel with
only a single declination (elevation) thoughout the year and fixed
azimuth pointing due south. I see that the fixed panel collects about
68 percent of the energy that the tracking system does. This is about
the number I also hear from the solar designers here at Gaiam (ne Real
Goods). Depending upon whether the glass is half full or half empty,
one can say that a fixed system collects about 70 percent of the
energy of a more complicated tracker, or a tracker collects about 1.4
times the energy of a fixed system.

Here I believe that there is economies of scale. If I was building a
large solar farm where I had someone on payroll to do maintenance,
then the tracker would be the best way to go. However, if I was just
putting in a system for the home, where I would have to call in a
service person whenever the system needed maintenance or PM, then it
may not be worth it. A good cost benefit modeling problem.

Plans for the software are to be able to correct the elevation several
times a year, instead of just having a fixed elevation. This will
increase the energy collected from the fixed collectors and make them
more attractive. I also want to be able to have a fixed inclinaton
( or settable several times thoughout the year) and then be able to
slew the right ascension of the array. This may be a good compromise
between a full tracker and a fixed array.

Joe

On Mar 28, 10:53 am, "John Allen" <johnaal...@gmail.com> wrote:
> I am very keen to learn about trackers. Seems to me like they may resurface
> as energy becomes more valuable. For a little while I did some manual
> racking and I noticed that I could pick up a couple extra hours that way but
> I needed to be able to track in two dimensions to get that early morning
> sun.
>
> I've been off line for a week but I'm back now.
>
> ja
>

> On 3/28/07, Joe Rich <RichMan...@gmail.com> wrote:
>
>
>
>
>
>
>
> > Timothy - There is one working here at the Solar Living Institute and
> > I could find out more while I am here. It uses two chambers with
> > amonia. Apparently when one chamber gets warmer than the other, the
> > amonia boils off to the other chamber and rebalances the system. BTW,
> > it is the only system working right now, all of the electronic
> > trackers are down. Says something for simplicity.
>
> > Joe
>
> > On Mar 27, 9:13 pm, Timothy <t...@alvco.com> wrote:
> > > Joe- I remember there used to be a passive, gas charged independent
> > > tracking sysem that was sold back in the 80's. Have you any info on
> > > these type of drives? t
>
> > > Joe Rich wrote:
> > > > When poking around the web looking for information on solar trackers,
> > > > I came across this interesting site of interest to home brewers. Lots
> > > > of pictures and schematics. Maybe some good ideas. Recommends using
> > > > C-band satellite tracking systems.
>
> > > >http://www.redrok.com/led3xassm.htm#led3xc3
>
> > > > Joe- Hide quoted text -
>
> > > - Show quoted text -
>

> --
> John A Allen- Hide quoted text -

[John Allen]

Nice progress!

I agree on about everything except the assumption that the fixed panel is pointing due south. I think that is the lucky exception. What is the comparison if the fixed panel is 45 degrees off, say to the SW?

I would be fine making a few manual adjustments every year and I know of at least one other person who does this, but I think that the 'mass market" is unlikely to actually make very many adjustments.

ja

--
John A Allen