Posts Tagged ‘batteries’
what is electricity? part 9 – the first battery
from Wikipedia, etc
Canto: So, going back to the eighteenth century, now. The exploration of electricity was becoming thoroughly fashionable. Lightning was an obviously powerful force that scientists of the day were looking to tame and harness. Most of these modern histories begin with Franklin, but what, or who, turned him on to the subject?
Jacinta: Well of course knowledge and influences developed slowly in the eighteenth century and before. I’ve already spoken of William Gilbert’s De Magnete, written some 150 years before Franklin’s work. Gilbert posited that the Earth itself was essentially a gigantic magnet, with an iron core, which was pretty clever in 1600. He studied static electricity, using amber, and called its effects an electric force, the first modern usage. He was one of the first modern experimentalists, undervalued in his own time, most unfortunately by Francis Bacon, who contributed so much to the development of new scientific methods.
Canto: The 1600s were important in Britain, of course, the period of their Scientific Enlightenment, but one of the most intriguing and brilliant experimenters upon electrostatics in that century was the German polymath Otto von Guericke. His work on vacuums and static electricity in the mid 17th century found its way to England and inspired Robert Boyle to experiment in these fields. But no great breakthroughs occurred, at least for electricity, and no real attempts were made to mathematise electrical concepts until the eighteenth and nineteenth centuries.
Jacinta: Yes, we won’t dwell for too long on these pioneers (famous last words), but J L Heilbron’s 1979 book Electricity in the 17th and 18th centuries: a study of early modern physics, much of which is available online, should guide us towards the advances made by Volta and the nineteenth century mathematisers, notably Maxwell.
Canto: Yes, Heilbron divides the physics of this period into three stages, the first, before 1700, was a relatively amateur, narrow form of neo-Aristotelian systemising (pace Gilbert), and the second involved new discoveries and experiments treated without systematic quantising, which gave way to a more modern, mathematical third stage leading to new discoveries and inventions, such as the battery, just at the end of the 18th century.
Jacinta: We’ve mentioned triboelectric effects in an earlier post. These were the first static effects, between all sorts of different materials, experimented with by scientific pioneers such as Newton and many others. The enormous variety of these effects were, and still are, difficult to quantise. Why was their attraction in some cases and repulsion in others? In fact, ACR, the attraction-contact-repulsion process, came gradually to be recognised, but with no understanding of atoms and particles, or elements in the modern sense, little sense could be made of it.
Canto: There were some attempts to characterise the phenomenon, which was considered a fluid in those early days. In 1733 the French chemist Charles DuFay, one of many electrical experimenters of the time, divided these fluids into two types, vitreous and resinous – the positive and negative forms of today, sort of. Perhaps he was trying to define an attracting and a repelling force.
Jacinta: Effluvia was in the air at that time… ‘particles of electrical matter, which effect attraction and repulsion either by direct impact or by mobilising the air’, to quote Heilbron. But I should mention here the work of Stephen Gray, one of those marvellous upwellers from the lower classes with great practical skills and an experimental spirit, who, like Newton, built his own telescope, with which he made discoveries about sunspots and other things. An obviously alert observer, he noted that electricity could be conducted over distances in various substances, while other substances, such as silk, damped down the effect, acting as insulators. These discoveries were of vital importance, but Gray is probably the most underrated and unrecognised of all the electrical pioneers.
Canto: With the ‘discovery’ of the Leyden jar in 1745 the idea of electricity as a fluid, or two fluids, was laid to rest. This instrument, the key components of which were a jar of glass with metal sheets attached to its inner and outer surfaces, and ‘a metal terminal projecting vertically through the jar lid to make contact with the inner foil’ (Wikipedia), was the first type of capacitor, though it took time for their storage capacity, and those of other devices, to be quantised. Today it’s understood that these early Leyden jars could be charged to as much as 60,000 volts.
Jacinta: Another important early device was called an electrophore, or electrophorus, first invented in 1762 and later improved by Alessandro Volta. These instruments, and the increasing realisation throughout the eighteenth century that this mysterious force, substance or capacity called electricity was a Big Thing, with enormous potential, kept interest in the phenomenon bubbling along.
Canto: An electrophore typically consists of a plastic plate, which won’t conduct electricity, connected to a metal conducting disc with an insulating handle. There are some useful demonstration videos of this, and I’m describing one. If you rub the plastic with some silk cloth, this will, as we now know, transfer electrons from the silk to the plastic, giving it a negative charge (the triboelectric effect). Placing the metal disc on the plastic will not enable too much transfer of electrons, or electron flow. It will in fact cause a polarisation in the disc, positively charging it on the side facing the plastic, and negatively charging it on its opposite side, due to like charges repelling, though this wasn’t known in Volta’s time.
Jacinta: The plastic plate, or sheet, has become a dielectric, I think, which is a pretty complicated concept, involving dielectric constants and relatively complicated mathematical formulae, but for our current purpose (and theirs in the 18th century) this electrophore was a useful demonstrator of static electricity. The metal plate was on balance neutral in charge, but in a sense magnetised, with a negative charge on its upper side, which could be grounded at a touch – causing a spark. Being replaced on the plastic, it could again have its charges separated, a cycle which could be endlessly repeated in theory, though not in practice – due ultimately to the second law of thermodynamics, perhaps.
Canto: So, the battery. It was a term coined by Franklin, giving a sense of overwhelming power, though what he created in connecting Leyden jars in an array was a capacitor.
Jacinta: In fact even one Leyden jar is a capacitor. So what he created was a battery of capacitors, though not quite a supercapacitor. I think.
Canto: Volta is famously supposed to have arrived, in a roundabout way, at the construction of an effective battery due to his dispute with a soon-to-be-former friend Louis Galvani (as described in part 4 of this series), and the dispute led him to further experiments. He came to realise that the reason Galvani’s dead frogs were ‘reanimated’ by electricity had to do with the wires being used, and the chemistry of the frogs.
Jacinta: And meanwhile this ‘reanimation’ business became popularised by Galvani’s nephew, Giovanni Aldini, among others, with popular displays and discussions which led to Mary Shelley’s Frankenstein.
Canto: And meanwhile again, Volta experimented with different wires, including zinc and silver, and with moisture, because he noticed that wetness had an electrifying effect. He soon found that these wires of silver and zinc, connected in a series of water containers, increased the electric effect. Further experimentation with silver and zinc discs, separated by cardboard saturated in salt water, enhanced the effect – the more discs, the stronger the effect. And this effect was permanent (more or less). A battery in the modern sense.
Jacinta: In effect. So voltage is electric potential, as we keep saying. So it’s there even when the battery isn’t connected to anything, a storage device which provides electrical flow when connected. And that potential is measurable, as in a 1.5v battery. Current is the actual flow, which is often quite small, especially in Volta’s original pile, though he was able to build a potential, or voltage of up to 20v. The key to an effective battery, I think, is to get as much current per volt as possible. That’s current flowing steadily, reliably and safely over time. A typical lithium ion phone battery of 3.7 volts delivers between 100 and 400 milliamps of current, whereas Volta’s pile will get you not much more than 1/2 of a milliamp of steady flow. And by the way, why did salt enhance the electrical effect?
Canto: That has to do with with the ionisation of the salt, which when dissolved in water splits into positively charged sodium ions and negatively charged chlorine ions. Sending a current through the water will drive the chlorine ions to the positive terminal and the sodium ions to the negative terminal. This creates a bridge of ions, somehow.
