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It can make more sense to build new renewable capacity than run old coal plants

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Re: It can make more sense to build new renewable capacity than run old coal plants

#51

Post by hannasanarion »

NullPrefix wrote: post #23
hannasanarion wrote: post #10

Earlier quoted context omitted.

No it wouldn't, because nuclear isn't reactive enough to produce energy to match the extreme afternoon demand curves when solar capacity drops and demand jumps. To account for those rapid jumps in non-renewable demand, you need an energy source that can ramp up really fast on short notice, like hydrocarbon fire.

> the extreme afternoon demand curves when solar capacity drops and demand jumps Does the hourly schedule variate day by day or can it be predicted? If you can predict when and how much power you will need to produce then it can be ramped up slowly, I assume.

"ramping up slowly" isn't an option when the demand curve is changing quickly, because there's nowhere for that extra energy to go. Energy storage isn't really feasible, so all the electrical grids in the world need to match supply to demand 1:1 in real time.

There are electrical dispatchers who are monitoring grid supply 24/7 and instruct plants on how much they are responsible for generating on a minute-by-minute basis.

Re: It can make more sense to build new renewable capacity than run old coal plants

#52

Post by [deleted] »

tefferon wrote: post #50
throwaway5752 wrote: post #5

Earlier quoted context omitted.

Are you sure about that? You should look at the fortunes of the engineering groups McDermott, CB&I, and Shaw and how the cost overruns associated with the Westinghouse contributed to so much trouble for those EPC companies and Toshiba. Nuclear has two big problems: difficulty with costs of constructing new plants and currently completely externalized storage of spent fuel. The latter is poorly defined and understood,…

is there any reason why we can't conceivably jettison nuclear waste out of orbit?

[deleted]

Re: It can make more sense to build new renewable capacity than run old coal plants

#53

Post by tlb »

tefferon wrote: post #50
throwaway5752 wrote: post #5

Earlier quoted context omitted.

Are you sure about that? You should look at the fortunes of the engineering groups McDermott, CB&I, and Shaw and how the cost overruns associated with the Westinghouse contributed to so much trouble for those EPC companies and Toshiba. Nuclear has two big problems: difficulty with costs of constructing new plants and currently completely externalized storage of spent fuel. The latter is poorly defined and understood,…

is there any reason why we can't conceivably jettison nuclear waste out of orbit?

Yes. Launch vehicles sometimes fail. They may explode, or they may not make it all the way to orbit and have to re-enter. Either way, this would scatter the radioactive material over a wide area.

Re: It can make more sense to build new renewable capacity than run old coal plants

#54

Post by icebraining »

papreclip wrote: post #40
air7 wrote: post #28

I don't understand the hype around wind and solar. Or rather I don't see how these technologies can ever be anything more than a minor player in the energy market: These technologies are extremely sensitive to weather conditions which means that other, more stable sources must exist and have "stand by" production cap to produce all the energy these tech won't under bad conditions. If so, what's the point? (I mean in…

Yea it's pretty obnoxious to be told "try not to use so much power during these hours: [when you get home from work - when you go to bed]. This is when we need electricity.

There's plenty of use you can move to other times, just ask anyone who has different peak/off-peak rates. A house with good insulation can be pre-heated/cooled in the afternoon. Washing machines can be programmed to run during the day. Even some cooking can be done that way, if you prepare in advance. Those alone cover quite a large chunk of home energy use.

Re: It can make more sense to build new renewable capacity than run old coal plants

#55

Post by nerpderp82 »

hannasanarion wrote: post #10
trianglem wrote: post #3

Earlier quoted context omitted.

Yes, the dream team would be a combination of renewable and nuclear.

No it wouldn't, because nuclear isn't reactive enough to produce energy to match the extreme afternoon demand curves when solar capacity drops and demand jumps. To account for those rapid jumps in non-renewable demand, you need an energy source that can ramp up really fast on short notice, like hydrocarbon fire.

The power supply and the energy supply will not have a single solution. It is analogous to the levels of caching in a Von Neumann cpu. L1 will capacitors, L2 batteries, bulk storage is pumped hydro and other GWh energy stores.

The duck curve is a smoke screen and should only exist for a region that doesn't have solar to the west of it. Those solar farms in CA should be feeding users a timezone over to the east.

Any source can then feed into those stores, wind, solar, hydro.

If your power solution is involves hydrocarbons, it should be a closed cycle.

Re: It can make more sense to build new renewable capacity than run old coal plants

#56

Post by nerpderp82 »

hannasanarion wrote: post #51
NullPrefix wrote: post #23

Earlier quoted context omitted.

