24-Hour Solar Energy: Molten Salt Makes It Possible, and Prices Are Falling Fast
Molten salt storage in concentrated solar power plants could meet the electricity-on-demand role of coal and gas, allowing more old, fossil fuel plants to retire.
By Robert Dieterich
JAN 16, 2018
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The first thing you see of the Crescent Dunes Solar Energy Facility, and you can be miles away, is a light so bright you can’t look directly at it. This sits atop a 640-foot cement tower, rising from the flat, empty Nevada desert around the halfway point on the highway from Reno to Las Vegas. The tower’s surrounded by a nearly two-mile-wide field of mirrors that send shimmering beams of light into the sky.
What people are actually seeing is a 110-megawatt concentrated solar power (CSP) plant, built and operated by SolarReserve of Santa Monica, California. It’s not from outer space, but there’s not yet anything quite like it of this size anywhere else on the planet.
SolarReserve is trying to prove that the technology that drives Crescent Dunes can make solar power an affordable, carbon-free, day-and-night energy source, dispatched on the electric grid like any fossil fuel plant. Here, concentrated sunlight heats molten salt to 1,050 degrees Fahrenheit in that shimmering tower; then the salt gets stored in a giant insulated tank and can be tapped to make steam to run a turbine.
If this plant and several similar facilities under construction, or soon to be, prove reliable, the technology is poised to take off. Solar photovoltaic (PV) panels can displace fossil fuels during the day, and wind turbines can do the same as long as it’s windy. But molten salt towers may be able to meet the challenge of electricity on demand, and push more older, dirtier fossil-fuel plants into retirement.
If molten salt was making 24-hour solar energy possible… It would be making it happen at least once-in-a-while. If the Crescent Dunes Solar Energy Facility is supposed to be an example of 24-hour molten salt solar power, it’s not a very good one.
The best month in Crescent Dunes short history was September 2016, when it averaged 9.2 hours of electricity per day.
Source: U.S. Energy Information Administration
Series ID: ELEC.PLANT.GEN.57275-SUN-ALL.M megawatthours
Hrs/d of Electricity
Dandy Don Meredith had “canard” for this as well…
From October 2015 through October 2017, Crescent Dunes generated 172,413 MWh of electricity. $737,000,000 divided by 172,413 MWh equals $4,274 per MWh… $4.27/kWh.
What your article fails to mention is that the site found out that once the “molten” salt starts to cool when the sun goes down, it rapidly crystallizes and freezes the entire circulation system. When the Sun comes up again, only the Tower remelts. They had no way to unfreeze the rest of the system. Thus a Gas Turbine Power unit was installed at the site to keep the salt molten enough to allow circulation at night. The better solution to Las Vegas Peak Power demand is NOT a Solar Furnace, but a large Scale Gas Turbine Generating Plant. So, once again, “Green, Renewable” energy depends on Fossil Fules to allow it to actually function! What a Joke!
They could have used big searchlights to keep the array warm.
Yeah, big search lights run on electricity produced by coal-fired power plants.
No, it just means they need to build another CSP plant to power the existing one.
They should install a second Sun. That would solve a lot of problems for the solar power industry.
And then Griff could write up the glowing (no pun intended) report on how successful it will be.
They can fix that easily by installing heaters…powered by electricity or gas of course….
powered by electricity or gas of course….
Powered by devoted environmentalists pedaling bicycle generators overnight for the good of mankind.
Why didn’t they use the PV to produce hydrogen, bind the hydrogen to a light metal or a chemical bond for daytime storage, and then use the stored hydrogen with a fuel cell for nighttime generation. The fuel cell exhaust could then be used to reclaim the surrounding desert?
Figuring out what to do with all the fuel cell heat could be another opportunity?
Just move parliamentary/government sittings to below the tower.
Plenty hot air. !!
Reminds me of Spain putting lights on the solar panels at night…………
What are you talking about!? We’ve created the very FIRST perpetual motion machine!? Woo Hoo!! Nobel Prizes for EVERYONE involved … handed out by former Beauty Queen, er Nobel Recipient … Barrack Hussein Obama !!
This is the first time I’ve heard of this, and I’m not finding any stories on the problems with the molten salt crystallizing and freezing the the system. What I have found suggests that a weld on one of the storage tanks was bad, thus resulting in a shutdown. Perhaps you could post a link or two, and include one referencing the Gas Turbine Power unit.
Doest it regularly take six months to re-weld a faulty weld in Nevada?
Is that documented somewhere? I just saw this on a molten salt storage website – “Heat loss is only 1⁰F per day”.
Guess that is a figure for the bulk storage tank, not the pipes. Sounds like some abysmal engineering going on here. Really, no one could anticipate the salts would cool and solidify?
If you were that stupid building a bridge you’d go to jail.
This was also my understanding – that natural gas was used to keep the system operational and the salt molten. Why are they not reporting that important input? Sorry, that’s a rhetorical question. If complete honesty was a requirement in “renewable” electricity generators there would be precious little that qualified.
But does this process generate plant-fertilizing atmospheric CO2?
If not, then it doesn’t add to the biosphere and help world-wide foodstuff production.
And so it shouldn’t be considered a step forward but a step backwards.
Millions of people have avoided starvation from a greening of the Earth made possible by fossil fuel combustion.
Let’s not be cowed into reversing this modern day miracle by Global Warming scare tactics.
Well the found to be necessary Gas Turbine Power Unit burns Natural Gas and so provides a CO2 Footprint to this “Green” Energy Facility!
It kills a bunch of birds when in operation. The birds will release CO2 as they rot, so there is CO2 release in the overall process
Spetzer86, you are right about killing birds. I watched the array and tower setup by Barstow, California and the glowing tower seemed to attract birds, and when they got close they started smoking and spiraled down tot he earth. Looked sort of like the movie versions of aerial dogfights in the Battle of Britain. The dead/dying birds will attract scavengers, like Democrats, oops, I mean vultures, and they will meet the same fate. Sort of a Ponzi-scheme of bird destruction.
Mirror arrays look like bodies of water to birds of prey. They expect to feed there and swoop in to look for game. By the time they figure it out it’s too late
They are called “streamers”,.. the birds with feathers aflame that is,…
I believe, also, that the light attracs insects, and then the birds follow the food chain. Road runners have been cut off from their normal trails by the huge amount of fencing, and make easy prey for coyotes. Among the other stats..
BTW, a Gas Turbine Generation Plant could have been built in 1/4 the time it took to build Crescent Hills and would have cost less than half as much! Additionally it would not only provide the 85MW Las Vegas was looking for for daytime peak demand, but it could also provide fast Dispatch Power to replace other sources when necessary, unlike the unreliable Solar Furnace! Oh, and another thing they found out after the plant was built – There is approximately a 30% cloud cover averaged over a weather year which further reduced the capability of the solar furnace installation. Seems they were so “lucky” to find a site just outside of Tonopah that they forgot to determine how much daylight time was available without any cloud cover. As has been mentioned here before, FORGET Label Generation Potential, look at ACTUAL Power Availability! So called “Renewables” have LOUSY available power!
Natural gas combined cycle is probably the only type of power plant that has a positive NPV.
Hydro power is pretty good. Niagara Falls, for example.
I just bet if you look a little deeper, where the plant was built provided a windfall (no pun intended) to one or more “well connected investors”. I don’t know this for a fact, but it has happened before.
The “research”, the connections for selling land, permits, the union labor to build id, run it, run the concessions and long-term operator contracts? It’s Nevada + democratic Senate head + democratic bureaucrats + democrat budgets from the toll booth operator in DC outside Dulles airport to the DOE to the elevator operator’s unions and bulldozer rental companies to the hotels and labor sites in Las Vegas.
Who needs strict economic analysis?
Birds get incinerated right in mid-flight. “Streamers”, they call them.
My favorite incident was when some mirrors misaligned, and set the tower on fire.
It’s not a bug, it’s a feature!
So it provides cooked lunch for the workers who are busy dusting the mirrors. Nothing wrong with that.
Please, please, please. Do not say “They taste like chicken”.
Would “they taste like bird jerky” be OK?
Haha! No, they taste like… crow?
Cleaning the mirrors … ugggh … sounds like a job for all those “undocumented” folks who will “do the jobs that limousine liberals just won’t do”
you ever smelled burnt feathers?
What do these Alarmists have against the poor birds? They think nothing of slaughtering them in their millions worldwide to produce a ridiculously small amount of electricity. We should not build more bird killers, we should be tearing them down.
It is known from ancient times that there has to be a sacrifice for our sins. So sombody has to die. But we are saving the polar bears. So bravely fly into death, little birds. Because you are dying for a good reason. You sacrifice will never be forgotten, ahem mentioned.
For every bird that get singed enough to die right there – I guess that there could be dozens if not hundreds singed only a little bit or slightly blinded. The latter could take weeks or months to die a hundred miles from the place and will never be counted.
Might be why Trump wants solar power on the top of his wall. He fancies a nice Mexican barbeque.
(P.S. A joke. If it offends you … grow up!)
One more thing that was “discovered” after the plant went operational — Instead of chopping up birds like Windmills do, the birds drawn to the bright light are incinerated once they enter the range of the mirror array. So whereas some birds might escape the whirling blades of the wind generators, the entire flock attracted to the bright light will be roasted. Nothing better than 100% “reliability” right? And Pilots are really upset at this impossible to look at Solar Beam coupled with the massive mirror array reflecting the sun’s light over an enormous amount of the sky and from almost any direction. So, in addition to unreliable power generation, Zero Dispatch capability, the area now has a Navigation Hazard covering a much wider area than the plant site for aircraft.