Jacinta: Yeah, great explanation. And apparently one of the most interesting features of Volta’s weak battery, or voltaic pile, at the time was its use in separating H2O into hydrogen and oxygen. This new chemical power – electrolysis – particularly interested Humphrey Davy in England. He proceeded to create the largest battery of the age at the Royal Institution, using it to isolate a large number of elements for the first time, including sodium, calcium, potassium, magnesium, boron and strontium. That was in the first decade of the 19th century – and electricity was really coming of age.
References (just some)
How Volta Invented the First Battery Because He Was Jealous of Galvani’s Frog (video – Kathy loves physics)
https://sciencing.com/salt-water-can-conduct-electricity-5245694.html
https://en.wikipedia.org/wiki/Humphry_Davy
what is electricity? part 8: turning DC current into AC, mostly
Canto: So before we go into detail about turning direct current into alternating current, I want to know, in detail, why AC is better for our grid system. I’m still not clear about that.
Jacinta: It’s cheaper to generate and involves less energy loss over medium-long distances, apparently. This is because the voltage can be varied by means of transformers, which we’ll get to at some stage. Varying the voltage means, I think, that you can transmit the energy at high voltages via power lines, and then bring the voltage down via transformers for household use. This results in lower energy loss, but to understand this requires some mathematics.
Canto: Oh dear. And I’ve just been reading that AC is, strictly speaking, not more efficient than DC, but of course the argument and the technical detail is way beyond me.
Jacinta: Well let’s avoid that one. Or…maybe not. AC isn’t in any way intrinsically superior to DC, it depends on circs – and that stands for circuits as well as circumstances haha. But to explain this requires going into root mean square (RMS) values, which we will get to, but for now let’s focus on converting DC into AC. Here’s a quote from ‘all about circuits’:
If a machine is constructed to rotate a magnetic field around a set of stationary wire coils with the turning of a shaft, AC voltage will be produced across the wire coils as that shaft is rotated, in accordance with Faraday’s Law of electromagnetic induction. This is the basic operating principle of an AC generator, also known as an alternator…
The links explain more about magnetic fields and electromagnetic induction, which we’ll eventually get to. Now we’ve already talked about rotating magnets to create a polarised field…
Canto: And when the magnet is at a particular angle in its rotation, no current flows – if ‘flow’ is the right word?
Jacinta: Yes. This same website has a neat illustration, and think of the sine curves.
Canto: Can you explain the wire coils? They’re what’s shown in the illustration, right, with the magnet somehow connected to them? And the load is anything that resists the current, creating energy to power a device?
Jacinta: Yes, electric coils, or electromagnetic coils, as I understand them, are integral to most electronic devices, and according to the ‘industrial quick search’ website, they ‘provide inductance in an electrical circuit, an electrical characteristic that opposes the flow of current’.
Canto: OMG, can you explain that explanation?
Jacinta: I can but try. You would think that resistance opposes the flow of current – like, to resist is to oppose, right? Well, it gets complicated, because magnetism is involved. We quoted earlier something about Faraday’s Law of electromagnetic induction, which will require much analysis to understand. The Oxford definition of inductance is ‘the property of an electric conductor or circuit that causes an electromotive force to be generated by a change in the current flowing’, if that helps.
Canto: Not really.
Jacinta: So… I believe… I mean I’ve read, that any flow of electric current creates a magnetic field…
Canto: How so? And what exactly is a magnetic field?
Jacinta: Well, it’s like a field of values, and it gets very mathematical, but the shape of the field is circular around the wire. There’s a rule of thumb about this, quite literally. It’s a right-hand rule…
Canto: I’m left-handed.
Jacinta: It shouldn’t be difficult to remember this. You set your right thumb in the direction of the current, and that means your fingers will curl in the direction of the magnetic field. So that’s direction. Strength, or magnitude, reduces as you move out from the wire, according to a precisely defined formula, B (the magnetic field) = μI/2πr. You’ll notice that the denominator here defines the circumference of a circle.
Canto: Yes, I think I get that – because it’s a circular field.
Jacinta: I got this from Khan Academy. I is the current, and μ, or mu (a Greek letter) stands for the permeability of the material, or substance, or medium, the wire is passing through (like air, for example). It all has something to do with Ampere’s Law. When the wire is passing through air, or a vacuum, mu becomes, or is treated as, the permeability of free space (μ.0), which is called a constant. So you can calculate, say, with a current of 3 amps, and a point 2 metres from the wire that the current is passing through, the magnitude and direction of the magnetic field. So you would have, in this wire passing through space, μ.0.3/2π.2, or μ.0.3/4π, which you can work out with a better calculator than we have, one that has all or many of the constants built in.
Canto: So easy. Wasn’t this supposed to be about alternating current?
Jacinta: Okay forget all that. Or don’t, but getting back to alternating current and how we create it, and how we switch from AC to DC or vice versa…
Canto: Let’s start, arbitrarily, with converting AC to DC.
Jacinta: Okay, so this involves the use of diodes. So, a diode conducts electricity in one direction only…. but, having had my head spun by the notion of diodes, and almost everything else electrical, I think we should start again, from the very beginning, and learn all about electrical circuits, in baby steps.
Canto: Maybe we should do it historically again, it’s more fun. People are generally more interesting than electrons.
Jacinta: Well, maybe we should do a bit of both. It’s true that we’re neither of us too good at the maths of all this but it’s pretty essential.
Canto: Okay, let’s return to the eighteenth century…
References
https://www.allaboutcircuits.com/textbook/direct-current/chpt-15/magnetic-fields-and-inductance/
Alternating Current vs Direct Current – Rms Voltage, Peak Current & Average Power of AC Circuits (video – the organic chemistry tutor)
what is electricity? part 7 – alternating current explained, maybe
Canto: So, alternating current is electrical current that alternates, or wobbles, or zig-zags, or cycles back and forth, at fifty or sixty cycles per second, aka hertz, but how and why?
Jacinta: Well, as Sabine would say, that’s what we’re going to talk about today. As always, when we look online for explanations, they tend to assume the reader or viewer has background knowledge by the bucketful. Here’s a typical example:
Many sources of electricity, most notably electromechanical generators, produce AC current with voltages that alternate in polarity, reversing between positive and negative over time. An alternator can also be used to purposely generate AC current.
It goes on to explain what an alternator is, but not very effectively for types like us.
Canto: We really need our own ‘For Dummies’ library.
Jacinta: The alternating current that’s used in our electrical grids has a neat sine wave form, undulating at precise intervals above and below a time line.
I’ll try to find out how we bring about alternating current, but first some points about its usefulness. As I think we mentioned before, AC is useful for transporting electrical energy, because it produces lower current at higher voltages (I DON’T REALLY UNDERSTAND THIS), so creating less resistance in the power lines, and so less energy lost as heat.
Canto: Some simple definitions, via Wikipedia et al, which we really need to keep reinforcing. Voltage is electric potential, or pressure, or tension. It’s usually analogised as water in a tank, or a boulder at the top of a mountain, ready to unleash its ‘tension’ by rolling downhill, and meeting resistance along the way, which makes things happen.
Jacinta: Did you know that there’s also three-phase AC power? OMG. But we talked in an earlier post about electrons only moving slightly, bumping the next electron along and so on. But, duh, I didn’t think that one through – that bumping action would be continuous, like people in a queue. You’d bump the person before and be bumped by the person behind, so the movement would be continuous, more or less, they’d all move from the positive to the negative. It’s what they call a chain reaction.
