A Tower of Molten Salt Will Deliver Solar Power After Sunset (ieee.org) 139
schwit1 sends this report from IEEE Spectrum: Solar power projects intended to turn solar heat into steam to generate electricity have struggled to compete amid tumbling prices for solar energy from solid-state photovoltaic (PV) panels. But the first commercial-scale implementation of an innovative solar thermal design could turn the tide. Engineered from the ground up to store some of its solar energy, the 110-megawatt plant is nearing completion in the Crescent Dunes near Tonopah, Nev. It aims to simultaneously produce the cheapest solar thermal power and to dispatch that power for up to 10 hours after the setting sun has idled photovoltaics. ... [The system] heats a molten mixture of nitrate salts that can be stored in insulated tanks and withdrawn on demand to run the plant’s steam generators and turbine when electricity is most valuable. ... Eliminating the heat exchange between oil and salts trims energy storage losses from about 7 percent to just 2 percent. The tower also heats its molten salt to 566 degrees C, whereas oil-based plants top out at 400 degrees C.
Downsides (Score:2, Interesting)
The article reads more like a fluff PR piece instead of providing any credible reason for why we should get about yet ano
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Re:Downsides (Score:5, Insightful)
In TFA they mention that there's a smaller-scale demonstration plant operational right now, so it's not like they're building this plant with no working experience. One would hope that the demonstration plant is operating well enough to have justified the construction of the larger one. In projects like this, scale often works to your economic advantage, so it makes sense to start building these things bigger.
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Unless we know the final cost of the 20 MW plant vs the 110 MW plant, I'm not sure how you can come to that conclusion. The source of funding has nothing to do with the economy of scale, as much as I'd also prefer things like this to be privately funded. Operational costs vs power output, and the longevity of the plant will also play a significant role.
We shouldn't have too long to wait to see if this is a great idea or a boondoggle. I'm not pretending to know enough either way to make a prediction.
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I see no reason to doubt that refinements in design can squeeze out a few more hours of run-time.
Re:Downsides (Score:5, Interesting)
Besides the flaws you cite, molten salt has been previously used e.g. in the Andasol solar (thermal) power plant in Spain.
https://en.wikipedia.org/wiki/... [wikipedia.org]
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The Andasol solar uses an HTF fluid circulating in the solar field [archive.org]. This plant will use molten salt in the collector as well as in the storage medium. This is the big innovation of this new plant as it has higher temperatures and lower transfer loss. My concern is that pumping molten salt around is very different than pumping hot oil around. Oil does not solidify of the temperature drops If the salt solidifies in the tank it is no big deal. You just pump hot oil through the heat exchanger until the salt me
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"How do you melt salt inside a pump and hundreds of feet of piping? "
Electric heaters. That was solved 50 years ago.
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Putting electric heaters inside a pump would make the pump more complex and therefore more expensive and prone to breakdown. See how the complexity of pumping molten salt around quickly rises?
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Which is why you don't put the heater inside the pump. Instead, you use an ordinary pump and pipe, and simply run an off-the-shelf (cheap) heating wire alongside them. Then you wrap the whole thing in insulation.
No, but I have seen how factories that have to do so do it. It's not a problem.
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Off the shelf heater wire that heats to 260 degrees Celsius+?
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Yes, it's called NiChrome and it's been around forever.
Re:Downsides (Score:5, Insightful)
I see no reason why you keep mentioning birds like it's some sort of game changer. In Canada between 16-42 million birds are killed each year through collisions with buildings. Should we stop building houses? http://www.ace-eco.org/vol8/is... [ace-eco.org] North America wide that number may rise as high at 1 billion. http://www.flap.org/faqs.php [flap.org] Not to mention that you conveniently left out the death toll on all animals from pollution/habitat loss from the fossil fuel generators which far exceeds the numbers of 'streamers' that these plants will generate.
Improvements on all fronts, should not be abandoned because those improvements are not perfect.
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Indeed. Massacring birds is the new Green.
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The issue with birds is not a simple matter of using averages over an entire country. Solar plants like this are situated in desert conditions where bird populations are very low to start with. It is not valid to equate the impact of loosing some birds in a high bird population area with losing the same number of birds in a low bird population area. The problem with these collectors is that the brightness attracts insects. The insects attract songbirds. The songbirds attract raptors. Losing 1000 songbirds f
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It's also not valid to equate the number of bird fatalities in areas with high bird population area with the number of bird fatalities in ares with a low bird population.
