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The future of solar doesn't track the sun

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Re: The future of solar doesn't track the sun

#121

Post by kyboren »

Calwestjobs wrote: post #88
nbadg wrote: post #21

Compelling analysis. But if hail damage is the primary concern, tracking seems like an X/Y solution. What about eg anti hail netting that can be rolled out when the weather forecast predicts hail? It seems to me like a middle ground might be automated deployment of hail protection, which by definition has lower aero loading than what amounts to a big semiconductor sail.

i used standard chain link fence on top of my small greenhouse and it works even with such big "holes", no mechanism, just manual labor but needs good forecast which can be issue.

> it works even with such big "holes"

I'm intrigued. Can you expand more on this? Why does it work? I guess because the hail is rarely coming straight-on at the holes and instead makes more glancing blows off the wire?

In any case I think it's a perfect example of a good hack. Original out-of-the-box thinking producing an effective but unconventional solution. Chapeau bas!

Re: The future of solar doesn't track the sun

#122

Post by solardev »

b_emery wrote: post #100
didgetmaster wrote: post #97

Earlier quoted context omitted.

I always thought that someone would invent a cheap, simple, reliable, and passive tracking system. No need for sensors or intelligent electronics. You have a simple motor that slowly tilts the array from facing East to facing West as power is being generated. The motor does not start until the panel is generating a certain amount of power. The motor runs at a fixed rate with a screw that takes about 7 hours to move t…

Like a big, very simple clock basically.

A big, not so simple clock moving a heavy array in all weather conditions, having to deal with constant changes in humidity, temperature, thermal stress, potential salinity, wear and tear, lubrication, gears, jams, etc.

A large reason solar is winning out over wind is because the lack of moving parts drastically simplifies installation and maintenance. A solar tracker isn't as complex or high up as a wind turbine, but it's still much more complex than a standard roof or ground mounted array that doesn't move.

Trackers made sense back in the 70s and 80s when solar PV tech was still new, but now it's far cheaper to just add more module capacity than to try to dynamically optimize each module's facing through the day.

Re: The future of solar doesn't track the sun

#123

Post by [deleted] »

weinzierl wrote: post #6

We researched this thoroughly in the early 2000s and came to pretty much the same conclusion even back then. For us the main problem was the reliability of the mover. If enough panels face the wrong direction for long enough it is worse than facing the sun in a good enough fixed position all the time. Our angle was to use a simple motor that runs with constant speed and use a special patented gear (called VIAX) to tu…

[deleted]

Re: The future of solar doesn't track the sun

#124

Post by xphos »

tappaseater wrote: post #15
xphos wrote: post #10

One cool observation of an grid wide advantage is that single axis really normalize the power curve per panel. There are many reasons way more consistent production would be better. I am curious if just having more fixed panels normalize production at scale

I'm probably not thinking this through, so go easy, but why wouldn't tracked panels also produce a normalized power curve? My assumption behind the question is that they follow the same track as Sol every day, which doesn't vary at least year-to-year.

No i am viewing from there graphs of power over the day not over the year.

Untracked panel production has a sharp peak at noon and that rises and falls pretty sharply before and after that. Maxing/stable between 10am - 2pm

Single Axis flattened that curve up very heavily so you were producing at or close peak production for much longer. 8am - 4 pm

The double axis seemed to just get slightly high magintude in power compared to the single axis which is good but definitely marginal.

The question would be is if you have an array of fixed panels can you fixed them in a way that flattens out the peak production but provides a more level and less peeking production for the grid as a whole. This is really important because its much harder to turn off/disconnect solar than other forms of power. The grid has to be sure it doesn't overcharge or undercharge the grid. If you do either you'll deviate from the target 60Hz (US) you can damage a switching and transformer infrastructure.

A less peeky supply is more predictable generally speaking and gives you more time to react to changes in the grid. The per cost question would benefit from answer this because it might make sense to install more panels in a fixed position that is not maximally optimal at an individual level but is maximal for the overall grid health. That investiment in deployment is worth it to make now because you'll never want to change it afterwards.