” the birds drawn to the bright light ”
I think its more than just brightness, it’s how the thing looks like water from a distance. In a bird brain, a large area of reflected sky indicates a body of water –
Climate contortionists will likely say that the birds have to “adapt”.
kentucky fried chicken…
Ah, so birds can adapt to this, but not to a postulated very gradual increase of temperature over say, 100 years?
(Yes, I know the above was tongue in cheek….)
This stuff is getting well beyond farce. It is great to think of great ideas and innovations for solving problems.
But green-lighting the poor ideas is not progress; Deep-Sixing them, and kicking the idea around some more, is the proper thing to do.
It is fine to have the occasional breathless science-news story about super-long battery life or whatever, when some grad student half-way manages to produce some innovation. That is part of our overall inventiveness and creativity. But we always know that this is just the beginning of a long line of innovation that may or may not lead to the long-life battery. We should not throw out our cell phone batteries that day, but we should wait to see if it hits the market at a competitive price.
Along with all of the clever criticism of these projects, people need to examine why such projects might move ahead, despite obvious likelihood of drastically sub-optimal performance.
An explanation for doomed-from-the-start projects is: someone is making money.
Here is the money-making process:
Government spends our money, not “their own” money;
we the taxpayers are at a great arms-length from such projects –
-we have no idea they are being cooked up,
-by time they hit the news it is far too late,
-we assume the experts know what they are talking about.
The firms that serve to profit commit to being financial supporters of the politicians.
This sets up a set-up:
A small party of co-collaborators work together to develop a ruse to use the apparatus of government to get a huge stream of this tax money flowing their way. The apparatus of government is such that it is most likely that NO ONE will ever get in trouble, and never have to pay back any money. [As noted above: if it were reasonably commercially viable, investors would be eager to take the risk and fund it.]
We the taxpayers need a way to break this cycle.
For these “innovative” public projects, the proposal should regularly call for – not only an “ecological impact statement,” but an assessment of the existing government entities required to approve the project, what individuals are involved to give approvals, an explanation of the ENTIRE chain of approval, and, in private-investigator style, a presentation of any ways that the individuals on the political side might profit from the money side. Ex: Solyndra, in retrospective analysis, would have shown political-contributor connections.
Require for that analysis to be publically posted, and criticized. If the story is not entirely told, there would be enough clues for the various Erin Brokovichs out there in the world to dig deeper.
Here is what we need to think:
Who is making money?
What political forces must align to approve such a project?
The whole Solyndra project evokes the play/movie “The Producers”. The connected Friends-of-Obama that got the multi-million dollar grants to construct Solyndra made a lot more money by going bankrupt than they would if the project succeeded. If successful, the owners would have had to eventually invest their own money, pay taxes, be audited, actually run a business, deliver a product at a reasonable price, etc. When you are bankrupt, nobody cares about the accounting, the money is just—-gone. This was the objective of the raid on the Treasury that Obama and the press characterized as “shovel-ready projects”.
Shovel ready! Ha ha ha! That’s great. Shoveling the money into the sewer, the blender, some back pockets. Great investment programs all need a shovel. Musk has several.
Do folks have any notion how much money Harry Reid off this scam? And previous scams (think “Indian vote”, gaming licenses, etc.) Like may Democrats in congress, Harry should be in jail. They might yet get Menendez.
… Reid made off …
Hopefully the data from the Crescent Dunes and Ivanpah concentrated solar power projects will be used to kill this concept. Neither one is providing the power the promoters claimed. Both have proved that bright lights attract insects, insects attract birds, birds attract raptors and they all get incinerated in the bright lights. Moreover my understanding is that even in the desert it does not take much of a cloud to disrupt the power – even contrails can be a problem. Then again we still have biofuels and Great Britain is importing wood in the name of the CAGW crusade so logic may not prevail.
Exactly! Ivanpah was the “prototype” which was Scaled Up to provide the Engineering basis for Tonopah. Unfortunately, they leaped to Molten Salt in the expectation of providing enough heat to boil water for the steam generator to produce power even after the sun went down. BUT, nobody tested the concept in a smaller scale first. Like most minerals when melted, once the heat source is removed and a seed of crystallization forms, then entire mass RAPIDLY crystallizes! They actually destroyed Positive Displacement pumps when the crystallization happened.
PD pumps do not do well pumping chunks. 🙂
Even if they had limited the molten salt to the role of a thermal mass for overnight storage, they would find that as the heat exchange system shift from store, to retrieve, the salts (not matter which one you pick) crystallize on the exchange pipes become a nearly perfect *insulator* slowing retrieval of the vast majority of the stored energy due to the low conductivity of the crystalline state of the salts.
(this from a spacecraft design project, the heat of fusion, and the specific heat are amazing for these salts, but the engineer… utterly impractical unless they are keep above the freezing point at all times)
You know, even the 482,000 MWh (50% capacity factor) is just plain wrong. If you do the math (and I’ve done so dozens of times), integrating insolation over a “big round spot on the desert floor” yields only 31.8% of the potential noon insolation day. Tops.
So, if it is a 110 MW plant then
110 MW • .318 = 35.0 MWh/h average
35 × 24 = 840 MWh/d, average
840 × 365 = 306,700 MWh/year … average at 100% clear-sky days
that would be the absolute max. Not 482,000 MWh. When your source says “expected production”, either they’re smoking goat chips, or they’re ignorant of trigonometry. Which most advocates are. Trig is “hard”, right?
IF ‘they’ were being somewhat realistic, giving 80% as the number of equivalent clear-sky ‘perfect conditions’ days per year, then their plant ought to, in practice, yield about 245,000 MWh/a or 672 MWh/d. And that’s not bad. Not bad at all.
Thing is… they got to hit 80% equivalent perfect-day insolation.
The plant needs to be OPEN and not undergoing repair 365 day/y
The mirrors all need to be almost perfectly clean.
The expected 482,000 MWh/yr included the molten salt storage.
Still doesn’t work. You cannot get more megawatt hours OUT than was put IN. Now, if the plant has a backup fossil-fuel fired salt heater, then of course they can get more OUT than the sunlight-provided energy going in.
My calculations were just taking “110 MW” plant “nameplate” factor, and multiplying by the amount of available insolation available over the course of 365 days, 24 hours a day, seasonal daily insolation pattern.
They weren’t expecting to get more MWh out than was put it. They were expecting something in the 30-40% range from the CSP and the rest to come from steam turbines driven by heat stored in the salt…
Assuming 12 hours of sunlight and 12 hours of darkness. This kind of plant would require 50% of the heat generated to go to the turbines for electricity during the day and 50% of the heat to go to storage in salt. This ignores any inefficiencies in either process. My guess is that for a 100 Megawatt plant, you would be lucky to have a capacity of 25% over 24 hours and that is assuming 100% sunlight for 12 hours.
I’m not saying their 50% assumption was a good assumption. I’m just explaining how they probably got there.
The plant’s performance pretty well says their assumptions were ridiculous.
However, the point is that the dufus writing for Inside Climate News said that Crescent Dunes established the possibility of 24-hr/d solar power, when the plant’s assumed maximum output was 12-hr/d and it has averaged 3.5-hr/d, when it’s been running.
STILL doesn’t work. The maximum one can get is 1/π (one over pi). And that’s a maximum possible, trigonometrically. 1/π = 0.31831…
That means, over the course of a completely averaged day (whole year), 31.8% is the maximum duty cycle possible for any “perfectly oriented” solar system, firmly emplanted on the desert floor. Necessarily rotating, vectoring mirrors cannot exceed this, either. Moreover, if you take the yearly seasonal angle-of-Sun calculations into effect, the number 31.83% is lowered in turn. But not lowered necessarily: one can north-south space the (reflectors, PV cells, etc.) so as to NOT shadow each other on the least-favorable day of the year, too. This counteracts the geometric part of seasonal specific insolation. The part that cannot be cured by spacing is the atmospheric extinction column effect.
For example: sunlight at high noon carries far higher heating value per m² than sunlight penetrating the much greater atmospheric column an hour before sunrise or sunset. Remembering that 1363 W/m² is the sunlight power hitting the top of the atmosphere, and “only 1,000 W” nominally gets thru at high noon, clearly the atmosphere absorbs/reflects/diffuses the other 363 W/m², at its “thinnest” (overhead) position.
Indeed, if one uses αsin(θ) … the nominal transmission (0.7337) times sin(θ) angle of the sun relative to the hour-of-day, that’s a pretty good proxy for air-column absorption overall. Matches instrumental on-the-ground metrology to within 5% or so. So the net equation is
E = ∫P(t)dt;
P(t) = αsin(θ)sin(θ)
P(t) ≈ ∫1000 sin(θ)² dt
P(t) ≈ 0.25 × 24 × 1000
P(t) ≠ 6 kWh/kW of plate.
This is very close to reality for most PV operations that work in the desert, averaged out over all the “good days” they are getting unimpeded sunlight. If 80% “good” and 10% “hazy” and 10% “fully cloudy” are a desert’s parameters (some are better, most aren’t) then you get
80%(100%) + 10%(50%) + 10%(20%) = 87% insolation for PV.