Canto: Interesting, but back to these analogies, I understood that a water tank has the potential to pour out water, and that a boulder has a potential to release kinetic energy down a mountain, but what is this potential energy that a battery has? It’s something called voltage, but that’s what I don’t understand. It’s the storage of a certain amount of electricity, like so much water. But I can visualise stored water. I can’t visualise stored electricity, or electric potential, or whatever.
Jacinta: Well, one day, understanding will dawn. Meanwhile, AC power, that’s when you get electrons to oscillate backwards and forwards, for example via a spinning magnet, which alternately repels and attracts electrons. It’s the movement of the electrons rather than their direction that creates the current.
Canto: Changing polarity. That’s what a spinning magnet will do (and maybe that’s what is meant by an alternator, or something like). And it will do it in an undulating rather than abrupt way. Very fast undulating – 50 cycles a second.
Jacinta: So I think we need to look at transformers, which are able to change the ac voltage, but not dc. Don’t ask why, at least not yet.
Canto: I’m looking at a vid which says that with AC the voltage varies, creating a sinusoidal function, as in the graphic above. But this explains nothing to me. Voltage is electric potential, but what really is that? I don’t want fucking analogies, I want the reality of it. How do you store this ‘electric potential’ in a battery, or whatever? And what really gets me about this and other videos are the comments – ‘great explanation’, ‘what a great teacher you are’, I’ve learned more from this than from months of study’ etc etc etc. And I’m thinking – am I a complete moron or what?
Jacinta: I feel your frustration, but we’ve promised to focus on AC, so just hold on to that question, which can be formulated as – How can a battery (or any other device) store electric potential for later use?
Canto: Which I suppose is something the same as – what is a battery (or an electric potential storage device)? How can you make one?
Jacinta: Anyway, a battery is used for DC energy, flowing from its positive to its negative terminal. That’s why, if you have batteries in series, like in the tube of my computer keyboard, they have to be in the right order, positive connected to negative terminals.
Canto: And if you have, say, three 1.5v batteries in series, that means you have 4.5v of ‘electric potential’?
Jacinta: Uhhh, let’s focus on AC. So, in Australia we typically have 230v household sources of AC electricity, oscillating, or changing polarity, at a frequency of 50 cycles/second, or 50 hertz. Imagine if you have a battery that’s spinning around so that the polarity is, well, spinning around too.
Canto: So if we have a 230v AC source in every home, is that like a gigantic spinning battery? I’d like to see that. Is that what an alternator is?
Jacinta: Well, if you look up ‘What’s an alternator’, you’ll generally find stuff about motor vehicles, but it’s definitely all about alternating current. And if you think polarity, you should think magnetism. So an alternator is essentially a magnet connected to an electric circuit, that changes polarity, usually by spinning, which creates a smooth alternation – back to the sine wave. We’re talking here about one-phase AC.
Canto: Yeah, we don’t presumably have alternators in our homes because it’s already AC in the wires, so it’s all AC?
Jacinta: Don’t confuse me. Running an electric current through a wire – usually copper – creates a magnetic field, and you can strengthen this magnetic field by coiling the wire. I’m not sure why, but this is essential electromagnetism, which we might understand one day. Anyway, this coil of wire is now an electromagnet, with its own polarity. Increasing the current induces a stronger magnetic field. If we run a magnet through the coil, we’ll create a stronger electric current, in DC form. Stop the magnet, and you stop that current. Reverse the magnet and you reverse the current. Push and pull the magnet in and out, and you create an AC current.
Canto: So that’s how sex can be electrifying – if it’s done fast enough?
Jacinta: Hmmm. The speed of the magnet’s movement does create a stronger current, as does the strength of the magnet.
Canto: Ahh, so it’s both the meat and the motion? Anyway, how to transform DC into AC – I’ve heard of a new device, or whatever – an inverter.
Jacinta: Ok, backing up, you’ve no doubt heard of the big battle between Edison and Tesla regarding AC and DC, back at the end of the 19th century. Well, Edison proved himself a bit of an arsehole during this battle, though the hero-worship of Tesla has since become a bit extreme. Since then, it’s been AC for big electrical networks worldwide, but DC is still used for car batteries and other smaller scale power. And, yes, an inverter is the device used to convert DC to AC.
Canto: Let me say that I do understand how AC works to create energy. It doesn’t matter if the movement is in one direction, or two, or a thousand. It’s the movement itself that creates the energy, which creates heat to boil your kettle or light your lamp.
Jacinta: Good, now there are rectifiers, which are a collection of diodes, which can convert AC to DC, but that’s for another post. An inverter comes in more than one type. Some use electromagnetic switches, reversing the flow abruptly, even brutally, with a pattern very different from our sine wave. More like castle crenellations. But electronic inverters use components such as capacitors and inductors – yes, they’ll be explained eventually – to smooth out the transitions. Transformers can also be used to change DC input voltage into a quite different AC voltage output, though of course, according to the law of conservation of energy, (first law of thermodynamics) you can’t get more power out of the system than you put in.
Canto: Changing the subject yet again, I was getting aerated about batteries, and I should’ve thought about them a bit more – I know that they get their electric potential from chemistry. I’ve been reading about Volta’s battery, made from zinc, silver and cloth or paper soaked in salty water. But that, and later improvements, and the mechanisms involved, are also for later posts.
Jacinta: Yes, a battery has an anode and a cathode and an electrolyte material separating them. A fun topic to explore more thoroughly. But we’re onto inverters. We need them to convert DC voltage providers, such as batteries and solar panels, into AC power for households. So batteries work to cause a current to flow, in say, a copper wire, and this creates a circuit between the cathode and the anode, heating up lamps and kettles along the way. But inverting the current, to create the sine wave pattern, or multiple such patterns, requires a magnet, coils and such. It’s complicated, so our next post will be horrible.
a pure sine wave inverter, apparently
References
What is Alternating Current (AC)? – Basic AC Theory – AC vs. DC (video)
Electric current (Khan Academy)
https://www.britannica.com/science/conservation-of-energy
https://www.explainthatstuff.com/how-inverters-work.html
what is electricity? part 2 – the mystery gets murkier
Canto: So we were trying to comprehend early ideas about electricity as a fluid, which led Franklin to define two ‘states’ of the fluid, ‘negative’ for having a deficiency, and ‘positive’ for having an excess. He also called the negative state ‘resinous electricity’ and its opposite ‘vitreous electricity’. Presumably he thought the fluid was in a balanced state before these different elements started rubbing against each other.
Jacinta: And they were trying to regain this balanced state, which made the sparks fly?
Canto: Dunno, but let’s return to Britain, where Francis Hauksbee (1660-1713), a lab assistant to Isaac Newton, was being inventive with air pumps and pneumatic engines, decades before Franklin’s 1840s experiments.
Jacinta: I’d ask you what a pneumatic engine is, but I suppose that’d take us way off topic?
Canto: Probably. It apparently has something to do with compressed air, and some kind of energy derived from un-compressing it, or something. Anyway, air pumps were used to create vacuums, or relative vacuums. Apparently, Hauksbee, an ingenious instrument maker, noted that glass was a really good material for viewing experiments, and in 1705 he performed a remarkable experiment with one of his air pumps and that mercurial, and very dangerous element, mercury (though ‘elements’ in the modern sense, weren’t known or at least defined at the time).
