Over the past few days I have been catching up on some reading in the scientific literature that shows up routinely in my mailbox or inbox. A surprising amount lately has been about energy storage. It appears that the storage problem is becoming almost universally recognized, but as is usual, not universally understood. When I read a paper filled with enthusiasm about some new breakthrough, the description is always limited to a very narrow technical discussion about how this particular idea works. It does not go into the details about how such a device would fit into a workable system. It is to little avail if a new technology comes with new burdens placed on the system in which it must work – this is one flaw of so-called renewables within the grid. They may add energy to a delivery network, but they can’t be dispatched arbitrarily, and contribute little to voltage/frequency support. They placed the burden of ancillary services on other parts of the system.
Two Achilles heels
Whenever I read about some new or improved scheme to store energy I ponder two things about it. These are two ubiquitous Achilles heels: 1) What limitations does the second law of thermodynamics place on it, and 2) what are the other constraints that would limit its usefulness in a system? I focus on the second law because the first law just refers to conservation of energy itself, and this is not where most limitations on the use of energy, or in fact limitations on any human activity, come from.
Losses on energy to work conversion imposed by the second law are called irreversibilities, or an even fancier term is “destruction of exergy”. What this means is that some energy converted in a system doesn’t contribute to useful work. Useful work is always and everywhere the goal. So, things that contribute to this problem include: 1) that heat can’t be converted 100% into work; 2) chemical reactions cannot be made to go to completion and lead to some amount disordered materials; 3) that high temperatures contribute to heat flow into the dead state, or as Willis Eschenbach terms them, to parasitic losses; 4) high pressures contribute to loss of the mechanical energy used to produce high pressure in the first place. This work also heads to the dead state; 5) long chains of conversion with little losses at each step; 6) fast rates of conversion. Be aware of these problems.
Systems issues include: 1) inadequate amounts of critical materials; 2) inadequate available terrain; 3) resources in the wrong places that require long distance transport; 4) demands for impossible slew rates (problems with time constants); 5) weight and volume constraints; 6) impossible demands of time span and huge demands for mass per unit of stored energy; and, 7) complexity. Table 1 shows general examples.
|General physical category of energy storage||Examples||Systems or second law constraints.|
|Kinetic energy (KE)||Rotating KE of the turbo-machinery in a thermal power plant||As mechanical energy it is 100% available, but is subject to varying amounts of friction. Severe systems constraints particularly duration.|
|Mechanical Potential energy (PE)||Pumped Hydro. Raising massive blocks.||As mechanical energy it is 100% available, but has frictional losses. Many systems constraints, mainly with regard to mass/terrain.|
|Thermal Energy||Molten salt reservoirs, hot rocks, glowing hot metals, etc.||Availability constraints following directly from the second law. Excessive materials demands. Parasitic losses.|
|Chemical Energy||Batteries. Hydrogen or hydrogen carriers like ammonia.||Many second law constraints from chemical equilibrium and the production of disordered products. Many systems constraints, such as exotic material.|
Let’s examine a couple of examples from my recent readings. How to power aircraft is a genuine problem to solve for advocates of renewable energy mainly because they like to fly places free of guilt. The December 2020 issue of Physics Today included an article on using hydrogen to power aircraft. The systems problems with hydrogen as a fuel begin with means to produce the hydrogen in the first place, storing it, transporting it, and so on. Yet, just assuming an available hydrogen supply, aircraft are also weight and volume constrained. One reader of this Physics today article wrote in to explain that through a constraint on available volume aircraft using hydrogen are limited to short hauls. So short in fact, that we would return to the air transport system of the 1930s.
The September 2021 issue of Physics Today included an article that began thusly,
“ Experts say lithium-ion batteries will be overtaken for grid-scale energy storage applications by other battery technologies and nonchemical storage.”
Experts say otherwise. One odd assertion in this article is that hydrogen is a non-chemical form of storage. As there are no sources of hydrogen, chemistry is central to its production and use. More revealing still is the artist’s rendering of a solar farm coupled to a gravity storage system like that proposed by Energy Vault(™). The storage facility is a tiny building four stories high that looks more appropriate to administrative offices. It wouldn’t store but a few moments worth of energy. There seems to be little recognition of the materials handling problems to make raised mass storage feasible as I outlined here some time ago. There are constraints on slew rate of schemes that raise massive blocks into a pile of stored energy, or pull rail cars upslope. Pumped hydro is a better method of storing potential energy, but in this case the systems limitation is the lack of available terrain and issues over water use.
Recently the “Science Magazine Table of Contents” came into my email inbox which allowed me access to a brief summary about thermal energy storage. Thermal systems of energy storage suffer ubiquitously from second law limitations about converting heat into work. They all involve taking valuable work and turning it into heat, which then is turned back into useful work at the typical 35-40% efficiency of a thermal power plant. There are long chains of conversion involved.
This article was broadcasting a recent improvement in thermophotovoltaic (TPV) devices which could absorb the broad thermal spectrum of radiation from a hot mass of material at nearly 2,700K, heated so by renewable energy, and turn this back into electrical energy. Yet, the efficiency indicated here is only about 40%, which is the same efficiency that a conventional thermal plant operating at far lower temperature can provide. As high temperatures lead to increasingly larger parasitic losses, high temperature storage of energy as heat has a problem with not only the second law, but also with any system requiring long duration storage. Unavoidable parasitic loss accumulates into a huge total energy loss which has to be made up with generating facilities. Secondary storage batteries have this same problem.
One of the most serious systems problems for renewable energy to solve is the various time-scales of response required to make a reliable grid. There is first the very short time scale of fractions of a second needed for automatic control systems to keep frequency and voltage within prescribed limits. Next there is a daily time scale of response needed to handle the daily variations in load. Following this is an unknown amount of storage to handle outages resulting from weather that may last for 10 days or more. Finally, there is the issue of seasonal shifting of energy supply which requires either a large overbuilding of generation or massive long-term storage, or some hybrid in between.
