A Tower of Molten Salt Will Deliver Solar Power After Sunset (ieee.org)

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 [The system] heats a molten mixture of nitrate salts that can be stored in insulated tanks and withdrawn on demand to run the plant’s steam generators and turbine when electricity is most valuable.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.

Comments

I don't understand the big deal here.

[Anonymous Coward]

Use of molten salts in thermal solar power generation has been around for decades. This is nothing new. TFS and TFA mention the use (or lack thereof) of oil several times. Is this the difference? I'm not familiar with this type of power generation but it is never explained exactly what the big deal is with this.

Re: I don't understand the big deal here.

[Anonymous Coward]

No, it's old news.

Re:I don't understand the big deal here.

[houstonbofh]

But no one has made it work before! And ours will work! Really! And everything will be different now! (We just need one more funding round before production)

Re:I don't understand the big deal here.

[ShanghaiBill]

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.

[Orne]

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.

Re:I don't understand the big deal here.

[Socguy]

I think you should look up the difference between fusion plants and solar thermal plants.

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.

Re:I don't understand the big deal here.

[Anonymous Coward]

But the first commercial-scale implementation of an innovative solar thermal design could turn the tide.

What's new? Clue's in the summary.

Re:I don't understand the big deal here.

[lgw]

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 interesting potential for solar. (Plus solar thermal scales to 11 billion people at US consumption levels, if only just.)

I hope this plant works out, and lives up to the hype.

Re: I don't understand the big deal here.

[Ichijo]

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.

Re: I don't understand the big deal here.

[peragrin]

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?

Re:I don't understand the big deal here.

[JustAnotherOldGuy]

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.

Re: I don't understand the big deal here.

[Pinky's Brain]

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.

Re:I don't understand the big deal here.

[Pinky's Brain]

Natural gas is great for backup, relatively cheap plants, expensive fuel.

Re: I don't understand the big deal here.

[Ichijo]

If you'll read the summary, a molten salt tower continues to generate power after the sun goes down. With demand-responsive pricing, the plant can satisfy 100% of demand until it runs out of heat, 10 hours after the sun goes down.

Re: I don't understand the big deal here.

[Anonymous Coward]

Seriously doubt that applies to Vegas.

Re:I don't understand the big deal here.

[lgw]

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, which is a great step.

Re:I don't understand the big deal here.

[CanadianMacFan]

They are providing power to Vegas which has the highest power usage in the evening up to midnight according to the article.

Re:I don't understand the big deal here.

[ShanghaiBill]

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.

[lgw]

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).

Re: I don't understand the big deal here.

[Barsteward]

there is nothing like preparing for the future....

Re: I don't understand the big deal here.

[Shoten]

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.

Re: I don't understand the big deal here.

[tlambert]

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, and the West Coast gets to lump it.

Of course, the West Coast could do it in the morning, well before sane people get up for the day.

And I guess God Help You if Larry Ellison decides to throw a party, and then even the rich people get inconvenienced, when the super rich decide to use more power than is normally available...

Re:I don't understand the big deal here.

[TapeCutter]

"Base load" in FUD dreamt up by coal miners and adopted by nuke enthusiasts.

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 :base load" curve into the required wavy demand curve can also be used with solar and wind, In the case of solar it may be that you need less of this infrastructure since peak sunlight conveniently coincides with peak consumption. If the people building this plant are contemplating molten salt for storage, it implies hydro storage is impractical or impossible in that particular location.

Re:I don't understand the big deal here.

[AK Marc]

I also don't understand molten salts. Yes, once we shut down coal baseload plants, we'll need them for baseload, but right now, peaks are the issue, and power usage peaks at peak sun (or just after), so storage isn't an issue.

Re: I don't understand the big deal here.

[AK Marc]

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.

Re:I don't understand the big deal here.

[Anonymous Coward]

what the big deal is with this.

The molten salt was 3d printed. Sure, 3d printing is 50 year old technology, but millennials are vapid and hung upon being trendy (because being trendy makes you unique) and 3d printing is very trendy.

Re:I don't understand the big deal here.

[blindseer]

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 unfavorable weather in parts of the nation. The problem I see is that "unfavorable weather" tends to include things like clouds, high winds, and lightning, things that tend to damage power grids. We don't need bigger power grids, we need them smaller. If power goes out in St. Louis then the people in Kansas City and Chicago shouldn't have to worry if the lights will go out when the sun goes down. That solar power on the coasts is going to have to cross the river, if the switching stations on either side were damaged in a storm then you don't have a big national grid any more.

Adding redundant power lines adds cost, which is reflected in people's utility bill. I'd rather see that money put toward thorium power than solar and power lines.

Re: I don't understand the big deal here.