Jacinta: I suppose elements wouldn’t have been defined until the atomic theory became a thing.
Canto: Anyway I’m betting that his experiments with mercury shortened Hauksbee’s poor life (he was accepted into the Royal Academy in 1703, just as Newton became its president with the aim of reinstating its grandeur, but he was given special ‘low class’ status). He’d created a version of Otto von Guericke’s electrical machine, made of glass, with air pumped out, and some mercury inside. He rubbed the sphere to create a charge, and the mercury glowed when he put his hand on it (the globe, not the mercury). Fantastical, but nobody knew what it meant, except that it could be used as a source of night-light, which actually happened, but much later.
Jacinta: But nobody had much idea about whys and wherefores at this time.
Canto: They presumably speculated. A similar phenomenon, in large, was St Elmo’s fire (he was the patron saint of sailors), a bluish glow around a sailing ship, or more recently, around an aircraft. We know now this is a form of plasma, the ionised state of matter. During thunderstorms the voltage differentials are greatest – it requires a particular differential for it to happen, and the shape of the body around which the light is seen is an important factor. Pointy objects create a more intense field (Franklin realized this). The violet-blue light is caused by the nitrogen and oxygen in the atmosphere.
Jacinta: Are you sure you know what you’re talking about?
Canto: I’m never certain about anything, that’s my vocation, or just my fate.
Jacinta: Pneumatic tyres are filled with compressed air, or gas. So that helps to understand what a pneumatic engine might be, maybe.
Canto: So Hauksbee had found a way to accumulate an electric charge, and in 1745, in Leyden, Holland, they found a way to store this charge – an instrument that came to be known as a Leyden jar. Let me quote from the scientific historian, Thomas Crump:
The so-called Leyden jar was simply a substantial glass chamber, with separate layers of metal foils on the inside and outside surfaces. The inside was charged by a metal chain connecting it to a charged body, which then lost its charge to the air.
And this was apparently the first capacitor. We’ve talked about capacitors and supercapacitors before, but of course we barely understand them. In any case this Leyden jar device allowed a lot of electrostatic potential to build up between the inner and outer surfaces – enough to kill small birds who came in contact. Nice.
Jacinta: Or were forced to come into contact. I know they tried it on monks too. Presumably they couldn’t find the nuns.
Canto: Anyway they now had some control over this electricity thing, even if they hadn’t a clue what it was. They had some idea as to how to create and release this electrical charge thingummy.
Jacinta: So now we come to Coulomb?
Canto: No, Alessandro Volta (1745-1827) first. I’m following Crump, for better or worse. But more importantly than people, it’s batteries we’re going to focus on now. And I’m not sure where to begin.
Jacinta: It was a term – battery I mean – first used by Franklin in 1749, but what he actually created were capacitors, devices that accumulated charge, until they were discharged. Batteries – I’m kind of guessing here – are devices that store charge more or less permanently, and can release charge in a controlled way, and be recharged in a controlled way.
Canto: And what is this thing called charge?
Jacinta: Well let’s continue to grope toward an understanding. So I’ll return to Franklin. He wrote a book, Experiments and observations on electricity, made at Philadelphia in America, published in 1751. His researches led him to believe that everything contained charge, positive and negative, but that they were almost always in equilibrium, a neutral state. Or the fluid, which could be ‘negativised’ or ‘positivised’ by friction, could be returned to balance by ‘discharging’ it.
Canto: And surely therein lay a mystery. How or why did this build-up of negativity or positivity get discharged? I just don’t understand it. Not just the discharge but the creation of the charge.
Jacinta: I suppose they – Franklin, Hauksbee and the rest – just made the observation and called it ‘charge’. From whence, ‘discharge’. Maybe you’re just overthinking it. They certainly didn’t know what was going on, they just noted this reliable cause-and-effect behaviour and sought to utilise it, and find out more about it. Anyway, keep on overthinking, it might be a good thing.
Canto: Okay, Franklin was exercised by the discharge side of things. He found that pointy objects – we now call them lightning conductors – were most effective at discharging this build-up of charge, and recreating neutrality, the safe, ‘natural’ condition. A great, practical solution for buildings. But he developed a theory of sorts, of zero-sum conservation of this thing called charge. Whatever was accumulated in, say, a Leyden jar, was restored on discharge, nothing gained and nothing lost. I think.
Jacinta: Well, here’s a quote from Crump’s book, which might unenlighten us further:
Franklin succeeded in giving Leyden jars both positive and negative charges, and showed that the force itself was stored in the glass of the jar with the charge being proportional to its surface area.
Canto: Yeah, that needs unpacking, if possible. The ‘force’ being stored, is that the charge? If so, why does he use different terms? Charge is either negative or positive, isn’t it? So he was able to give these jars either a negative or a positive charge/force, but not both at the same time, though it’s ambiguous in this quote.
Jacinta: What I think he’s saying is there’s this force, which we now call electricity, which can either be negatively or positively charged, and its strength will be proportional to the surface area of the glass jar. I don’t think he was giving the jar different charges at the same time, but how he knew that the charge was sometimes positive, sometimes negative, or what that even means, I’ve no idea.
Canto: Yes, I’m more confused than ever. Let’s try to understand Leyden jars a bit more. Apparently it was invented in 1745 by one Pieter van Musschenbroek as a ‘cheap and convenient source of electric sparks’. That’s from Britannica on electromagnetism. So, to be more precise about this first jar, it was a glass vial partially filled with water, which ‘contained a thick conducting wire capable of storing a substantial amount of charge’.
Jacinta: Presumably that ‘thick conducting wire’ corresponds to the ‘metal chain’ in Crump’s description. I don’t know what the water’s for.
Canto: And Britannica makes no mention of the ‘separate layers [how many???!!] on the inside and outside surfaces’.
Jacinta: Okay, here’s a simplified picture, which might help.
So, in this one there’s no water, but I’ve seen other pics that indicate a jar more than half-filled with water, so who fucking knows. Note that there’s one layer of tin foil on the outside and another on the inside. Note the metal rod passing through a cork into this evacuated jar, and then a wire, presumably of some kind of metal, connecting to the tin foil.
Canto: Is tin a good conductor?
Jacinta: Apparently so. Not as good as silver or copper, but better than lead. And please don’t ask me why some metals are better conductors than others. It’s so frustrating trying to learn from the internet, even when you know which sites to avoid. For example, take this statement on what I’d expect to be a reliable site:
Although Leyden Jars allowed the storage and dissipation of electricity, there were still issues present. One issue was the lack of energy from the charge. While it could only attract small objects like a bit of paper, that was all it could basically do. Also, it could only perform that function after the jar was charged, which also took lots of time.
And then this, from Britannica:
The Leyden jar revolutionized the study of electrostatics. Soon “electricians” were earning their living all over Europe demonstrating electricity with Leyden jars. Typically, they killed birds and animals with electric shock or sent charges through wires over rivers and lakes. In 1746 the abbé Jean-Antoine Nollet, a physicist who popularized science in France, discharged a Leyden jar in front of King Louis XV by sending current through a chain of 180 Royal Guards. In another demonstration, Nollet used wire made of iron to connect a row of Carthusian monks more than a kilometre long; when a Leyden jar was discharged, the white-robed monks reportedly leapt simultaneously into the air.
Canto: Hmmm. One of these descriptions is not like the other. Where’s Micky Faraday when you need him?
