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Solar Just Hit a Record Low Price in the U.S

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Re: Solar Just Hit a Record Low Price in the U.S

#121

Post by rsynnott »

wtetzner wrote: post #57
overcast wrote: post #34

Earlier quoted context omitted.

Why does it have to be electric heat? Natural Gas is doing a good job right now. Let's work on supplying electricity, for things that require electricity first. When we've moved away non renewable energy sources for electricity generation, then move onto the heating issues in colder climates.

But even with natural gas, don't you end up needing electricity to move the heat through the house?

Very little, generally. The pumps on a water-based radiator system are typically tiny.

Re: Solar Just Hit a Record Low Price in the U.S

#122

Post by philipkglass »

swebs wrote: post #73
rb808 wrote: post #11

There is an interesting part about solar generating electricity when its sunny - it will help population move to warmer climes. If you live in Ohio heating in winter is a problem, solar isn't going to keep you warm on a cold night (ok batteries can help but they're expensive). If you live in the South West though its perfect as Winter nights dont require much heat and the biggest loads are AC at the times when there…

We've built oil pipelines, why not "electricity pipelines" made of refrigerated, super conducting cable?

High voltage direct current lines can already cover vast distances. Siemens has started supplying equipment for a Chinese HVDC project that will transmit 12 gigawatts over 3300 kilometers:

https://www.siemens.com/press/pool/de/pressemitteilungen/201...

That's a long enough line to stretch between California and East Coast states.

Getting rights-of-way for big interstate transmission projects is harder than actually building the projects after those rights are secured. Superconducting cables can carry more power per cross section than HVDC lines, but they're a lot more expensive and immature. Nobody has yet found a project that would justify full-scale superconducting lines over more conventional high voltage lines built with ordinary resistive conductors.

Re: Solar Just Hit a Record Low Price in the U.S

#124

Post by CompelTechnic »

rsynnott wrote: post #96
inputcoffee wrote: post #71

The true price of solar is the price to produce reliable, continuous energy. That requires something to smooth out the signal and store the energy, most probably a battery. The solar + battery price is also going down, though not as fast as the solar only piece. But that's the metric we should be following. When that hits $30 per MWh, it'll be game over.

I wouldn't bet on batteries, or at least conventional batteries, being the long term solution. There's interesting work being done with air pressure storage, flow batteries (the largest batteries currently under construction are mostly flow batteries in the 500MWh-1GWh range, though the technology is still in its infancy), and big scary vacuum flywheels. All of these are far less developed than lithium ion cells, but…

One weird thought I had the other day: high voltage DC transmission lines are getting more popular. I wonder if it would be economical for a high voltage DC line to form a loop around the entire planet, so that the load can follow the sun through a complete cycle.

Re: Solar Just Hit a Record Low Price in the U.S

#125

Post by ghouse »

inputcoffee wrote: post #71

The true price of solar is the price to produce reliable, continuous energy. That requires something to smooth out the signal and store the energy, most probably a battery. The solar + battery price is also going down, though not as fast as the solar only piece. But that's the metric we should be following. When that hits $30 per MWh, it'll be game over.

False equivalence. A similar argument could be made of nuclear power (which needs to run at/near 100% output), or supercritical coal (similar operating constraint to nuclear). Do we need to add batteries to those as well to make an apples-apples comparison? (Incidentally, much of the pumped hydro in the US was built to integrate nuclear power).

Unless you're trying to power the grid with a single power plant (like on a small island), argument made above doesn't hold. The grid is a network of generators (and loads) with different operating characteristics.

Re: Solar Just Hit a Record Low Price in the U.S

#126

Post by julienchastang »

rsynnott wrote: post #87
julienchastang wrote: post #80

Note the picture in the article is the Ivanpah concentrated solar thermal power facility in California (near Las Vegas, NV). The article concerns photovoltaic not concentrated solar. I drove by Ivanpah not long ago and it is a site to see, the towers look about as bright as the sun, but my understanding is concentrated solar is not as attractive economically as PV.

Probably not now, no (though it does have the interesting property that, with certain designs, it keeps producing power some time after the sun goes down). At the time solar power towers were developed, though, PV was rather expensive and inefficient; the dramatic advances of the last couple of decades weren't really expected.

Also, I believe they have to be pre-heated in the morning with natural gas diminishing the carbon advantage. Too bad, they really do look impressive.

Re: Solar Just Hit a Record Low Price in the U.S

#127

Post by rsynnott »

preparedzebra wrote: post #65

The internal combustion engine seems to have been milked for all the efficiency our current materials can get out of it, while new materials and economies of scale in solar tech keep pushing prices lower. However, material science could also revolutionize the efficiency of engines and make them cost competitive with solar again. Solar-ification seems to be the trend, but it is not guaranteed.

Internal combustion engines are generally not used in power plants. Modern thermal plants use either gas or steam turbines. The best thermal plants currently have efficiencies approaching 65%, and there are theoretical limits; there's not too much more blood to be squeezed from that stone.

Re: Solar Just Hit a Record Low Price in the U.S

#128

Post by ghouse »

rsynnott wrote: post #106
immad wrote: post #78

Earlier quoted context omitted.

Why can't existing energy infrastructure handle the gaps? Does it take too long to boot up a natural gas plant just for the night? Would still make a huge dent to energy needs and the existing infrastructure already in place.

That's what's generally happening. It's a bit of a limiting factor, though. As you have more and more renewable, you need more and more gas plants which mostly sit around doing nothing, which isn't free. There's also the opposite problem, particularly in the case of wind turbines; if you have enough, then your base-load (ie coal, nuclear, hydro) plus renewable may sometimes exceed demand. This happens from time to ti…

> As you have more and more renewable, you need more and more gas plants

This is only true if the load on the grid is growing. In North America, it is not. Otherwise, you already have enough dispatchable generation available when the sun isn't shining or the wind isn't blowing.

Re: Solar Just Hit a Record Low Price in the U.S

#130

Post by digikata »

rsynnott wrote: post #96
inputcoffee wrote: post #71

The true price of solar is the price to produce reliable, continuous energy. That requires something to smooth out the signal and store the energy, most probably a battery. The solar + battery price is also going down, though not as fast as the solar only piece. But that's the metric we should be following. When that hits $30 per MWh, it'll be game over.

I wouldn't bet on batteries, or at least conventional batteries, being the long term solution. There's interesting work being done with air pressure storage, flow batteries (the largest batteries currently under construction are mostly flow batteries in the 500MWh-1GWh range, though the technology is still in its infancy), and big scary vacuum flywheels. All of these are far less developed than lithium ion cells, but…

I think the key is that we can start to develop infrastructure just fine on lithium cells, and it might even accelerate the development of more efficient alternatives develop because it proves the market to investors.
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