The present grid handles the very short time scale problem by relying on the rotational KE of its turbomachinery which stores several seconds worth of demand in spinning mass. All other time-scales are covered by using stored fossil fuels on site right up to 95% capacity factor of the plant. It is not overly complex and we have nearly a century of systems engineering experience making this system 99.9% or more reliable.
Wind plants have very little rotational energy to aid in the very short time scale stability issue and solar has none. One remedy is to add “synchronous condensers” into a renewables grid to act as an analog to the rotating turbomachinery of thermal plants. These solutions are parasitic which only consume energy in exchange for short term stability. Solutions to the longer term system problems rely on cascading elements of diverse energy storage and conversion schemes that require lots of mass, lots of ground space, exotic materials, transmission utilities, embodied energy, excess generating capacity, and so forth. Not only are such elements unproven themselves, but we have zero systems engineering experience with them. Could they be made to work? Who knows? Have a look at their heels.
- I have taught engineering thermodynamics for twenty years. I find the first law of thermodynamics is relatively easy to understand even if people have some difficulty applying it. However, the second law is far more difficult for people, even chemists, physicists and engineers, to fully fathom. I am still learning about applying parts of it after five decades of use. It is entirely in control of all processes of energy use. It runs the universe. Since energy costs money to convert and deliver, the second law even controls the expense of activities that people wouldn’t think of as related to thermodynamics. I think it even covers the zeroth and third laws of thermodynamics. Thus, while the best textbook on Thermodynamics, Zemansky’s Heat and Thermodynamics calls friction a third-law issue, I think it more correctly belongs to the second law.
- Dead state is an engineering concept. It is a physical state where despite being full of apparent energy, has none that can be used to do work. We usually consider the dead state to be a temperature of 288K, a pressure of one atmosphere, an electrical potential of Earth ground, chemical species in equilibrium at minimum Gibbs free energy, and a relative humidity of 100% saturation.
- Owning two VW Beetles, I am familiar with the characteristics of German engineers, which is to make complicated designs work. The rest of us aim for simplicity.
- David Kramer, Hydrogen-powered aircraft may be getting a lift, Physics Today, 73, 12, 27 (2020); doi: 10.1063/PT.3.4632
- Peter Rez, Hydrogen as an aviation fuel, Physics Today, Readers Forum, September 2021, p. 11. While Mr. Rez contemplates hydrogen used in fuel cells to run a turbofan or turboprop sort of aircraft, hydrogen could be used as a combustion fuel. Yet this would involve the second-law constraints of turning heat into work, along with all the other mass, volume, and complexity constraints of hydrogen. In particular hydrogen possesses a lot of energy per unit mass, but a unit mass takes a lot of volume. It makes little sense to go this route.
- David Kramer, Better ways to store energy are needed to attain Biden’s carbon-free grid, Physics Today, September 2021, p. 20. Biden’s?
- Not only are the best places for pumped hydro already being put to use, but legal battles over water ownership and usage limit it even more.
- Robert F. Service, Thermal Batteries could efficiently store wind and solar energy in a renewable grid, Science, Vol 376, Issue 6590, online version 13 April 2022. doi: 10.1126/science.abq5215
There are a number of principles at work that seem to have been forgotten. Perhaps Murphy’s law is a corollary of the 2nd Law.
For instance, a direct CCS project in Iceland for capturing CO2 to reduce global warming stopped working because it got too cold.
Yes. And Kevin also forgot to mention, in his otherwise excellent explanation, the stages of the processes where miracles do occur.
If Bing Crosby were still alive, you could make a nice family film out of all those miracles! Maybe Frank Capra to direct…
The first principle about the Great Transition is the climate changers lied about the cost-
National Grid expects higher profits amid growing energy bills (msn.com)
Either that or they don’t have a clue about real science engineering and economics in which case you can’t trust anything that pops out of their computer models or mouths.
“Either that or they don’t have a clue…”
Thats a Bingo!
How blessed your students are, Professor Kilty — including all of us!
Thank you for the useful information communicated well.
btw: Your recent technically precise riposte to an earnest, but, naive, commenter proposing bird-slaughter-prevention cages around wind turbine blades was very cool. Droll and accurate.
You’d reckon those with a flair for envisioning Utopia and the next Great Leap Forward could make smaller quantum leaps in the neurons now wouldn’t you?
Brilliant Basics Pedestal Fan 40cm White – TX-160B | BIG W
Thank you for the compliment, but I don’t recall the comment you allude to…I make lots of comments.
Your memory is correct. I misremembered a comment by Michael S. Kelly on this thread:
as being yours.
The 2 laws can be summarized quite simply and accurately by the description I was given years ago by a physics teacher: the first law says the best you can with energy is break even. The second law says you can’t even do that.
Another consequence of the second law is that if a self organized thermodynamic system has more degrees of freedom than constraints, it will tend towards an optimum state. For the atmosphere, this optimum state is maximum surface warmth (radiant emissions), given the available solar energy. This means maintaining this ratio as constant as possible. The reason is that average clouds establish the average ratio and that it takes energy to change the average amount of clouds which is otherwise unavailable to warm the surface leading to a non optimum state. By considering the self organizing convergence of the planets radiant energy balance by clouds as behaving like a converging Mandelbrot fractal, this ratio can be calculated and is about 1.62 as the solution to Yn+1 = Yn^2 – 1 when in the steady state, Yn+1 = Yn.
At 288K, the surface emits about 390 w/m^2 from about 240 w/m^2 of incident solar energy resulting in a ratio of 390/240 = 1.625 and within 1% of the predicted value.
Wow, mathemagical witchcraft from co…evil…
No…that is the Golden Ratio. ~1.62 Appears everywhere in nature.