Jacinta: I can but do my best. Let’s get back to batteries, again. Franklin’s ‘battery’ was really a capacitor, as mentioned, a way of accumulating more electric charge, and temporarily storing it, until it was required for a sort of ‘big bang’ release, I think. You can do this with Leyden jars linked together:
The above ‘device’ was used for demonstration purposes back in the day. Franklin’s electrostatic machine, though, didn’t look anything like this. It was a mammoth device of cranks and pulleys, created with much help from his friends. The mechanisation was presumably for creating as great an accumulation of charge as possible. Crump writes that Franklin built a glass and lead battery consisting of eleven condensers connected in series – which is clearly not his electrostatic machine. And apparently it wasn’t a battery, either, at least not in the modern sense. And WTF is a condenser? Anyway, this confusion has gone on long enough. We’ll try to clear some of it up next time.
References
Thomas Crump, A brief history of science
https://en.wikipedia.org/wiki/Francis_Hauksbee
https://en.wikipedia.org/wiki/St._Elmo%27s_fire
https://www.britannica.com/science/electromagnetism/Invention-of-the-Leyden-jar
https://www.bluesea.com/resources/108/Electrical_Conductivity_of_Materials
https://en.wikipedia.org/wiki/Franklin%27s_electrostatic_machine
on fuel cells and electrolysers and other confusions
Canto: So it seems the more you look towards future technologies, the more future technologies there are to look at. Funny that. Two future developments we want to focus on in these next few posts are the graphene aluminium ion batteries being researched and developed in Queensland for the world, and the whole field of green hydrogen technology, a topic we’ll start on today.
Jacinta: Yes and the two key terms which we’re hoping might enlighten us if we can get a handle on them are fuel cell and electrolyser.
Canto: But first, I’ve just watched a brief video, admittedly five years old, a lifetime it seems in nuevo-tech terms, in which Elon Musk, who I’ve generally considered a hero, describes hydrogen fuels as silly, and seems at the end to be lost for words in expressing his contempt for the technology.
Jacinta: Yes, and the video appears to have been unearthed recently because all the comments, mostly well-informed (as far as I can discern) are only months old, and contradict Musk’s claims. But let’s not dwell on that. What is a fuel cell?
Canto: Well, we’re looking at the possibility of fuel cell electric vehicles (FCEVs), which presumably will operate in direct competition with Tesla’s EVs. Interestingly, one of the claimed deficits of EVs is their long charging times, which the new graphene-aluminium ion technology should greatly reduce. If FCEVs become a thing, the ‘old’ battery driven things will become known as BEVs, even before the EV term has really caught on.. Anyway, fuel cells produce electricity. You don’t have to plug them in, according to BMW.com (which may have a bias towards hydrogen in terms of investment). However, they don’t really show how the hydrogen is produced, and their image, shown above, presents a hydrogen tank without explaining where the hydrogen comes from.
Jacinta: Yes, so here’s how BMW.com begins its explanation:
In fuel cell technology, a process known as reverse electrolysis takes place, in which hydrogen reacts with oxygen in the fuel cell. The hydrogen comes from one or more tanks built into the FCEV, while the oxygen comes from the ambient air. The only results of this reaction are electrical energy, heat and water, which is emitted through the exhaust as water vapor. So hydrogen-powered cars are locally emission-free…
Canto: Which explains nothing much so far. Hydrogen reacts with oxygen. How? By reverse electrolysis. What’s that? The name implies splitting by electricity (but in reverse?), but I’d like more detail.
Jacinta: Yeah we’ll have to go elsewhere for that. In the image above you see a battery pack, much smaller than those in EVs, and an electric engine or motor. The BMW site reckons that the generated electricity from the fuel cell can either flow directly to the electric motor, powering the vehicle, or it can go to the battery, called a ‘peak power battery’, which stores the energy until needed by the motor. Being constantly recharged by the fuel cell, it’s only a fraction of the size of an EV battery.
Canto: Okay, that’s the BMW design, but I want the science nitty-gritty. I’ve heard that fuel cells go back a long way.
Jacinta: Yes, and we may need several posts to get our heads around them. I’ll start with the English engineer Francis Thomas Bacon (illustriously named), who developed the first alkaline fuel cell, or hydrogen-oxygen fuel cell, also known as the Bacon fuel cell, in the 1930s. This type of fuel cell has been used by NASA since the sixties. But the Wikipedia article again skips some steps.
Canto: So alkaline is the opposite of acidic, sort of, and car batteries require acid, but I don’t know what the difference is, in electrical terms.
Jacinta: Hopefully all will be revealed. One basic thing I’ve learned is that a fuel cell requires a cathode, an anode (collectively, two electrodes) and an electrolyte. So let’s take this slowly. The cathode is the one from which the conventional current departs – CCD, cathode current departs. Conventional current is defined as the direction of the positive charge. In the case of hydrogen, that’s just protons. The electrons go in the opposite direction. The anode, which maybe I should’ve mentioned first, is the electrode through which a conventional current enters the fuel cell or device. Think ACID, anode current into device. Now, the cathode and anode must be made of particular materials, which presumably relate to the fuel you’re trying to split, or electrolyse.
Canto: Hmmm, I’m wondering if a fuel cell and an electrolytic cell are the same thing, or one is a subset of the other. Apparently not, according to Wikipedia.
For fuel cells and other galvanic cells, the anode is the negative terminal; for electrolytic cells (where electrolysis occurs), the anode is the positive terminal. Made from, with, or by water.
So, shit, what’s a galvanic cell and how does it differ from an electrolytic cell? From the above description, it sounds like an electrolytic cell (anode positive) is the opposite of a fuel/galvanic cell (anode negative). We need to know what electrolysis actually means – not to mention galvanisis. And I believe reverse electrolysis is a thing.
Jacinta: Shit indeed. So at least from the above we know that electrolysis always involves water. Or does it? Okay, a galvanic cell, also known as a voltaic cell (Luigi Galvani, Alessandro Volta) combines two metals and an electrolyte (in Galvani’s case, a frog’s leg). Galvani and others thought the frog, or some other creature, was necessary for the current – ‘animal electricity’ became a thing for a while. Volta showed that this was not the case, though there was much argy-bargy for a while. But enough easy history, we need to tackle tough science.
Canto: So I don’t know if the currently titled hydrogen fuel cells are correctly described as alkaline fuel cells, but there are some videos, such as one by Philip Russell, describing very simple hydrogen fuel cells, driving a small fan. Russell explains the process very carefully, and I’ll go through it myself for my understanding. He has a tiny blue fuel cell connected by two tubes to two glasses of water. In one glass, hydrogen will be collected from one side of the cell, and oxygen from the other side in the other glass. He connects the fuel cell to a small solar panel via two wires, one red one black. He says that ‘to the negative side [holding the black wire] I’m going to connect to the side [of the cell] that produces hydrogen and the positive side [red] I’m going to connect to the side that produces hydrogen’. And now I’m confused. Both sides will produce hydrogen? How? What does that even mean?
Jacinta: In DC circuitry, black is conventionally negative and red positive. The difference between AC and DC may have to be explored because I think it’s relevant to all this nuevo-tech. Now, considering that Russell plugged the wires into opposite sides of the cell and said twice ‘the side that produces hydrogen’, the logical conclusion is that he made a mistake, but I can’t be sure. After all, what does he want to produce other than hydrogen?