Besides, since it's a power plant and in the middle of a desert, can't you j
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rig strobo lights or loudspeakers or something to drive away whatever birds wander near?
Airports have been trying to drive birds away and have had little success. If jet engine noises wont drive birds away then neither will loudspeakers. Birds get acclimatized to situations.
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And natural gas is super cheap.
The combination of cheap gas and people who care about animals more than humans will prevent these from being built in the US. In more sensible countries with more expensive gas, these should be a good way to generate reliable power.
Re: Downsides (Score:1)
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Or a Youtube video feed for added revenue.
As many have pointed out... (Score:4, Interesting)
... and many more will, this is an old design, already in use.
Personally my favorite solar thermal concept is the compact linear fresnel reflector. They're much more dense (land area used per unit power generated) than pretty much all other solar tracking methods. Also, they only require single-axis tracking in long linear rows - but unlike other single-axis tracking methods like parabolic troughs, you don't need a receiver (heat pipe) running through the middle of every reflector; a reflector is *just* a reflector. The alternation of directions in which light gets reflected reduces blocking between reflectors, and thus increases how close you can space them. And the high density means less distance for the hot water to flow, and thus less heat loss, further increasing the power generation per unit area.
Marmora (Ontario) wants pumped storage (Score:4, Insightful)
My cottage is quite close, the project is described at http://ecogeek.org/2013/04/ope... [ecogeek.org]
This approach is low-cost, and used in Brazil among other places: https://en.wikipedia.org/wiki/... [wikipedia.org]
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pumped storage is only of use for peak smoothing and generally only has enough capacity for a couple of hours' operation per day.
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Yes: we're lucky in that we have a former open-pit mine on the top of a ridge, close by a river in a valley (the Crow), with a fall from the bottom of the pit to the surface of the river that's higher than Niagara Falls!
I wan't expecting that: I think of the area as gently rolling, but apparently it's typical of lots of areas along highway 7. Who knew!
molten mixture of nitrate salts (Score:1)
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Not much. It cannot go critical. If it leaks and dumps all the stuff on the ground, oh well, Scrap it up and haul it away. It won't poison water tables or irradiate anyone.
Worst it could is burn someone unlucky enough to get too close to it when hot.
Excellent! (Score:4, Interesting)
I like seeing things like this. I'm not excited about the solar power aspect, I actually think that is a fool's errand. I'm excited about seeing people research molten salt power transfer systems and high temperature power generation.
One big problem holding up research in molten salt fission reactors is that the power generation systems it relies upon for much of its efficiency gains have not been tested fully. If we can prove to the powers that be, like the US Department of Energy, that we can handle molten salts safely then we can get that much closer to getting a molten salt reactor built.
Looking into how these concentrated solar power plants work I had to ask myself, what do they do when the sun doesn't shine enough to keep the salt molten? They claim ten hours of storage capability, that might get them through the night I suppose. What if the morning sun is obstructed by clouds? Well, I found my answer when looking at the Ivanpah Solar Power Facility.
https://en.wikipedia.org/wiki/... [wikipedia.org]
To get these things started in the morning takes a lot of natural gas. I understand the need for a power plant, any power plant, to have backup power on site in the case of the need to shut down the primary electric generation when there is loss of a connection to the grid. But the need to do this every morning does sound a bit counter productive. This is a plant that is supposed to reduce our reliance on fossil fuels. That's what I thought the whole point of solar power was supposed to be.
Perhaps, after we prove molten salt solar can work when the weather agrees, then we can put a small modular thorium reactor on the site to warm up the salt in the morning and provide a base load of power for when the sun doesn't shine. Of course, once you can show that small modular reactors of about 100MW capacity can keep the solar power plant running then people will begin to wonder why they bother with the large expensive solar tower when the reactor keeps running regardless of the weather. At some point they'll tear down the tower to make room for more reactors.
That's the whole point to me, moving towards small modular thorium reactors. Of all the technologies we have out there right now I see that as the one true solution. We'll still see wind, solar, hydro, geothermal, and so on in the times and places where it is cheap but small thorium molten salt reactors can be used in so many places. Make them on an assembly line like a Boeing airliner and we should see a new one built every month. In twenty years we should see the grid powered by more than 50% nuclear fission.
I still think that nuclear fusion will prove viable within my lifetime, but only when done on a multi-gigawatt scale. That is going to be very expensive to build initially but once built it should run for a long time using common elements as fuel. Until we have a leap in technology like that we have three choices:
- Nuclear fission
- Continued fossil fuel use, with all its pros and cons
- Expensive unreliable wind and solar
So, go build your concentrated solar power plants, those would make great sites for a future thorium fission power plant.
