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How cheap does solar power need to get before it takes over the world?

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Re: How cheap does solar power need to get before it takes over the world?

#71

Post by dangravell »

WaylonKenning wrote: post #27
martinald wrote: post #11

I think the issue is that OK, say we managed to get to 100% electricity being solar when the sun is shining. You'd still have the time the sun is not shining, which would likely be more expensive than before (a gas powered plant would only be running half the time - effectively doubling its capital/construction cost per kWh). So you'd definitely have an improvement on some levels but I'm not sure that would really he…

Everyone seems a bit obsessed by batteries as a storage method, when we have more traditional methods: - Pumped-storage hydroelectricity - https://en.wikipedia.org/wiki/Pumped-storage_hydroelectricit... . Sure it's not suitable everywhere. - There's always Molten Salt as well - http://www.solarreserve.com/en/technology/molten-salt-energy... . Also, solar isn't the be all and end all of renewable energy generation. Wi…

PCM being used for domestic hot water now, see companies like http://sunamp.co.uk/products/sunamppv/ .

Much better than water - higher energy capacity means smaller units and higher performing insulation making losses much lower.

Heat loss is a bit problem in stored water DHW scenarios and will get even more of a problem if we begin building houses properly (which surely has to happen at some point).

Re: How cheap does solar power need to get before it takes over the world?

#72

Post by evgen »

dredmorbius wrote: post #68
extrapickles wrote: post #57

Earlier quoted context omitted.

Compressed air storage rings of a scam to me. They never mention how efficient it is to compress the air and turn the air back into electricity. It's always how efficient their storage tank is, which on paper gives batteries a run for their money. When sizing an industrial air system a rule of thumb is to budget 7-8hp of compressor for 1 hp of air motor. That is 12% efficiency, or only worth it if you had no other so…

My understanding is that the grid-scale stuff will be using natural geological reservoirs -- basically re-filling old gas wells with air. My understanding isn't particularly deep, and I'd like to run numbers on storage, volume, pressure, etc. But I suspect this'll have to be big enough that constructing cans really isn't viable.

Doesn't this run into insulating problems for the resevoir? How do you prevent the pressure from being lost as heat?

Re: How cheap does solar power need to get before it takes over the world?

#73

Post by spacecowboy_lon »

icefox wrote: post #24
martinald wrote: post #11

I think the issue is that OK, say we managed to get to 100% electricity being solar when the sun is shining. You'd still have the time the sun is not shining, which would likely be more expensive than before (a gas powered plant would only be running half the time - effectively doubling its capital/construction cost per kWh). So you'd definitely have an improvement on some levels but I'm not sure that would really he…

Of course if the more solar we get combined with cheap computing a market will emerge where there are two prices of electricity. Car charging will probably be first where they turn on/off depending on the solar output. Refrigerators and AC could follow.

Bit of a problem if you have to do that "turn of electric car charging" if you have a non trivial number of electric cars.

Re: How cheap does solar power need to get before it takes over the world?

#74

Post by amazon_not »

erikpukinskis wrote: post #36
WaylonKenning wrote: post #27

Earlier quoted context omitted.

Everyone seems a bit obsessed by batteries as a storage method, when we have more traditional methods: - Pumped-storage hydroelectricity - https://en.wikipedia.org/wiki/Pumped-storage_hydroelectricit... . Sure it's not suitable everywhere. - There's always Molten Salt as well - http://www.solarreserve.com/en/technology/molten-salt-energy... . Also, solar isn't the be all and end all of renewable energy generation. Wi…

Batteries have some advantages that can offset the cost a little: 1) You can move them around, as in an electric car. That's useful if you want to do mobile stuff like driving. Or if you just flat-out want to move the facility somewhere it will be more useful. 2) They can be efficiently decentralized, which benefits reliability, and decreases transmission loss. But anyway, the solution is to use any and all technolog…

> Or if you just flat-out want to move the facility somewhere it will be more useful.

While an interesting theory, I can't think of a single scenario where this would be economically justified.

> 2) They can be efficiently decentralized, which benefits reliability, and decreases transmission loss.

Transmission losses are about 6%, so not really any economic gain.

Re: How cheap does solar power need to get before it takes over the world?

#75

Post by spacecowboy_lon »

Gibbon1 wrote: post #12
ZeroGravitas wrote: post #2

It says a lot about the progress of solar if the big worry is that it won't provide 100% of all energy by itself. Even cheaper solar would be nice but I'm not sure why it would be better than a radical battery breakthrough or some cheap and cheerful fusion thing or some mix of different solutions.