80%(100%) + 10%(25%) + 10%(0%) = 82.5% insolation for CSP systems
CSP depends on specular sunlight. it doesn’t work at all with diffuse sun.
I must say Goat Guy is right.
This is an ongoing problem with solar power project a vast overestimation of the amount of power they will actually produce. It is a curious phenomena. At times it appears the engineers are simply ignorant about how the sun and sky actually works.
Problem is insolation values are highly variable – all sorts of things adversely impact it. The values are idealized – they are what you should be reviving at that latitude, at that season. But a cloud, contrail, anything at all really, reduces the actual insolation from that idealized number. And there is always something, every day, even in the desert, that slightly reduces insolation. How many times do you look at the sky, even in the desert, and find it perfectly clear? And each of these small reductions adds up to a very big loss in efficiency.
And that, more than anything else, is the consistent problem with solar power – vastly overestimating efficiency, and underestimating losses.
I’m not convinced a CSP can’t work, just that it is unlikely to work very well.
That’s exactly my thought as soon as I read the 50% stuff.
Let’s be generous, maybe the nameplate 110MW was NOT the peak power (sun at mid-day, shining with no cloud) as it is always calculated by the PV peddlers. Maybe.
So the “estimated” energy output may end up be 50%, maybe.
On the other hand, the money lost to finance this 110MW scam is a certitude.
Yes, that could be (not defining “nameplate megawatts” the same way as the entire engineering industry uses the term). But that’s silly, too. I just think they missed on their trigonometric assumptions. It happens. Its why we have seasoned engineers in charge of checking marketers claims. Someone has to actually do the math with more depth than the calculator on one’s smart phone. LOL GoatGuy
The expected 50% capacity factor included heat stored in the salt to run a conventional steam turbine…
I’ll wager they did not miss on their trigonometric assumptions. They were exactly right on their gullibility of politicians assumptions.
LOL – I wish I could give you a +1
contrived extra comes from gas … not sun.
Plus the incident W/m^2 power flux fluctuates with the seasons because of the tilted axis.
yes indeed, tho that relationship is highly dependent on latitude, too. It almost doesn’t matter at the equatorial tropics. Above the arctic circle, its extreme. Of course.
However, as I noted above, for both PV and CSP, the latitude factor can be counteracted with north-south panel/reflector spacing. Enough so that panels/reflectors are not shadowing each other on the worst day of the year. Easy to compute, actually. Spacing = height/cos(latitude + 23.5°). The Earth’s tilt is 23.5°. Take as an example “San Francisco” at 37.8°. height/(cos(37.8 + 23.5)) = 2.08 × height.
For angled-toward-sun PV non-moving panels, Height = N-S width • (latitude + ½ 23.5). But let’s say it is 2 meters of height. 2.08 × 2 = 4.16 meters panel-to-panel.
Then by definition one’s going to have fully lit panels even in the dead of winter, should there be sunlight to illuminate them. The shadow from each southern neighbor won’t impinge on “my” panel. At any time of the day, either. Obviously, spacing needs to be larger the more away-from-equator you are. At the equator exactly, spacing is height/(cos(23.5)) = 1.09 × height. You can almost place the panels ‘edge-to-edge’, at a tilt of 0°.
‘smoking goat chips’ Good one, GoatGuy. LMAO
Excellent. In that case it does not need subsidies any more, does it? Let market forces work.
However, environmental damages (like vaporized birds & blinded pilots) are expected to be be payed for.
Seriously… there are #not# many birds to incinerate in the desert. Damned few, actually. It is not a problem.
they surely are few, but all the more valuable. If you care about environment — which is supposed to be the whole point, isn’t it?
Perhaps, but the ones present are exceedingly rare, and in need of protection! /sarc
There weren’t many to start off with.
But they were attracted by the lights, and stayed to feed on the insects that were also attracted by the lights.
So – not many birds in a real desert, but plenty of birds around a solar tower in teh desert…
California solar power plants ignite birds mid-flight
“Damned few, actually. It is not a problem.”
Counting HOW exactly? If a bird’s vision is only slightly impaired by extreme light as it flies through or if a bird’s flight feathers are only slightly singed, it could easily make the difference between successful hunting and starvation … weeks later … hundreds of miles away.
Who is counting them birds?
No, I’m not kidding: modifying a landscape to “make power” is always disruptive. Put in a coal plant, and you’ve at the very least have piles of coal covering what once might have been wetlands, or pastureland. You’ve got piles, and piles, and settling ponds full of fly-ash and other waste product. Bird lands in that, and they’re dead. Period. No one to sing songs for them. Millions die every year, unheralded.
Perhaps a natural gas plant is nearly byproduct free – only a CO₂ emitting tower. Since CH₄ methane is essentially sulfur-free, CO₂ and H₂O are really the only byproducts. And a whole lot of either hot water, or steam from turbine-condensing towers. Usually not very lethal.
And perhaps the nuclear power plants are equally innocuous, nominally. Oh, when they go all Three Mile Island or Chernobyl or Fukushima, sure… then they’re glowing radiation-emitting monsters for centuries. But the rest of the time, they emit nothing. Except like all thermal power plants, either steam or heated water.
I’d put CSP (concentrated solar power) on the level of a coal-fired power plant, environmentally. I’m not completely dismissing peoples’ fried-fowl concerns, but I just don’t see “the problem” as much different from those fly-ash and scrubbing-tower settling pond environmental issues, relative to birds. And maybe CSP is less-so: its only lethality is during operation. When the sun goes down, there are no settling ponds. Coal is probably worse. Likely.
your point was clear beforehand without this long comment. I don’t disagree with it.
If the goal were to produce energy, of course some damage to environment, including death of wildlife, would make sense.
BUT: since the goal is supposedly to save the planet, the wildlife etc. then it make no sense to fry / chop birds with solar furnace / windmill. That was my point.
Ever heard the term “Pacific Flyway”?
@GoatGuy January 24, 2018 at 10:22 am
I am not telling concentrated solar is a no-go, just no subsidies for it whatsoever and have it pay for all environmental damage, that’s all. If it is still economical, fine.
Cost and land use footprint of grid extension made necessary by remote siting should be included.
Did they include running the heaters at night to keep the molten salt from re-freezing?
While its “a problem”, the solution is simple, using gravity, they empty the lines. This would be for a longer-term event than overnight. Overnight, reflective shutters are erected at the focal point, and the pumps are left on, keeping the molten salt reflowing. It doesn’t freeze, and the reflective shutters keep the tower from leaking away more than 1% or so of the thermal energy retained by the salt overnight.
How much energy can they extract from the salt overnight to generate electricity before the salt freezes?
“How much energy can they extract from salt overnight to generate electricity before the salt freezes?”
Excellent question. But it has a relatively easy engineering answer. I’ll quote a good source:
A commonly used thermal salt is the eutectic mixture of 60% sodium nitrate and 40% potassium nitrate, which can be used as liquid between 260–550 °C. It has a heat of fusion of 161 J/g, and a heat capacity of 1.53 J/(g K). … Regular table salt has a melting point of 800 °C and a heat of fusion of 0.52 kJ/g.
So, the answer is related to…
• How hot is the stored salt?
• How much of it is there?
• What’s the minimum temperature margin spec?
For example: in a NON-freezing salt spec, the eutectic NaNO₃ + KNO₃ may well be heated to 400°C (above which it starts to decompose), and the minimum working temperature spec is 275°, and we have 1,000 metric tons (1,000,000 kg) of the stuff then…
E = 1530 J/(kg K) × 1,000,000 kg • ΔT
ΔT = (400 – 275)
ΔT = 125°C
E = 1,530,000,000 × 125
E = 191 billion joules (of heat) and at a Carnot efficiency of about 32%, you get
Eout = 191×10⁹ × 0.32
Eout = 61×10⁹ J. Since 3.6×10⁶ J is 1 kWh, that becomes
Eout = 17,000 kWh.
Eout = 17 MWh.
This is for a NON-FREEZING molten salt storage-and-use cycle. Clearly, if a 110 MW (plate) plant wants to ensure almost complete coverage for both the usual nightly, seasonally and weather-related sunlight extinctions, then it perhaps needs 10 or so full-days of storage capacky. Given a plate output of 110 MW, and a 0.25 kWh/kW-h plate output factor, for 6 kWh/KW plate, per day average, then it needs 10 times that or 60 kWh/kW of plate. 110 MW × 60 = 6,600 MWh of stored molten salt. At the above figures, 1,000 T gave 17 MWh of storage capacity.
Needed = 6,600 × (1000 t ÷ 17 MWh/t)
Needed = 388,000 tons of molten salt.
If on the other hand, a safe way to have a freezing-salt storage system can be engineered (very complicated), then things could be somewhat less salt-mass dependent.
E = 1530 J/(kg K) × 125° + 75%( 161,000 J/kg heat-of-fusion) + 1250 J/(kg K) × 100° for solid
E = 437,000 J/kg thermal
E = 437,000 × 32% conversion to electricity ÷ 3,600,000 J/kWh
E = 0.0388 kWh/kg
We decided we need 6,600 MWh or 6,600,000 kWh …
M = 6,600,000 ÷ 0.0388
M = 170,000 metric tons
Which is a bit less than half the molten salt local storage requirement. It does however require ridiculously complicated freezing-salt handling and thermal conduction strategies. Not simple. In my OLD engineer’s mind, I’d just spec more molten salt, and truely keep it as a liquid at all times, and keep the whole system simple.