Canto: Actually he said that one of the glasses will be collecting oxygen, so clearly he should’ve said oxygen for one of those two sides. But which one? Let’s continue with the video. So he’s connected the solar panel to the cell and he says ‘now we can collect solar energy and turn it into hydrogen and oxygen’. So the mistake hypothesis seems right, and that might have to be clarified with other videos. We plan to look at about a hundred of them, because our skulls are thick. So Russell next takes us inside the fuel cell. The outside is of blue-tinted glass or plastic. Inside we see ‘a perforated metal sheet’ (at least on one side). Apparently this is a hydrogen flow field, which ‘allows the hydrogen gas to escape from the fuel cell’. This again makes little sense to me. How did the hydrogen get in there in the first place? Hopefully all will be explained – or not. Next to, or behind this flow field is an anode consisting of a palladium catalyst. And in a fuel cell, the anode is negative.
Jacinta: According to Britannica, palladium is a type of platinum metal which makes an excellent catalyst:
Because hydrogen passes rapidly through the metal at high temperatures, heated palladium tubes impervious to other gases function as semipermeable membranes and are used to pass hydrogen in and out of closed gas systems or for hydrogen purification.
Canto: Good, so between the two electrodes is our electrolyte, consisting of a polymer electrolyte membrane (PEM) which ‘allows the transfer of the hydrogen gas and hydrogen ions’. Again this isn’t particularly enlightening but we’ll explore it later. Next to the the electrolyte membrane is the cathode (positive), and then comes the oxygen flow field, ‘which allows the oxygen to come in and escape from the fuel cell’. Again unclear.
Jacinta: It’s a start, sort of. We’ll glean what we can from this little video and supplement it from other videos and info sites. So electricity is coming into the fuel cell which breaks down the water coming from the two glass jars. I’m confused, though, about the glass jars and the tubes leading to, or from, the fuel cell. They’re filled with water (which I’m presuming is highly purified) and they’re delivering water to either side of the fuel cell, via these tubes, which are attached, in each of the glasses, to something like a suction cup, which will, it seems, have something to do with gas coming from the fuel and being sent through the tube to the bottom of the glass jars – hydrogen along one tube, oxygen along the other. So the water is presumably being depleted from the jars and the two gasses are being collected at the bottom of the jars, to judge from the look of the setup. But how are these tubes able to deliver water one way and collect gas in the other direction at the same time?
Canto: Haha and we’re only halfway through this teeny video. And we next go to a diagram which again upsets our thinking, as it shows the anode as positive, whereas Wikipedia says the anode is negative in fuel cells. It seems we’re being stumped by nomenclature. What Philip Russell is demonstrating appears to be an electrolytic cell or an electrolyser, but it’s being called a fuel cell. A website from energy-gov, linked below, has a diagram of a fuel cell/electrolyser very similar to Russell’s. They call it an electrolyser. They’re conspiring to confuse us!
Jacinta: Anyway, Russell explains his thingummmy, and I quote: ‘We have, in the middle, this polymer electrolyte membrane [PEM] surrounded by the electrodes, and on either side, the anode and cathodes[!]. When we start, water enters through the anode, and here, when it reaches the cathode and anode [!] things start to happen. The water is broken down into hydrogen ions by the electrons in the battery, and this then produces oxygen gas. The hydrogen ions travel across/through the PEM where they are reacted with electrons and this forms hydrogen gas which escapes through to the cathode side of the fuel cell’.
Canto: Yes, clear as far as it goes. So this is electrolysis he’s talking about isn’t it? Is it really this simple? Probably not, in scaled up versions. Anyway, Russell finishes up by disconnecting his wires from the solar panel and connecting them to a small fan, which immediately starts to function. The fuel cell has reversed, according to Russell, and is producing electricity from H2 and O2.
Jacinta: Yes, the way he presents it, it’s all very simple. But I don’t think so. We’ve scratched the surface of this technology, and informed ourselves in very small part, but there’s a long way to go. We need to struggle on, in our brave, heroic way.
References
https://www.bmw.com/en/innovation/how-hydrogen-fuel-cell-cars-work.html
https://en.wikipedia.org/wiki/Alkaline_fuel_cell
https://en.wikipedia.org/wiki/Galvanic_cell
https://www.britannica.com/science/palladium-chemical-element
https://www.energy.gov/eere/fuelcells/hydrogen-production-electrolysis
some chatter on the National Energy Guarantee and our clouded energy future
Sanjeev Gupta – making things happen
Canto: I think we need to get our heads around the National Energy Guarantee, the objections to it, and the future of energy in Australia – costs, viability, environmental issues and the like.
Jacinta: Oh no. So what is the National Energy Guarantee?
Canto: Well if we go to the government’s website on this we’ll get a spinned version, but it’s a start. They say it’s an attempt to guarantee reliability, affordability, baseload security, reduced emissions and further investment into the nation’s energy system. They describe it as a market-based, technology-neutral response to the Finkel Review. They estimate a savings of around $120 between 2020 and 2030.
Jacinta: Sounds a bit vague.
Canto: Well there’s quite a bit of vagueness on their website frankly, but they present information on future projects, such as Snowy 2.0, which sound exciting but we’ll have to wait and see.
Jacinta: So, going to our favourite website on these matters, Renew Economy, I find outrage from the renewable energy sector about the latest government decision on the NEG:
Federal Coalition MPs voted on Tuesday [August 14] to support the National Energy Guarantee that proposes to ensure no new investment in large-scale wind, solar or battery storage for nearly a decade, and also expressed their support for a new government initiative they hope will support new coal-fired generation.
A lot of the critics’ ire is directed at modelling by the ESB (Energy Security Board) – established a year ago ‘to coordinate the implementation of the Finkel reform blueprint’ – which fails to account for major state and corporate investments in renewables.
Canto: And apparently the claimed savings to the consumer are partly based on the reduced cost of renewables which the federal government wants no part of! It’s like not having their cake but eating it too. Interested parties and opposition leaders have asked to see the modelling, and have received nothing beyond a single spreadsheet.
Jacinta: And since we’ve been talking about the OECD lately, this new NEG’s target for renewables puts us behind the majority of OECD nations. Only five of them – including the USA and Canada – have lower targets than us. And yet the potential for reduced emissions here is greater than just about anywhere else.
Canto: Well it’s no wonder that states such as Victoria and Queensland are unwilling to sign up. They have major renewable energy plans in store, and are challenging what would seem to be a baseless federal assumption, that bringing prices down means excluding renewables. In fact the Feds are quite contradictory and confused on the subject.
Jacinta: Well there’s a good chance the conservatives will get rolled at the next election, so I’m hoping that Federal Labor have all their energy plans ready. And speaking of optimism, here in South Australia we’re apparently still on target to be 100% renewable, energy-wise, by 2025. The AEMO has made this prediction in its Integrated Systems Plan, which is a 20-year blueprint for renewables around the country. There are quite a few projects being developed here in SA, including a 280 MW solar plant in Whyalla, courtesy of British billionaire Sanjeev Gupta…
Canto: Yes, Gupta has argued that the Federal proposal, or promise, to underwrite new power stations, which the conservatives have seized on as a way of advancing the coal agenda, can actually be used to build more solar farms with storage – what he calls ‘firm solar’. I don’t think it’s going to be much of a battle though. There’s no appetite for investing in new coal power stations among the cognoscenti. And another company looking to take advantage of the underwriting mechanism is Genex, which is building solar and hydro projects in Queensland.
