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A Californian company proposes using weighted electrically-driven rail vehicles on inclines to store energy. At times when the capacity of electricity supply exceeds demand the vehicles would be driven up inclined tracks, and when demand exceeds generation they are allowed to run down, generating electricity as they fall.
This link includes a video that shows a prototype vehicle (which appears to be built on a conventional locomotive chassis), an interview with a promoter, and an animation of a "farm" of these devices. There is a shortage of hard data, such as how much energy could be stored, for how long, and how steep the tracks are, etc., but a quick calculation shows that some thousands of these vehicles would be required for them to be useful. The control panel for this prototype has a power dial that appears to go up to only 20 kW. The promoter in the interview focuses instead on how the construction material can be recycled at end of life.
(Score: 0) by Anonymous Coward on Tuesday July 03 2018, @04:15PM (23 children)
Why is an article like this on the front page?
You can't store "2 to 3 gigawatts" because wattage is a rate of power delivery or rate of energy per unit time. 3 gigawatt seconds is less than one kilowatt year. To know how much power it stores we need a unit of energy and not power.
This article is useless and written by a marketing drone, rather than anyone who is competent to evaluate its relevance.
(Score: -1, Troll) by Anonymous Coward on Tuesday July 03 2018, @04:35PM (10 children)
SoylentNews constantly runs bullshit pop "science" like this these days. It's nearly as bad as Slashdot.
(Score: 2, Redundant) by takyon on Tuesday July 03 2018, @04:40PM (7 children)
A journalist used the wrong unit. In an article from 2 years ago. Boo fucking hoo, AC.
[SIG] 10/28/2017: Soylent Upgrade v14 [soylentnews.org]
(Score: 4, Informative) by c0lo on Tuesday July 03 2018, @05:25PM (6 children)
Dismiss it all you like, but the question remains: how much energy is it supposed they store this way?
And all for the want of a proper unit.
https://www.youtube.com/watch?v=aoFiw2jMy-0 https://soylentnews.org/~MichaelDavidCrawford
(Score: 2) by frojack on Tuesday July 03 2018, @06:02PM (5 children)
How long is the train?
How heavy is each car.
How fast is it allowed to roll?
Arguing about an un-dotted i or un-crossed t when there are journalism majors involved seems a waste of time.
Having custom build gen-cars seems to be the most expensive way to go here. Almost assuring this will never be built.
Too many gen-sets, too high maintenance.
A standard gondola car or takonite car [staticflickr.com] (short heavy cars lots of wheels per length) with a heavy load connected to a very few gen-cars or cable-pull loop would be a lot less maintenance. You could then afford to stock pile an almost unlimited number of cars on the up-hill side if you have space.
No, you are mistaken. I've always had this sig.
(Score: 2) by c0lo on Tuesday July 03 2018, @06:28PM (4 children)
Almost there. The questions should be:
1. what's the delta-H for each car?
2. what's the mass of the car
3. how many cars
1 metric tonne car for 100m delta-H will have 981kJ of potential grav energy.
Potentially, add these:
4. what's the rolling resistance
5. how long is the track
6. what's the efficiency of the electromechanical drive/generator
and with those one can compute the efficiency of the energy storage. With good engineering, I guess we can see an efficiency of about 80-85%.
The "how fast it is allowed to roll" gives info of max power.
I didn't intend to argue - just to point to takyon he was gratuitously dismissive on this occasion.
https://www.youtube.com/watch?v=aoFiw2jMy-0 https://soylentnews.org/~MichaelDavidCrawford
(Score: 2) by mhajicek on Tuesday July 03 2018, @06:48PM (3 children)
80% seems way high to me. Maybe 80% storage and 80% extraction, so 64%, and I think that's optimistic.
The spacelike surfaces of time foliations can have a cusp at the surface of discontinuity. - P. Hajicek
(Score: 5, Interesting) by VLM on Tuesday July 03 2018, @07:18PM (2 children)
Back of the envelope time, a mechanical HP is about one electrical KW (to one sig fig) and a Big Boy 4-8-8-4 which is one hell of a steam locomotive, exerted about six kilo-HP to haul three kilotons (of coal, not a-bombs) over the Wasatch mountain range. So six megawatts will haul a hell of a large and heavy, yet commercially manageable and maintainable train around relatively normal ish looking tracks and coal cars. I don't think it really reasonable for this crazy gadgetry to vastly exceed that general mechanical performance of "tossing around trains at sane speeds and masses using about 10 MW continuous"
So figuring this gadget the dude is building is of similar Rube Goldberg machine status to a 4-8-8-4 steam engine, I figure the "buncha gigawatts" refers to one train of about 10 MW power flinging a large but not ridiculous train load of ballast around for "hundreds of seconds" which at 4-8-8-4 speeds would imply a track in the single digits of miles long for a total energy storage (or expenditure) of single digit gigawatt-seconds. Build a track 100 miles long and make it steeper and maybe some parallel multiple tracks and yeah sure "gigawatt hours" of energy, sure, very hand wavy.
Of course a beowulf cluster of 4-8-8-4 steam engines on an arbitrary number of parallel tracks would be impressive and both power and energy scale linearly with the number of steam locomotives. Given they weigh a million pounds each I would imagine moving a couple hundred in precise concert might generate interesting (measurable?) gravitational waves, up close anyway. I bet it would generate some seismic activity, at least.