[rch7]

Big commercial customers typically don't have smooth pricing.
But still, it is more profitable to sell electricity when price is up in afternoon or around sunset, not just at random time when it may be cheapest. The price difference may be big enough to justify extra investment into molten salt storage.

Re:I don't understand the big deal here.

[fahrbot-bot]

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.

Re: I don't understand the big deal here.

[Anonymous Coward]

Smooth pricing makes electric cars less economic. That whole "charge it at night when the power costs less" is one of the few things that make them attractive from a price perspective.

Re: I don't understand the big deal here.

[Anonymous Coward]

Then poor people should go get better jobs. Problem solved.

Re:I don't understand the big deal here.

[nojayuk]

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.

[davester666]

Bonus, you can have a nice relaxing salt bath. You can literally feel all your worries leaving through your pores.

Re: I don't understand the big deal here.

[Anonymous Coward]

Right, so rich people install (sufficient efficient for them, but much less efficient overall compared to a central plant) Tesla batteries in their garages, which poor people simple pay higher prices when they actually use power. Or someone will come along and build a solar thermal plant anyway so they can profit on the arbitrage between day and night pricing.

Re: I don't understand the big deal here.

[Shoten]

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 frequency events take place when you aren't able to balance load and generation properly. Oh, and also because the more units you have, the more effort your GMS (Generation Management System) has trying to maintain that balance. This problem is about balance, rather than how centralized the source of the balanced resource is.

As for "better" power plants...I'm curious what design you're referring to? The issues I'm citing are pretty much across the board. What is this "better" plant you speak of?

Re:I don't understand the big deal here.

[blindseer]

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...

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.

Re:I don't understand the big deal here.

[jklovanc]

Take a look at this German production report. 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.

Re: I don't understand the big deal here.

[Ichijo]

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?

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.

Re: I don't understand the big deal here.

[Lotana]

At 566 degrees C all your worries will be leaving permanently.

Re: I don't understand the big deal here.

[Ichijo]

Ideally, power demand would be flat and constant...the same amount, all the time.

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 doesn't exist with flat rates because the average price is the only price.

Re: I don't understand the big deal here.

[tlambert]

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?

Re:I don't understand the big deal here.

[mspohr]

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/...

Re:I don't understand the big deal here.

[nojayuk]

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 funding, no metal bent, no concrete poured on that project either which is a shame as it's a very interesting concept with the ability to burn waste actinides with minimal fuel reprocessing.

India's interest in thorium is as an adjunct fuel for their heavy-water reactors mixed in with a lot of 20%-medium-enriched uranium and plutonium. There are geopolitical reasons for this decision to work on using thorium as an adjunct fuel but at the moment they're building out several PWRs, mostly Russian VVER-series designs. Their fast-breeder is a conventional sodium-cooled design, not speciafically built to use thorium. It is outside NPT and IAEA safeguards so fuelling it could be a problem.

Experimental reactor designs actually being funded, built and operated in the real world are the Chinese HTR-PM helium-cooled pebble-bed reactor and the Russian BN-800 fast-spectrum reactor, both based on existing engineering predecessors (the ill-fated German HTHR-300, the Chinese HTR-10 and the ex-Soviet sodium-cooled BN-350 and BN-600).

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. There was a molten-salt reactor fuelled with U-233 and later on U-235 at Oak Ridge but it never used thorium in any way. The Powerpoint Rangers pushing thorium claim it would be easy to add a breeding core to such a design and there would be no serious technical challenges involved despite the very high temperatures involved, the intense radiation environment required for the breeding process and its effects on structures carrying molten fuel. That last factor was not something plutonium breeder reactors have had to put up with and their success record is not good even using fixed arrays of solid fuel.

Re:I don't understand the big deal here.

[jandjmh]

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 would not need to fire up their relatively dirty and inefficient gas turbines so much in the evening.

Re: I don't understand the big deal here.

[Anonymous Coward]

Its more efficient previous heat storage solutions. The concept is good, solnova stations in spain first started coming online in 2006 and are working well and are still adding capacity.

https://en.m.wikipedia.org/wiki/PS20

Its a good way to do it, can expand the hours of solar delivery in to the night and can back the system up with natural gas (one of the cleaner forms of fossil fuel) if you need to keep the generators running when the sun is not available and all stored energy is depleted. The more of these stations that are built the better.

Re:I don't understand the big deal here.

[haruchai]

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.

Re:I don't understand the big deal here.

[haruchai]

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.

Re: I don't understand the big deal here.

[Anonymous Coward]

In many countries demand is limited by increasing the daily connection charge the larger the customers main current rating.

This helps limit peak demand and provide additional funding for utilities to build capacity.

Having flat connection rates means the poor are funding generation capacity for the wealthy to buy at anytime at any price, while poor adjust their usage habits to keep costs under control

Re:I don't understand the big deal here.

[DanielRavenNest]

> 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

Same company as the original story, by the way, NV Energy.