But that’s because I’m a practical engineer, not a group of otherwise barely-employable grad students, professors, industry fat cats and endless graft-takers trying to cop-a-buck out of the Great Greenwashing Project.
The whole point of molten salt storage is to generate power 24/7. That means no freezing.
You are all missing the fact that you can’t get energy out of the salt if you don’t put it in there first. Assuming 12 hours of light and 12 hours of darkness means that if you want 110 Mw out, you need a 220 Mw plant during the day so that half goes to electricity and half goes to heating the salt. It’s the same problem with all storage of energy from renewables, a huge amount of the generation must go to charging your energy storage device regardless of what it is, salt, batteries, pumped water, etc.
Well it is worse than that. You need the power you are going to use now. The power you are going to use later. And the power to feed the entropy beast, that eats up a lot of the power you put into storage and pull back out.
I always ask – why can’t you simply have molten salt storage/batteries/pumped storage with a natural gas plant? I mean, you could run a much smaller plant, very efficient, full time, storing half the power at night for release during the day. Why don’t we do that? Why have we never done that?
Because every time you transfer, transform, and store energy you suffer losses. Plan on losing 30% of whatever you store. Overtime that cost, plus the cost of the storage, is vastly more than you will ever save by having a smaller, more efficient plant. That is WHY electricity has always been generated and used “on-demand” We don’t want to do it this way, but unfortunately the laws of physics say we must.
And this is why price parity for renewable power is such a joke. Solar and wind cannot be at parity with other power sources, they must be much, much cheaper. In fact, they need to be nearly free.
I think they use the flaming birds.
Green Capitalists want to steal $100 Trillion for Massively unsustainable RE: https://wattsupwiththat.com/2017/07/05/monumental-unsustainable-environmental-impacts/
Build Natural Gas Power and the MSR….the Case for the Good Reactor https://spark.adobe.com/page/1nzbgqE9xtUZF/
This is one of those issues that the engineers most likely knew about and the issue was not addressed until after the plant was running for a while. That way this very expensive issue is addressed after the initial great publicity and fanfare about the success of the project. The media has moved on and everyone is congratulating themselves on a great success. Also the costs for the fix would not be included in the published initial capital costs. Keeping the the already subsidized costs of the plant even lower.
They also have a bird killing problem.
Call me cynical. 🙂
Mmmm… you may want to reword that:
Cynical → bad, won’t believe the bûllsnot under any circumstance
Skeptical → good, doesn’t trust the bûllsnot, but is open to revising opinion.
After years of dealing with the bullsnot, I’ve gone from skeptical to cynical. At least as far as certain players are concerned.
Pondering my position. 🙂
And Harry Reid walked with a lot of cash.
The maintenance and operation cost must be high. All those moving parts and automation. Keep it simple stupid principle is an old good engineering principle. This is opposite.
This would make a great monument site on the national trail of failed green projects driven by political influence outside the competitive market. Jimmy Carter’s Beulah ND needs to be on there too.
…and Rifle, CO
Rifle wasn’t “green”… Apart from the Green River Oil Shale.
True but it was a large-scale example of policy distortion and misadventure from market solutions resulting in government guarantees for oil delivered at $70 per barrel at a time when the market had rebalanced at $20
The Los Angeles Times first reported about this facility back in March of 2016, and actually went to print w/ this:
It was a battle to get them to issue a correction.
At the same time, the LAT’s which has a history of huge fawning coverage for the Ivanpah Solar Plant [Brght Star] remained silent – never reported on this news, even as other outlets were:
From the Wall Street Journal –
The article also falsely stated that, “SolarReserve has gotten around the corrosion problem by encapsulating the salt in ceramic balls.”
I spoke with the project manager of the firm, who admitted that the ceramic ball concept had only been worked on in the lab – was not associated with the project. I challenged the reporter on this, but when he filed the correction on the first item, “storing electricity,” he simply repeated the fake ‘ceramic ball,’ thing.
Needs to have his removed.
That has to be a decision designed to keep the readers uninformed on an agenda item.
LAT’s article here w/ flaky ‘fake’ correction: http://www.latimes.com/business/technology/la-fi-cutting-edge-solar-salt-20160320-story.html
I wonder if CSP is being pushed by C. Figueroa at Davos this week. She sure pushed the technology as being ready to go a few years back!
The state of Nevada, where Crescent Dunes is located, had to modify their net metering program-
What are the odds that the free energy from the sun planned for Crescent had anything to do with the changes.
The free energy from CSP is kind of like the free water you get from the sky when you open your mouth up when it’s raining, or snowing.
If turkeys do that, they drown. Or so I’m told.
Solar-thermal plants were the technology I focused on when I sat down in a “Well let’s just see” exercise. It was what made me realize the materials problem. Solar-thermal plants take 10X the concrete and steel of an equivalent capacity of nuclear. Wind only takes 5X. But either way, we’re not going to use renewables to power the world if we want it done quickly because we don’t have the materials/labor to spare.
Robert Dieterich could start by learning the difference between cement and concrete. The tower is concrete.
Well… concrete has cement in it… 😉
Does that count as part of the concrete? Hopefully that tower has a lot of rebar… 😉
Is that opinion cemented in place?
The evidence is rather Concrete though
😉 Yup…and large and small aggregate and water. Sometimes there are admixtures in their to get things like air entrainment or plasticizers to make it flow better. But mostly you need the rocks and the sand for the cement to glue together.
Otherwise it’s like building a model airplane with nothing but this…
By nothing, I mean not even the model kit… LOL!
You just publish cold, heartless numbers. For enthusiasts, the Crescent Dunes is a dream come true. It works so well that SolarReserve plans to build ten more plants like that (providing that our generous support would continue).
When the towers are decommissioned, I hope conservatives do not vote the funds to dismantle them.
Leave them up as monuments to collective stupidity. Or intellectual fads.
Thermal solar died and was burried more than a year ago, and plans for additional plants were cancelled.
I thought so too , after Ivanpah’s problems , so I googled for latest news on Ivanpah and the most recent that I could find was this :(2017)
-“Beleaguered California Solar Plant Finally Produces Enough Power
California’s Ivanpah solar thermal power plant is composed of a massive number of mirrors all pointing at a central columns topped by boilers, far out in the Mojave desert, but the three-year old facility has struggled with one major problem in its short lifespan: it doesn’t produce enough power. At least, it hasn’t produced as much as it was obligated to under its contract with a utility…until recently. Bloomberg reports:
The Ivanpah Solar Electric Generating System in Southern California initially failed to meet contractual obligations, and a yearlong forbearance deal with Pacific Gas & Electric Co. expired Wednesday. After fine-tuning the complex facility that uses 170,000 mirrors, output is up and it’s no longer at risk of defaulting on the deal, according to David Knox, a spokesman for operator and co-owner NRG Energy Inc. […]
It took NRG longer than anticipated…to bring the water to just-the-right temperature each morning and position all those mirrors to optimize the power of the sun. “It took a lot of choreography to get everything just right,’’ Knox said.
Three years is a long time to spend tinkering, but according to one of the facility’s spokespeople, Ivanpah’s power output has increased dramatically since its inception. The fact that the plant was nearly shut down by regulators for breaching its contract wasn’t just bad optics for Ivanpah’s operators or the state of California, it was a blemish on the reputation of the fledgling solar thermal industry. It’s heartening news, then, that the facility has managed (apparently) to finally right the ship.
Energy sources need to be tailored to their environments, and it stands to reason that deserts are, generally speaking, good places to site solar thermal plants. That doesn’t mean that these facilities are exempt from operational difficulties, as Ivanpah has shown. It also doesn’t preclude these kinds of facilities from environmental concerns, as Ivanpah has also shown by the fact that facility is attracting and then igniting (mid-air!) up to 28,000 birds every year. Renewables have their own attendant green issues, just as their hydrocarbon-powered alternatives do.
And speaking of fossil fuels, let’s not brush past the fact that this facility relies on natural gas to start the turbines every morning that the solar-heated steam runs during the rest of the day. We’ve said it before, but it bears repeating: shale gas and renewables are natural complements to one another. The now functioning Ivanpah plant is a great example of that.”-
Basically the message to the general public like me is that this technology works and s being adopted worldwide.
I would simply like to know if this information is correct – although global warming will have to advance enormously before these towers become a feature in the sodden fields and under the grey skies of Cheshire and Lancashire.
I believe it is correct – except for one misleading thing. The “fine tuning” involved burning more gas – 48% more. 1.4 billion cubic feet per year. So it might be better to call this a solar assisted natural gas plant.
And Harry Reid walked with cash.
thanks for the Dandy Don thing
How old does someone have to be to remember Don Meredith, Howard Cosell and Frank Gifford on ABC Monday Night Football?
45+ most likely.
close to 50
(as old as you have to be to remember your dad cursing at the tv whenever nixon came on… ☺)
My Dad cursed at the TV when any Democrats came on… Ayyyy!
(as old as you have to be to remember your dad cursing at the tv whenever nixon came on… ☺)
My favorite Don Meridith quote happened when Cosell was talking about Joe Namath’s stats. He said something like “Namath has passed for over 40,000 yards, that’s 23 miles”. To which an astonished Meridith replied “Gosh, that’s further than Mt. Vernon to Sulfur Springs”. Coming from a good ole East Texas boy, the comparison is understandable, but I laughed until I choked to think of the reaction of a National TV audience to a natural, but completely obscure reference. I remember Cosell’s reaction was astonishment, but he kept it together. My fondness for Dandy Don was aligned with the old phrase: “You can take the boy out of the country, but you can’t take the country out of the boy”.
