Author Topic: Tracking-Latitudes increases percentage?  (Read 3905 times)

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pwhipple

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Tracking-Latitudes increases percentage?
« on: April 03, 2016, 06:21:50 PM »
It has occured to me that the farther North or South of the equator a pv mounted tracking system is the greater the percentage increase one would expect,  the extreme would be a system at the North pole making a 360 circle in the summer following the sun? I'm at 53N and my summer days are extremely long and the sun scribes a long arc across the sky. I know most say put the money towards a few more panels, my question is there a latitude where tracking beats a few more panels? I have never seen this topic brought up so figured I would see what others thoughts were.

SparWeb

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Re: Tracking-Latitudes increases percentage?
« Reply #1 on: April 03, 2016, 08:33:11 PM »
Not frequently discussed, but probably true in the highest latitudes.

I'm writing from 51 North, so I know what you're asking.  Most data tables I have in books etc, are for US locations, below the 49th, of course.
I haven't gone to check in a while, but the PVWATTS program probably allows you to include "azimuth" tracking in the calculation.  If it's there, then you can do your own research to see how tracking the sun benefits total KWH production.  If you try a few different latitudes, you may find the "tipping point" where tracking boosts summer production enough that the doldrums of winter are overcome.  I haven't tried this but if you want to try, let me know what the results are!
No one believes the theory except the one who developed it. Everyone believes the experiment except the one who ran it.
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frackers

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Re: Tracking-Latitudes increases percentage?
« Reply #2 on: April 04, 2016, 04:37:32 AM »
Some great background and definitive information at http://www.solarpaneltilt.com/
Robin Down Under (Or Are You Up Over)

Mary B

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Re: Tracking-Latitudes increases percentage?
« Reply #3 on: April 04, 2016, 03:57:19 PM »
Reading that adding 30% more panels would compensate for fixed tilt... with the price of a tracker, the headache of moving parts in a high wind location(I had 80mph gusts last Friday night) more panels makes the most sense!

pwhipple

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Re: Tracking-Latitudes increases percentage?
« Reply #4 on: April 05, 2016, 05:57:26 PM »
I tried out the PVWATTS, thanks for the reference, handy program.  I tried the difference between tracking and not tracking at my latitude, for the highest output month it increased a 10kw system from 1478 to 2324 or almost 45%.  Quito, (on the equator) went from 1232 to 1817 or 38%. Interesting stuff!

MattM

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Re: Tracking-Latitudes increases percentage?
« Reply #5 on: April 05, 2016, 06:37:22 PM »
The farther north there is an incentive to maximize available light.  The sunlight is more abundant in the South.  I cannot imagine tracking in the south, but can see the reason for it up north

SparWeb

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Re: Tracking-Latitudes increases percentage?
« Reply #6 on: April 05, 2016, 10:59:21 PM »
If you look hard enough - and believe me it's not as easy as just using PVWATTS - you can find another solar energy calculator on the NRC website. 
It can also be configured for your location (in Canada!) and you can select various panel tilt angles.  I have used this to cross-check the PVWATTS (close but not exactly the same).
I don't think it calculates the effect of azimuth tracking, so it's only good for checking the non-tracked PVWATTS result.
No one believes the theory except the one who developed it. Everyone believes the experiment except the one who ran it.
System spec: 135w BP multicrystalline panels, Xantrex C40, DIY 10ft (3m) diameter wind turbine, Tri-Star TS60, 800AH x 24V AGM Battery, Xantrex SW4024
www.sparweb.ca

Mary B

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Re: Tracking-Latitudes increases percentage?
« Reply #7 on: April 06, 2016, 06:31:08 PM »
Using PV watts I can go from 2.4kw of panels to 3.6 and have the same output as using a 2 axis tracker. ~$1k in panels versus $2k++ for a tracker...

madlabs

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Re: Tracking-Latitudes increases percentage?
« Reply #8 on: April 06, 2016, 07:32:31 PM »
I have always wanted to build a tracker. I have most of the stuff and all the tools. I have all the stuff I need to build and program a controller too. And by golly, what a fun project. Watching it follow the sun would be awesome! But..

I just can't justify the effort, time and resources, not to mention the ongoing maintenance. Fun is fun, but a static rack is too easy to build and make storm proof and once properly coated, needs no help from me for years. The panels just sit there and crank out the juice. When I built the rack for my 4.3kW's worth of panels I had it powder coated so it will be many years before I need to do anything to it.

All that said, it is a fun project. And while I avoided a tracker, I am in the middle of restoring a 1946 Hallicrafters SP-44 Skyrider Panadapter and making an interface for a moderen radio for it. So I'm not against silly projects but I am well aware that it makes no sense. As long as a tracker is the same for you, then go for it! We'll help all we can.

I did help a pal make one once. After fiddling with various sensors, we ended up making a lookup table that set the panel angle according to date and time instead. Worked well, but was much more expensive and time consuming that just adding a couple more panels.

Jonathan


clockmanFRA

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Re: Tracking-Latitudes increases percentage?
« Reply #9 on: April 07, 2016, 04:16:18 AM »
Its all ways a trade off.

However, my static 3kW PV frame cost me about $400 in materials, concrete, steel, rails, cables etc.

My 2kW trackers cost me about $1100 in materials, concrete, metals, activator ram, Daves Australian Electronic control, (LED type sensor, but looks every 10 minutes, and auto parks at night) etc. But I get a 1/3rd more output than the static array over the year.

Using good MPPT controllers, means I can squeeze a good 10% plus out of the PV in ambient light conditions.

For home built stuff, that's cost effective, I have found that 2kW size, 8 x 250W, is the max size to play with in those violent Winter storms.

 
Everything is possible, just give me time.

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3 Hugh P's 3.7m Wind T's (12 years) .. 5kW PV on 3 Trackers, (8 yrs) .. 9kW PV AC coupled to OzInverter MINI Grid, back charging AC Coupling to 48v 1300ah battery