Solar tracking mount electronics
 

I have a very old 10.5 foot TVRO dish in my backyard that I'm thinking might be a good place to mount a few PV panels.

Today, I found a site that sells Solar trackers!
Heliotrack.com - Heliostats and solar tracking

My next step is to insure my actuator (dish mover) has built-in limit switches.
If it does, I'm half way to having a pretty neat tracking mount.

I would remove the dish and install an 8'x8' (or 10'x10'?) PV panel mounting rack.

From what I've read, tracking panels can kick up the amount of kWh "harvested" per day, by quite a bit.

So, has anyone seen one of these units working?
http://www.heliotrack.com/images/dua...ker-sensor.jpg

I have two of the Zomeworks passive trackers -- no motors, just sloshes refrigerant back and forth in outriggers. They work pretty well. Rain confuses them -- but when it's raining, the solar ain't so good. They can be slow to wake up on a cool morning. And our winds have wallowed the axle hole a bit. But so far no major failures; they have survived 119 mph gales.

I like your power tracker idea; the dish mount should be pretty strong. You ought to see 30% gains in the summer, tho far less in winter when the sun takes a shorter path. If you can track for cheap, by all means do. Buying Wattsun or Zomeworks trackers new is marginal; it may be cheaper and far easier to add two extra panels and skip the trackers. Better yet is an MPPT controller like the Blue Sky or Outback MX-60, which gives 25-30% output gains in winter, when you want it most. They're about $400 more than a 'dumb' controller like the Morningstar or Trace.

I still got trackers, just cuz they are cool.:)

http://sites.google.com/a/wildblue.n...t/trackers.jpg

Use Both??
 

Thank you Bob!
Those MPPT controllers aren't as expensive as the 200W per-panel inverters that I was looking at. As a matter of fact, the MPPT units I just looked at will be perfect for my
limited funding. :)

I wonder, would there be any gain if I used the above sun tracker with the MPPT unit?
It sure seems like that would help. (Since the sun tracker will cost me very little).

Cheers,
Rich

Rich: Both is better -- MPPT and tracking complement each other perfectly. Tracking pays off in the summer, adding 3-4 hours of charging time per day over fixed mounts. MPPT is great in northern climates in winter, when cold PV panels make waaaay over faceplate voltage. For instance, here's my Outback solar controller this morning (this demo would be more impressive if I knocked all the snow off the panels :D):

http://sites.google.com/a/wildblue.n.../yurt/MPPT.jpg

The nominal 24V panels are making 34VDC at the controller, while the batts are cruising along at 26V. Electrons flow downhill, but you only need a little gradient -- like 1 volt. The rest of that excess voltage is wasted, burned away as heat at the controller or in the battery. An MPPT controller tracks the battery voltage, down-converts the panel voltage to just a bit higher, and turns the excess volts into Amps. The panels are making 27.5 A, but 33.7 A are going into the batts. That's a 22.5% increase, even with nearly-full batts. It can be a 30% gain when grid-tied or when your cells are thirsty.

Dang! That's slick!
 

Too cool. Having a little micro processor looking at the PV power flow and adjusting the input load to the panels for best power delivery, (in real-time) has got to be the BEST way to charge batteries or feed the grid.

I read your post describing your off-grid home system, which sound great but I'm wondering about your inverter setup.?.
I can't wait for your web page!

Thanks,
Rich

got one moving in austia
 

hello I could recomend theanalogguy regarding the controller I have 2 of them workimg here and they are fine. here a picture of my DIY units and if you want information to the surplus please note the link
Solarstrom und Photovoltaik Erträge | Erneuerbare Energie | Sonnenertrag.eu

best greetings from austria
lobensommer

Red Rock Energy Heliostats makes and sell a solar tracking chip for satalite dish motors, nice guy too.

$90 worth of fun?
 

Thanks! I looked at the EST1 http://www.theanalogguy.com/EST1%20WEB%202006-07-23.htm
and I think it would be suitable for my dish, but I'm not sure how
'built-in limit switches' switches work.

It seems logical that they have a mechanical gear link to the motor,
and they would open the circuit at the end of travel.
BUT, if the circuit is Open, How do you get the motor to restart in the other direction??

The only thing I can think of, is a backwards diode across the switch, that will allow reversed current to bypass the open contacts.?.

That's got to be it!

Anyways, maybe this weekend I can take a battery out there and run the
motor down to the end and see what it does.
If it works okay, I'll be able to proceed with the project. :cool:

That site has a ton of info. Every time I visit, I find something new to read.

Today, I found a diagram that shows the end-limit switches for a dish mover.
With their escape diodes!

http://www.redrok.com/images/cdsrely1.gif

Upper right side.. Now I can understand how a limit switch keeps from
hanging up the mount..

Thanks,
Rich

Well, I took the motor off the dish, opened it up and there is no end-limit switches..

Have to look around for another Actuator, or figure out another way to do it.