Taylor, you would have loved the saints’ (late) radio color analyst Hokie Gajan, who was cajun. The follow is a back & forth with him and saints’ play by play voice Jim Henderson:
Gajan: Coach Philips used to tell me, “Son, if you can read the name on the back of that jersey, don’t block that man!”.
Henderson: I’m surprised Bum knew you could read.
Gajan: Well… He actually said number.
I still have that hair style, just a different color.
Style may not be the right word. I pay for a hair cut twice a year since retiring.
How do you know need a hair cut? When a homeless person in Humboldt, Ca offers you a joint. We were heading south from Washington State later than planned because of dual cataract surgery for my wife. The weather was a challenge but we enjoyed the redwoods.
Going south you leave a beautiful state for the state of freeways.
We parked in a vacant lot next to an auto parts store checking the fluids, lights ect. A homeless guy from the nearby encampment wondered over and asked if I needed help and offered me a joint.
I am thinking of getting a sign made for the motorhome if we go back to the ‘no state’ that says ‘seeking sanctuary’.
Dandy Don was a good Singer/Philosopher: Turn out the lights, the party’s over”
And not a bad actor too!
Once Meredith, Howard, and Frank were on camera outside the Cowboys stadium, pre-game, in the rain. Meredith was holding the umbrella over the three of them as Howard delivered his pompous analysis. Meredith, grinning like a Cheshire cat, carefully positioned the umbrella to direct a steady rivulet of rain onto Howard’s toupee. Howard either couldn’t feel it, or persevered like a trooper. I watched it live, and will never forget. MNF was never the same after Don Meredith left.
@Taylor Ponlman January 24, 2018 at 9:34 am My favorite Cossell story was a Raiders game that CMG were covering. It was in the days when the raw feed was linked to the studios in New York and then up-linked to the affiliate stations. No encryption. A private individual could aim their private very large dish at the satellite and capture the network feed. A bar in South San Francisco was doing that during a very dreary Raiders game. The up-link was alive during the game at half time when Cossell said something along the lines of “Have you ever seen such a boring effing game in your life?” Of course it played live in the bar. The story made the local papers the next day. Embarrassment followed as did encryption of the signal..
RayG – Here’s another one, though not MNF related. My father had a satellite dish in those days as well. Was watching the announcers chat with Dan Marino during commercial before a post game interview. Marino: “I couldn’t hit the effin’ (he used the full f-word) side of a barn today.” Broadcast goes back live and here’s Marino now describing how his passing was “not as accurate as I might have hoped today.” Miss those old unscrambled off-air live feeds.
Facts getting in the way of a ‘good’ story. Like the GEICO ad of Washington crossing the Deleware—turnpike: surprising!
One wonders where the electricity generated was to be transported for use? Moving electricity is expensive and lossy. Tonopah is not a big power consumer. And I am not sure about the mines up the valley as markets either. They are heap leach facilities that once in place do not require gobs of power to function.
The concept was appalling, it was proven impractical 30 years ago(*). How they could secure financing for this, with close to nil improvement over 3 decades older prototype, blows my mind.
(*)When 1973 oil crisis occurred, the world literally panicked (except Roma’s Club scaremongers, who boasted “we told you, see?”). When 1978’s crisis doubled down, engineers scrambled, and considered molten salt solar power-plant, among other solution.
Themis was ordered in 1979, completed in 1983, thoroughly tested until 1986, and proven actually not that good an idea than it could be believed beforehand. So just shut down, instead of scaling up as would had been possible. Nuclear was just way better, and fuel not that expensive, after all (nor expensive enough to make up for the hassle of solar-derrick).
It was in a most perfect place: as much sun as in Atacama desert, no cloud or wind or dust issue…
Since so many people are still nuts about this idea, well, research is going on, so they are not disgruntled (well, my guess is, they are anyhow, and believe some conspiracy theory on how big oil/evil nuclear killed the project…)
“The concept was appalling, it was proven impractical 30 years ago(*). How they could secure financing for this, with close to nil improvement over 3 decades older prototype, blows my mind.”
Here’s the caption from the picture/advertisement above which thanks Obama!
“In September 2011, the Department of Energy issued a $737 million loan guarantee to finance Crescent Dunes, a 110-MW concentrating solar power (CSP) plant near Tonopah, Nevada. It uses power tower technology that concentrates solar energy to heat molten salt, converting that heat into electricity. Upon completion, Crescent Dunes became the largest molten salt power tower in the world.” Thanks Obama! US DOE”
Is that the DOE thanking Obama or the Crescent Dunes CEO?
The Themis thing is quite famous among solar energy lovers, there is no way the DOE couldn’t know Crescent Dunes’s result: too expensive energy. Building a research facility, like, 1 MW, that would had been OK. However, spending $737 million from taxpayers for a 110 MW real world project , that is, $6.7 per W, this should have send people in jail
You would need 40 of these units to replace both Diablo Canyon nuclear power plants.
Also, bear in mind that the peak load in California can be over 40,000MWh for each hour. The entire years output for this unit would power the grid for 12 hours on a hot summers day.
It would make a great crop circle…in the desert, among the brush and the cacti.
I suspect Stonehenge is the remains of a failed solar project. 😉
now that makes sense
Yes, enriching the builders at the expense of the users but possibly before a governing authority got in on the act as an intermediary.
The French were mucking about with molten salt at THEMIS in the Pyrenees thirty years ago.
Didn’t work then either.
Visitor centre is quite nice though.
The first USN reactor for its second nuclear submarine USS Seawolf (SSN 575) was molten metal/salts.
It too failed, was pulled out and replaced with a “conventional” liquid water pressurized reactor. That design ran until the late 80’s.
The coolant was liquid sodium metal. No salts.
It didn’t fail so much as it wasn’t quite as compact nor did it generate quite as much power as the Navy wanted so it was replaced with a PWR.
But the design did work. There was also a similar reactor that was run at Oak Ridge for a number of years without a failure. But since the DoD wanted reactors that generated plutonium (used for nuclear weapons), the molten metal/molten salt rectors weren’t suitable as they used a small amount of uranium as a seed and thorium as the working fuel. Very little if any plutonium was created with those reactors.
Another shoot, ready, aim green project to prove we are ready for renewable energy. All one needs to do is look at the true results of all these attempts to realize we are not ready yet. The MSM and politicians continue to mushroom the people with hopes they won’t see the man behind the curtain but rising home electricity costs and taxes, industrial plant closures, and black outs can’t be hidden with propaganda. The truth is catching up.
“… environmental justice news”
Really? This is just another name for the UN’s insane agenda of wealth redistribution under the guise of climate reparations which is justified by the worst pseudo science I’ve ever seen and which is further supported by models whose code quality and robustness would never get past any kind of rigorous code review. Even the flat Earther’s can make a better pseudo-scientific case for their position than the climate alarmists can.
I wonder what the over/under bets are for November’s “Solar Thermal” Capacity Factor due out later today.
My little PV system located in Northern CA set a record low for output last November-it’s CP was 10.6%. The average CP for my system in November 13.1%.
My SWAG for all the generators classified under “Solar Thermal” for November 2017 is a Capacity Factor of 14%.
I wonder if Davos would be open for guests this week if they had to meet their power needs SOLELY with generators operating with CP’s in the low teens?
13% sounds very good. Of course Northern California is a large area.
Seattle has more sunny days than Sacramento in February because of tulle fog.
Above 2000′ in the foothills has a more sun but there is no such thing as a good solar resource. Just less bad.
The general public can be persuaded to believe in energy fairy tales because they have so little concept of the phenomenal amount of energy being fed into the power grid. Your average two-unit nuclear power plant puts out about 2.6 million horsepower, and it does it around the clock, day and night, regardless of weather, clouds, or birds bursting into flame. Replacing that with a big tank of hot salt is just not going to work out.
Heat storage, water pumping or any other storage scheme takes an unaffordable power source, adds the inefficiency and expense of converting it then adds the inefficiency of returning it to power which is in turn outrageously expensive. My grandmother use to say, “If ifs and buts were soups and nuts then every day’d be Christmas.” I say, “If schemes and dreams were silver and gold, we’d all be rich.”
What is the purpose of the molten salt, if it is then cooled to make steam to generate electricity? If the purpose of concentrating sunlight is to make steam, why not have tubes containing water at the focal point of parabolic mirrors, and make steam directly from solar heat? Then they wouldn’t have to worry about the salt freezing at night or on a cloudy day.