Jacinta: Yes, the conservative dinosaurs can bellow all they like, and they may even have some popular appeal, but the smart developers and investors are the ones who’ll carry the day, and they won’t be investing in coal. Anyway, Gupta has very ambitious, transformative plans for Australia’s energy system, which he sees – irony of ironies – as being green-lighted by the Federal underwriting proposal, which is neutral as to the source of the energy used. I don’t know how all this works out financially, but obviously Gupta does, and he’s suggesting we could become a truly cheap energy producer, particularly in solar. He envisions 10GW of solar capacity across the country. He’s also keen to build electric vehicles in Australia, which we may have mentioned before, though maybe not in South Australia, which was the original idea.
Canto: And he’s also planning a storage battery near Port Augusta, due to commence later this year, which will out-biggen the recent Tesla battery. And speaking of the Tesla battery, which has been in operation for around nine months now, it might be worth having a look at how successful, or not, it has been.
Jacinta: Well, I’ve found an analysis of its first four months of operation here, on a blog called Energy Synapse, though it’s a bit difficult to follow. It points out that the battery has two essential purposes; first, to provide stability to the grid, and second, to ‘trade in and arbitrage the energy market’. Energy Synapse was only looking at its success in trading. I would’ve thought its first role was more important, but I suppose that’s because I’m not much of a trader.
Canto: What does arbitrage mean?
Jacinta: Well, it’s about trading in a commodity with a fluctuating price. The key for making a quid, of course, is to buy low and sell high. In the battery’s case, you have to buy energy to recharge it, and you sell it to the grid when need arises. That may not be something under your control, so I’m not sure how you can successfully arbitrage in such a situation. From what I can work out, during the period December to March, the battery was getting plenty of use. December can largely be ruled out as a testing period, but January – a high volatility period – and February were pretty successful, March less so. Estimated net revenue for the 4-month period was $1.4 million, which sounds pretty good to me. But presumably the summer months are better for the battery as that’s when the grid is under greatest pressure? It would be great to have a measure of its performance over the winter. In fact, a full 12 month review would probably be necessary, if not sufficient, for testing how well it trades. But the battery’s efficiency, its rapid response time and proven capability in smoothing out the effects of outages elsewhere, has captured the attention of the public and of other investors. People and companies much smarter and more onto this ball than I am, are getting into big batteries – not just Gupta’s Simec Zen Energy, but CWP Renewables in Victoria, and individuals throughout the country who are installing home battery storage to combine with solar.
Canto: And very recently the federal government has been under attack from its ultra-conservative wing for providing any comfort at all to the clean energy sector, and it’s even possible that the Prime Minister will lose his job over it. It’s bemusing to me that a party which always claims to be the pro-business party is at odds with the business community over this, with Abbott arguing for a hostile takeover of AGL’s Liddell coal-fired power station – a kind of nationalisation… It seems Abbott wants the whole nation to be operated on what he calls ‘reliable baseload power’, essentially from coal.
Jacinta: Well, NSW seems to be going through the horrors at present regarding reliable energy. Its a state heavily reliant on black coal, and it’s been suffering power shortages recently because power stations are undergoing maintenance or units are non-operational. It seems the dependence of industry on a few key providers is causing problems, and dispatchable supply from solar and wind is variable. It seems that leadership in co-ordinating the state energy system is lacking. And of course, that’s where Abbott is coming from. So maybe he’s half-right, he’s just hampered by his pro-coal, anti-renewables tunnel vision.
Canto: Meanwhile the NEG is being roundly criticised, indeed summarily dismissed, by all and sundry, and all we can really be sure of is that leadership in the field of energy will come from particular state governments and private corporations for the foreseeable future.
References
https://energysynapse.com.au/south-australia-tesla-battery-energy-market/
https://theconversation.com/a-month-in-teslas-sa-battery-is-surpassing-expectations-89770
https://reneweconomy.com.au/full-absurdity-of-national-energy-guarantee-laid-bare-75082/
the ACCC, coal, renewables, arguments, and the future
Well as I watch my readership reduce to almost zero in its usual ups and downs I wonder whether to write just for myself or to attract a readership, so I’ll just go ahead and write, but I was amused to listen to Senator Matt Canavan, our Minister for Resources and a member of the Nationals, responding to the ACCC’s recommendations for bringing energy prices down. At one point he remarked ‘who cares where we get our fuel from?’, and compared the different fuel varieties to different types of ice-cream in a sweet shop. Presumably he was referring to encouraging an energy mix, but for someone who presumably knows something about resources, since he holds that portfolio (though that’s hardly ever proof of expertise in government), it struck me as bizarre. Who cares where we get our fuel from or what type it is? The Chinese government cares, for one. It has worked hard in recent years to combat pollution in Beijing, largely in response to adverse publicity. China’s capital, ranked as the fifth most polluted city in China in 2011, has since dropped out of the top twenty, largely due to the adoption of cleaner, greener energy and technology. Unfortunately, many other cities in China’s highly populated and industrialised north-western region still suffer from an environment which has reduced life expectancy there by some 5.5 years, according to a joint study by Chinese and American university teams in 2013. This sadly suggests that the Chinese government appears to be more concerned with its international image than with protecting its own citizens from hazardous emissions. On the bright side, Beijing’s improvement indicates what can be done to improve environments when governments and industry get their act together.
Just as oils aint oils, fuels aren’t just fuels. Remember kerosene? I remember huddling over a kerosene heater in the seventies, along with student housemates. But in other parts, kero isn’t a past-tense energy source. In many of the poorest countries, particularly in Africa, it’s used for lighting, even though it’s toxic, causes frequent burns and fires, and produces inferior light. It has proved difficult to wean consumers from kerosene in these countries, even though there are potentially cheaper options available. There’s an interesting article about the problems and possible solutions here.
But really, since energy generation (i.e. using x,y, or z as fuel) is the number one cause of air pollution and global warming emissions, it’s not like comparing caramel praline with black raspberry crunch. Coal is of course the worst in terms of emissions. As of 2016, some 44% of US electricity comes from coal, but it accounts for 80% of that country’s power plant carbon emissions. Australia has great reserves of coal, but it exports much of it to China and, more recently, South-East Asia. In fact Australia has experienced a recent boom in coal exports, earning a record $56.5 billion in 2017. Unsurprisingly many conservative pollies are clamouring for more coal mines and more local use of the resource as a solution to our seemingly ever-rising energy costs. Maybe we too can pull out of the Paris Agreement? Of course, our massive coal exports do tend to undermine that agreement, while the government can congratulate itself on keeping domestic use within more or less acceptable limits (see graph above). Currently, we’re the largest coal exporter and the third largest exporter of carbon pollution in the world, behind Saudi Arabia and Russia. But of course it’s not our fault that other countries want to pollute with our resources, is it? We just take the money and keep our country clean (as do Norway, Denmark and Indonesia).
So considering our dubious status in terms of global emissions (but, as many experts point out, it’s a little arrogant to expect developing and transitioning countries like China, our biggest coal customer, to rapidly abandon a fuel that the developed world has used for so long, thereby gaining ascendancy), it’s interesting to note that AGL, Australia’s largest owner of coal fired power stations and biggest emitter of carbon dioxide, is continuing its push away from coal in spite of government pressure. Of course the government itself is divided on this, with Turnbull and Frydenberg largely at odds with the Nationals on the question of transition, but looking into the future, it seems inevitable that demand for coal will decline – the only question is the rate of that decline, which of course depends on how quickly other nations move away from coal. All of those nations have signed the Paris Agreement. Already, coal ports such as Newcastle, and Australia’s mining regions, are looking to diversify, and energy experts are debating the pursuance of a coal tax to support the industry as it transitions.
