The future of solar doesn't track the sun

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 zap the neighbor’s dog?

If you buy a bunch of commodity modules (panels) without moving parts, you generally don't have to maintain anything except maybe replace the inverters in a couple decades. And you can do that with any electrically compatible parts.

If you have a moving motor, suddenly you need to find all the specific parts for that particular motor, and hire a specialist crew to maintain and replace it, requiring a team with not just electrical knowhow but motor mechanics too.

That's largely incompatible with the US model of solar deployment we have now, which is largely "install and forget" using whatever equipment is currently cheap and available. It's very likely that the equipment manufacturer won't be around in a few years, and that installation company probably won't be for much longer. So any additional possible failure mode should be avoided.

At commercial or utility scale it might be different, but generally it's still more cost effective over time to just buy more modules to offset the less than optimal facing than to try to actively adjust their direction with moving parts. Modules keep getting cheaper. Motors, and more importantly, shipping and labor don't. Installing an overcapacity upfront is still cheaper than maintaining the trackers later.

The insane energy density of fossil fuels means this is an excellent “emergency” back-up plan should the sun not shine often enough.

Merely a 10 watt panel in the Netherlands has been fine whilst camping for weeks, but obviously I have to severely compromise on modern life - 10 watts powers a lamp for a few hours in the evening and a phone charge each day.

Some people are really into that. I’m really into same-day Amazon delivery and 30 minute latency on fresh pizza that I didn’t have to cook.

Trackers are useful when the majority of the incoming sunlight is direct (America has a mix but the western half and parts of the south have a lot of direct).

Trackers are essential when you use concentrated sunlight.

A tracker that doubles the amount of sunlight hitting a panel is not free, but it also makes the panel take up 2x the area, or more, to avoid shading its neighbor.

The thing people tend to forget about trackers is they offer this trade-off where you can trade shaded area for power per rated panel. When land is cheap and panels (or arrays, heliostats, power towers, etc.) are expensive, trackers make sense.

The reverse has been the case for the past ten years, and continues to get more true by the day. I doubt we will ever see the day return where land is cheap again and/or PV are expensive again.

This highlights the need for grid scale storage (be it batteries, pumped hydro or something else) to balance Solar PV, and to bridge gaps when the wind isn't blowing.

I live in an area with frequent, often day long power failures during winter storms. So my house is designed around that.

When I bought a new hot water tank, I spent a little extra for the super insulated one. The result?

I can take a shower during a power failure, and still another not as hot 24 hrs later! When you consider that the first shower injected cold water into the tank, that's fairly impressive.

On long power failures, on the third morning I can even take a lukewarm shower, with no cold water at the shower (I have individual hot/cold controls). This is far preferable to a shower at 5C water temp (from my well in winter)

And where did any eacaped heat go? Why... into my house! Surely not a loss.

So yes, water tanks rock.

You describe a simple and elegant solution to some portions of these problems and what you are doing with your hot water "battery" is smart.

I am forced, however, to ask:

Where do you live and how large is your family ?

My suspicion is that you do not live in the United States and your family is relatively small ... ?

Modern, "first world" ("global north" ?) 21st century homes do not match your model in a number of different ways:

- Unlimited, temp stable hot water comes from a tankless water heater. People don't "run out" of hot water anymore.

- A family - even a relatively small family - runs a 30A dryer daily. Our family of five runs it 1-2x daily.

- Many, many people now have electric cars and some households have two of them.

- I agree that laptops and phones and personal electronics are a rounding error here but microwave ovens, toasters, coffee percolators, etc., are not - and people use them. I will note in passing that both our dishwasher and our microwave oven require 20A circuits.

I am optimistic that we (as a society) can satisfy these demands with solar power - I just want to make sure you appreciate just how much demand for electricity a modern US household has.

FWIW, we are planning on going entirely off-grid, purely solar with lifepo batteries, in the next 18-24 months.

For a lot of applications, panels are so goddamn cheap now and breakeven happens so fast that "Just buy twice as many panels" is the best solution to any problem that doesn't involve land area. Winter production in a snowy/leafy climate at a latitude tilt, though, is the exception to the rule; Production is so impaired without regular maintenance that twice as many panels is not very helpful. But set those panels vertical, at a range of orientations, and snow/leaves stop being an issue, you get sizable exposure with the sun low on the horizon, the maintenance requirement goes away, and you get an appreciable amount of power earlier in the morning and later in the afternoon, you just don't get quite as much at noon.

[1] https://news.ycombinator.com/item?id=42591918

I don’t see the logic? As panel prices drop, installation costs start dominating overall cost of energy produced and so economic pressures will be on simpler and simpler PV installations. Laying a panel almost flat on the ground amongst thousands of others will be a cheaper process - both initially and in terms of ongoing maintenance - than anything that involves sending workers up ladders or cherrypickers attaching and wiring a panel onto the side of a building.

So grid scale will start to dominate over domestic or “novelty” (e.g. floating panels on reservoirs) and simpler and simpler approaches to installation (like removing tracking) will become attractive.

These effects are already apparent. Basically the opposite of what you’re predicting?

But even under your interpretation, you aren't always right. If you're far-ish north of the equator you want south facing panels (and the reverse) and if the cells are cheap enough it makes sense for those panels to be bifacial, with one side permanently facing away from the sun, to get a bit of extra energy from ambient light. Especially in winter when there is less sun (so energy is at a premium), and highly reflective snow resulting in a lot of ambient light.

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.

You want high tensile strength and some level of flexibility/elasticity to absorb the hailstone energy over a greater-than-zero distance. Or to shatter the hailstone well above the solar panel.

Probably too light-blocking to leave up continuously, and maybe awkward and failure-prone to deploy automatically.

So insurance is probably more cost-effective for most installations.

Nets are flexible. The energy of the collision goes into accelerating the net at the point of the collision. The net can quickly spread that energy into accelerating the surrounding areas of the net and so on. Unlike with a rigid cover this is not nearly instantaneous, so you don't have all the kinetic energy of the hail being poured into the net at once. That and the ability of the net to rapidly spread energy means that you don't get enough energy anywhere to break the net. It just stretches as it decelerates the hail.

You can see how this works by watching a soccer game and observing how the nets at the goals stop balls. Hailstones that weigh more than a soccer ball are extremely rare, as are hailstones that are falling faster than many strikes and penalty kicks in a professional soccer game, and you don't see many soccer balls breaking through the net.

People have calculated how fast a soccer ball would have to go to get through the net and found that it is over 220 mph. The largest recorded hailstone is estimated to have had a terminal velocity of 168 mph, based on size, mass, and atmospheric conditions. That hailstone had about 16% more kinetic energy than a 220 mph soccer ball and so might have broke the net, but soccer nets are by no means the strongest nets that can made. And remember that was the largest hailstone ever recorded--we are talking a once in decades event.

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!

Literally laying them flat on minimally cleared land would win the simulation. Fewer panels, fewer acres, less mounting hardware, less labor, more power. Real world conditions not included in the analysis, such as wholesale electricity prices over a day and land not being flat, drives a lot of these choices.