> the extreme afternoon demand curves when solar capacity drops and demand jumps Does the hourly schedule variate day by day or can it be predicted? If you can predict when and how much power you will need to produce then it can be ramped up slowly, I assume.

"ramping up slowly" isn't an option when the demand curve is changing quickly, because there's nowhere for that extra energy to go. Energy storage isn't really feasible, so all the electrical grids in the world need to match supply to demand 1:1 in real time. There are electrical dispatchers who are monitoring grid supply 24/7 and instruct plants on how much they are responsible for generating on a minute-by-minute b…

> Energy storage isn't really feasible

You couldn't be more Dam wrong.

Re: It can make more sense to build new renewable capacity than run old coal plants

#57

Post by 08-15 »

throwaway5752 wrote: post #5
mikece wrote: post #2

"[Wind and solar are] even close to being competitive with the marginal costs of running the coal and nuclear plants we already have." Is that still true without incentives, green grants, rebates, and tax credits? Because without all of that and with mountains of red tape nuclear still produces energy at the lowest cost, and without emitting any CO2.

Are you sure about that? You should look at the fortunes of the engineering groups McDermott, CB&I, and Shaw and how the cost overruns associated with the Westinghouse contributed to so much trouble for those EPC companies and Toshiba. Nuclear has two big problems: difficulty with costs of constructing new plants and currently completely externalized storage of spent fuel. The latter is poorly defined and understood,…

The cost for dealing with the spent fuel isn't externalized. The problem is that the government promised to deal with the waste, charged a fee for doing so, forbade utilities from dealing with the waste themselves (Nuclear Waste Policy Act of 1982), and then... did nothing.

That little bit of waste can be dealt with, and comparatively cheaply. Think about it, you can produce 8TWh of electricity, sell it for maybe $400M, and you only have to deal with one ton of waste. That's not a big deal, but doing it is illegal.

Don't blame the industry for a dysfunctional government.

Re: It can make more sense to build new renewable capacity than run old coal plants

#58

Post by Maximus9000 »

toomuchtodo wrote: post #44
bluGill wrote: post #43

Earlier quoted context omitted.

The amount of storage needed is massive. 1000s of hoover dams (including the lakes on both sides) for example. Batteries might work, but so far they haven't scaled that large.

It's about 6000 Tesla Megapacks [1] for the entire US, roughly 20 square miles of land use. "Using Megapack, Tesla can deploy an emissions-free 250 MW, 1 GWh power plant in less than three months on a three-acre footprint – four times faster than a traditional fossil fuel power plant of that size. Megapack can also be DC-connected directly to solar, creating seamless renewable energy plants." We need more Gigafactori…

How much does 1 megapack cost?

Re: It can make more sense to build new renewable capacity than run old coal plants

#59

Post by 0000011111 »

ReptileMan wrote: post #45
0000011111 wrote: post #26

I learned from Professor Vaclav Smil that while Wind and Solar are practical energy solutions in the United States population ~340mil. It is not practical in all regions in more populous countries such as China (population ~1.4 Billion). There are large regions in the country where Solar is not a good solution due to fog. And Wind is not a good solution due to lack of wind. We have a global climate system. As is such…

You could cover the arabian peninsula and sahara with panels and use UHV lines to connect to china.

I am all for that.

I just think it is more realistic to first build nuclear power plants within 50km of every city with a population greater than 1mil people in China.

I am not sure a there has ever been a UHV line longer than 3,000km? Efficiency loss only increases the longer a UHV line is.

Re: It can make more sense to build new renewable capacity than run old coal plants

#60

Post by 08-15 »

hannasanarion wrote: post #10
trianglem wrote: post #3

Earlier quoted context omitted.

Yes, the dream team would be a combination of renewable and nuclear.

No it wouldn't, because nuclear isn't reactive enough to produce energy to match the extreme afternoon demand curves when solar capacity drops and demand jumps. To account for those rapid jumps in non-renewable demand, you need an energy source that can ramp up really fast on short notice, like hydrocarbon fire.

You're a victim of a common misconception. Nuclear reactors can ramp up and down as quickly as the control rods move. Check out the Borax experiments (from shutdown to full power in seconds) and the TRIGA reactor (from shutdown to gigawatts and back to shutdown in milliseconds).

What can't ramp quickly is the steam turbine connected to the reactor, but that's more of a design decision than a technical limitation. The German nuclear plants ("Konvoi" series) can in fact ramp faster than the German gas turbine plants, because that was a design requirement.

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