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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

#71

Post by lucb1e »

mr_world wrote: post #65

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

Consider where that methane / natural gas is coming from. Their homepage says (with the world's most convoluted hyphen-omitting compound adjective, but basically see the last 6 words):

> March 2024: Terraform completes the end to end demo, successfully producing fossil carbon free pipeline grade natural gas from sunlight and air.

If you take carbon from the air, mix in energy from the sun to turn it into a fuel, then burn the fuel (undoing the reaction), where is the pollution?

There's more efficient ways to solve the climate problem than to install ginormous amounts of gas production, like you can run a heat pump instead of creating methane from that energy, but it's a solution that'll please even the old farts (no pun intended)

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

#72

Post by turtlebits »

rini17 wrote: post #2

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.

Yep, but you're severely limited in terrain types. Unless you need the "fence" cover, I can't see it being worth it due the efficiency loss.

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

#73

Post by turtlebits »

tmjdev wrote: post #31

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...

There are lots of consumer facing companies selling panels. You'll need to buy in bulk (generally a pallet), but you can easily get them for $0.30 / watt.

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

#74

Post by edent »

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...

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

#75

Post by johnea »

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…

This was going to be the gist of my reply.

I don't have the depth of experience with solar installations cited in your comment, but I have worked with systems that expected automated moving parts to continue to function in an outdoor environment. They all required near continuous maintenance.

Having a high level of cynicism regarding the utility industry, I wonder if the preference for moving parts is due to the requirement that only a large company with a constantly employed force of service personal can manage such a system. This would provide a certain amount of cost-of-entry that only large utilities could provide.

To quote what a utility company's compliance office once said to me, in a different context, "Only big companies can do that".

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

#76

Post by hx8 »

adamcharnock wrote: post #66

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 ha…

I honestly don't think I would be comfortable off grid without 4x+ that size. Of course, environments vary so significantly that these numbers don't translate well when discussing them without geographic context.

My primary concerns would be consecutive cloudy days, and winters with very short days. While my actual heating/cooling needs are more mild than global averages, I think the combination of short daylight hours and increased heating needs makes off-grid solar unviable for climates closer to the poles, especially those not near sea level. I do think relaying on propane or wood for heating might make off grid viable for these locations, but that introduces questions of scalability and increased carbon footprint.

There is some argument that burning wood should be considered carbon neutral if the trees are replanted and used as a renewable resource (Carbon is released to the air, and then captured by the next tree in a cycle), but the land intensive approach wouldn't scale to meet the heating needs of a significant portion of the population. Additionally it ignores the carbon required to grow, harvest, process, and transport the trees or the alternative uses the wood might find elsewhere.

My point is for others to take their local climate into consideration before thinking that 5kw/14kWh would be enough for them to go off grid.

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

#77

Post by UltraSane »

adamcharnock wrote: post #66

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 ha…

What is the appeal of living off-grid?

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

#78

Post by gpm »

adammarples wrote: post #16
rini17 wrote: post #2

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.

North South is exactly opposite of what you need, the sun is never north

I'm pretty sure by north-south they are talking about the direction the panel lies in, i.e. the faces point east/west.

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.

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

#79

Post by lm28469 »

rsync wrote: post #63
Calwestjobs wrote: post #39

Earlier quoted context omitted.

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" ?) 2…

Americans basically live like energy is unlimited, free and has no side effects, the rest of the world doesn't have that chance, last time I checked the average US household used anywhere between 3x and 4x more electricity than the average EU household

They tend to prefer huge houses with relatively complex designs (less optimal in term of area/volume ratio) / poor insulation, they make up for it by relying on tech for heating/cooling pretty much year round.

Your tankless water heater is a good example of something that is completely inadequate for solar setups, they draw insane amount of energy over very quick period of time. But I think that's the core of the issue, if you want to keep all the nice things modern American houses have you're going to need a lot of money and a lot of sun. On the other hand if you're a bit more frugal, with so called "passive house", you can get by with a much smaller setup.

> I will note in passing that both our dishwasher and our microwave oven require 20A circuits

And a tankless heater will need 5 times that, unless you're using gas but I wouldn't count that in a "modern first world 21st century home".

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

#80

Post by sneak »

hx8 wrote: post #76
adamcharnock wrote: post #66

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 ha…

I honestly don't think I would be comfortable off grid without 4x+ that size. Of course, environments vary so significantly that these numbers don't translate well when discussing them without geographic context. My primary concerns would be consecutive cloudy days, and winters with very short days. While my actual heating/cooling needs are more mild than global averages, I think the combination of short daylight hou…

In these sorts of rare situations it is of course possible to run a generator to charge everything up. Off-grid doesn’t mean on an island.

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

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