Yes, the method you describe could work (does work physically) but is poor economically and poor reliably. The pipes lose an incredible amount of energy in the long run between the individually heated solar panels and the central collector. Those thousands of feet (meters) of small pipes all have to be welded up, hundreds of thousands of welds inspected (they are boiler-quality individual welds) and certified, and all supported and insulated between arrays and the central power plant. Since every panel needs to be physically and uniquely aimed at the sun as it travels across the sky between east and west, every individual array needs some flexible, leak-proof steam-quality joint between the array and the distribution piping. But, if any part of the array is dirtier or and part of the distribution piping slightly dirtier or slightly more clean than the “average” array and pipe, then the distribution network needs to even out the pressures and temperatures of the steam before it hits the turbine – or the turbine blades erode from excess water damage. The return distribution piping is equally complex: you have to get pressurized condensate from the central power plant back out to every array. That pure water is at least cooler than the steam, but is at higher pressures to ensure flow out and back against pressure turbulence losses. Steam traps and drains add two more problems to the huge array of pipes – and you cannot afford to throw away any of tons of the expense clean, filtered and de-ionized and chemically-treated water circulating all the time. Worse, before you can make power each morning, all those thousands of meters of pipes, insulation and arrays that have cooled overnight since the previous afternoon have to be re-heated by the sun each morning until all of the network is back up and at saturation temperature for the steam turbine. Solar heating is slightly more efficient than the 6 hours available from photovoltalic cells each day (on average over the year), but these overnight losses are too great to overcome in most areas of the world than can afford the expense of solar power.
Another way (as done in other sites) is to put a large metallic absorber “wall” in front of an array of mirrors (picture huge vertical movie screen in front of a series of seats – each seat being a steerable mirror pointed towards the “stage”), and put the receiving array of pipes behind the heated metal panel. This simplifies a few of the problems.
When you supper heat water inside a pipe the pressure inside the pipe increase. To contain the pressure you need to make the pipes thicker. Thicker pipes cost more. Furthermore in order to store if you want to enough energy for 110MW for 10 hours you would a very large tank with very thick steel walls. .
IN a molten salt system the pressure in the pipe stays constant. There molten salt storage tanks are not perfectly sealed a small amount of air can leak in and leak out. The pressure at eh top of the tank is only 1 atmosphere. That means you can use thinner pipes and less steel. Using a fluid that can stay a liquid at high temperatures and low pressure reduces material costs, and allows for a substantial amount of storage . You cannot do that with water.
I foresee a possible event in which the salt solidifies due to local loss of heat in parts of the plumbing which cannot be readily reheated to molten salt temperatures. The consequences would be similar those of a concrete truck having it’s load solidify. No solution except to scrap the system…
Convert to Star Wars application?
on energy matters such as this ENGEERS should be given the top jobs. They have a habit of making things work.
That, cognog₂, will never work. There is a continuüm of people who graduate from university in the sciences, related to their individual ability (as groups) to abstractly and quantitatively work shît out:
8 – top flight PhD post-grad students. Working toward professorship.
7 – PhD grad students in the ‘hard sciences’ … chemistry, ChemE, physics, EE, MechE, geology, petrology.
6 – PhD grad students in the ‘soft sciences’ … renewable energy, any of the -osophies, pre-med, bio, stats.
5 – Masters students in the hard sciences
4 – PhD grad students in the ‘non sciences’ … Literature, Law, Language, Letters, Human Behavior,
3 – Bachelors in hard sciences, mathematics, engineering
2 – Masters students in the soft and non-sciences
1 – Bachelors in soft and non sciences
0 – High School graduates and below.
You definitely would LIKE to have level 5 and above doing the engineering, implementation, operations and metrology (measurements) for any truly commercial grade power plant, at least in the area-specific management level employment.
But when “Massive Green Energy Projects” are being funded, all that is attracted are 2, 3, 4, and 6. The professors (9) don’t have morality high enough from grabbing big chunks of the endowment cash to fund their departments, fûque the project however it turns out. So long as they get “plausible deniability” (the ability to state with straight-face, either “we told you so” or “the suppliers fûqued up the project”), they feel morally well-shielded against negative critique of their involvement.
Thus it goes.
Like algae covering a foetid oilfield sluice pond.
Does it also fry birds?
Coeur de Lión, no. In the French tradition of using correct terms, it flash-roasts the birds. Very fast. It also may be able if the bird-in-question flies into the concentrated beam at the right angle, to singe away the feathers as well. Nicely roasted AND plucked.
Cressent dunes was never designed for 24 continuous operation. The customer (the utility) wants it to produce power for 8 to10 hours after shutdown. Which is exactly what it has been doing. If you want to see a solar tower with 24hour operation, go to Spain and look at the Gemasolar plant. Gemasolar was a followon project to the US Solar 2 expeirmental power plant. This 20MW plant was designed for 24 hour operation using molten salts. And it has successfully done that. As long as they have clear skys it produces power.
Adding a natural gas or biomass burner to it and it can still produce power during cloudy weather. No need to build a sepperate backup power plant if this is done.
Multiple trough and tower solar thermal power plants use molten salt thermal storage. None have had any problem with salt freezing. It is stored in insulated tanks and it would take months without sun for it to freeze. The only problem that has occured was at Cresent dunes. They had a leak in one of the molten salt tanks. Last year it was off line form months for repairs. Much of the repair time was probably to allow the tank to cool so that it was safe for crews to repair it.
The operators at Crescent dunes found that birds were not drawn to the the white hot receiver on the top of the tower. In fact it is so bright that looking at it continuously is uncomfortable. Birds tend to turn away from the bright light before they reach the power plant.
What they did find was that birds mainly died when the system was in standby mode. In standby mode the mirrors were focused just above the tower and the reciever was black and cold. The birds could not see the light because it was passing through clear air. They then reprogramed the mirrors so that in standby mode the light was not focused at any one location. That solved the Cresent dunes problem. Today the biologists hired to do the monitoring are finding very few dead birds.
Crescent Dunes has never averaged more than 9 hours and 12 minutes of total generation per day.
The plant’s best month was September 2016. The 110 MW power plant only generated 30,514 MWh. 1,017 MWh per day. That’s 9 hours and 12 minutes worth of 110 MW.
It was supposedly designed to achieve a 50% capacity factor with the molten salt. It’s never topped 39%. It’s averaging less than 15% in the months that it is actually functioning.
it was commissioned only a couple of month earlier in 2016 and the weather was not that great at that time. Then they had the leak in the storage tank. There are at least a dozen solar thermal power plant in the world that are using molten salt storage. Some for over 8 years. Gemasolar ran for 24 hours a day for 39 days straight about a year after it was started up.
Sounds like Elon Musk excuses.
1 day in 2011. The designers claim it can average 20-hrs/d…
Read more at: https://phys.org/news/2011-07-gemasolar-solar-thermal-power-hours.html#jCp
36 days in 2013…
The Inside Climate News article cited Crescent Dunes as an example of 24/7 solar power. It was only designed for 12/7, it’s never delivered more than 9/7. It averages 4/7… When it’s working. It’s best month since the salt leak was repaired was 4.1 hr/d in September 2017.
David Middleton said:
“Sounds like Elon Musk excuses.”
I think he makes a perfectly reasonable point. We know that other plants have achieved 24 hour operation for 36 days. Not a bad start for a technology that has never been deployed on such a large scale before. We also know that Crescent Dunes was never designed for 24 hour operation. The break down doesn’t tell us that the plant can’t do what it was designed to do. Coal plants break down too.
I say watch this space, and have another look in a year from now.
Gemasolar has only achieved a capacity factor of 63%…
The design capacity factor was 74%… Just under 18-hr/d at full capacity.
The 24-hr/d marathon was over one 36-day period.
“Energy storage provides a firm, reliable electricity product on-demand, day and night.”
You miss the point.
Themis wasn’t closed because it didn’t work. It DOES work. This kind of power plants DO work.
It just is way too expensive.
$0.975 billion construction cost (+ undisclosed operation cost) for a best 12-month long production of 130 GWh. Basic Math is
amortization of construction cost; let’s use half a century. (just for the show, this is obviously way to long): $19.5 Million a year
Add the cheapest money government guarantee can buy: 1%. Another $9.75 Million
Add operation cost, maintenance, tax and whatever. Well, let’s make it free, because, “this is kind of magic” as Queen sang
That’s a minimum yearly cost of $29.25 Million.
For 130 GWh a year production. $0.22 per kWh.
that’s roughly 10x more than hydro, 7x than gas, 6x than nuclear, 5x than coal, and even 2x than wind.
In any other business, if something is paid so much more than the competition, with taxpayers money as a bonus, you call the police for racket, money-laundering, and corruption, FBI and IRS investigate, and people go to jail. Well, Nevada, Las Vegas, and Washington are notoriously NOT is such business, are they?
“Adding a natural gas or biomass burner to it and it can still produce power during cloudy weather. ”
You can’t run a gas turbine on biomass. So what you suggest is that we build a complete steam turbine power plant with cooling towers and everything out in the middle of the desert.
The best solution would be to made nanobots that can build other nanobots, that can make silicon-graphene solar panels out of simple desert sand. These could create a global solar-power field for nothing, in addition to producing panels for making buildings that would not only shelter people from the sun, but also convert it to electricity AND store it.
But manufacturing solar panels is not cost-effective, since they cannot create and store energy efficiently enough to justify the cost vs. the standard grid.
“The best solution . . . make silicon-graphene solar panels out of simple desert sand.”
You must be joking! . . . else please site one reference where large amounts of pure carbon are commonly found mixed with desert sand.
When you consider the number and scope of forestry and mining projects that have been refused permits because of owls, eagles’ nests, apparently endangered species that might be present, the silence of the green machine about these bird killers, and the bird- and bat-killing windmills, is quite appalling. There could be no better illustration of the hypocrisy of the so-called environmental movement.
