The need to (or not) carefully track the sun for solar

The notion of more efficient tracking on equator is counter-intuitive indeed. (Other than cleaner air conditions in some areas).

Quito on equator, fixed flat panel, 72% of optimum annually.

Winnipeg, flat panel - less value in tracking than on equator? In other words, flat panel in Winnipeg is more than 72% of optimum? (or better than whatever % of optimum is flat panel in Quito, I didn't check numbers in the article)

Not clear on what Mex means. As you go North in summer you get more daytime out of the 24 hrs, so that would mean longer time shoulder hours away from South pointing. (near the Equator ISTR daylight/night are more equal for times)

So I would think ? that would mean more value for tracking around to the E in the morning and W in the evening farther North? Of course when you do that the sun is low, so you should tilt the panels up quite high those times.

MEXICOWANDERER wrote:
One thing that is not mentioned often is the closer you get to the equator (lower latitude) the more "efficient" tracking becomes.

Closer to equator it would make even more sense yet not to bother with tracking or even a tilt, and just mount it flat. Here it is in more details.

Fixed horizontal panel in Quito Equador, i.e. zero tilt, is 72% optimal annually. With 2-axis tracking you would've gained 38% more than what you have with flat panel.

In Northern Canada you would want at least a fixed annual tilt (41.1 deg, according to this guy) - this would result in practically same efficiency as flat panel in Quito, i.e. 70% of optimum.

So, my verdict is: all-day automated tracking is not worth the trouble. Maybe only in rare scenarios, like a very small trailer, very dark and rainy weather, and no other energy sources. If none of the above applies to you, - get more panels.

Gain up to...

Save up to...

Lose up to...

These are hallmark hooks of salesmanship. One thing that is not mentioned often is the closer you get to the equator (lower latitude) the more "efficient" tracking becomes. The same for clearer atmosphere the entire day with uninhibited horizons. Nazca, Peru, would meet that upper limit.

Boon Docker wrote:
Ninety percent of the information I have read states that you can gain up to 40% by tracking vs non tracking. That does take into consideration energy consumed using an automatic tracking system.

Simple...add 40% more solar panels and you just made the difference up at less cost.

I have a full wall slide so all vent pipes and such are on the curb side. I installed 4 256w high voltage panels. NO SHADOWS and I'm loving solar. No tilting necessary. ONLY time i run the diesel sipping Onan Quiet Diesel is when DW uses convection microwave. No tilting for me thanks.

MEXICOWANDERER wrote:
The big issues with on the earth trackers is a) theft b)the wind may have an entirely different idea of where to place your tracker.

The first ten percent and last ten percent of a day's irradiation are not worth the trouble harvest wise IMHO especially Oct - Feb

a) - yes.
b) - yes.

The first 10%... In central Baja my charging starts about 6.30 am in winter, if I'm parked with the "correct" side to South-East. But then, with what little energy I need there, 10% would be negligible. So, - Yes to this one too.

The last 10% - Yes. On a good or average day (same thing) the last 40-60% of irradiation are not important to me because battery is floating since 11 am. Shade from coco palms in Michoacan jungle highlands would be a pain for sure :)

I'm curious why the OP needs tracking (or thinks that he does). In Ca it's easy to install enough wattage on the roof not to need tracking. Sometimes in South West people have "tilting" arrays on the roof, not really "tracking", and even those become rare now that panels are so cheap that you can cover the whole trailer if you want.

Manual tilting-tweaking on the ground is popular with small portable installs for 2 reasons:
1) they are few times smaller than an average permanent roof install (= not enough harvest),
2) easy to tweak on the ground.

I made my permanent 500W roof array tilt-able manually to one side. Wasn't difficult to do but it turned out that I don't need those extra 15-20% of harvest that badly. Climbing the roof and possible wind effects (winds there can be sudden and fierce like Santa Ana winds in SoCal) make it not worth the trouble.

Some other info.

IN days of old when Solar Installers were truly bold.. Panels were very "Senistive" to the angle of incidence.. They wanted to look STRAIGHT at the sun.

You can see some big "Trackers" in Las Vegas alongside one of the freeways that were early Solar Installs.

More recently I've been reading of "New Technology" that "Widens" the field of view.. Not sure what they are up to but if you get like 80-90% with the sun off at say 45 Degrees.. Why bother tracking????

Not far from where I am and I'll be passing it in two Tuesdays is a large solar farm.. IT DOES NOT TRACK.

BFL13 wrote:

This is great. Thank you for sharing the photo.

MEXICOWANDERER wrote:

THIS is the alternative to sitting next to the panel all day.

http://www.budgetastro.net/tracking-the-stars.html

I think I turn mine 4 times during the day, but soon that will be 0.

Thanks for the link. I think I've seen that one before but it always helps to revisit stuff like that.