06/16/2016
Solar Tower Site
Description

We have started installing solar powered Micro-POPs. 

For the cost, its cheaper to do solar than pay monthly meter fees & minimum useage commercial rates from the electric company. 

 

We used the SunMax 260 watt panel. 

Since its tower mounted we had to come up with a custom mount. We bought the mounts made for the panel and added a frame. Its simply UniStrut & threaded rod & misc nuts, bolts from Home Depot.

 

Initial tests look good. We have it setup running 12volt configuration. UBNT radios run fine like this. 

On a completely cloudy day, we still got 16-17 volts from the panel and its enough to charge the batteries, in 12volt configuration. 

We used two 12 volt 30AH gel-cell batteries, wired in paralell & fused (10amp) between each battery & the controller. 

We used this solar controller.
https://www.amazon.com/gp/product/B00MB0N8K6

 

20160602_170913.jpg20160602_170950.jpg20160602_171008.jpg

Solar Tower Site

by on ‎06-16-2016 01:03 PM

We have started installing solar powered Micro-POPs. 

For the cost, its cheaper to do solar than pay monthly meter fees & minimum useage commercial rates from the electric company. 

 

We used the SunMax 260 watt panel. 

Since its tower mounted we had to come up with a custom mount. We bought the mounts made for the panel and added a frame. Its simply UniStrut & threaded rod & misc nuts, bolts from Home Depot.

 

Initial tests look good. We have it setup running 12volt configuration. UBNT radios run fine like this. 

On a completely cloudy day, we still got 16-17 volts from the panel and its enough to charge the batteries, in 12volt configuration. 

We used two 12 volt 30AH gel-cell batteries, wired in paralell & fused (10amp) between each battery & the controller. 

We used this solar controller.
https://www.amazon.com/gp/product/B00MB0N8K6

 

20160602_170913.jpg20160602_170950.jpg20160602_171008.jpg

Comments
by
on ‎06-16-2016 01:43 PM

Looking at Michigan's average sunshine hours I think you might be in for some headaches over Winter.

Do you have any voltage monitoring to preempt outages?

At a minimum I'd be going for double the solar and triple the battery capacity.

by
on ‎06-16-2016 02:00 PM
I did this in Northeastern Arizona several years back...the wind there gets up to around 60mph sustained. We only lost one to the wind...literally...we never found it!
by
on ‎06-16-2016 05:31 PM

Looks good.  I would suggest getting close to 100ah per radio though.

by
on ‎06-16-2016 05:48 PM

What about the aerodynamic, no steers on the tower?

In case of high winds what go first the panel or the tower?(Dynamic side pressure)

 

Just my opinion.

by
on ‎06-16-2016 06:38 PM

"Looks good. I would suggest getting close to 100ah per radio though."

 

This ^^ is exactly right.  After running many solar powered equipment sites for the last 6 years at lat. 37 N, that battery capacity has proven to be necessary for 5 days of reduced or no sun.

 

by
on ‎06-17-2016 07:41 AM

As others have said, you need WAY more battery capacity.  100AH @ 12v per device is a good starting point.  We typically budget a bit more than that for longer battery life.

 

I like the creative use of strut and all-thread for the mount.  Consider investing in a metal chop saw and a stock of aluminum angle for the frames in the future.  Far lighter than steel and easier to work with.

by
on ‎06-17-2016 03:22 PM

very nice 30ah isnt nearly enough, its the start of what seems like enough.

Just speaking from experience here in the desert of arizona.

by
on ‎06-17-2016 07:20 PM

Yes, => 100ah per radio is good advice. Done right (overdone a little), solar can be very reliable.

 

Also using big cables between the panels and the charge controller is good. Determine voltage drop for 25a over whatever distance you have for the panel wiring and minimize it. (It's going to be 10x as much of a problem compared to 120v)

by
on ‎08-09-2016 11:53 PM
I don't believe that all-thread will hold up. All-thread isn't ridgid and will bend pretty easily. You will very likely get to the tower to a missing panel, or one that has twisted and broken with bent up all-thread. As was suggested before, alluminum angle is a much better option. you can easily drill ubolt/bolt holes to attach it together in rectangular form with 1 cross brace so it is easy to mount the panel. The top attachment to the uni-strut is good.
by
on ‎12-31-2016 12:53 PM

This may be a little late but  I am going to inject my 2 cents worth. First of all I would go with a mppt charge controller not a pwm. They are a little more expensive but make a big difference when temps get down. I will guess that those two radios will draw under 10 watts, so it looks like you will have plenty of solar panel for that. The problem is basically everything everyone else has said, you need more storage for sure, 100 amp/hours at 50% of battery. So 200 amp/hours total is the least I would do, more the better. With 100 amp/hours of real storage you should see about 5 days of storage give or take, that may seem like a lot but not really, at least it isn't where I come from. 

 

    The charge controller is extremely important, because solar panels work so much better when they are cold, they produce more voltage. This extra voltage seen at the charge controller will fool the pwm into thinking the batteries are fully charged, believe me I have seen this happen, it has bitten me in the ass. Any how the batteries never get fully charged when it gets cold out with a pwm, you need the mppt I would use this one. https://www.amazon.com/Tracer1210RN-Solar-Charge-Controller-Regulator/dp/B008KWPGS6/ref=sr_1_5?s=law...

 

Do the research and find out, there is a lot of info out there about this, sorry if I am telling you something you already know, because I found out after the fact you may have already figuerd this out.

 

Steve