Exactly, but unfortunately, the alarmists don’t consider the climate to be a function of natural processes.
The deeper reason for why this particular value arises in nature is that it can be quantified in an infinite number of ways as functions of itself, powers of itself and 1, each of which has a unique slope as the value varies around 1.618 and without the need to introduce additional free variables. That is, there are an infinite number of degrees of freedom without introducing any new constraints.
It’s a far better predictor than any computer model, moreover; it’s based on actual physics, math and supporting data. You can’t say that about anything coming from the alarmist camp.
When I tried to understand the second law of thermodynamics, I came to the realisation that I was better suited to geology than chemistry and physics.
Geology is chemistry and physics… just real slow.
Mount St. Helens created a petrified forest in a few days. Is that real slow?
If you are holding your breath…
I became a mining engineer……..
I completed a BSc in geology and geophysics at UBC in 1962 and the physics guys had some “translations” of the Laws of Thermodynamics.
I can recall only two:
First Law: “Things are going to get a whole lot worse before they get any better”.
Second Law: “Who says it is going to get any better?”.
Third law: No quitting.
Or as the immortal “Prof” Allen Ginsberg said:
You can’t win.
You can’t break even.
You can’t leave the game.
There is also a zeroth law: There is a game.
You might find a less unsavory source by using an attribution to Dr. Dwight Wayne Batteu from Astounding Science fiction, Volume 58 Number 4 from 1956.
I wish I still had his book, Stupidotheorems, I loaned and lost years ago. The only other one I remember is:
The new town is full of corners.
The old town is full of streets.
The home town is an open field.
I recall the laws stated:
Excellent explanation Kevin. Few “exciting new technology” announcements bother to consider the systems and integration aspects. I expect you’ll get some questions on the concluding heels remark. Well done.
Seriously, dk blank. The average consumer doesn’t realize that
“Our marvelous, just-plug-it-into-your-electric-outlet and go for miles and miles on a single charge!!”
is still, essentially,
the always-10-years-away “Flying Car.”*
*by definition the Flying Car is:
an affordable to the average consumer, reliable, safe, viable alternative to a wheels-on-the-ground, vehicle.
I am still wondering if a single one of the electric cars will save us crowd, have considered what happens in a place under evacuation from a hurricane?
I am 100% sure if they have, they decided not to think on it much.
The “smart woke ones” (a dichotomy if I’ve ever made one) will be towing gasoline or diesel generators mounted on “irony trailers” behind their BEVs when they need to evacuate a natural disaster.
So you’re saying 3 people will evacuate safely in their EVs?
Assuming an EV can pull a trailer satisfactorily. I haven’t seen one advertised yet, and wonder what the effect of a trailer would have on the mileage before you have to start the engine.
Better to build the engine into the vehicle.
Mr. McGinley: Based on my observation of comments here, the “EVs will save us” crowd have become well-practised at avoiding such negative nellie considerations. The solution to any negative point you may raise is just over the horizon for these folks, they are the iconic image of Mark Twain’s jab about how much easier it is to con a person than to persuade them they’ve been conned.
Just ask any inhabitant of Naples what they think about living next to Vesuvius.
Heh. Powerful evidence smashing the EV market developers’ smoke and mirrors promotion, Mr. McGinley.
I guess “perpetual motion” always needs a little shove.
No, a perpetual shove.
With enough lackeys to keep a bucket brigade filling the tiny upper reservoir of Fludd’s machine (Figure 1) it could be made to work, but the work, the perpetual input, would come from the lackeys, not the machine.
Reductionist mistraining of over specialized scientists has caused holistic environmental policy to be displaced by a ludicrous obsession about CO2 and CH4 molecules. Solar and wind power need something like 200 times more space than gas per unit of energy produced. Bioenergy is like 1000x more space. Adding more bits and bobs won’t make any difference. With currently available tech, Net zero = Net environmental decline. It’s that simple.
The absurd lack of judgement, to allow UNFCC / IPCC to be dictating environmental policy priorities, is sickening. There is nothing in the training of IPCC scientists (physics geeks?) to be preaching on environment. Nor is there anything in the mandate of IPCC to give them any authority in this matter. What they know is but 1% of what’s going on out there.
The initial IPCC mandate was to focus on how to respond to man-made glow-bull warming
rather than first researching to what extent it did exist. Why would any real scientist support
an unproven hypothesis!
The IPCC is NOT run by scientists but by economists! Scares me!!! 😮 😮 😮
Yes, the land area required is one of those “systems” issues that I am alluding to.
The Second Law of Thermodynamics is a very narrow subset of The Universal Law – TANSTAAFL.
Nah, it’s merely a formalized way of stating that “there’s no such thing as a free lunch”
I’ve always said engineering 101 should put wind and solar to bed as primary sources of electricity.
To bed? How about “to sleep”.
Perchance to dream.
But that would also mean that fossil fuels are useless as well. After all fossil fuels are nothing more than solar energy stored in chemical bonds via a ridiculously inefficient process. Solar panels are at least several orders of magnitude more efficient at converting solar power to electricity than the process of sunlight -> photosynthesis -> organic matter -> coal.
Yah, but… coal, oil, and gas work anytime, day or night. Solar? Not so much.
yea, but they don’t work for shit when the sun don’t shine
The arrogance on display, stating humans do it so much better than nature! The natural process auto assembles and is self-sustaining. It is also completely biodegradable. And Nature’s energy storage solution is orders of magnitude better, holistically, than ours.
Except that fossil fuels are already made
or bury it in the Marina Trench
I thought I would brush up on the second law, so I went to the wiki page. Oh dear.
When something is first discovered, the explanations and equations are often complex. Over the years people find concepts which are easier to use.
Example: You could solve a series AC generator – capacitor – resistor circuit using calculus. The simpler way, developed by Steinmetz, is to use phasors and Ohm’s law.
