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Molten Salt Reactors

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Re: Molten Salt Reactors

#101

Post by pfdietz »

AnthonyMouse wrote: post #100
pfdietz wrote: post #69

Earlier quoted context omitted.

Hydrogen has low capital cost. The capital cost/energy of storing hydrogen underground will be much less than the cost of storing that energy in a battery. If you have a storage scenario where the energy is stored for very long times, there will be few cycles of that system over its economic lifespan, so minimizing capital cost (even if that means much lower round trip efficiency) is very important. One would still u…

> In particular, simple cycle gas turbine power plants with efficiency of 40% cost maybe $400/kW. Compare this to $8-10K/kW for a new nuclear power plant. The problem being that it only operates ~2% of the time compared to ~100%, and has a shorter operating lifetime in practice, and that isn't counting the cost of storing the hydrogen nor the energy cost to produce it.

Yes, the power will be expensive during that 2%. But it will not contribute all that much to the total cost of operating the grid. In particular, it would be cheaper than forcing the consumers to pay for nuclear the other 98% of the time, just so it would be available during that 2%.

Re: Molten Salt Reactors

#102

Post by paulsutter »

pfdietz wrote: post #95
paulsutter wrote: post #92

Earlier quoted context omitted.

PV for baseload? How does that work? Everyone will use candles at night?

> PV for baseload? It's remarkable you were able to read that into what I wrote, when that wasn't at all what I wrote. The point I was making was that intermittent renewables can screw up the market for nuclear, even if the renewables themselves do not supply baseload. You may be under the misapprehension that if there is a base level of demand on the grid, then that base level of demand can only be supplied by basel…

Right but only because you’re ignoring storage which is the only way to make PV really work (duck curve is an absurdity caused by lack of storage).

Sorry I missed your point, but your still misunderstanding what’s needed.

Re: Molten Salt Reactors

#103

Post by AnthonyMouse »

pfdietz wrote: post #101
AnthonyMouse wrote: post #100

Earlier quoted context omitted.

> In particular, simple cycle gas turbine power plants with efficiency of 40% cost maybe $400/kW. Compare this to $8-10K/kW for a new nuclear power plant. The problem being that it only operates ~2% of the time compared to ~100%, and has a shorter operating lifetime in practice, and that isn't counting the cost of storing the hydrogen nor the energy cost to produce it.

Yes, the power will be expensive during that 2%. But it will not contribute all that much to the total cost of operating the grid. In particular, it would be cheaper than forcing the consumers to pay for nuclear the other 98% of the time, just so it would be available during that 2%.

If it's dozens of times more expensive during that 2% because it has to recover 100% of its cost in 2% of the time then it does contribute quite a bit to the total cost of operating the grid, whereas nuclear only has to make up the difference in that time between the market price the rest of the time and its overall average cost.

Storage also has the further disadvantage that you have to over-spec it. It has to be built for the highest capacity you might need and the longest duration, which you don't know ahead of time. If you build less than you need you're in big trouble, but if you build more, you pay for it and get nothing.

Re: Molten Salt Reactors

#105

Post by darkpuma »

tim333 wrote: post #68
darkpuma wrote: post #48

Earlier quoted context omitted.

It seems to me that the simplest reactors tend to be the most dangerous. I'm thinking of the Windscale fire and SL-1 in particular. One of the theories for what went wrong at SL-1 is that it was a murder-suicide, caused by the man tasked with physically manipulating the control rods of the reactor. I think robotic control is better for something like that. Robots are more predictable. One of the aggravating factors a…

The Windscale reactors were built in a hurry in 1950 to produce nuclear weapons after Russia managed to test it's first atom bomb in 1949 and are not really representative of modern power generating technology.

Obviously Windscale wasn't modern and SL-1 certainly wasn't either. My point was that simple designs are poor designs, that modern designs are complex for good reason. The added system complexity of automation is well worth it when it comes to nuclear power.

Re: Molten Salt Reactors

#106

Post by ivanhoe »

_0w8t wrote: post #63
ivanhoe wrote: post #55

Earlier quoted context omitted.

The cost of manufacturing energy is not the only cost when you need to distribute energy on a large scale. Electrical grids are prone to oscillations and having less and bigger power sources makes things a lot easier and more reliable (and that means cheaper also). You can store energy but that again increases complexity of the grid and costs (even super-cheap storage will always be more expensive than no storage). T…

Grids must be very stable because there is no storage at the end points. If electricity consumers are very OK to be without electricity for few hours per day that alone makes grid much cheaper.

Ideal consumer, from the power network point of view, is as constant as possible. Each time you cut off a consumer node it creates harmonics and surges that need to be compensated upstream. Lots of nodes going on and off simultaneously (and they will as the whole parts of the city have the good sun at the same time) are engineering nightmare, existing grids are just not build to handle it, so they'll need to be upgraded, plus the maintenance costs will go up.

Re: Molten Salt Reactors

#107

Post by Mirioron »

jillesvangurp wrote: post #62
Mirioron wrote: post #54

Earlier quoted context omitted.

Aren't roof solar panels very inefficient? They can't track the sun and you can't have good density from them either. Furthermore, they don't work for office buildings and apartment buildings. > Not to dismiss it entirely but arguing cost increases seems a bit far fetched in light of current trends in the market. I think what the parent was saying is that because solar and wind don't reliably produce energy, we will…

> Aren't roof solar panels very inefficient? They are good enough. Low efficiency just means we have to buy more of them. Obviously we'd need solar plants (and maybe wind parks and other clean sources) to also power those with limited access to roof surface. Of course, bad weather doesn't mean solar stops working; it just reduces the output. The effect is typically very local as well. So, all that means is that you n…

Bad weather in northern Europe means that everything is covered in snow for a long time. I think that's slightly more than just reduced output. The snow also tends to cover am area that's hundreds of kilometers in every direction too.

Re: Molten Salt Reactors

#109

Post by Reason077 »

jabl wrote: post #81
Reason077 wrote: post #58

Earlier quoted context omitted.

Solar is getting so cheap that it's becoming economical in places that might surprise you. The UK sits further north than almost all of the USA (excl. Alaska), and has a climate not exactly known for its abundant sunshine. But large-scale solar farms are now commercially viable here without subsidy. (eg: https://www.clevehillsolar.com )

Up here the yearly sunshine is pretty good, close to Germany or so. The problem is that almost all of it comes during the summer. In the winter months when demand peaks, solar produces practically nothing. So without seasonal storage becoming economical, it's not a solution to decarbonizing. Closer to the equator where seasonal variation is less and demand is driven more by air conditioning than heating solar is an e…

> "The problem is that almost all of it comes during the summer. In the winter months when demand peaks, solar produces practically nothing."

In the UK, this turns out to be seasonally complementary with our wind turbines. In the winter months, wind speeds are stronger and more consistent (especially off shore). In the summer, there is less wind, but the gap is made up by solar. The net result is pretty consistent renewables production year-round.

> "it's not a solution to decarbonizing."

Every kWh of energy produced by a solar panel in the UK (or wind turbine, for that matter) offsets a kWh that would otherwise be produced from fossil fuels, typically from imported natural gas.

Re: Molten Salt Reactors

#110

Post by usbseeker »

jillesvangurp wrote: post #32

The elephant in the room with any kind of fission reactor is that they are going to need a lot of security. Even when the fuel and waste product is not weapons grade uranium, it's still highly radioactive and a great source of material for a dirty bomb. Basically anything that goes boom combined with small amounts of radioactive material and a bit of wind is a great way to depopulate e.g. large cities. So, having lot…

It's not an elephant in the room, it's just so obvious that it's not something that needs explained.
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