Use chemical energy, not thermal energy for storag (Score:2, Informative)
Molten salt is terrible for electricity storage.
Thermal energy capacity: 0.13 kWh/kg [nrel.gov]
Electrical conversion efficiency: 25% [nrel.gov] at best
Electrical storage capacity: 0.03 kWh/kg
Amount of mass to store 12 kWH (one household overnight): 400 kg
Amount of mass to power a large city overnight (1 million households): 1 Empire State Building
Sodium-sulfur battery electrical storage capacity: 0.5 kWh/kg
Charge/discharge efficiency: 80%
Useful storage capacity: 0.4 kWh/kg
Amount of mass to store 12 kWh (one household overnight):
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I chose a battery type for comparison that's made of dirt-cheap materials, which is highly reliable and very simple. (Far simpler than molten salt plumbing. Just imagine designing valves and pumps
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Think global (Score:2)
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Solar thermal is a solution to the wrong problem. Electricity demand, and thus prices, are highest in the daytime, and lowest late at night. So by shifting production from day to night, they are turning gold into lead.
There may be a time, decades hence, when solar makes up a big enough slice of electricity supply, that it needs to provide base load power. But that time is not now.
Re: I don't understand the big deal here. (Score:4, Informative)
Actually, it depends on the time of year. Demand is only highest (peaks) in the daylight hours during the summer, when air conditioning load is at its highest. During the spring and fall, when the temperatures are moderate, it's not uncommon that the peak is in the evening with lighting load (really lights + TV + commercial resteraunt use). In winter, it's definitely evening peaks with higher overnights with electric heating load. So, from a wholesale power perspective, you only need to cover that 7pm to 9pm period before load drops off (bedtimes) to smooth pricing.
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Why do you need to smooth pricing? By allowing prices to rise and fall throughout the day in response to supply and demand, you don't need to add supply between the time the sun goes down and the time people go to bed at night.
In other words, you can treat it as an economics problem and save your customers a lot of money on power plants and fuel. This is why the world is switching from flat rate pricing to time-of-use pricing.
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You still need to have power to supply.
Solar thermal gives you additional revenue source for your solar plant by operating in hours beyond sunlight.
if your plant runs 24/7 then you earn money 24/7. If your plant only runs from 9-5 then you only earn money from 9-5.
how is that not an economics problem?
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All the power is generated during the day, so if you can sell it all there is no need to store it.
Once we get to the point where we have too much power during the day (like Germany) then it makes sense to store it.
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The power may be worth more later making up for the cost of storing it.
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... the plant can satisfy 100% of demand until it runs out of heat, 10 hours after the sun goes down.
You'd probably want to keep enough residual heat overnight to supply the morning peak that occurs before the sun comes up.
Re: I don't understand the big deal here. (Score:5, Informative)
Why do you need to smooth pricing? By allowing prices to rise and fall throughout the day in response to supply and demand, you don't need to add supply between the time the sun goes down and the time people go to bed at night.
In other words, you can treat it as an economics problem and save your customers a lot of money on power plants and fuel. This is why the world is switching from flat rate pricing to time-of-use pricing.
The goal isn't to smooth pricing...it's to smooth the peaks and valleys of demand.
The grid has to be built for peak, not average...in other words, if 5% of the time, the total load of a utility's customer base is 4.5 gigawatts, then they have to be able to provide 4.5 gigawatts, even though 95% of the time the demand is half that, at most.
Ideally, power demand would be flat and constant...the same amount, all the time. Steam plants experience metal fatigue when they throttle up and down, and this is already a major problem with most utilities now. It's also way harder to regulate an efficient burn at multiple rates...which in turn, means it's harder to regulate emissions, which leads to limits on capacity if they exceed emissions of certain sorts (and, just to make it fun, those standards have just been tightened...a LOT). Those are both a big deal: too much leaking in the heat exchange coils in the boiler, and the whole plant has to come offline. Even getting close to the limit on emissions for a period, and the plant comes offline to avoid overshooting it...the plant goes into reserve mode, needed only for emergencies. And this, in turn, increases the impact of the peaks/valleys situation on the rest of the utility. And what I just described assumes 100% controllable, fuel-based generation (nuclear, petroleum, coal, gas). Now, these peaks are predictable (and predicted...there's a whole industry around the metrics and predictive load management involved), but it still poses a challenge. The steeper the walls of the peak, the faster and harder you have to spin up the generators, and the greater the stress, as well.