Re: I don't understand the big deal here.

[Ichijo]

Because demand for electricity is constant throughout the day?

Re: I don't understand the big deal here.

[GrantRobertson]

"You can literally feel your worries melting away"

FTFY

Re: I don't understand the big deal here.

[tlambert]

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 to make the infrastructure happy, rather than expecting infrastructure to behave differently to make the humans happy, is pretty misanthropic.

Re: I don't understand the big deal here.

[Anonymous Coward]

I'm reminded of a meeting I went to about people discussing exactly this: Because it was expensive to drop power poles in rural areas, either the person getting the pole should pay for the wires, substations and such... move to the city where there is infrastructure, or deal with candles. Similar with roads. If a road isn't tolled, it should be paid for by the homeowner whose house it goes by, or it just shouldn't be kept up, as it has no financial benefit.

Maybe if we do this and follow values of such moral leaders such as Ayn Rand, we will return to a new age for the US... quite similar to the Gilded Age, where being fired was being tossed out of the company-owned city, then arrested for vagrancy. Any protests or talk of unions would be answered by the definite un-subtle reply from NATO 5.56 rounds served in liberal quantities by a private police force.

Re: I don't understand the big deal here.

[Anonymous Coward]

There are a ton of things that can be used with "excess" capacity. Desal plants are the first and foremost example, but from what I have seen, people rather be forced to move elsewhere than have anything like that due to NIMBY, especially in California (where the residents chose to have rolling blackouts and brownouts as opposed to building new plants not that long ago.)

Of course, there is another item as well. Thermal depolymerization is something useful. It may "waste" energy, but it is the only way to 100% recycle the plastic polluting the environment. Not "downcycle"... true recycling of water bottles and other crap into usable crude oil ready for reuse for making new stuff. I have a few friends in Japan who actually have home thermal depolymerization machines. The active tank doesn't have that much capacity (about a cubic foot or 28 liters)... but it will take any plastic or organic matter tossed in, and render a nice amount of clean mineral oil out. The oil isn't that valuable... but the used condoms and other shit that isn't winding up in landfills and lakes is the important factor.

Re:I don't understand the big deal here.

[RubberDogBone]

It hasn't been done exactly like this before in the US. That's all.

Re:I don't understand the big deal here.

[blindseer]

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 the easier it is to make sure the neutrons hit a thorium or uranium atom before it hits the wall of the container.

All we need to do is have the DOE decide that LFTR does sound like a safe design and issue a license. It is not the DOE's job to decide if LFTR is economical, just that it is safe.

The Powerpoint Rangers pushing thorium claim it would be easy to add a breeding core to such a design and there would be no serious technical challenges involved despite the very high temperatures involved, the intense radiation environment required for the breeding process and its effects on structures carrying molten fuel.

Now you are just telling me you watched none of the videos that I linked to. Just about any of the videos that feature Kirk Sorensen has him explain how they plan to design a core that can hold up to the temperatures of the molten salt, maintain integrity even with the given neutron flux, and assure that enough thorium is bred to maintain criticality.

The short answer to your concern is that the core is made of a high nickel alloy specifically designed for these high temperatures. They maintain breeding and criticality by making the core the right shape and size to make sure neutron loss is minimal. We've shown we can make a core that can maintain integrity under the neutron flux of these reactions because we've made breeder reactors before.

You keep talking about how it can't be done, the people that are making it happen will prove you wrong.

Re: I don't understand the big deal here.

[Ichijo]

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.

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?

Re:I don't understand the big deal here.

[nojayuk]

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 a miracle occurs" in the middle. I've seen some of the early attempts to convince folks that thorium was the Answer to non-existent problems before I decided life was too short and went TL;DR on the subject. To engage my interest it will take working hardware, a real molten-salt mostly-thorium reactor that runs for a year or more continuously (or at least 90% uptime) with significant thermal output (10 MW would be a good start, even 7 MW like the ORNL uranium-fuelled reactor produced) and a plan to decommission such a reactor in the future after 50 or 60 years of neutron irradiation and radiochemical contamination of components in direct contact with molten fuel (not something that causes a problem with existing solid-fuel reactors, even breeders).

the people that are making it happen

Until they have funding to build and operate a complete operational test reactor for at least a few years nobody is "making it happen", they're selling dreams. Sorry.

Re: I don't understand the big deal here.

[tlambert]

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.

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.

Re: I don't understand the big deal here.

[lsatenstein]

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 coincide. The power plant has to structure and manage capacity for these coincident peaks. What the power plants can organize, is dual electrical inputs to homes. One input could be powered off at serious peaks. What would be powered off could be electrical water heaters, swimming pool pumps, and Central A/C units. (Of course, only for a max of 2 hours during that peak).

