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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

#61

Post by philjohn »

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 have an east/west array on my roof, as my house is positioned with the front facing west.

In the winter it's outperformed by a south facing array (northern hemisphere) but in the summer the east array gets a ton of sun before midday, and crucially, it's getting a ton of sun when the temperatures are a bit cooler, so it performs very well.

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

#62

Post by philjohn »

leoedin wrote: post #27
tgsovlerkhgsel wrote: post #19

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 a…

Yeah - you can’t talk about renewable energy generation without also considering when it is generated. Then future price of energy will be incredibly time dependent. Finding a way to generate at a different time than everyone else - whether by east/west panels or time shifting with batteries or building a different kind of renewable generation is where all the big profits will be.

It already is on wholesale markets - in the UK you can get on Agile Octopus which gives you half hourly prices. When there is a glut of renewables on the grid you can end up being paid to use energy.

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.

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

#63

Post by rsync »

Calwestjobs wrote: post #39
tgsovlerkhgsel wrote: post #19

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 a…

but, 70% of MY! yearly households electricity consumption is literally into [PV!] hot water. Hot water tank is cheapest energy storage device on planet. and i do not have to worry to shower in noon, i can just charge my water tank during day, even when im not home. and use hot water in evening. for very little price - no need to use heat pump, resistive heater is super cheap. hot water tank can be made even DIY to lo…

I read, and appreciated, your entire comment - thank you.

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.

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

#64

Post by mrshadowgoose »

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 actually use this exact example when encouraging careful attention to paradigms where a fundamental variable is slowly but consistently changing.

It's essentially equivalent to a boundary on a phase diagram: Cost/Watt has fallen past a critical threshold, and suddenly this dramatically different approach just makes more sense.

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

#66

Post by adamcharnock »

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.

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

#67

Post by Gibbon1 »

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…

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.

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

#69

Post by photochemsyn »

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…

Another interesting configuration is vertical bifacial panels aligned on North-South axis and interspersed with farming rows. Low-cost panels make it feasible and it doesn't much block agricultural production if the panel rows are spaced far enough apart.

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

#70

Post by turtlebits »

tzs wrote: post #51

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 aft…

Too much complexity and maintenance. Solar panels are dirt cheap, and with fixed mounts, zero maintenance. The rack you mount them on costs more than the panels.

The only reason I can see for added complexity is if you're space constrained, and in almost all cases, not cost efficient.

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