Renewable energy is great, except that it throws another wrench into the works. Let's say you're getting a lot of your power from solar...but then clouds move in. Effectively, for your non-renewable generation, you've just introduced a peak because it has to throttle up to take up the slack. So you end up with lots of peaks of various sizes, instead of the one or two big peaks per day. And even worse, these peaks aren't predictable.
If, however, your solar generation capacity includes a way to continue generating power after the clouds roll in, you've done two things. One, if the cloud layer is short-lived, you're able to simply disregard it and life goes on. Two, if it isn't, then you've bought more time to spin up capacity more slowly...which means less stress on the boilers, and also more options to choose from. Maybe you fire up a CT peaker, which has less trouble with variable load but takes 20-30 minutes to come online, for example. But ultimately, what you've done is taken one of the biggest problems with renewable generation and dramatically reduced it.
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Ideally, power demand would be flat and constant...the same amount, all the time.
So this is the 1000 year old problem of centralization vs distribution. We can solve the problem with "better" power plants, or batteries in every home. Either one gives the same result, though not at the same cost, or with the same control.
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Ideally, power demand would be flat and constant...the same amount, all the time.
So this is the 1000 year old problem of centralization vs distribution. We can solve the problem with "better" power plants, or batteries in every home. Either one gives the same result, though not at the same cost, or with the same control.
No...this has nothing to do with centralization versus distribution. The power grid is largely unified; that 60Hz rate of AC in the wires of your home is perfectly in sync with the rate on the other side of the city, or even the state, for example. Peaks and valleys have nothing to do with centralization or distribution: the problem actually is a little worse for power companies that have a lot of little generation units spread around, because the challenge of sync gets worse that way and under/over frequ
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If you raise the price of something, demand goes down, and if you lower the price, demand goes up. So it seems possible to flatten power demand by varying the price, just as eBay does in order to prevent too many people from winning the same auction.
This gives the poor a way to economize by taking advantage of lower-than-average electricity prices during times of high electricity production and low demand--an opportunity that
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Flat use versus time of day is a BS argument. To implement TOD pricing, we would need to cook our meals at off-hours, to watch TV programs at off hours, and to insure that some kids go to school in off hours.
We live in a society synchronized with the wall clock. For example. Kids arrive from school at 4pm. There is some playtime, then homework. Supper is between 6:30 to 7pm, then more homework and a shower and to bed sometime after 8:30pm.
The peaks at the majority of households are always going to coinci
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Why do you need to smooth pricing? By allowing prices to rise and fall throughout the day in response to supply and demand, you don't need to add supply between the time the sun goes down and the time people go to bed at night.
In other words, you can treat it as an economics problem and save your customers a lot of money on power plants and fuel. This is why the world is switching from flat rate pricing to time-of-use pricing.
Because poor people need lights in the dark too?
I get that you could leave the capacity restricted, and then let rich people price poor people out of the market by bidding the cost up considerably, but why?
It also seems to me that this would significantly advantage the East Coast, since you're not going to run out of sunlight in the U.S. until it's significantly later in the day/night cycle there, than when you run out of sunlight on the West Coast. So they'd just pull from the grid at non-inflated rates,
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Because it would give the poor a way to save money that doesn't exist today, by doing their electricity-intensive chores when electricity is cheaper than average. With flat rate pricing, they always have to pay the average rate.
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Because it would give the poor a way to save money that doesn't exist today, by doing their electricity-intensive chores when electricity is cheaper than average. With flat rate pricing, they always have to pay the average rate.
You are aware that this wouldn't be a problem in the first place, if we weren't trying to use a power generation technology whose output varied based on time of day, right?
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Because demand for electricity is constant throughout the day?
Because it isn't, and building excess capacity is wise.
And if you aren't using that excess capacity, it shouldn't *not* be generated, instead it should power desalination plants and other things that can run on an as-demand basis. It's stupid to have to use electricity to heat water because you have to use hot water instead of warm water on your dishes, because you have to leave the food to cake on until it's OK to run your dish washer, according to the power company.
Expecting humans to behave differently
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Unless the desalination plant operator isn't willing to pay what it costs to generate that electricity. Then it's cheaper to shut down a power plant or two. Saving your customers money is a good thing, right?
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Unless the desalination plant operator isn't willing to pay what it costs to generate that electricity. Then it's cheaper to shut down a power plant or two. Saving your customers money is a good thing, right?
Costs exactly the same amount to run a nuclear plant, whether or not you choose to use the power. It's not like you can ramp production up or down quickly.