It feels to me like thermodynamics hasn’t had its Steinmetz yet.
I remember the joy of Laplace vs Fourier! 😉
I don’t.. thankfully ! 😉
As a comparison you could consider Newton’s three laws of motion. People sort of get the second law of motion that you need force to make stuff at rest begin to move — its sort of like understanding that energy is needed to do work. However, Newton’s third law introduces something utterly at odds with their intuitive understanding. How is it possible that a tiny object pushes back on a big object with the same force the big object applies to it? Yet, without that fundamental understanding mechanics becomes a complete mess to analyze.
By analogy the first law of thermodynamics seems reasonably intuitive — you can’t get more work than you have energy to make work. Yet, if energy is neither created nor destroyed why do we ever have an energy crisis? The intuitive understanding is that there should be plenty of energy around us to do whatever we want. The second law of thermodynamics makes this mystery clear if a person can understand it — not all energy is available to make work. Its details can be pretty daunting to work out, but everything we try to do has some element of the second law (of thermodynamics) involved.
Kevin–clearly written review–TKS– and above I wrote popular “explanations” of Thermodynamics:
First Law: “Things are going to get a whole lot worse before they get any better”.
Second Law: “Who says they are going to get better?”.
Despite having a classical engineering degree, grad courses in heat transfer, and a career checking that the second law hadn’t been broken by overzealous process engineers specifying heat exchangers with possible internal temperature crosses, many dQ/T graphs for multi-stream heat exchangers, and reaching the point where ”the third time studying entropy doesn’t matter any more”, I never really felt I “understood” entropy until I read “Entropy Demystified: The Second Law Reduced To Plain Common Sense” by Arieh Ben-naim” and his later books. I recommend this book to readers so inclined. The mental image of the results of tossing a huge number of dice causes an “ah-ha” moment.
Steinmetz version of the three laws:
1) You Can’t Win
2) You can’t Break Even
3) You Can’t Even Come Close.
But you are forced to play.
Does gravity bend light passing near the sun or is some refraction going on? Which paradigm requires easier math?
The curvature of space-time seems inadequate to explain gravity:
Imagine a satellite launched into space with rockets and fuel to 1) overcome its earth-derived orbital speed relative to the sun (so that the earth was racing away at its orbital speed) and 2) to overcome its acceleration toward the sun imparted by the free-falling earth from which it was launched. What would happen to that object, once it is sitting poised above the sun, without “horizontal” orbital speed or “vertical” acceleration toward the sun (and those processes played out over a long enough period of time so that the receding earth’s gravitational pull was negligible vs. the sun)?
Once its rockets fell silent, wouldn’t it begin to accelerate toward the sun? Yet, curvature of space-time wouldn’t impart that motion. I could place a ball on an inclined surface in a zero-gravity environment and that incline would not induce the ball to roll down the surface. So what would cause my object to accelerate toward the sun?
If gravity is the slope, what imparts acceleration “down” that slope? Thanks for any replies. Sorry in advance if I’m “not even wrong”.
Also, the notion that the effect of gravity is limited by the speed of light seems nonsensical to me:
Neptune orbits at a distance of 15,000 light seconds from the sun. It travels 4/5th of its diameter (24,000 miles) along its orbital path in that amount of time. Therefore, the curvature of the space between them must be changing continuously.
But the updated information of the revised curvature of space between them supposedly cannot propagate any faster than lightspeed. Therefore, they ought to never be attracted to each other, but only to a memory of each other.
Yet, it is patently obvious Neptune and the Sun are attracted to their instantaneous locations, otherwise Neptune would be slowly slipping away from the Sun.
We often read how we view distant objects – the Andromeda galaxy, for instance – as they appeared long ago, because it took light from them millennia, sometimes thousands of millennia, to reach us. But it seems gravity is aware of the current positions of even distant objects. At the least, the attractive property of gravity propagates at orders of magnitude faster than the speed of light (In the case of Neptune, at least 15,000 light seconds per second). Perhaps gravitational attraction is oblivious to time, untouched by it.
Gotta disagree about the Germans – most excellent example being electronic fuel injectors – as manufactured by Siemens and fitted to VW common-rail diesels of circa 10 years ago
Also with VW, exhaust gas recirculation valves
The Germans build robust engineering, they work to tight tolerances, use the correct materials for the job and they test test test to chase out the bugs and flaws.
A bit like the Italians = fantastic engineers but they don’t do the testing.
Complication and getting it work while making it look simple and humdrum boring is the Japanese forte = The Very Best Example being Soichiro Honda and the little engines he designed and the ones we all know and love in lawnmowers, generators, quad and motorbikes.
= engines that are factory set, with no adjustors (fuel, ignition etc) yet they always start, run as sweet as nuts for ever and ever and ever.
And he used Turpentine as his fuel – petrol in Japan during WW2 was, shall we say ‘restricted’
That last bit being the Achilles Heel for most little Honda engines, their very reliability means that folks neglect the basics like air filters and changing the oil, often after merciless thrashing.
To play with the 2nd Law and get your head around it, you need Carnot’s Heat Engine Law
That has got to be the most elegant, eloquent and minimalist expression of anything, while explaining almost everything we see around us.
Basically, it tells you the efficiency of any given or proposed heat engine and allows you to quantify the parasitics.
It doesn’t tell you hat form the parasitics are in or where the lost energy is going – you just need to maintain faith in the 1st Law that The Energy is still around somewhere and ‘headed to a better/happier place.
Often referred to as the ‘exhaust’ of the engine although that defines it too strongly and has myriad confusing meanings
The ‘exhaust’ of the Carnot Engine is the “Tc” term and straight away, tells you that any and all heat engines can only have 100% efficiency if there is a place/thing with a temperature of zero Kelvin
Wrap your head around that (hello NASA, this destroys the notion of Black Holes and Big Bang), an object or place with a temperature of zero kelvin does not exist anywhere or any time, exactly because The Universe is cooling.