Homes would need to be constructed with R40 insulation in the walls, R50 in the ceiling and as well, triple pain thermal windows. so as to retain the selected house temperature. When is that new building code going to be introduced?

Is that going to happen any time soon?

Re:I don't understand the big deal here.

[Anonymous Coward]

That all sounds great except for the economics. It still appears that fission in any form is the most complicated and most expensive way to produce power.

Re: I don't understand the big deal here.

[Muad'Dave]

... 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.

[Agripa]

The power may be worth more later making up for the cost of storing it.

Re:I don't understand the big deal here.

[stoatwblr]

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.

Re:I don't understand the big deal here.

[stoatwblr]

"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 does), so unless you plan to kill off more than 50% of the planet's population a crash plan of nukebuilding needs to be underway. Conventional fission for now and LFTRs as soon as they're available.

Uranium plants don't scale to this kind of rollout requirement because there's not enough uranium, it's insanely expensive to enrich to the 3% level needed to run a conventional plant(*) AND the resulting U238 "depleted uranium" is itself a weapons proliferation risk (U238 is used as the casing of H-bombes to dramatically increase the yield.). Thorium on the other hand is a nuisance waste product of rare earth mining which doesn't need any special treatment before it's used in the nuclear cycle. The US DOE buried a few (ten-)thousand tons of it in Utah some time back, simply to get rid of it.

(*) The actual cost of enriching uranium for civil nuclear use is a classified military secret in the USA.

Re:I don't understand the big deal here.

[stoatwblr]

"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.

Re:I don't understand the big deal here.

[stoatwblr]

"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 the twee safety issue of the blades being known to go more than a mile if they break so you need an exclusion zone around each one.

  Yes, Denmark produced 110% of its demands - for less than 2 hours, on a warm afternoon with historic low demands. The rest of the time they buy in coal sourced power from germany (it's filthy lignite coal) and the germans have resorted to supplementing their "nuclear free" grid capacity with power generated in french nuclear plants instead of german ones.

Re:I don't understand the big deal here.

[stoatwblr]

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 plants are built, the renewables sites are a gigantic waste of money and space.

Re:I don't understand the big deal here.

[haruchai]

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.

Yes, Denmark produced 110% of its demands - for less than 2 hours, on a warm afternoon with historic low demands

Actually, it peaked at 140% and it was high for a LOT longer than "less than 2 hours"
From a low of 390 MW at 10pm on July 7th, 2015, wind power production on the DK-West grid rose to 1 GW by 2am on July 8th, then to 2 GW by 8am and peaked just over 3GW by 3pm on July 9th.
At no time between 9am on July 8th and 7pm on July 10th did wind power on DK-West drop below 2GW and for the bulk of that period of two and a half days it was above 2.6GW. Gross power consumption on DK-West varied from 1.8GW - 2.8GW during that time.

For DK-East, wind power production from 6am on July 8th to 9pm on July 10th varied from 400MW to 920MW and for >80% of the time was above 800MW.
DK-East gross power consumption was from 1 - 1.6GW during that period.

  "Interconnectors allowed 80% of the power surplus to be shared equally between Germany and Norway, which can store it in hydropower systems for use later. Sweden took the remaining fifth of excess power". Looks like it was of some benefit to the neighbors.
and "The figures emerged on the website of the Danish transmission systems operator, energinet.dk, which provides a minute-by-minute account of renewable power in the national grid. The site shows that Denmark’s windfarms were not even operating at their full 4.8GW capacity at the time of yesterday’s peaks"
(from http://www.theguardian.com/env...)

Re:I don't understand the big deal here.

[stoatwblr]

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 then the hot side can be 700-110C instead of 350C and that in turn means the cold side doesn't need to be water cooled at all (remember all heat engines work by transporting energy from the hot to the cold side) which in turn means that plants don't have to be located next to rivers or the sea

Because MSR systems have the fuel dissolved in the salt, xenon is free to outgas in the circulation pumps's surge chamber where it can be extracted (along with helium and other gasses). That in turn means that MSR plants can more-or-less load-follow.

The shorter version is that judging nuclear plants by current commercial designs (which haven't changed much since they were first developed for submarines in the 1950s) is very shortsighted. MSRs were proven practical 45 years ago but killed for political reasons. In the last decade there's been a resurgence of interest and there's active research going into making sure that corrosion and "freezing" issues are solvable (the salts freeze at ~400C, which means if they escape from the reactor they won't go far and that in conjunction with being unpressurised means that any leak is likely to be self-sealing, but you still don't want anything getting out as it's fiercely radioactive and therefore harmful to anyone in the immediate vicinity)

MSRs can be made with or without Thorium Cycle. The big advantage of using thorium is that it's _cheap_, plentifully available and the byproducts of making reactor fuel can't be used to make H-bombs, plus the waste output of the reactor itself is decreased by at least 90%

Re:I don't understand the big deal here.