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This is industrial power generation for the grid, not a toy for your roof. They are taking a step towards solving the problem of base load. Solar is great, but it's not steady. If you can store enough energy to make it through the night, solar becomes something really special.
The other important element of this is cost. I don't have a problem with natural gas power plants myself, but bring solar down below that price for base load, and why bother with anything else? For us non-greens, this is the inter
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Natural gas is great for backup, relatively cheap plants, expensive fuel.
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California operated some plants that worked that way for a while: solar thermal with gas generator backup. Seemed to work OK. The problem is: these solar plants are more expensive to operate than gas generators. Gas is nearly free these days, but these solar thermal plants can still make sense to build as a hedge against changing fuel prices; however if you're relying on gas for base load that's less appealing.
If this plant live up to the hype, it's cheaper and stores power longer than previous efforts,
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They are taking a step towards solving the problem of base load.
Except "base load" is NOT a problem. It may be a problem someday. But it is not a problem today. The problem today is that solar costs three times what it needs to cost to be competitive. Unless that problem is solved, everything else is irrelevant.
Solar is great, but it's not steady.
When it is less than 1% of the supply, it doesn't need to be steady.
The solution to steadiness is smart meters and demand driven pricing, not molten salt.
Re:I don't understand the big deal here. (Score:4, Interesting)
We will eventually have 11 billion people consuming power at US levels - likely before the end of this century. Smart meters won't fix that. Solar is the only thing that scales (unless fusion finally stops being "just 20 years away"). Efficient PV panels and Tesla batteries are very high-tech solutions, and it's unclear that they could be available cheaply at that scale. Solar thermal, though, is quite straightforward.
This plant isn't good enough to be more than an experiment, and useful to hedge against a steep rise in fuel prices, but it's an incremental step. There seem to be many more incremental steps available for various approaches to solar thermal (I'm not the biggest fan of this exact design, but the power storage aspect is nice). Solar thermal just isn't a hyper-optimized mature field grasping for 1% improvements - there's lots of headroom here.
We're going to need a power generation solution that scales over 10x current world generation, and we're likely to need it in the lifetime of some /.ers. A solution with no exotic toolchain requirements, and no raw material requirements that won't scale, and that works for base load doesn't leave many options. (Obviously, solar isn't good for high latitudes, and gas generation isn't going away, but we're going to need something new for base load until fusion finally shows up).
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While I agree with most of what you say I have to disagree here:
Solar is the only thing that scales (unless fusion finally stops being "just 20 years away").
Thorium fission can scale. Recent developments show that we can build small modular reactors as small as 20MW or so, and make them as big as one GW. Much bigger than a gigawatt or three and it starts to make sense to just build more smaller ones from the same dies, cheaper to build and manage.
It bothers me on how people will claim we can make wind and solar work if only we build a massive continent wide power grid to compensate for the unfavo
Re:I don't understand the big deal here. (Score:4, Informative)
Thorium fission can scale.
Thorium (specifically Th-232) doesn't fission. It has to be bred up into U-233 by absorbing a neutron which can then fission by being hit by another neutron releasing energy. Fission of U-233 releases an average of about 2.2 neutrons to carry out further breeding and fission. This breeding-fission process is a bit knife-edge compared to regular PWRs, BWRs and other uranium-fuelled reactors where only one neutron is required to fission a U-235 nucleus and produce 2+ more.
What recent developments in "thorium fission" can you point us at? There's a lot of Powerpoint presentations and glossy brochures being waved around by folks looking to make a buck from research funding and subsidies but no-one is bending metal and pouring concrete right now on anything based on thorium as a primary source of nuclear energy. There ARE some experiments with thorium going on; PWR-style fuel pellets with thorium mixed in with uranium and plutonium are being exposed in a test reactor in Norway at the moment and there's an experimental Chinese pebble-bed reactor which can use some thorium in the fuel pebbles but that's about it.
As for modularity, it's not a new thing in regular uranium reactors -- see the units used in submarines, icebreakers and large aircraft carriers for the past fifty years and more as a worked example. The Russians are building a "power barge" carrying a ship reactor to produce about 40MW of electricity for coastal communities in Siberia and the Chinese are pouring concrete on a commercial modular power reactor (about 105MWe) but it's going to be a pebble-bed design fuelled entirely by uranium and plutonium to begin with. It might use a small amount of thorium in the future but that's a long way off and its commercial viability is still to be proven. Previous attempts to commercialise pebble-bed reactors capable of using some thorium such as the German THTR-300 were not a success.