Further to Steven F’s post above:
I found some interesting facts on operational problems at the Crescent Dunes Plant described on the Basin and Range Watch website ……http://www.basinandrangewatch.org/CrescentDune.html
They have links to a series of articles from the Pahrump Valley Times that are critical of the plant and its management. The Times reports that the plant management and press interfaces have been very hostile to any inquiries from the Times. Here’s the boiled down situation that the Times has reported on:
October 2016 – Plant was shut down to repair molten salt tank leak. It was leaking along a longitudinal crack adjacent a tank weld.
January, 2017 – The Times reported a contentious interview with the plant management and that the plant was to restart shortly and all would be well and there were no other issues (reported by the plant operator).
July, 2017 – The plant had not been in operation since October, 2016, and the Times could not get information on why it had taken 8 months to restart the plant. There was obviously more to the problem reported in October, 2016.
October, 2017 – Plant was shut down again due to a tank leak. Workers with respiratory problems reported this to OSHA and OSHA was investigating. Apparently there was a subsequent tank leak which the plant operator performed a temporary patch on it to enable operation of the plant. There was speculation that this leak would need to be permanently repaired later, but the operator needed to get the plant up and running due to optics and it’s past poor performance.
The Plant contends that it has solved the bird killing problem. The Basin and Range Watch folks disagree and have put counter arguments on their website including pictures of birds in the process of being vaporized. Basin and Range Watch have had problems obtaining bird mortality data from the BLM and have had to sue through FOIA to obtain this.
Basin and Range Watch have also reported that the plant has had “issues” with molten salt piping vibration. The piping system is designed for flowrates in excess of 5000 gpm and application of positive displacement pumps. Pipe vibration issues are very difficult to solve at the best of times and there is likely a lack of experience in systems pumping highly dense liquids such as molten salt. Note that I could not find any acknowledgement from the plant personnel of the vibration problem reported by Basin and Range Watch.
Meant to power Vegas, eh? Wouldn’t like to be in their shoes (or concrete boots) when the wiseguys turn up asking why their casinos have gone dark…
I found a news article about the bird deaths at Crescent dunes that contained a link to a spreadsheet of the dead birds found at Crescent dunes.
The number found is very low and many are listed as possible preditation deaths.
IT’s hard to kill many birds when the power plant only works 4 hrs/d.
A more recent source:
“The number found is very low”
Vaporized birds are hard to find. And to find all ordinary “roasted” birds will require essentially constant presence at the site. Scavengers are very efficient, and while aerial scavengers are liable to be roasted too, there are plenty of mammalian and reptilian scavengers even in a desert.
Good point tty. Common sense isn’t so common after all is it.
I wonder how the birds around that tower are getting on. There were early reports of massive carnage that did not account for injuries to sight and partly singed feathers. Eventually, I suppose that the birds will learn, like us, that these solar and wind installations are very, very bad news for us all.
The output was for 2 years, and a reasonable projected life might be 20 years, so $0.427 per kWh is a better approximation if other problem did not exist. This is still so bad that you do not need to claim $4.27 per kWh. The other problems (bird kill, long term clouds, freezing salt in pipes, etc.) make the case even stronger. Also, besides cost, there is operation costs, distribution costs, and need for profit. I would guess a final cost would be $0.80 per kWh retail, with significant dispatch problems. A real non-starter.
The $0.427 per kWh or $4.27 per kWh is just the DOE $737 million loan guarantee. The total construction cost was $975 million… $5.66/kWh through Oct 2017… 😉
$970,000,000 is the total build investment.
Doesn’t matter whether the money came from green fairies or brick-faced bankers.
Everyone wants a return on investment.
Call it 6.5%/year, for “industrially risky” investments backed by government guarantees for 75% of the load.
P = $976,000,000
I = 6.5%
n = 365 days/year
Y = 20 years
pmt = $238,900 a day.
Nameplate = 110,000 kW
Nominal seasonal/diurnal cap factor: 27% / over year
Nominal weather/atmospheric clarity: 80% / over year.
Useful output per day: 570,000 kWh/day, nominal
$238,900 ÷ 570,000 ignoring all operational costs… entirely
= $0.419 per kWh.
The actual rate must be higher because of parasitic costs. Cleaning the reflectors, refurbishing gone-dead actuators and 2 axis reflector azimuth drives. Managing the staff. Production-room operators. Onsite engineers and maintenance staff for non-mirror upkeep. Government or industry required EPA observers. Code violations, fees, tariffs, impounds. Unnecessary, but regulatory contention shutdowns. Union troubles. Pulled delivery contracts, contingency based.
Without even trying to exaggerate, the price per delivered kilowatt hour might well be 50% higher. $0.60/kWh.
I’m sorry. That is RIDICULOUSLY EXPENSIVE. Especially given “economies of the Olde Days” that somehow no longer seem to be part of the “American Get ‘Er Done narrative”. In present-day constant dollars, (2016 dollars) Diablo Canyon cost $13,200 million. It produces 2,250,000 kW, with a 96% cap factor. Doing the same math with a 20-year, 4.0% (safe) yield, you get
P = $13,200,000,000
I = 4.0%
n = 365 day/year
Y = 20 years
pmt = $2,630,000 a day
96% cap factor
51,300,000 kWh/day useful poewr generaion
$0.052 or 5.2¢ per kWh.
Of course, that too is “before management, engineers, EPA goons, maintenance, tariffs and impounds”. The parasitics kicks the 5.2¢ up to maybe 7¢.
And – of course – the original State Buildout Bonds were not for $13,200,000,000, but more like $5,900,000,000 in 1985 original dollars. The beauty of CPI inflation diluted the original expenditure over 55% in REAL money terms, since. The cost of power produced TODAY is less than 3¢/kWh.
And of course “they’re” going to decommission this 75+ year useful-life plant in what, only 38 years? Dumb as a box of bricks. A perfectly working 2.2 gigawatt plant, delivering power flawlessly at less than three cents per kilowatt hour.
Plant mechanical and fluid flow design issues can be overcome in 2nd and 3rd generation systems. At what cost????? Dunno. Bird Carnage – still an issue. This plant hasn’t operated sufficiently to benchmark the effect on wildlife. (IMHO)
There may not be any 2nd or 3rd generation CSP’s in the near future…
Behind every stupid green energy scheme you will ultimately find an assumption involving a high “social cost of carbon” and an assumption of long-term interest rates being effectively zero. Thus you can build anything, except what you already have. Just give yourself to the dark side.
I didn’t have the time to read all the comments but it seems to this layman that, if melting salt is the goal, nuclear can do the same job with a smaller footprint.
Not really “the goal”, actually. The goal is the “store energy locally to change the hours-per-day with which it can be turned into electricity and fed to the grid, following diurnal and seasonal customer demand”.
Now that is quite different isn’t it?
As a for-instance, here in California you, anyone can easily look up the forecast electrical energy demand for the state. [ https://www.caiso.com/Pages/TodaysOutlook.aspx ]. Its one of the beautiful and useful chestnuts given to us ‘for free’ by the power company. Go, take a look.
Now that you’ve peered at that, what did you see? I personally saw a “2-hump camel back” curve, with demand rising in the morning, peaking, dropping during the day, then rising back up in the evening to cover peoples’ cooking, heating and entertainment energy use. In the Summer, the curve is substantially different; if one uses a rather difficult-to-display “seasonality and temperature” set of curves tho, every day of every year looks remarkably similar to similar kinds of days in prior years.
Which is the basic requirement for systems that CAN be forecast.
In any case tho’, if one looks at the “sun availability curve” for the same days, you’ll find a serious mismatch between the demand-by-time curve and the generation-by-time curve for any solar power operation. The curves are “kind of” the same (generation increases during daylight, then falls off at night), but in the end, there are huge gaps between them.
The PURPOSE of molten-salt thermal energy storage is to have a CHEAP TO MAKE AND SCALE energy storage scheme that can be directly fitted to the solar-THERMAL type power generation system. To store excess captured heat when not needed by demand, and to release it later (or the next day) when demand rises, but the Sun isn’t yet in the mood to accommodate.
That’s the idea. The idea is also impacted by the kind of solar power production. In the case of CSP (concentrated solar power), the big ol’ mirrors focus all the sun’s energy on the top of a tower, where black-black heat absorption fins can accept the sunlight and in turn rapidly heat up circulating molten salt as the heat collection agent. Which is kind of “perfect”: The Sun’s heat doesn’t need to be converted first to electricity then stored in giant ridiculously expensive batteries. Instead, it is just stored in its native form: as heat. Heat which can be used almost any future time (with sufficient thermal insulation around the tanks) to generate power, in no way different than if had been used directly at the time of collection.
That at least is the promise.
In practice, with partially developed collection field(s), with dysfunctional rotating mirrors (which need to be ‘feathered’ to point a harmless direction), with overly pölïtical and/or politicized schedules for operation, schedules for scientific run-process testing, for overly-stretched out maintenance operations, for staff that doesn’t work Graveyard shifts, and all that … in the end, the scheme has failed, and will remain doomed to fail. UNTIL such time as “management” is thrown out completely, the PhD students told to go home, the failed parts in the system repaired and if needed “improved” to stop failing, and the plant RUnited Nations COMPETENTLY as a commercial, reliable power plant. Until that time, its all bûllsnot.
“Which is the basic requirement for systems that CAN be forecast.”
Which is true for California, but not for colder areas where peak demands are during cold snaps. Which can not be forecast more than a few days in advance. To make things worse they usually occur at times of little wind and little or no sun.
GoatGuy, when someone comes up with the credentialism bs I immediately think of Irv Culver. Met him once.