[haruchai]

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 traditional nuclear or not.

What's needed is to have another MSR/LFTR built, say 20 - 50 MW, run it for at least 3 years with >60% uptime , connected to varying loads and let it be the primary electricity source for something near-mission-critical, say a military base. Pull that off while demonstrating the advantages of the tech before trying to sell it as the power plant of the future.

Re:I don't understand the big deal here.

[stoatwblr]

"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 conventional nuke systems, it's also substantially better than most thermal plants other than OCGTs and smaller diesel piston systems (cogen systems take a long time to cycle up/down)

And that one of the prime requirements for new generation nuclear _is_ the ability to throttle up/down quickly. You simply can't do that _at all_ with fuel rod or pebble-based systems, as the neutron poisons which build up in the sealed units under such circumstances constrain throttle-up to "several hours' delay".

Until MSRs are commercially practical, conventional nukes are the best way forward. The waste problem is several orders of magnitude less complicated than that of coal (300 years cooling results in low level waste) and several more orders of magnitude smaller than a coal plant's tailings pond (a swimming-pool's worth of waste over the life of the plant rather than several square miles of ash slurry). The big bad nooclear bogeyman is less worrying when you shine a light on him and don't let your system get corrupted by beancounters (or "experimenters") compromising the safety designs (several USA reactor control rooms, including TMI), bypassing interlocks (Chernobyl), or running plants far beyond their design lifespan (Fukushima), or do stupid things like using molten sodium as your coolant (various breeder reactors but the example I'm thinking of specifically is Monju) or run exposed graphite in the core (Chernobyl and Windscale/Sellafield - although the latter was a military reactor producing plutonium for bombs)

Once MSRs _are_ commercially viable (Fusion may happen but it's realistically at least a century away and we don't have that much time to wean ourselves off carbon) then the fact that they can load-follow and easily idle means a lot of the complication in the current grid can be done away with. More importantly they're likely to do so at rates which mean that Solar(PV|Thermal) and Wind become even more hopelessly uneconomic than they already are.

Discounting Hiroshima/Nagasaki, the entire worldwide death/injury toll from mad-made nuclear effects (military and civilian) in the last 70 years is far less than 1 year's road deaths in a tiny country like New Zealand (331 died there in 2012). If you take out the military incidents, the number comes down to less than 100 and most of those (41-56 depending on the source) are people who died fighting the fire at Chernobyl. Putting it in perspective: That's less than one _day_ of United States road deaths (average 99/day in 2012).

I really don't like the idea of building new water cooled/moderated nuke plants on safety grounds but I don't see that "we" (the planetary population) have much choice. We need viable base-load alternatives to carbon _now_, not in 30 years' time (solar and wind can never provide wide-area baseload, even with storage systems in place) and we need to take into account a quadrupling of demand in the developed world (replacement of carbon-based winter heating systems and more-electric vehicles), plus at least 50 times more as the developing world moves ahead (energy and potable water access are the driving forces behind most wars and refugee crises. If you want to start heading those off, you need to stop dropping bombs and start building energy systems.)

Downsides

[Elledan]

Previously such thermal solar tower designs have caught a lot of flak for a number of reasons, including their ability to light passing birds on fire ('streamers'), their maintenance-intensive nature (lots of mirrors and associated electronics to clean and maintain), the risk of massive arrays of mirrors reflecting light for passing pilots, as well as their relatively low power density.

The article reads more like a fluff PR piece instead of providing any credible reason for why we should get about yet another one of these plants.

Re:Downsides

[houstonbofh]

Especially since the plant is not up and proven yet. I am skeptical whenever I see "We are going to do this cool new thing that will change EVERYTHING!"

Re:Downsides

[Dutch Gun]

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.

Re:Downsides

[Gamasta]

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/...

Re:Downsides

[Socguy]

'If by cool new thing' you mean 'run for a few hours longer after dark.'

I see no reason to doubt that refinements in design can squeeze out a few more hours of run-time.

Re:Downsides

[Socguy]

If this company thinks they can operate this plant, I see no reason to stop them.

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... North America wide that number may rise as high at 1 billion. http://www.flap.org/faqs.php 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.

Re:Downsides

[Kohath]

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

[finlan]

So, if you work there, there's always roast chicken in the canteen?

Re:Downsides

[Anonymous Coward]

More recently in the Gemasolar plant (20 MW) in Spain, they were able to achieve continuous operation 24h a day, with a record of 36 days. I think this is the smaller-scale demonstration that they mention.

https://en.wikipedia.org/wiki/Gemasolar_Thermosolar_Plant

Re:Downsides

[Anonymous Coward]

A couple of birds dead should make us not power a civilization? Does that matter? Are you fucking tripping? People die in car accidents all day long. No pain, no gain.

