Guest skewering by David Middleton
From Inside Climate News…
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.
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 | |||
| Month | MWh | Capacity Factor | Hrs/d of Electricity |
| Oct-15 | 1,703 | 2% | 0.5 |
| Nov-15 | 1,831 | 2% | 0.6 |
| Dec-15 | – | 0% | 0.0 |
| Jan-16 | 1,508 | 2% | 0.4 |
| Feb-16 | 9,121 | 12% | 2.9 |
| Mar-16 | 7,099 | 9% | 2.1 |
| Apr-16 | 2,158 | 3% | 0.7 |
| May-16 | 11,485 | 14% | 3.4 |
| Jun-16 | 6,216 | 8% | 1.9 |
| Jul-16 | 25,560 | 31% | 7.5 |
| Aug-16 | 28,267 | 35% | 8.3 |
| Sep-16 | 30,514 | 39% | 9.2 |
| Oct-16 | 5,410 | 7% | 1.6 |
| Nov-16 | – | 0% | 0.0 |
| Dec-16 | – | 0% | 0.0 |
| Jan-17 | – | 0% | 0.0 |
| Feb-17 | – | 0% | 0.0 |
| Mar-17 | – | 0% | 0.0 |
| Apr-17 | – | 0% | 0.0 |
| May-17 | – | 0% | 0.0 |
| Jun-17 | – | 0% | 0.0 |
| Jul-17 | 9,420 | 12% | 2.8 |
| Aug-17 | 9,192 | 11% | 2.7 |
| Sep-17 | 13,666 | 17% | 4.1 |
| Oct-17 | 9,263 | 11% | 2.7 |
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.
“Crescent Dunes is expected to generate 482,000 megawatt-hours of clean energy per year“… 100% output of 110 MW is 966,240 MWh/yr. They only expected a 50% capacity factor with the fracking molten salt storage.
Inside Climate News needs to edit their headline…
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.
https://www.eia.gov/electricity/monthly/epm_table_grapher.php?t=epmt_6_07_b
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.
Steve Zell
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.
Green.
Like algae covering a foetid oilfield sluice pond.
Green.
And stinky.
GoatGuy
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.
LOL GoatGuy
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.
Regarding Gemasolar…
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…
http://reneweconomy.com.au/solar-storage-plant-gemasolar-sets-36-day-record-247-output-12586/
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.
https://www.eia.gov/opendata/qb.php?category=1810648&sdid=ELEC.PLANT.GEN.57275-SUN-ALL.M
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%…
https://en.wikipedia.org/wiki/Gemasolar_Thermosolar_Plant
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.
From solarreserve.com:
“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.
http://www.eenews.net/assets/2016/08/12/document_gw_01.xlsx
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:
http://www.basinandrangewatch.org/CrescentDune.html
“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… 😉
Better estimate.
$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.
Then…
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.
Sigh.
GoatGuy
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…
https://www.utilitydive.com/news/crescent-dunes-csp-plant-producing-power-after-8-months-offline/447804/
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.
GoatGuy
“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.