The future of solar doesn't track the sun

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 turn that simple movement into a sun following motion. The bet was that a still simple mechanical gear would be more reliable than complicated electronics.

In the end none of our simulations made us confident any moving solution wouldn't eat the profits.

EDIT: For anyone interested, here is the patent. I think it is a really nice idea. https://patents.google.com/patent/EP0114240A1/en

I just spent 6 years living off-grid, running 5kw of solar, and 14kWh of storage. I setup a fixed array that I welded together myself. I could certainly see that tracking wasn't worth it even then.

However, in the off grid-setting I did discover some nuance. Sometimes you could really do with some power around sunset or sunrise. In the winter, being able to more reliably run my air-source heat pump at sun-up would have been very handy. Or likewise, some extra power to run the AC (which is the same device) in the early evening in the summer would have also been handy.

There were plenty of cold mornings when I was keeping an eye on the solar grafana dashboard, waiting for that hockey-stick moment when the sun swung into the right place!

I did consider the possibility of setting up an additional east or wast facing array to capture sun at the extremes of the day. Unfortunately that would have required its own MPTT charge controller, and would have just been more complexity in general.

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-angle light wasn't a factor). I'd never thought of such an array on this scale, at this low angle, before.

I don't think most of the people reading this article quite understand that this is a completely different kind of array topology to flat-plate fixed-tilt, or tracking-based systems. Do yourself a favor, if you consider yourself intellectually curious, and if you came away from skimming this article thinking there's nothing new under the sun, read it again with a keener eye toward the novelty of it.

Looking at the graphs, the tracking arrays may have the added benefit of generating power in the mornings and evenings. If everyone builds non-tracking arrays, power during peak will become almost worthless if solar is a big part of overall generation capacity, so the economics might change even with panels being cheap.

Of course, just building 2x as many permanently tilted panels might also work.

Edit: the article actually addresses this: "[fixed setups] can pack 250% more installed power into the same space when compared to a single-axis array" - so even if only the power in the morning/evening has value, there is little reason to install tracking ones.

I wonder if you could make a DMD [1] where instead of mirrors the tilting part is tiny solar panels?

The panels would only have two positions, but you could install half the DMD devices so that the two positions are south and southeast, and half so they are south and southwest. You could then have half your panels southeast and half south in the morning, all of them south midday, and have southwest and half south afternoon.

That would get you at least some tracking and it should be mechanically a lot more reliable than the systems that move large panels.

DMDs were designed for use in video projects, where they have to move the mirrors more times in 4 hours of video than a solar array would need to move the panels in 1000 years.

[1] https://en.wikipedia.org/wiki/Digital_micromirror_device

We have an east/west roof with solar on it. It is less efficient than our previous roof which was pure south - but it smooths out the generation and gives us more electricity in the evening.

I have some pretty graphs at https://shkspr.mobi/blog/2020/04/comparing-solar-panel-gener...

When panels are cheap what about vertical mounting? Less susceptible to hail and snow. And maybe placed north-south, to maximize production in morning and evening when it's needed most.

Nature has come up with moving limbs on animals, but none of the trees seem to be tracking the sun. Branches are in fixed positions.

I used to work on solar power plants and solar tracking technology back in the late 2000s. Even back then, I remember frequently discussing that "eventually panels will be cheap enough that we'll just wallpaper the world...". It's really nice to see that coming true.

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

The graphs show huge price drops over the last ten years. I wonder, how different does the price look for residential solar panel installations? Presumably the labor will start to dominate the cost if it doesn't already?

I always see articles about the decreasing cost of solar, but where are these costs collected from? Is it just not available at a consumer level? Maybe I missed the sources in the article somewhat...

I don't understand how east-west arrays differ much from just a flat area. At the end of the day, don't they capture all sunlight in some large square? The east-west array only captures a bit differently around the outer edges. Can somebody explain? Is solar panel efficiency that dependent on incidence angle?

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.

How does using these the power from your panels to generate natural gas help solve climate change? Unlimited abundant natural gas sounds awful

I thought this might be an article about a solar updraft tower, which also doesn't track the sun, or require solar panels.

The article fees disingenuous, flat panels collect the maximum sunlight from a given area of land and require fewer panels than the arrangement shown. Angling them helps the rain wash them and reduces the amount of mounting brackets unless you’re laying panels flat on the ground. Similarly total KW over the day isn’t why tracking mounts are so common instead it’s the increased value of electricity in the mornings and evenings so the actual economic benefits != total kWh.

However, the bit where it’s talking about increasing the angle means creating gaps between panels or the shadowing is going to offset any gains while also requiring far more panels and more land at which point you might as just angle the panels based on latitude.

"Sunlight at angles below 15 degrees is considered nearly uncapturable due to the effects of the ozone layer scattering sunlight."

Surely it is Rayleigh scattering that is important, not scattering off ozone?

I really like that how it's possible to put bifacial panels vertically along north-south direction to get solar power off peak. It should reduce cost of installation (it's basically multiple rows of fences), snow removal and cleaning. Washing down panels from dust could probably be automated too and if you build them up a bit higher you could have a meadow underneath or even a field of something. Hail should also be probably less of a concern. You need more land of course but it's still awesome.

So, a sloped half cone is ideal if you have the space?

I think this has been common knowledge for a while now.

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