Re:I don't understand the big deal here. (Score:4, Informative)
Thorium (specifically Th-232) doesn't fission.
I am well aware of that but using "thorium fission" as a shorthand for "thorium cycle fission" seems common enough that I thought it would not need explanation. I assumed that people that knew what LFTR was would know what I meant and everyone else could search on "thorium fission" in Google, Wikipedia, or wherever and figure it out by clicking on the first link that shows up.
This breeding-fission process is a bit knife-edge compared to regular PWRs, BWRs and other uranium-fuelled reactors where only one neutron is required to fission a U-235 nucleus and produce 2+ more.
A lot of nuclear engineers seem to disagree with you. There are several techniques to make thorium cycle viable, the most popular are molten salt variations. Molten salt allows poisons that would normally accumulate in solid fuel to boil out. Iodine and xenon are the biggest concerns and those simply cannot remain in solution for long, and there are techniques to speed the removal from the core adding efficiency.
What recent developments in "thorium fission" can you point us at?
Here's a good place to start:
https://www.youtube.com/user/g... [youtube.com]
There's a lot of Powerpoint presentations and glossy brochures being waved around by folks looking to make a buck from research funding and subsidies but no-one is bending metal and pouring concrete right now on anything based on thorium as a primary source of nuclear energy.
I believe that China and India would disagree with you. Right now in the USA and Canada thorium fission is being held up by regulators that don't know what to do with thorium yet. I suspect we'll see a boom in LFTR and DMSR shortly after China demonstrates their first MSR. It used to be that the USA was first in technology, now we race to be second place.
Previous attempts to commercialise pebble-bed reactors capable of using some thorium such as the German THTR-300 were not a success.
Let's see, steam turbines, helium cooled core, small manufactured fuel pebbles, and a one off design. What could possibly go wrong? Water creeping into the helium coolant. Pebbled fuel breaking in the reactor and getting lodged in piping. Difficulty in sourcing fuel. Not a high point of thorium as a fuel.
LFTR uses molten salt as coolant and fuel carrier, any leaking between them does cause contamination but it will not stop operation. Leaks can be repaired and operation resumed. There is no water cooling to create concerns over flash boiling, corrosion of metals, or contamination of fuel. LFTR does not require "manufacture" of the fuel, it's a stable salt with very low chemical and nuclear reactivity. Once melted it can be simply poured into the core. Waste products are removed as part of normal operation, they won't accumulate to levels that would cause massive release if there is a catastrophic failure. Any kind of large failure would be limited to destruction of the core, it can't "blow it's top" like water cooled and solid fuel reactors of the past.
This design was tested and operating fifty years ago. However, because we've learned a lot in the last fifty years in material science, manufacturing, and so forth that design would not be considered viable today. What it does do is show the physics work and if we can only get the DOE to get their assess off their thumbs then maybe we can see thorium as a fuel before another fifty years pass.
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I hate to break it to you but China is not building any kind of a molten salt reactor (MSR) never mind one where thorium makes up part of the fuel stream. They've talked about it, yes but then again a lot of Powerpoint Rangers have done so over the past ten years and more. They're not funding, pouring concrete or bending metal on an MSR, the one true sign that anyone is taking the production of a prototype reactor seriously. They have discussed building a BN-series fast-spectrum reactor as well but no fundi
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Just so other folks understand, no-one has built and operated a thorium-fuelled molten salt breeder reactor so the design hasn't been tested as you claim.
Now you are changing the rules.
I didn't say that people were building thorium cycle molten salt reactors right now. I said we've proven that molten salt reactors do work. I said we've proven that thorium cycle fission does work, it was done in solid fuel reactors. I said that thorium cycle reactors are running right now, and India is doing it. Putting all these technologies together in one design is nearly trivial. One thing that must be done is make it big enough to support breeding, the bigger it is
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Putting all these technologies together in one design is nearly trivial.
I'm sorry but that statement makes me die a little inside. That sort of reasoning is why I call the thorium boosters Powerpoint Rangers.
Yes I didn't watch any of the thirty or forty half-hour-long Powerpoint presentations on Youtube because none of them actually show hardware in operation, they show TED talks by graduate students and Twue Beweivers with glossy brochures, simplified diagrams and wishful thinking and a lot of "and then
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"Their fast-breeder is a conventional sodium-cooled design"
Uh yeah. A metal which burns furiously when exposed to air in its molten state.
"Just because you can, doesn't mean you should" applies in spades. Ask the Japanese why.
