Am I reading this correctly? Vertically they produce 77% compared to 90% of the tilted panels? In what graph is the lower number better?

Also: "Specifically, [Dave] is using bifacial solar panels– panels that have cells on both sides. In his preferred orientation, one side faces South, while the other faces North. [Dave] is in the Northern Hemisphere, so those of you Down Under would have to do the opposite, pointing one face North and the other South."

Isn't that the same thing? Is one of the sides specifically meant to face the sun? Maybe I'm just not as knowledgeable about solar panels, but what sunlight is being harnessed by the backside of the sun facing panel? Are they catching reflected light, otherwise, they are directly in shadow.

It's such an interesting optimization problem. Maximizing annual production isn't the only goal. It's also about: never running out of power, having surplus power when useful, minimizing installation cost, minimizing maintenance cost, guarding against dust and hail, minimizing use of land, etc.

Approaches range from straight vertical to flat on the ground: https://erthos.com/earth-mount-solar/

Utility scale fields tend to have single axis trackers which can optimize output. They are expensive though. I wonder if a manual rack that could lock at 30 or 90 could work and be cost effective.

Come on: "Specifically, [Dave] is using bifacial solar panels– panels that have cells on both sides. In his preferred orientation, one side faces South, while the other faces North. [Dave] is in the Northern Hemisphere, so those of you Down Under would have to do the opposite, pointing one face North and the other South."

That is not the kind of thing I come here for.

In their field?

I read somewhere (maybe in Dave's youtube comments) that the price of fencing is high enough that some folks have used bifacial vertical solar panels as a fence.

Article doesn't give a whole lot of context, but there's two key innovations here:

1. Bi-facial solar panels: can take in sunlight from either end

2. Mounting bi-facials vertically so they can take in sunlight from both directions.

I've been hearing experiments about these for a few years now. There's three main benefits to the vertical arrangement that could, given certain situations, make it more economically valuable:

1. In places with high-albedo snowy winters, this arrangement can boost winter production, which if you have snow, tends to be the energy-heavy time of year.

2. Keeps panels cooler. Panels lose efficiency when they get hot, and by having them vertical, they can run cooler. Losses in less direct sunlight are somewhat offset by efficiency gains from cooler operations.

3. More power during shoulder periods (anti-duck-curve). Especially in places like California that have high solar penetration, prices for excess energy are minimal during peak solar activity. Vertical arrangements give more power in the morning and evening, which is when traditional fields are just ramping up or ramping down. Thus, even if you're making less power overall, you can be making more valuable power by having more production during these ramp-up/ramp-down periods.

Unclear how much of an effect these counter-acting forces actually add, but I understand solar developers are looking into these arrangements.

At 45°N latitude, I keep mine nearly vertical year round. I used to adjust them 4 times a year for more optimal production. There are issues beyond angle of incidence. Being nearly vertical keeps the snow off in the winter. In the summer it reduces the cleaning required (it's a sea bird rookery, so that's kind of a lot). Beyond that, the telemetry needs are constant year round so if the panels can cover the needs in the winter, then summer is no problem.

My current strategy for small installations when you have an equator facing wall or fence is slap the panels on it and be done with it.

This setup almost certainly took more carbon to make than it will ever replace. This is usually true anywhere it snows regularly. There are a couple of exceptions, but unless you are above 7000ft of elevation you are just making the problem worse. This guy should donate this setup to someone in Mexico where it would make sense.