If you wanna get psychedelic, start wondering whether is is cooling or not, see where that goes.
(Oh hi Alice, fancy seeing you here. btw, where is this place?)
iow: If a place with zero Kelvin did exist, all interactions between matter and energy (e.g. inside the GHGE) would be 100% efficient and thus, The Universe would not be cooling – it would be (haha) ‘frozen’ at whatever temperature it was at its moment of creation.
The Place of zero Kelvin (zero everything in fact) would be ‘everywhere else’ from the place/point that the Big Bang occurred
and the more you think about that, the worse it gets
So lets take Carnot to the Earth surface and atmosphere interactions.
Earth surface = average temp of 15 Celsius (288K)
Earth atmosphere (troposphere) = average temp of minus 15 Celsius (258K)
Considering the surface radiating (pure energy) into the troposphere and put those numbers into Carnot tells you that only 11% of what the surface radiates is absorbed by the atmosphere.
(Temperature rise is equal Work Output because that’s what temperature is = the physical jiggling about of molecules & atoms)
The other 89% goes to ‘the cold place’
Where that place is or how it gets there is irrelevant – and don’t fret over the 1st Law, the energy can look after itself.
(It’s in the care of The Parasites)
Then, let’s consider CO2 ‘re-radiating’ – even if it did actually radiate, at minus 79 Celsius (194K) and radiating into Earth’s surface at plus 15 Celsius (288K) That gives you a heat engine efficiency of minus 48%
So when someone next tries explain the GHGE, ask them to explain an engine with negative efficiency – because that is what they are trying to tell you.
Never mind that The Universe cooling and eventually freezing solid, the GHGE says that The Universe is heating up.
With a bit of craft, you can find input and output temperature for most energy systems and that is The Great Joy of Carnot
How it is sooooo simply expressed yet says sooooo much about pretty damn well everything we see around us, but especially Climate
Peta- Have you ever applied the 2nd Law to the concept of multiverses, where one universe begets
another. Wouldn’t the buildup of entropy be a limiting factor, essentially “gumming up the works”?
Secondly, if a universe can randomly inflate itself, how do the laws get set? Why do any even exist?
Which are included? Why does gravity fall off as (1/r)² and not 1/r or any other relationship? Instead
of it being directly between the center of gravity of both objects, what if it were perpendicular to that
line, like a torque? What if the 2nd Law was 1/Tsubc so there would be perpetual motion? What’s matter?
What’s gravity? Why not something else? So many questions, so little time!
Given all the other unworkable options, the number of universes needed to even get one to work
may be infinite. Ramblings from someone who may have too much time on his hands! 😉
Got to disagree about the disagree about the Germans and Engineering.
“We do not have this problem in Germany!”
They seem to make technically excellent designs. This is wonderful, until you start asking for practical excellence in application. Then?
“We do not have this problem in Germany!”
Also, they draw in 1st Angle!!! I mean seriously?!
Having helped people work on their VWs, I fell in love with German engineering- simple
designs “für das Volk”. A rearview mirror that you can unscrew externally- EZ. The VW bus
ran the heat ducts for the back through the front door. They were good at keeping basic
ideas basic rather than going high-tech.
I had a 1961 Beetle. Popular Science ran an article back then about the top 10 safety defects in cars and mine had 4! From collapsing seats in backend collisions to carbon monoxide from leaky heating systems. All of 36 horsepower, mine wouldn’t make 60 mph into a headwind. The 6V battery was under the backseat and one day it fell through the floorboard driving down the Interstate after battery acid leaked out. The defrost was on each corner of the windscreen and would “defrost” maybe three inches of frost. Oh yeah, great engineering.
I never owned one & those were things I’d have discovered if I had. The VWs
I worked on were newer & they may have gotten some of those “bugs” worked
out by then. I also rode in a buddy’s Bug to school & it had zip, plenty of heat,
& handled well on winter roads. To him, that 4 speed was meant to be used as
we passed everything in sight!
I had two. A ‘67 and a ‘70. My favorite thing was the windshield cleaning fluid container used air pressure from the spare tire to spray. When the sprayer no longer worked you knew to fill the tire.
I still have my grease stained first edition copy of the Idiot’s Guide. Rebuilt 3 engines with only a pair of vise grips and a large hammer (also a few sockets).
Got well over 60K miles on each one. The bodies would rust out before the engines died. There is nothing like using an ice scraper on the inside of the windshield when it’s -10F.
My dad had a beetle around ’59-60 & I remember scraping the windshield while he was driving down the road. If it was real cold I could always see my breath
All I can say is when I first had to repair the window lift mechanism on one of the Beetles I found the Germans had designed a near Rube Goldberg device that ultimately involved plastic clips. These failed in Wyoming because we are much colder than Germany. The fix was to replace with metal clips.
About Italian engineers being brilliant but not doing enough testing.
You should read about the key engineers at Alfa Romeo who from around 1920 designed race cars that would stay together and win two of the most severe road races in history.
Targa Florio and Mille Miglia.
Then in the mid-1950s Alfa decided to mass produce cars for the popular markets. Design and testing did not have the constraint of a budget.
Just do it!
Peta, WRONG AGAIN. Carnot tells you NOTHING about what proportion of the surface radiation is absorbed by the atmosphere. Nothing. It has no way to do that. It knows nothing about the water vapor content. It knows nothing about how many clouds exist (everybody knows that it stays warmer on a cloudy night than a clear one.) The rest of your post relating to cosmology is just as ignorant.
Peta, you make claims that some fifth graders could quickly debunk.