Re:Downsides

[0123456]

Indeed. Massacring birds is the new Green.

Re: Downsides

[Anonymous Coward]

So, if you work there, there's always roast chicken in the canteen?

Given chickens' very limited abilities in the area of flying, I doubt they're going to be getting anywhere near high nor far enough to risk getting fried from this.

Roast buzzard, on the other hand...

Re:Downsides

[Anonymous Coward]

Previously such thermal solar tower designs have caught a lot of flak for a number of reasons, including their ability to light passing birds on fire ('streamers')

Pretty sure it should be possible to design a semi-automated drone or something similar that will (if necessary) actively scare birds away from the area of the beam, assuming it becomes enough of an issue.

Re:Downsides

[khallow]

Glancing at Wikipedia, it appears they picked up a $737 million loan guarantee from the DoE to fund a 110 MW plant. So no economies of scale apparent.

Re:Downsides

[Anonymous Coward]

Well how else do you expect us to make all this popcorn chicken?!?

Re:Downsides

[Cederic]

Or a Youtube video feed for added revenue.

Re:Downsides

[Dutch Gun]

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.

Re:Downsides

[jklovanc]

The Andasol solar uses an HTF fluid circulating in the solar field. 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 melts again. If the salt solidifies in the pumps and pipes between the collector and the storage tanks there is a much bigger problem. How do you melt salt inside a pump and hundreds of feet of piping? Another issue is that hot oil is nowhere near as corrosive as molten salt. With the tank method all you need to be corrosion resistant is the tank and heat exchangers in the tank. With the new technology every pipe, pump, solar collector, etc would have to be highly corrosion resistant. That can get very expensive and they may need to be replaced quite often.

A tank of molten salt with a couple of heat exchanges in it is very different than pumping molten salt around.

Re:Downsides

[khallow]

The 20 MW plant was just under half the cost (and a ludicrous $33/W). I instead based my conclusion on the price of the 110 MW station which at $975 million was almost $9/W. If you're not seeing vastly cheaper costs at that size a plant, then it's probably because the business plan is to sink the construction costs in other businesses you own rather than build anything of value. Thus, there is no incentive to create much less exploit economies of scale since that just reduces the take.

Re:Downsides

[jklovanc]

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 from a population of a millions is nothing. Losing a few hundred raptors from a population of a few thousand is a big problem. All birds are not created equal. These towers could cause the extinction of some bird species.

Re:Downsides

[dave420]

So in your perverted mind "kill fewer birds" = "massacre the birds". Energy sources like this kill fewer birds than the habitat devastation and pollution caused by the energy sources they replace. This really isn't difficult to understand...

Re:Downsides

[stoatwblr]

"How do you melt salt inside a pump and hundreds of feet of piping? "

Electric heaters. That was solved 50 years ago.

Re:Downsides

[jklovanc]

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?

Re:Downsides

[ultranova]

Putting electric heaters inside a pump would make the pump more complex and therefore more expensive and prone to breakdown.

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.

See how the complexity of pumping molten salt around quickly rises?

No, but I have seen how factories that have to do so do it. It's not a problem.

Re:Downsides

[ultranova]

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.

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 just rig strobo lights or loudspeakers or something to drive away whatever birds wander near?

Re:Downsides

[jklovanc]

Off the shelf heater wire that heats to 260 degrees Celsius+?

Re:Downsides

[jklovanc]

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.

Re:Downsides

[stoatwblr]

Yes, it's called NiChrome and it's been around forever.

And?

[Anonymous Coward]

Lots of these towers have thermal storage. Note that they say they can "dispatch" power for 10 hours, not that they can maintain full rated load for that time.
This is at best a generator during the day and a peaking plant for the first 10 hours after sundown, which means something else needs to provide base load at night and feed the gap in the last few hours before sun up.

As many have pointed out...

[Rei]

... 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.

Voting with their feet

[Anonymous Coward]

A tower of molten salt to power the Las Vegas strip? Hmm. Steve Wynn and Sheldon Adelson (my heroes!) are trying to buy their power from elsewhere. Government should stop trying to 'help so much'.

Re:Voting with their feet

[PPH]

Las Vegas ... pillar of salt.

Just don't look back when you leave.

Re:Voting with their feet

[KGIII]

I don't know, you're asking for "a Lot."

Ha! I kill me.

I'm not proud. Low hanging fruit and all that.

Before Anyone Gets Too Excited

[Anonymous Coward]

While the article and the summary are misleadingly worded to suggest that this will be a cheap source of electricity, I'd like to point out:
From the article:

Crescent Dunes’ 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.

Re:Before Anyone Gets Too Excited

[lgw]

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 the cheapest today isn't stupid. Solar is a great hedge for variable fuel prices, as the cost and availability is stable.

Re:Before Anyone Gets Too Excited

[tomhath]

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.