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"Solar is the only thing that scales"
Unfortunately, it doesn't scale. Those massive plants in California don't even produce enough to supply all the housing within their county, let alone export surplus or be reliable industrial suppliers.
We're unlikely to see practical commercial fusion before the end of this century. In the meantime we need to drop CO2 emissions by 80% or risk poisoning the oceans in a global anoxic event (this will kill off large land animals including us far sooner than global warming
Re:I don't understand the big deal here. (Score:4, Informative)
> The problem today is that solar costs three times what it needs to cost to be competitive.
Read this article and say that solar is still 3x competitive range:
http://www.pv-tech.org/news/buffett_projects_record_low_cost_is_part_of_pricing_trend_says_first_solar [pv-tech.org]
Same company as the original story, by the way, NV Energy.
Re:I don't understand the big deal here. (Score:4, Informative)
They are providing power to Vegas which has the highest power usage in the evening up to midnight according to the article.
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No city in the world has a flat demand curve, no coal/nuke plant can meet that non flat demand curve without extensive use of hydro storage and fast switching gas fired turbines. In fact there is no technology that comes close to meeting an average city's demand curve without storage. The exact same infrastructure we currently use to bend the flat
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Solar thermal is a solution to the wrong problem. Electricity demand, and thus prices, are highest in the daytime, and lowest late at night. So by shifting production from day to night, they are turning gold into lead.
From TFA:
Smith expects that NV Energy, the Las Vegas–based utility contracted to buy Crescent Dunes’ output, will want it mostly during the utility’s unusually late demand peak, which the Vegas Strip’s nightlife routinely stretches toward midnight.
TFA and TFS also say, "Engineered from the ground up to store some of its solar energy," and presumably "some" means "not all" with the not all part going to daytime demand.
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Take a look at this German production report [fraunhofer.de]. Take a look at page 248. That is a weekli production report. Notice that how much solar is actually already being produced. Notice that every day just before solar comes on and just after solar goes off there is a peak of production from other sources. Being able to shift solar production into those areas would mean less coal and gas being burned. As solar becomes more prevalent it becomes even more useful to shift solar production out of daylight hours.
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Electric demand peaks from 3pm to 9pm.
Solar production peaks from 9am to 3pm.
Molten salt shifts the production to meet demand.
See the California Duck Curve for a good illustration.
http://www.greentechmedia.com/... [greentechmedia.com]
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You don't understand because you are not fully informed. Solar production peaks at noon. Electricity demand peaks much later - it varies by time of year and location, but it is never so early as noon.
I have time of day metering at my house. In the summer, peak rates are 1PM to 7PM. In the winter, peak rates are 5 to 8 PM.
I send the most power to the grid from my solar panels at a non-optimal time. If I could shift when I send that power to the peak demand time I would get paid more, and the power company wo
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If I understand one of the weaknesses of solar thermal is that partial cloud cover can cause a dramatic drop in power production, much more so that with solar PV. So thermal storage would allow the plant to ride out any unexpected cloud cover, even for hours at a time, if enough stored power is available.
But I agree that, for now, the solar production should be used in the daytime, when other forms of power generation are available for overnight demand.
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That entirely depends on the country - and the energy sources.
OIl/gas-based heating accounts for at least as much energy consumption as electricity does at the moment. With them inevitably being banned in the future (plus EVs spreading), night consumption will only rise.
Nuclear molten salt is a better answer though.
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Solar thermal plants around the world have been in continual operation for the better part of a decade now. They work and each new generation brings improvements.
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Perhaps but the dramatic price drops that have been seen with wind & PV have yet to happen for solar thermal.
I've heard that a big part of the problem is there's not enough standardization - every project, especially when it's by different companies, is built like a one-off plant.
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"Perhaps but the dramatic price drops that have been seen with wind"
In the current environment, the only time a wind turbine is profitable is when it's blades are stationary because the operator is being paid not to connect it to the grid.
The big units have a nasty tendency to catch fire (overheated gearboxes) or simply destroy gearboxes with monotonous regularity and the total power output if you carpeted an area the size of the UK with the things is about the same as 2-4 conventional plants, plus there's
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The French nuclear plants, although a remarkable achievement, have had mutiple shutdowns of many units due to lack of adequate cooling - just when they're most needed ( during summer heat waves ).
"supplementing their "nuclear free" grid capacity with power generated in french nuclear plants" - it's true that a very significant chunk of French nuke power is exported - because it's too difficult to ramp more than a few plants up & down so the benefits cut both ways.