Irv would have figured the scam out in a couple of minutes.
By all means. We (you and I and Irv) agree.
I don’t know about the characteristics of molten salt => solid (if it freezes solid like ice or goes through a molasses like stage) but if you get a plug of sorts anywhere in the circulatory loop you’ve got a major issue. Block/restrict the flow and there will be overheating at the heat source. Possible that a tank would experience pressure build-up/over pressurization due to flow restriction at/approaching pump intake. Any engineer/designer not considering issues at low pressure side of pump is an idiot! A bigger idiot if not considering entire loop. Someone please tell me this has not happened on a billion $$ project.
$737 million for 110 MW CSP plant = $6.70/watt capacity
Solar PV is $1 to $2/watt
If you want expensive power and you hate birds, CSP is the answer
Conspiracy theorists say CSP was invented by bird haters because wind turbines aren’t killing enough birds
David said total cost is $975 million. That’s $8.86/watt capacity. You must really hate birds to pay that price
In my opinion, CSP is a Ponzi scheme built to fleece the ignorant sheep that don’t understand one iota of economics and fall for every wolf wrapped in solar panels and/or smoke and mirrors.
Don’t underestimate the greed of the globalists envirofascists. There’s a sheep born every minute to be fleeced by them.
It all boils down (no pun intended) to another failed attempt to replace fossil fuel with so called “renewable” energy. The people are being lied to, plain and simple. It’s not that nobody wants renewable energy. … fossil fuels are renewable by definition. ….. it is obvious to anyone that technology isn’t capable of providing a suitable fossil fuel replacement without utilizing nuclear power today. The alternative to do without is not acceptable.
Why do they lie? If it was a 110mw plant, it would produce 2640 mwhr per day but it does not. So many scientists here cannot simply say that it does not work.
Nobody in Vegas cares about the thermal efficiency of salt, they just want their air conditioning to work.
No, you’ve got that wrong, Grey – but in a “friendly sort of way”.
All power plants have “capacity factors”. For instance, its very commonly above 95% for most nuclear power plants in America. Meaning that a plant with a “nameplate power intensity” of 1,000 MW will produce that or close to it 24 hours a day, 95% of the year. This is – now explained in this way – probably obvious.
A PV operation, having no other means ot produce electricity (say) is 100% dependent on the Sun. The Sun in turn is variable every day, rising at a low angle in the East and setting in a low angle in the West. Further as the seasons go, the Sun’s relative position in the sky may range in a huge 15+ hour a day arc in the Summer, and a shallow 9 hour arc in the Winter. This again, explained this way, I’m certain is obvious.
What’s not so obvious is that the “capacity factor” of sunlight, averaged out over the year, and taking into account the “interference of the atmosphere itself” limits the yearly capacity factor of a solar photovoltaic plant to about 25% to 27% in the central stripe of North America. (Say latitude 32 to latitude 40).
The nameplate energy intensity of a PV or concentrated-solar-power (mirror) power plant may be STATED as “110 megawatts”. But realistically, the total power generated per average solar day, over the year is 25% to 27% of 24 hours times 110 megawatts. Kind of sad, isn’t it? But given the definition of capacity factor, it is entirely consistent-in-use with how its used on nuclear, coal, gas, geothermal and oil fueld power sources.
See? It should be clearer.
The point I was making that all plants are rated in hourly capacity. a 100mw plant produces that and for 24 hours. Yes annual capacity is lower due to maintenance etc.
Calling it a 110 mw plant is thus a fraud from the outset.
Nonsense. A 1200 Mwatt power plant is out for maintenance every 1-1/2 to two years for a single planned outage of 30-45 days for refueling. 60 days if you’re going to replace the entire generator core and rotor – a twelve year to 24 year need, if at all. A smaller 275 to 650 Mwatt GT power plant is down for rotating outages (hot gas inspection of 18-24 days or major inspection of 24-30 days) every 24 months. Those are planned – the rest of the time the plant is available for 100% power every day.
Solar can deliver rated power for no more than 6 hours a day year-long average, wind turbines historically have a 17-22 percent load availability.
Grey, it may well be ‘fraud Lite’ to call a 110 MW nameplate factor solar plant 110 MW, but unfortunately it is the industry standard to which all plants so far built – whether WIND derived, SOLAR, geothermal, nuclear, natural gas, bunker oil or coal fired … have adhered to. One doesn’t get to pick the naming standard just because the Capacity Factor is fraudulently low for anything solar. It doesn’t work that way.
For the longest time, I actually railed against just such misleading naming. However, as I’ve “smarted up” in the last 25 years, I’ve found it better to have the misleading nameplate specific power rating, then also know the idiosyncrasies of the solar diurnal (daily) and seasonal (earth tilt) cycles. And use the 0.25 to 0.27 factor in keeping with solar’s actual, on the ground cap factor. You just need to “remember the cap factor” to get the right output results.
So … peace brother.
But I’ve moved on.
GoatGuy you keep making reference to PV plants, which this plant is not. This plant turns solar energy into heat in the salt and then turns heat in the salt into electricity, but not immediately. The nameplate capacity is the steam plant that generates electricity using the heat in the salt. This capacity does not have a fixed relationship to the rate at which the sun can heat the salt. So one could have a small steam plant that runs 24 hours a day or a large one that runs intermittently, the total amount of energy captured from the sun has to equal the electricity plus losses but it is entirely up to the designer what size steam plant he installs, and hence the capacity factor.
Since demand is variable we do not want 100% capacity 24 hours a day, one of the problems with nuclear plants is that they are difficult to throttle back. Note that many hydro plants average a quarter of their nameplate capacity because that is wanted to match supply and demand. In this case the designers have opted for 50% average capacity, i.e. the heat in a typical day is enough to run the steam plant at full power for half the time, or part power for longer.
The key thing about this design is that it produces dispatchable power, it is 110 MW when it is wanted not when the sun is shining.
Granted this plant is not working as it is meant to but that is another issue.
It takes too long to build a solar thermal plant.
Sorry that is one of the BS arguments anti-nukes use.
Over the years I have read a lot of interesting papers on solar thermal plants. There are some interesting challenges that us steam plant engineers have yet to solve.
What is important is not how long it takes to build but how long it last and how well it runs. In other words how much power is produced after the money to build it is spent.
Starting a new nuke up required lots of problem solving, it was rewarding work. Ultimately it is about succeeding not the number of failures.
South Korea has gotten very good at building nukes. They built a 1000+ MWe nuke in about the same time as this 110 MWe solar plant. After testing and commissioning, the plant ran to the first fuel cycle without shutting down.
Goat, Dont you think that there is a little bit of difference between 95% over a year and 30% over a day. Therein lies the fraud.
South Australia will see your 110MW solar system and raise you a 150MW system, also built by Solar Reserve. See:
Of course, our politicians are bragging about having the ‘World’s largest’ without explaining the detail described in this blog entry.
We now have ‘the world’s largest battery’, will soon have ‘the world’s largest molten salt solar tower’ but hear nothing from the same pollies about the world’s highest electricity costs. They are keen to tell us that all of these disparate, intermittent sources will have a downward effect on power prices.
We even have several diesel-powered generators standing by for our illustrious ‘energy’ minister to turn on when he feels we may be short of power.
The fool that calls them a drongo is no idiot.
Just when has any of these fancy projects worked? NEVER is the answer.
And by ‘worked’ I mean supplied a substantial amount of benefit to the population at a price that is no more expensive than is currently charged. Progress is all about getting more bang for your buck, all else is BS.
Science may say it’ll work but real world engineering say it BS.
It’s about time people got wise, don’t ask a scientists about practical matters, ask the engineers before wasting other peoples money.
While were at it don’t ask scientists about politics, or social policy, monetary policy, art, engineering, or anything else that your money is riding on; ask scientists for their ADVICE about science matters, that is their specialty.
What did they expect with post-modern scientific method? Nobody thought of the cooling salt, did they. Let me rephrase that: Someone probably DID, but they were shouted down for being a denier, and for not giving a flawed “opinion” a “chance”. How else could they have overlooked that little detail?
So, its really a 35 MW plant that cost one billion dollars. A gas plant would cost 30 million, be built in a fraction of the time, requiring a fraction of the space, operate 24/7, little maintenance.
Who is kidding who?
Projects like this can fail. It’s innovative, but maybe it didn’t work. Why is there so much venom towards alt-energy in the skeptical community? I really don’t get it. As an AGW skeptic, I LOVE science. I love that humans try to do things like this. And they fail, and fail again. But eventually, something great happens.
Sad from the hating – color me an ashamed skeptic.
It’s called “economics,” not “venom.”
Because not only did it (this particular scheme of renewable energy) not work, but no other renewable energy have succeeded in doing ANYTHING except paying off the donors to politicians who forced the taxpayers to sponsor and subsidize these renewable energy schemes. A near-continuous waste of taxpayer resources of cash, land, energy, and effort: All going to the men and woman who donate to the politicians, and the groups who have accepted the CAGW religion of “faith” that these schemes can actually “power the world” . But the energy and enthusiasm in the academic community and news media abounds! Yet the lies and the real world problems behind the enthusiasm are deliberately ignored, until like Solyndra and Tesla and these massive desert-destroying monstrosities they fail in rusted piles of metal and glass that realists have to spend more money on removing and cleaning up.
Putting it simply, it does not work, billion dollars down the drain.