And of course building a cluster of a thousand 4-8-8-4 steam engines would require more energy to refine all the steel and build all that equipment than the system would ever store and provide over its lifetime. The "couple amp-hour" battery in my phablet, charged and discharged 1000 times before the battery dies (or explodes?) is a remarkably small equivalent of gasoline (although I forget the exact amount) and the energy cost of building and delivering my cell phone battery likely exceeds that. To some extent potential energy storage is kinda like "hydrogen fuel" its not a source of energy and its not a very good store of energy given the energy required to make it.
(Score: 2) by bitstream on Tuesday July 03 2018, @11:58PM (1 child)
Cog and rack railway is the way rather than normal tracks that can't handle much of a grade at all. Though, it will not relieve one of the issues of motor power.
(Score: 2) by VLM on Wednesday July 04 2018, @12:15AM
Hmm I know there were geared cog steam engines but Shay engines were not cogged, only geared... pretty much, I think ... I'm so over the high tech imagery of this probably scam "invention" but I like the image of implementing it all with steam locomotives and commercial instant electric hot water heaters as boilers for the sheer spectacle of it. Imagine a thundering herd of 4-8-8-4 Big Boy locos brought back to life hauling Sisyphus sized car loads of granite up a hill only to spin gears on an alternator on the way down. I mean, if its not going to make sense and not going to work as a system, at least look cool as heck while not working.
Some kind of sci fi book plot steam punk fever dream.
(Score: 4, Informative) by Snow on Tuesday July 03 2018, @04:54PM (1 child)
Everyone is free (and encouraged!) to submit their own stories.
Be the change you want to see!
(Score: 5, Funny) by c0lo on Tuesday July 03 2018, @05:29PM
Ahem... yes... may I begin? Good. So...
"It was a dark and stormy night"
https://www.youtube.com/watch?v=aoFiw2jMy-0 https://soylentnews.org/~MichaelDavidCrawford
(Score: 4, Touché) by maxwell demon on Tuesday July 03 2018, @05:06PM (5 children)
You mean, how much energy it stores, right?
The Tao of math: The numbers you can count are not the real numbers.
(Score: 2) by DeathMonkey on Tuesday July 03 2018, @05:30PM (3 children)
I love watching the semantics bite the semanticist!
That's why I never correct others' speeling errors.
(Score: 2) by frojack on Tuesday July 03 2018, @06:05PM (2 children)
Muphry's law [wikipedia.org] bites all asses sooner or later.
No, you are mistaken. I've always had this sig.
(Score: 0) by Anonymous Coward on Tuesday July 03 2018, @06:32PM (1 child)
"If you write anything criticizing editing or proofreading, there will be a fault of some kind in what you have written."
Nope! If you can withstand the urge to correct people then you are safe.
Thanks for sharing btw
(Score: 2) by Immerman on Tuesday July 03 2018, @07:15PM
Nope. All statements of the form "If [FALSE] then [X]" are logically true. If you withstand the urge to correct people, then their statement fits that form.
Now, lets see who can find the fault in what I have written. Or have I managed to prove them wrong?
(Score: 2) by FatPhil on Wednesday July 04 2018, @03:53PM
Energy is the potential to do work, power is the doing of work. What actually enters the storage is the doing of work, and as it as stored it becomes future potential work, and when it's released, it's released again as work. So what's being stored is power, in the form of energy.
Great minds discuss ideas; average minds discuss events; small minds discuss people; the smallest discuss themselves
(Score: 3, Interesting) by requerdanos on Tuesday July 03 2018, @05:19PM (2 children)
Because many journalists, and tech site story submitters, and tech site editors are bad at measurement, especially in the areas of idiotic and variable units of measure (elephants, school buses, double-spaced typewritten pages, Libraries of Congress) and of measuring using units of measurement suitable to the measurement (as in this case).
Even worse is that lots of people assume that if an idiotic or non-applicable unit of measurement is used, that a "you know what I mean" get-out-of-science-jail-free card should apply, even if no one knows what was meant, not even the one originally doing the measuring or reporting.
Add onto that the situation that even facts, such as the things being measured, don't much matter anymore to many people.
It's a self-propagating cycle so bad it could make the Kessel run in less than fourteen parsecs.
(Score: 2) by bitstream on Tuesday July 03 2018, @05:48PM
Dump idiotic journalists?
/dev/null ?
(Score: 2) by darnkitten on Thursday July 05 2018, @08:32PM
If we used typewriting monkeys as ballast, how many complete works of Shakespeare could we generate, and could we convert them to Libraries of Congress?
(Score: 3, Funny) by bitstream on Tuesday July 03 2018, @05:20PM
1.21 gigawatts?! [youtube.com] [video]
Journalists are exempt from physics. Didn't you know? ;-)
From truth as well :p
(Score: 2) by suburbanitemediocrity on Tuesday July 03 2018, @06:15PM
I didn't RTFA, but I did read abut this system at least 10 years ago. A little surprised to see it is still around.
(Score: 2) by JoeMerchant on Tuesday July 03 2018, @07:09PM
AC is ignorant of the difference between science, physics, and basic units of measure.
Yes, lots of people get the units of measure wrong when talking about Watts vs Watt-hours.
Bitch if you like, but don't expect it to improve.
🌻🌻 [google.com]