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I'm aware of the drawbacks of current nuke tech in hot weather. The reality is that water-cooled nuke plants simply don't get hot enough to be very efficient.
The other reality of watercooled fuel-rod based plants is that you _can't_ turn them up and down much. Doing so results in neutron poisons (primarily xenon) building up quickly and knocking out the reactor's criticality until they break down (which takes hours) - you can turn it down fast but bringing it back up can take a day.
If you use a MSR plant th
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I'm well aware of the history, promise and hype around molten-salt reactors and have seen several of Kirk Sorensen's presentations and some of the old ORNL docs. I think MSRs / LFTRs / whatever are worthy of research and development and would encourage serious spending dollars be allocated.
BUT...... the only known MSR was a test machine, never used thorium, never produced electricity and was frequently shut down.
That's not good enough to displace - yet - to displace other proven technologies be they tradit
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"What's needed is to have another MSR/LFTR built, say 20 - 50 MW, run it for at least 3 years with >60% uptime"
Indeed.
Bear in mind that the "frequently shut down" part of the ORNL plant was mostly "friday afternoons, because noone wanted to stay around during the weekend and look after it" and "tests to ensure it could be restarted quickly" (which it could be). It could be throttled from high to low and back again almost as quickly as a hydro system - which is not only substantially better than conventio
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Yep, I remember all the hype about this in the mid 1970's....and it was "just around the corner" and "almost ready to happen" then too.
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It hasn't been done exactly like this before in the US. That's all.
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At 566 degrees C all your worries will be leaving permanently.
Re: I don't understand the big deal here. (Score:2)
"You can literally feel your worries melting away"
FTFY
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molten salt nuclear systems can turn up/down faster than coal plants
The ORNL MSR was switched off every Friday afternoon and fired up again on Monday morning, because noone wanted to nursemaid it over the weekend. Whilst only 8MW it means it got subjected to thermal stress cycles out of all proportion to what any power plant would see.
Molten salts for solar thermal systems are the "battery" which helps relieve the grid of the "spiky" nature of current renewables generation, but the reality is that if MSR pl
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Crescent Dunesâ(TM) generation earns about $190 per megawatt-hour, including the value of federal subsidies
Which translates to $0.19/kWh. That's 46% higher than the U.S. national average of just under $0.13/kWh.
Very true. Solar thermal has the advantage of being low-tech and scalable, and will be key to bringing 11 billion people up to US levels of consumption, but right now it has 2 big problems: cost, and overnight power generation. This plant is an incremental improvement in both (if it lives up to the hype).
Natural gas is astonishingly cheap right now, and generation plants operate for a very long time compared to the volatility of fuel prices, so building some generation capacity around fuels that aren't th
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Solar thermal has the advantage of being low-tech and scalable
What part of this project is "low-tech"? I must have missed that when I read the article.
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Building PV panels that are efficient enough to be worthwhile requires a very long toolchain. A bunch of mirrors and a steam turbine don't. Thermal energy storage is a much lower tech idea than the Tesla battery pack. As the soar thermal field evolves, there will be a variety of high- and low-tech improvements and experiments, and the prototypes of new ideas are always going to be complicated and expensive, but that doesn't preclude an eventual evolved design that's quite straightforward.
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Gas will stop being super-cheap when the export facilities are completed and companies can sell it on the international market for a lot more than it is currently being sold for in the US.
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Well, eventually. Energy demand is very low now, with almost every economy in the world having issues. If that should ever change, however: watch out. Energy prices will go nuts.
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No, the point is that people in other parts of the world pay a lot more for gas. So once these export facilities are built, the market price in the US would be the much higher global market price, less the $2.15 cost of exporting it.
In Britain for example, some of our gas comes from the North Sea, and rest is imported, either by pipeline from Russia, but they aren't very reliable and we try to avoid them, or alternatively we import it as LNG from places like Qatar.
To give you an idea, in the US, gas costs
Re:Voting with their feet (Score:4, Funny)
Las Vegas ... pillar of salt.
Just don't look back when you leave.
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I don't know, you're asking for "a Lot."
Ha! I kill me.
I'm not proud. Low hanging fruit and all that.
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Nitrate salts need to be mixed with other ingredients to become explosive. Nitrate salts alone are not explosive [wikipedia.org].
The most extended mixture contains sodium nitrate, potassium nitrate and calcium nitrate. It is non-flammable and nontoxic, and has already been used in the chemical and metals industries as a heat-transport fluid, so experience with such systems exists in non-solar applications.
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