Re:Before Anyone Gets Too Excited

[lgw]

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.

Re:Before Anyone Gets Too Excited

[jonbryce]

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.

Re:Before Anyone Gets Too Excited

[lgw]

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.

Re:Before Anyone Gets Too Excited

[rch7]

It can be sold for a lot more only after it liquefied, shipped to other continent, and regasified again. The extra cost comes at around $2.15 per Mcf and it leaves no room for raising US domestic price significantly.

Re:Before Anyone Gets Too Excited

[jonbryce]

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 about $2.36 per MMBtu, in Europe it is and $6.15 and in Asia it is $9.10. So obviously anyone who can buy gas at $2.36, ship it across the Pacific and sell it for $9.10 stands to make a lot of money.

Re:Before Anyone Gets Too Excited

[Anonymous Coward]

Lower tech than fracking or deep-sea drilling.

Marmora (Ontario) wants pumped storage

[davecb]

My cottage is quite close, the project is described at http://ecogeek.org/2013/04/ope...

This approach is low-cost, and used in Brazil among other places: https://en.wikipedia.org/wiki/...

Re:Marmora (Ontario) wants pumped storage

[Anonymous Coward]

Yes, pumped storage is great, where you can do it. However, like hydro power and solar, it doesn't make sense everywhere. Looking at the total lifetime cost, it just doesn't make sense unless there is a natural place to pump the water, which requires significant vertical change and a good path for the water. Otherwise, we would use it a lot more.

Re:Marmora (Ontario) wants pumped storage

[davecb]

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!

Re:Marmora (Ontario) wants pumped storage

[stoatwblr]

pumped storage is only of use for peak smoothing and generally only has enough capacity for a couple of hours' operation per day.

molten mixture of nitrate salts

[praedictus]

What could possibly go wrong?

Re:molten mixture of nitrate salts

[Anonymous Coward]

What could possibly go wrong?

The plant folds because solar thermal is 2.5x as expensive as most other sources of generation? When your technology is more expensive than offshore wind and still not fully dispatchable because you only have a middling reserve of stored energy, you're gonna have a bad time.

http://www.eia.gov/forecasts/aeo/pdf/electricity_generation.pdf

Re:molten mixture of nitrate salts

[RubberDogBone]

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.

Experimental Option

[Anonymous Coward]

I wonder if the decommissioned Fast Flux Test Facility on the Hanford site could be used to carry out experiments on this technology? It has a large capacity closed loop sodium system. Eastern Washington does not lack sunlight. And the facility is only a few miles from the Pacific Northwest Natational Laboratory.

LCOE

[Anonymous Coward]

The only thing that matter, "What is the level cost of electricity?"

Anyone know?

Excellent!

[blindseer]

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/...

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.

Re:Excellent!

[Anonymous Coward]

You make a lot of interesting points. I'm also a fan of Thorium Molten Salt Reactor research, so I concur that advancements in any molten salt area may be beneficial to Thorium reactor research down the road. We've only seen a few Thorium reactors worldwide, and the thorium molten salt design has yet to be tested. I foresee it as the answer to all our future energy needs if it's proven successful.

I was not aware that these solar facilities burned through so much natural gas daily to get started... but, burning 125 MWh per year of natural gas to produce potentially 1 TWh of electricity is still not a bad trade-off.

Nuclear Fusion tech is happy just to break even, which is why I unfortunately do not share your enthusiasm for it. It takes incredible heat, pressure, and luck of quantum mechanics to produce fusion -- by that, I mean that even the entire mass of the sun alone and its gravity isn't enough to produce fusion... it's a quantum tunneling effect from having so much hydrogen in one place that eventually one hydrogen will tunnel close enough to another to fuse with it, not heat and pressure alone that makes it happen. For the tunneling effect to work efficiently and sustainably, you need a lot of hydrogen -- like, a star's worth. That's because there's a very small probability for each hydrogen atom to tunnel -- and an even smaller probability that it will tunnel next to another hydrogen atom (close enough to fuse). Think about that for a moment. Even the Sun can't sustain nuclear fusion without quantum tunneling. We can't re-create the tunneling in the lab unless the lab were the size of a star. By this fact alone, we'll never be able to create efficient fusion reactions in a lab or even an advanced reactor. We have to create temperatures and pressures significantly higher than the sun and/or focus lasers to coax fusion while containing the plasma. We may be able to get out more energy than we put in, but it's unlikely to be practical.

The most modern Tokamak design hasn't reached 60% of break-even, though they hope, theoretically to reach 10x break-even... maybe... one day. You know -- give 'em another 20 years of funding. They may promise a unicorn or some flying pigs as well.