Someone should point out the Atmos Clock to the green energy crowd. It’s a very neat apparent perpetual motion machine that will seemingly run forever with no apparent source of power. The power actually comes from small changes in ambient temperature and barometric pressure. But it would be fun to write up a proposal on replacing fossil fuel power with a scaled up device to harness the energy available in the continuous change of environmental temperature and pressure.
using hydrogen to power aircraft
Jet engines using hydrogen, don’t, unfortunately. They burn only 25% of the supplied hydrogen. The rest escapes unused. So an airliner with 40 tons of hydrogen fuel will use only 10, the remaining 30 tons are carried uselessly. They probably leave the atmosphere to space.
(However increasing loss to space of hydrogen could result in an increase in atmospheric oxygen.)
That makes no sense….you could run your lawn mower on hydrogen and burn probably 99% of the hydrogen in the pressure tank….but hydrogen isn’t energy dense enough to be a sensible airplane fuel….for the same reason you wouldn’t want a pressure vessel mounted on your lawn mower.
As far as efficiency is concerned, Li-ion batteries are only significantly bettered by capacitors, but scaling makes them dicey for handling just the daily storage needs for a 100% renewable electric power system.
The only capacitors storing meaningful charge are supercaps (using the Helmholtz double layer physics that also produces lightning). At best, using my patented materials, they are 1/10 the energy density of LiIon. And their voltage varies linearly with state of charge (half discharged means half the voltage of full charge). So they are not suited to grid storage at all.
Indeed, the frustrating thing about them is their voltage begins to decline with the very first little Delta of charge taken from them; so, they need a boost circuit on output if a constant voltage is needed. However, all storage systems work like this — the pumped hydro reservoir declines in height as water is withdrawn, the thermal storage temperature begins to decline (or perhaps some of its mass changes phase) as heat is withdrawn…
An unstated point was that supercaps are even less scalable for grid storage than lithium-ion. I also suspect that self discharge rate is higher in supercaps for a given Coulomb/AH capacity than Li-ion. Neither would be good for long term storage, i.e. several months.
OTOH, boost/buck converters can be made to have ~99% efficiency, so the variable output voltage of a supercap is not a huge drawback.
One more point, the energy stored in any linear capacitor (which excludes X7R and related dielectrics) is proportional to the square of the voltage on the cap. 50% charge in terms of energy corresponds to 70.7% of rated voltage.
I feel the need to break it down into the simplest possible terms:
The “net zero” crowd have absolutely no idea what they are talking about.
All the rest is just the details.
There seems to be a general misunderstanding regarding storage for electrical grid systems. Yes storage is used but for frequency support, not for the intermittency of renewable generation. That is simply not a feasible answer as the required capacity is so large.
Pumped storage has been around for decades, long before any wind or solar was connected to grids. It is capable of injecting large amounts of power in a very short time to compensate for a sudden deficit of input to demand. This is for short duration and allows the rest of the generators to increase output to match demand. Chemical batteries can also fulfil this role.
The other characteristic is inertia which large rotating generators have and wind and solar do not. Ideas such as flywheels being used to compensate for renewable’s lack of inertia miss one point. Like storage above, the inertia keeps the turbine speed closer to the set frequency until the turbine governor opens or shuts to maintain frequency. If it is required to open because of a sudden load increase there is the reserve of power in the boiler or lake, in the case of hydro, to do the real work. It is not just the rotating mass of a large generator so adding flywheels to a system does very little in comparison.
Kevin – why no mention of the compressed air energy storage project in the U.K. and elsewhere?
It has the same problems as all the others, but should at least be mentioned. It illustrates your 2nd law of thermodynamics issue rather nicely.
Good point. There are so many ideas and conceptual designs about energy storage that one would be hard pressed to cover them completely. My point was that “hydrogen” and thermal storage are currently in vogue as indicated in the email and magazine articles which arrive.
I remember as child, I liked to play with little cars with spring leaf rotor…
A good friend of mine – but very challenged with tech – thought he’d come up with the solution to battery range for EVs: In all seriousness, he explained his solution thus: An EV would have two sets of batteries. One set would power the vehicle and, while in motion, the car’s motor would also run an alternator – much like those on an ICE – and this would maintain a charge in the second set of batteries. Then, when the first battery-set neared depletion, the EV would automatically switch to the second battery set and the alternator would recharge the first. Repeat ad infinitum.
After some time trying to explain the error in his design I had to admit defeat. I often suspect he posts comments here under the pseudonym of Griff….
He forgot to mention that the alternator is not driven by the drive engines, as this would increase the consumption on the batteries in use, The vehicle only needs drive on 2 wheels, so the alternator can be driven from the other free spinning wheels. Not only does it work, but it never needs recharging. /sarc
It no longer surprises me to see people propose such things. It is a thorough misunderstanding of the second law, but as I said the second law is really a conceptual stumbling block for nearly everyone. Yet, the second law is in control of everything, especially important to systems.
When I taught thermodynamics I in engineering school I had noticed a curriculum disconnect in which thermo-I would not get so far as introducing the concept of availability, but thermo-II would begin just beyond and focus on power/refrigeration cycles. I was actually criticized by one faculty member for adding availability to my syllabus, saying something to the effect of “how would an engineer make use of such concepts?”
If mechanical engineers can’t see the utility of the second law, then we really should abandon all hope in making mature decisions about energy.
It is a thorough misunderstanding of the second law, but as I said the second law is really a conceptual stumbling block for nearly everyone.
Is it really THAT big of a problem?
I’m far from being anything like an expert, but the basic gist of the second law seems pretty clear: You will always get less (usable) energy out of something than you put into it.
I think it is and I base this on experience after having had several hundred engineering students through my course. They do pretty well until I introduce enthalpy. Then the wheels start to come off their carts. Entropy and related items are a step beyond that.
It is easy to say that the second law says we can’t be 100% efficient, but quantifying that is more difficult. When you say, “get less usable energy” (work in other words), how much less? Is there a limit to how little less you can get away with? If I have a hypothetical process with mass coming in, mass going out in several different places in different states, energy input, work out, and heat being lost, is there a way to tell if the hypothetical process violates the second law, or tell at what rate it creates entropy? Quantifying it is a bit more involved.