If you run the numbers pumped heat storage can likely do the job of time shifting electric power from daylight hours to night time. The pricing structure will flip though, electricity at night costing probably 2-3 times peek daytime rates. One would expect industrial users would adjust and avoid using power at night[1]. That would reduce demand. [1] Think of a mini-mill (steel) that currently runs its electric furnac…

I thought blast furnaces ran 24/7 and if they shut down you need to effectively rebuild parts of them.

Re: How cheap does solar power need to get before it takes over the world?

#76

Post by imaginenore »

marvin wrote: post #64
p1mrx wrote: post #53

Earlier quoted context omitted.

Li-ion 18650 cells held 2300mAh in 2005[1], and 3350mAh today[2]. That's an increase of 45% in just under 11 years. If capacity were really growing at 8% per year, then 18650 cells should have a capacity of 5300mAh by now. [1] http://www.candlepowerforums.com/vb/showthread.php?88468-Tri... [2] http://www.candlepowerforums.com/vb/showthread.php?417736-Te...

Did you compensate for cost in this example?

Cost has nothing to do with this argument. He is talking about energy density.

Re: How cheap does solar power need to get before it takes over the world?

#77

Post by imaginenore »

p1mrx wrote: post #53
eru wrote: post #19

Earlier quoted context omitted.

> The real big breakthrough would be somme big improvement on storage. I'm not convinced this will happen quickly (at least not in anyway similar to the declining cost of PV panels). The consumer electronics industry has been paying $$$ for decades for better batteries/battery r&d and has seen pretty poor gains. Actually, it's not too bad, just slower. Batteries improve around 8% per year, if I remember right. That's…

Li-ion 18650 cells held 2300mAh in 2005[1], and 3350mAh today[2]. That's an increase of 45% in just under 11 years. If capacity were really growing at 8% per year, then 18650 cells should have a capacity of 5300mAh by now. [1] http://www.candlepowerforums.com/vb/showthread.php?88468-Tri... [2] http://www.candlepowerforums.com/vb/showthread.php?417736-Te...

That's 3.5% per year growth. Not bad.

Re: How cheap does solar power need to get before it takes over the world?

#78

Post by olau »

WaylonKenning wrote: post #27
martinald wrote: post #11

I think the issue is that OK, say we managed to get to 100% electricity being solar when the sun is shining. You'd still have the time the sun is not shining, which would likely be more expensive than before (a gas powered plant would only be running half the time - effectively doubling its capital/construction cost per kWh). So you'd definitely have an improvement on some levels but I'm not sure that would really he…

Everyone seems a bit obsessed by batteries as a storage method, when we have more traditional methods: - Pumped-storage hydroelectricity - https://en.wikipedia.org/wiki/Pumped-storage_hydroelectricit... . Sure it's not suitable everywhere. - There's always Molten Salt as well - http://www.solarreserve.com/en/technology/molten-salt-energy... . Also, solar isn't the be all and end all of renewable energy generation. Wi…

Wind pioneer and former CTO of Siemens Wind Power is currently working on energy storage using rocks instead of a molten salt - he's blogging about it in the Danish engineering news site ing.dk.

Molten salt is efficient because of the phase change, but also much more difficult and expensive to handle than a big (well enormous) bunch of hot rocks. Last thing I heard, he's currently trying to get demonstration plant up and running - it sounded like they'd already done some experiments at Siemens before he left.

Anyway, nowhere near ready, but just to show that there are still low-tech options out there being examined.

Another low-tech option is biomass, either wood chips/pills or other stuff processed into methane.

Yeah, it's not as cheap as coal, but with good grid connections we need less storage than people seem to think, at least according to the research papers I've seen.

Re: How cheap does solar power need to get before it takes over the world?

#79

Post by Inthenameofmine »

Qwertious wrote: post #61
graycat wrote: post #43

Earlier quoted context omitted.

Short summary: The issue is not the cost of solar but the cost of storage.

Currently, peak electricity costs are in the daytime. This makes no sense if storage is the biggest problem of the present.

So I guess the electricity companies also get most of their margins during daytime? Of that's the case, solar might screw up traditional electricity's business model much earlier, even without storage and feed-in laws.

Re: How cheap does solar power need to get before it takes over the world?

#80

Post by AlexC04 »

kitsunesoba wrote: post #33
AlexC04 wrote: post #26

I think the biggest impediment to widescale solar adoption is legeslative. If you follow hackernews, you'll regularly see articles about places like Florida (and possibly Nevada if memory serves) where solar could easily power homes, but disingenuous legislative instruments and manipulativly worded ballot initiatives are housed to effectively block solar adoption. This is an example of the top result in Google news h…

Another example of what you mentioned: http://arstechnica.com/science/2015/12/north-carolina-citize...

That reads like satire.
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