The Stellarator design and Wendelstein 7-X specifically are beautiful -- but are computer drafted and are incredibly sensitive to the tiniest construction flaws, so they cost billions to design and maybe trillions to build full scale, working reactors. The W7-X is more of a proof of concept, and it's super expensive.

Thorium fission is the most likely candidate for cheap, efficient, low-pollutant energy of the future. Fusion, while not written off as a pipe dream, just probably won't be able to fulfill a significant role for several hundred years at the rate it's progressing -- that includes that it generally takes decades to design, more decades to approve, then another decade to build a full scale facility. We're looking at 50 years minimum -- assuming there's some breakthrough where they believe they can design a sustainable, viable fusion power plant immediately.

Then, there's the NIMBY factor. Sure, put a Thorium Molten Salt Nuclear Fission Reactor in my back yard. I'm OK with it, but you put a full scale Stellarator within a mile of my house, and we're going to have a problem. Big difference between shutting down a shielded fission reactor when it malfunctions and when a nuclear fusion reactor malfunctions -- those magnetic rings fail, and it's a mighty big boom when the plasma escapes during operation.

Re:Excellent!

[Anonymous Coward]

I'm not excited about the solar power aspect, I actually think that is a fool's errand.

Yeah, harvesting energy from the sun, what an absurd idea. It's not like it's some kind of practically near limitless source of free energy that is currently sustaining nearly all life on this planet.

Use chemical energy, not thermal energy for storag

[goodmanj]

Molten salt is terrible for electricity storage.

Thermal energy capacity: 0.13 kWh/kg
Electrical conversion efficiency: 25% 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): 30 kg
Amount of mass to power a large city overnight (1 million households): 1 large submarine

Both systems use cheap, common materials, both systems are proven reliable over decades, but you get about 10 times as much energy storage when you use chemistry.

nitrate salts

[Tailhook]

Boom. The other word for "nitrate salts" is "bomb."

For better or worse, we're all going to be reading about the unhappy end of a molten salt storage system somewhere. Either a steel melting all-alarm fire or a smoking crater.

Re:nitrate salts

[jklovanc]

Nitrate salts need to be mixed with other ingredients to become explosive. Nitrate salts alone are not explosive.

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.

Re:nitrate salts

[TeknoHog]

On the other hand, it makes sense to pay nitrates for your after-sunset electricity.

Re:Use chemical energy, not thermal energy for sto

[Anonymous Coward]

Not sure I agree with you there. Even if salt doesn't have high efficiency, it's salt! Just use more. Salt is cheap and widely available. Make a bigger thermal storage vessel. And I'm pretty sure the mechanical design is simple and has a lifetime measured in decades.

On the other hand batteries degrade over time, they are more complex, and have a lifetime (except for the most exotic designs) measured in a small number of years. Also batteries can short out or catch fire.

Ultimately the engineers at this site chose a molten salt design. I think I'll trust their judgment over yours.

I'm confused

[Anonymous Coward]

Storing heat energy in molten salts is like, 1960's technology, how is this innovative? Even Wikipedia has references to using this in solar power in 2011.

Re:I'm confused

[Anonymous Coward]

Much of our modern tech are old ideas, just new implementations.

Why only ten hours?

[jcr]

Seems to me that you'd obviously want enough heat capacity that you could provide power around the clock. Add heat whenever you have sunlight, draw power whenever you need it. Ten hours of reserve shouldn't be that much cheaper than 14 hours of reserve. We're just talking bigger tanks, right?

-jcr

Think global

[SpaghettiPattern]

How about setting up solar power plants around the globe an exchange power. Get the power from the plants that are currently basking in the sun. A kid can think of that. Electric energy trading is already a reality.

Re:Use chemical energy, not thermal energy for sto

[goodmanj]

Even if salt doesn't have high efficiency, it's salt! Just use more. Salt is cheap and widely available...On the other hand batteries degrade over time, they are more complex, and have a lifetime (except for the most exotic designs) measured in a small number of years. Also batteries can short out or catch fire.

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 to carry a liquid that freezes unless the pipes are glowing red-hot.) You're right that batteries can short out and catch fire, but molten salt is basically on fire all the time, so I'm not sure it's a win.

Ultimately the engineers at this site chose a molten salt design. I think I'll trust their judgment over yours.

These guys aren't general electrical engineers picking the best of all options, it's a solar-thermal company filled with solar-thermal engineers who cut their teeth doing solar-thermal experimental projects, and are out to prove that solar-thermal can work. And sure, they might be right, but the fact that every solar thermal plant up until now has been unable to compete against other renewables and fossils doesn't give me hope.

Tower of Salt

[ChrisMaple]

Located near Sodom?

Re:Downsides raptor extinction

[Anonymous Coward]

Not to mention the downside of the towers causing the extinction of raptors.

solar power electricity heating salt?

[Anonymous Coward]

Can current solar electricity farms heat the salt enough to produce night time electric power ?