“Quantifying it is a bit more involved.”
Absolutely, and I certainly did not mean to dismiss how complex that can be. My oversimplified summation is (obviously) nothing more than a starting point. It seems like you’re saying they have trouble even grasping that much, unless I’m misunderstanding.
Yeah, those other questions can lead down some pretty deep rabbit holes…
I recall my profs seemed to really like complicated looking differential calculus equations full of PdV’s and dQ’s. The best profs always made more sense with some simple examples with real world numbers. Dropping a hot steel block into a lake of constant temperature, compared to dropping it into a fish tank that warms up…whats the before and after entropy of of the block and the universe ?….that type of thing solved before dazzling everyone with the universal differential equation seemed to convey more knowledge…..
That two batteries thing would never work.
You need to put a windmill on the roof of the car.
And some PV cells in front of the headlights.
That’ll do the trick!
Most grateful for this. it is indeed very rare to have any mention of these Thermodynamic Laws in any articles relating to so-called ‘Renewables’. Hence a great deal of irrelevant rubbish clutters up the airwaves ,driven primarily by emotional wish lists and conjecture.
Unfortunately these Laws render most, if not all, these schemes for getting something free somewhat useless, with the overall result being a NEGATIVE net return on the investment in energy terms. Sadly though there is much room for manipulation in the presentation aspects where the Laws are subtly omitted in the logic to the advantage of those advancing the scheme; leaving the rest of us to pick up the TAB.
We are now seeing the costs of these TAB rising; as more Renewable Energy is developed.
For those unacquainted with the second Law: It requires energy to be provided to low intensity energy sources in order to enable ‘Useful’ energy. The more ‘Useful’ energy you require so the more energy needs to be supplied. As the First Law only allows some 70% of heat energy to be converted into mechanical energy ; you can see why there is a nett NEGATIVE result.
There are still plenty of people out there intent on ripping us off. Hence the politics.
It’s the same form of innumeracy in energy conversions that the same Socialists and Communists and Double Dumb Asses (but I repeat myself) exhibit when they decide that they can control market forces and centrally plan economic activity. They know better than consumers what each individual needs. They know that wind power is free, and are surprised how expensive free medical care gets.
As a famous tee-shirt and baseball cap slogan says, “We cheat the other guy, and pass the savings along to you.”
Where is Griff? I am sure he can dispute this.
Simply put about net zero, you cannot get there from here. Ever. At any cost.
What amazes is how many people (BoJo) have no clue as to why.
It is a fundamental disconnect, isn’t it? You need technology to build the “net zero” system, but a net zero system can’t renew itself. In terms of Figure 1, you can first fill the upper reservoir, but once it is drained the machine won’t work.
South Australia, widely regarded as the most world’s most advanced gigawatt-scale grid in the transition to wind and solar, set a new record high instantaneous share of 136.6 per cent of domestic demand on Sunday.
South Australia grid reaches record high of 136.6 pct renewables | RenewEconomy
Makes you wonder why they’re spending $2.4billion on an interconnector to NSW black coal on top of the interconnector to Victorian brown coal now doesn’t it?
Department for Energy and Mining | Work begins on SA-NSW Interconnector (energymining.sa.gov.au)
That’s on top of the syncons-
South Australia’s constrained renewables to be unleashed as four new syncons spin into action – pv magazine Australia (pv-magazine-australia.com)
and of course the unicorn Hornesdale Tesla big battery that could power 30,000 homes for an hour but there’s no money in that so it makes a bundle providing FCAS while the standby diesel generators that can consume 80,000L/hr of diesel were installed. No matter it’s that 136.6% renewables that’s supposed to give you the warm fuzzy while you’re paying your power bills. That’s how they change the climate in South Australia.
So, they have a nickname for them now, do they? Syncons. You know for some people being able to use the “lingo” is the equivalent of understanding something complex. If you can’t understand the lingo, then make some up.
Do folks understand what synchronous condensers do? They are a parasitic drag on a system meant to help stabilitze it in the very short term.
What can I say to this madness Kevin as I’m only one vote? That peak output was of course a nice sunny Easter holiday Sunday with a bit of wind about the SE of Australia as you can see here on the 17th-
Wind Energy in Australia | April 2022 | Aneroid
Run your mouse over the graph to see the 3.6% of installed capacity at night between the 5th and 6th when the sun doesn’t shine. As fast as they’re building interconnection east NSW and Vic are building out fossil fuels with solar and wind to catch up to SA.
I’m doing alright (on original solar FIT and modest backup RV genny with the wherewithal for whatever it takes when the train wreck occurs) but the mind boggling thing for me is how can such group infantilism/stupidity exist in this day and age? I suspect the sublime irony is it’s the very productivity of fossil fuels that has permitted so many navel gazers and stinkers in residence to hold sway.
SA often uses less electricity than Tasmania. It has precious little in the way of actual manufacturing or other major users.Its only a small fraction of the NEM.
If they do have a windy sunny day, the excess is barely a drop in the ocean.
And there often times when wind and solar are producing basically nothing, and SA has to rely on close to 100% mainly gas, but also diesel generators and interconnects.
Would it enhance your post to include definitions for energy and work?
I was deeply skeptical at first with what I learned in Thermodynamics long ago; that energy is “the capacity to do work”.
I like your invocation of Newton’s first law of motion below, because work is a force acting over a distance.
If folks can get that, they may eventually understand power vs energy; and we could stop correcting units (KW vs KWHr)😉
The problem here is defining “energy”. As we have encountered greater and greater complexity in the natural world, our definition of energy — i.e. what we call “energy” in a situation — has had to change to keep up. It all started with mechanical work and mechanical PE directly as an integral of Newton’s second law. Then with the discovery of radioactivity people first thought that conservation of energy might be a dead letter, but then by the time we get to nuclear bombs and reactors it is all made clear through E=mc^2…
Hence the somehow unsatisfying definition I quoted.
