Mounting Pole or Panels?

Alaska Man

Looking for some feed back before I make a decision and spend any cabbage.

I'm off-grid with 880ah battery and generator back up.

I have four panels right now on the south facing gable end of the homestead. They are mounted with a hinged top so in the summer I can tilt them out to about 56° and in the winter lay them flat on the wall and grab the low winter light. the 960W array if fine for the summer up here in Fairbanks, Alaska. In the winter I will need to grab every electron I can. My conundrum is..... should I spend the money on a Pole Mount and rack that I can twist manually to follow the sun and put the existing panels there (The rack will be built to hold 8 eventually) or should I buy the other panels, charge controller, wire etc. It turns out they will both cost about the same. Which I ever I do this summer I will do the other next.

The Solar guy is suggesting I go into debt and do both now. I hate debt and except for a couple grand I have on a credit card to protect my credit rating I'm debt free.

Suggestions?

vtmaps

Re: Mounting Pole or Panels?

Alaska Man wrote: »

I'm off-grid with 880ah battery and generator back up.

what voltage system? hint: you can put that in your signature

Alaska Man wrote: »

In the winter I will need to grab every electron I can. My conundrum is..... should I spend the money on a Pole Mount and rack that I can twist manually to follow the sun and put the existing panels there

I've never been to fairbanks, but I heard that in the winter the sun doesn't move very far. That means there is much less to gain by trying to track it.

--vtMaps

Alaska Man

Re: Mounting Pole or Panels?

It's a 12Volt system Classic 150 controller and Xentrex Freedom series Inverter/Charger. I'll add to the siggy line in a minute.

You are correct, in the summer I would be track about 280° but in the winter I doubt I would have to move the mount at all. Just adjust it down perpendicular to the horizon. At Solstice we get about 3 hours of light, but it also -40° so the panels work better. The Candian Solar Black Panels are the ones I'm looking at 250W for an extra 1000W of PVs.

niel

Re: Mounting Pole or Panels?

that's a difficult thing to answer as to what is best for you. a poor man's rotor is the cheapest, but is a pita to go out there and move it all of the time and noting that up there the sun loves to travel great distances along the horizon. one could opt for a good solar tracker if one actually exists, but i'm not sure it will be as viable for extra collection during the winter months. and then there's mounting another array in another direction, but i doubt it will face too far off from the original south anyway in winter as the sunrise/sunset period will be small and will tend to be best in the southern direction.

most likely what i would do if i read you right is just mount the first array you have planned aimed south with adjustable elevation for different seasons. next year go for array #2 and also aim it south with the same adjustability in elevation as you need more winter production. this allows you to save a few $ in your piggy bank anyway even if you must still borrow the rest unless the installer is willing to give a discount for the 2nd array now. you will have to judge for yourself which is better for you and what works out financially.

Alaska Man

Re: Mounting Pole or Panels?

I was originally planning to mount the new panels on the western wall so I could collect the late summer sun. I could be making some power up until midnight or longer. I guess since the wall is above a long porch roof I could hinge the southern edge and in the fall just pull it out off the wall and face it south?............ just thinking out loud, It would have to be one skookum rack. May end up costing me as much as the pole mount......... hmmmm

BB.

Re: Mounting Pole or Panels?

PV Watts can help... For Fairbanks, 1kWatt array, 0.52 eff (off grid), fixed array to 65 degrees from horizontal.

Month    Solar Radiation (kWh/m 2/day)    AC Energy (kWh)
1      0.77          12   
2      2.38          36   
3      4.56          76   
4      5.90          91   
5      5.09          73   
6      5.12          68   
7      5.00          68   
8      4.30          60   
9      3.39          47   
10      2.21          33   
11      1.14          17   
12      0.39          6   
Year      3.36          588    

and the same thing with 2-axis tracking (best you can do):

Month    Solar Radiation (kWh/m 2/day)    AC Energy(kWh)
1      0.86          14   
2      2.72          42   
3      5.76          98   
4      7.93          126   
5      8.30          127   
6      8.89          128   
7      7.89          115   
8      6.03          89   
9      4.40          64   
10      2.53          39   
11      1.27          20   
12      0.43          7   
Year      4.76          867    

Lots of improvement possible in the summer--In the winter, not very much.

You can play with tilt and seasons to see what works well or not.

-Bill