[RE-wrenches] Seasonal Adjusters

[R. Walters]

This is a funny thread as I spend some of my time doing commercial  
installs in Hawaii, where tracking and tilt adjust is definitely not  
happening, and you're lucky to get the panels facing even close to  
south. The rest of the time though, I'm working with off grid  
customers that some may actually track azimuth manually by loosening  
the bolts on their top of pole rack.  Tilt adjust in New Mexico for  
off grid is pretty important, as we have short but intense winter  
days followed by lots of snow that doesn't slide off unless you have  
at least 40 degree tilt.

Also, I've run the numbers for Wattsun trackers with grid tie, and  
the economics pencil out in favor of tracking. (PV Watts lets you  
compare the benefits for your area)
If there is actually unobstructed area for tracking (very rare) I ask  
the customer if they're interested. If they seem mechanically  
inclined and like the idea, I might do it.
But if its a little old lady, who doesn't want to mess around, I set  
everything for a year round setting, and never look back.

BTW, I once tried Unirac's roof mount with tilt adjust: very flimsy,  
and hard to work with.

R. Walters
Solarray.com
NABCEP # 04170442	



On Aug 13, 2009, at 2:36 PM, Ezra Auerbach wrote:

> I so totally agree - during the winter there's not enough sun to  
> make a difference where we tilt the modules, and in the summer we  
> dump power anyway so we've set them for a nice spring/fall angle  
> and forgot about them for the last decade of so. The funny part is  
> I spent all kinds of extra dollars on my racking so it could adjust  
> it seasonally and through the day too. Never have done either with  
> this racking simply not worth the trouble.
>
> Ezra
>
> DragonSun Consulting
> On 13-Aug-09, at 11:25 AM, Jeff Yago wrote:
>
>> I realize your client is set on doing this, but I installed  
>> adjusting tilt racking on the 5 kW solar array I installed on my  
>> home over 15 years ago and I can tell you after the first year of  
>> adjusting these heavy sections I finally selected an average  
>> position and they have not moved in 14 years.
>>
>> I know there is a drop in the "calculated" performance between my  
>> fixed mount and a semi-yearly tilt adjustment, but when you take  
>> into account all the variations in weather, temperature, cloud  
>> cover, system load, and battery state of charge, which are not  
>> under our control, will impact system performance far more than  
>> this tilt concern.
>>
>> I say pick the best tilt angle that matches the season of year  
>> that has the most system loading and forget about installing a  
>> high cost adjustable mounting that most likely will never be used.
>>
>> Jeff Yago
>>
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