Do you have a better one?
Untrue … all that is needed is to define the system so that heat is work. To use a simple example. I take a container with a few gas molecules and place it in a vacuum. I then instantaneously remove the container so that there is no time for them to interact, and convert the heat into outward motion of the gas.
All the heat is converted to work. The reason this works, is because I am defining the work as being the same movement as the heat, but expressed in a different place (outside the container that is instantly removed).
That shows the key thing about thermodynamics, work and heat are the same, the difference depends on how you define your system.
What you are doing is simply looking at the first law rendering of the issue. Sometimes “heat” is exactly what we want, say for cooking on a range top, and then a resistance heater will turn 100% of the electrical work into heat (of course second law issues of heat transfer now mean that 100% of this heat isn’t useful to the cooking). But the power cycle of a thermal plant is meant to turn heat of burning coal into work (electrical work), and this cannot be done at 100% efficiency. There are advanced ultra super critical coal plants that do a decent job though, with efficiency approaching 50%.
The best energy storage system in use today is a uranium dioxide nuclear fuel pellet.
Nano-nuke in my car…. instead of a plume of fire out the exhaust on the drag strip, there is a giant cloud of glowing steam LOL. Nuke to steam to electricity to grid wire, to my car’s hot little Lithium battery… sounds very expensive. Why not NG 3 tier generation system…. a lot cheaper. Better yet CNG tank in my car.
Yup, they harness the energy of supernova explosions, and have held the charge for billions of years.
Although drastically simplified, I’ve always liked this summary of the three laws:
(I’ll grant the third may not be fully accurate, but the first two definitely sum up the basics)
The Quantum Holy Grouse is hiding in the forest of possibilities.
I thought it was the Holy Quail and Indiana Jones found it.
I could be mistaken.
Using large spinning weights to even out wind derived power would work keeping the output steady over a period of minutes. As mentioned above, it is parasitic – you will always use more power than you can retrieve, but at least some variability of the power is removed.
Battery storage for a wind farm is even better – it too can be used to even out power and to even replace it for a matter of minutes to maybe a few hours.
If you have 1) lots of water and 2) elevation nearby you can use elevated water as your battery. This is a giant step forward as your battery can be picking up “free” energy all the while (in the form of feeder streams). Trouble is, it can’t be used in most places.
One could in theory use elevated water next to the ocean, using saltwater marshes as your storage. No telling the ecological damage that would take place, but it could be done… The efficiency would be extremely low due to the low elevation of the water.
The problems with all of these schemes are high-cost, low efficiency, and impact to terrain.
One can solve all of this by using a gas or nuclear-powered gas turbine. Power can be delivered reliably and steady, they both have some amount of rotational energy storage in them allowing for a controlled rollover of power to another facility, they are highly efficient, and impact by far less terrain. One could even construct a wind turbine on top of each reactor to keep the greenies happy (they would not actually be hooked up, just there to turn freely).
The engineering problems are not that hard to solve given some rationale choices. It is the stupidity of green activists that seems intractable.
Oh, and I am now claiming my F-150 pickup truck is electric, I had to charge the battery after all. (It sat too long without use) I added a plug to make attaching the trickle charger easy – so it is now a plug-in electric vehicle. I want my rebate!
Kevin, You called losses on energy to work conversion imposed by the second law irreversibilities. If I understand the second law and efficiency, even a reversible heat engine loses some heat to the enviroment that cannot even theoretically be converted to work. Thus the efficiency based on a Carnot cycle is (Thot-Tcold)/Thot where these are the temperatures of the reservoirs that the heat is flowing from and to. Irreversible heat engines just perform at a fraction of the possible limit of a reversible engine. It would be more appropriate to call losses on heat to work conversion Second Law losses so people don’t think that a more efficient engine can exceed the theoretical limit of (Thot-Tcold)/Thot.
A completely reversible heat engine would achieve 100% efficiency only when compared to a Carnot engine, the (Thot-Tcold)/Thot you mention. This is possibly very far below the 100% efficiency of turning energy completely into work. There are forms of energy that are 100% available to be turned into work — mechanical energy for instance. Irreversibilities work against achieving the theoretically possible efficiency. So, a mechanical source of energy suffers friction and is less than 100% efficient; a heat engine turns out to have some irreversibilities like heat loss, or turbulence and viscosity in its working fluids and can’t achive the Carnot limit.
Part of the difficulty with thermodynamics is its jargon. Irrevesibilities is just a general term for things like friction, turbulence, viscosity, heat loss, diffusion, pressure leak, incomplete or competing chemical reactions, mixing, …
Thank you. An excellent, succinct summary of the issues.
There is no shortage of technically competent scientists and engineers to explain all this to politicians, media, envirotards, and the rest.
They simply cannot have what they want. Not without destroying the civilisation so painfully built over the centuries. Yet here we are, several decades into the global warming-based “renewables” swindle, galloping down $hit Avenue without saddle. I am filled with trepidation about what the world will look like when these schemes unwind.
Good article. The lefties are pushing this green energy believing that SOMEONE will figure out all this technical difficulties. As the article points out all the fixes are complex, not really workable, expensive, and often require lots of land to implement. A lot of lefties who are intelligent enough to know what the problems are do not seem willing to straighten out their greenie friends.
Thank you for this fine explanation.
I have posted on several threads on this site some version of the following:
Please show me a Solar PV, Wind, and Battery installation which both delivers electricity solely on the output of the system, but is able to produce more PV, wind, and battery systems with the output of the system.
Unless and until there are many such systems in operation, this is just the perpetual motion machine shown in your first diagram, with many bells and whistles and subsidies to hide that fact.