Re: The future of solar doesn't track the sun

#125

Post by cake-rusk »

thechao wrote: post #119
Gibbon1 wrote: post #67

Earlier quoted context omitted.

I saw some guy in Britain that replaced his old fence with one made of solar panels because the cost difference between that and traditional was nil.

I have a fence that gets absolutely blasted with High Grade Texas Sunlight. It shortens the fence’s effective life by years — this idea is brilliant . Now I just gotta price out 80 sq m of solar panels. EDIT: The fence gets at least 4 hours of direct sun in the winter; up to 7 in the summer. I can easily install 10KW of panels. I don’t have any way to store the power. I suppose I could build a giant Tesla coil and za…

You can push excess power into the grid. It will reduce / reverse your electricity bill. Look into local regulations.

Re: The future of solar doesn't track the sun

#126

Post by otherme123 »

weinzierl wrote: post #6

We researched this thoroughly in the early 2000s and came to pretty much the same conclusion even back then. For us the main problem was the reliability of the mover. If enough panels face the wrong direction for long enough it is worse than facing the sun in a good enough fixed position all the time. Our angle was to use a simple motor that runs with constant speed and use a special patented gear (called VIAX) to tu…

Our research around the same time came to the conclusion of a sun tracker, with wind protection, would be the best option. The panels were very expensive (a 400'ish W panel that today cost $80 costed around $2,500-$3,000), so aiming for the absolute best performance for the panels was key.

The trackers fail sometimes, but I would say once a year or so. The electronics are not that complicated, and its reliability was higher than the motor itself. I remember calculating with fixed tracking of the sun (because you know were it is at all time) vs photocells that tell the motors were to move and by how much. The trackers win because when the day is cloudy the best performance is to put the panel flat and let it rest there (instead of tracking a sun that isn't there so the motor that day consume more energy that the panels generate), and with enough cloudy days the tracker outperform the fixed tracking by a significant amount.

It's not until recently, with 400W panels under about $500, that tracking no longer makes sense, at least in our latitude.

Re: The future of solar doesn't track the sun

#127

Post by tinodb »

mchannon wrote: post #56

I've been in solar energy as my primary vocation since the 1990's. I've built solar cars, I've built solar panels, I've installed solar panels, I've designed solar trackers. I know this industry inside and out. I'd never heard of an east-west array before (though I did experiment with one-cell-wide "crinolations" at 60 degree angles, did not find any value to using them but it was a different application where low-an…

I guess trackers really are an American thing? I’m in solar for ten years in The Netherlands, and I don’t think any utility scale fields use tracking. For residential roofs east-west placed systems have been an option for the same amount of time. They are now gaining popularity in The Netherlands because of net congestion during midday.

Re: The future of solar doesn't track the sun

#129

Post by poulsbohemian »

freehorse wrote: post #87
UltraSane wrote: post #77

Earlier quoted context omitted.

What is the appeal of living off-grid?

Sometimes the appeal is not in the "off-grid" itself, but in living in a remote location where having access to the grid is impossible or inconvenient (it does not have to be too remote either to not have easy access to the grid).

This is what I observe as a Realtor and living in a somewhat rural area - there are some people who like the idea of living the self-sufficient lifestyle, there are others who are convinced Armageddon is upon us and they are going to be ready, but mostly its because they found a beautiful location that speaks to their soul and the only way they can make it work is to use off-grid resources.

Re: The future of solar doesn't track the sun

#130

Post by thechao »

cake-rusk wrote: post #125
thechao wrote: post #119

Earlier quoted context omitted.

I have a fence that gets absolutely blasted with High Grade Texas Sunlight. It shortens the fence’s effective life by years — this idea is brilliant . Now I just gotta price out 80 sq m of solar panels. EDIT: The fence gets at least 4 hours of direct sun in the winter; up to 7 in the summer. I can easily install 10KW of panels. I don’t have any way to store the power. I suppose I could build a giant Tesla coil and za…

You can push excess power into the grid. It will reduce / reverse your electricity bill. Look into local regulations.

I've got a co-op that won't net meter below a fixed cost that's close to my monthly. I just like the idea.
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