But Canavan and the Nationals are having none of this. They point to the above-mentioned boom and a currently accelerating demand, though Canavan is realistic enough to admit that future forecasts are reliably unreliable. Much will depend on cost declines and advancing technology in renewables, as well as various political scenarios.
Naturally the renewable energy sector is looking critically at what one of its experts calls the ‘series of scattershot proposals’ by the ACCC on reducing our electricity costs. The ACCC’s recommendation that the small-scale renewable energy scheme (SRES), a subsidy which mainly applies to rooftop solar, should be wound down, is seen as unfair if not counter-productive by the sector. The SRES is already slated to be wound down by 2030, and its earlier abolition (by 2021, according to ACCC recommendations) would mainly affect low-income and rental householders. There’s currently a new boom in rooftop solar, with rising energy costs being the main cause. So penalising future adopters of rooftop solar seems an odd way to reduce the problems they’re adopting solar to avoid. As to the possibility of new gas- or coal-fired power plants, a dream of the Nationals and renegade ultra-conservative Tony Abbott, that’s unlikely, considering changing public attitudes and the reasonable likelihood of a change of federal government by next year. The good thing about the ACCC’s analysis is that the behaviour of retailers, and the phenomenon of price gouging, have finally been criticised, and the idea of states writing down the value of their networks has been floated. Consumers shouldn’t have to bear the burden of extra energy infrastructure and errors in predicting future energy demand.
There have been many interesting responses to the report, to say the least. Danny Price, a leading analyst of the national energy market over three decades, regards the report as overly political in that it shies away from criticising the lack of a much-needed bipartisan approach to energy policy. Confusion and ideological squabbling over carbon pricing – the disastrous scrapping by the Abbott government of a carefully formulated carbon tax being the low point – has been a disincentive to major investment, and banks here are refusing to finance new coal-fired power stations, which would only be built via massive government subsidies. Consequently we’ve seen an upsurge in interest in renewables from consumers and business, which also reflects worldwide growth, with major oil companies like BP joining the fray.
Of course the problem of reliable back-up power remains, and analyst Ian Verrender has criticised the ACCC report for omitting his best solution – gas. Gas turbines are more flexible than coal generators as well as producing fewer emissions. Australia is a major exporter of gas, but our companies have been providing little for domestic consumption, a situation which was only partly remedied by recent federal intervention. Yet the Nationals are more interested in coal than gas, in spite of its many problems, and its inefficiencies in providing precise back-up supply. Gas, hydro and batteries are far more efficient in this respect.
A recent study by the Australian Energy Market Operator (AEMO) has also backed renewables (though apparently the current federal government isn’t listening). It has released its Integrated Systems Plan, reported on here by Giles Parkinson:
Based on its “neutral” scenario, which comprises existing federal and state government policies, the lowest cost replacement [for retiring coal-fired suppliers] will be solar (28GW), wind (10.5GW) and storage (17GW and 90GWh). Just 500MW of flexible gas plant will be needed, and no new coal. It says this portfolio in total can produce 90TWh (net) of energy per annum, more than offsetting the energy lost from retiring coal fired generation.
AEMO has also highlighted the need for new transmission infrastructure, as transformative and disruptive energy developments continue around the country. The need for forward planning should be obvious and governments – especially the federal government – ignore this at their peril. A change of federal government may be the answer, but only if the incoming government has a thorough-going plan to integrate and manage this clear and obvious national move away from fossil fuels. Such plans are already being drawn up – we just need the will, and some bipartisan support, to implement them.
the continuing story of South Australia’s energy solutions
In a very smart pre-election move, our state Premier Jay Weatherill has announced that there’s a trial under way to install Tesla batteries with solar panels on over 1,000 SA Housing Trust homes. The ultimate, rather ambitious aim, is to roll this out to 50,000 SA homes, thus creating a 250MW power plant, in essence. And not to be outdone, the opposition has engaged in a bit of commendable me-tooism, with a similar plan, actually announced last October. This in spite of the conservative Feds deriding SA labor’s ‘reckless experiments’ in renewables.
Initially the plan would be offered to public housing properties – which interests me, as a person who’s just left a solarised housing association property for one without solar. I’m in community housing, a subset of public housing. Such a ‘virtual’ power plant will, I think, make consumers more aware of energy resources and consumption. It’s a bit like owning your own bit of land instead of renting it. And it will also bring down electricity prices for those consumers.
This is a really important and exciting development, adding to and in many ways eclipsing other recently announced developments in SA, as written about previously. It will be, for a time at least, the world’s biggest virtual power plant, lending further stability to the grid. It’s also a welcome break for public housing tenants, among the most affected by rising power bills (though we’ll have to wait and see if prices do actually come down as a result of all this activity).
And the announcements and plans keep coming, with another big battery – our fourth – to be constructed in the mid-north, near Snowtown. The 21MW/26MWh battery will be built alongside a 44MW solar farm in the area (next to the big wind farm).
South Australia’s wind farms
Now, as someone not hugely well-versed in the renewable energy field and the energy market in general, I rely on various websites, journalists and pundits to keep me honest, and to help me make sense of weird websites such as this one, the apparent aim of which is to reveal all climate scientists as delusionary or fraudsters and all renewable energy as damaging or wasteful. Should they (these websites) be tackled or ignored? As a person concerned about the best use of energy, I think probably the latter. Anyway, one journalist always worth following is Giles Parkinson, who writes for Renew Economy, inter alia. In this article, Parkinson focuses on FCAS (frequency control and ancillary services), a set of network services overseen by AEMO, the Australian Energy Market Operator. According to Parkinson and other experts, the provision of these services has been a massive revenue source for an Australian ‘gas cartel’, which has been rorting the system at the expense of consumers, to the tune of many thousands of dollars. Enter the big Tesla battery , officially known as the Hornsdale Power Reserve (HPR), and the situation has changed drastically, to the benefit of all:
Rather than jumping up to prices of around $11,500 and $14,000/MW, the bidding of the Tesla big battery – and, in a major new development, the adjoining Hornsdale wind farm – helped (after an initial spike) to keep them at around $270/MW.
This saved several million dollars in FCAS charges (which are paid by other generators and big energy users) in a single day.
And that’s not the only impact. According to state government’s advisor, Frontier Economics, the average price of FCAS fell by around 75 per cent in December from the same month the previous year. Market players are delighted, and consumers should be too, because they will ultimately benefit. (Parkinson)
As experts are pointing out, the HPR is largely misconceived as an emergency stop-gap supplier for the whole state. It has other, more significant uses, which are proving invaluable. Its effect on FCAS, for example, and its ultra-ultra-quick responses to outages at major coal-fired generators outside of the state, and ‘its smoothing of wind output and trading in the wholesale market’. The key to its success, apparently, is its speed of effect – the ability to switch on or off in an instant.
Parkinson’s latest article is about another SA govt announcement – Australia’s first renewable-hydrogen electrolyser plant at Port Lincoln.
I’ve no idea what that means, but I’m about to find out – a little bit. I do know that once-hyped hydrogen hasn’t been receiving so much support lately as a fuel – though I don’t even understand how it works as a fuel. Anyway, this plant will be ten times bigger than one planned for the ACT as part of its push to have its electricity provided entirely by renewables. It’s called ‘green hydrogen’, and the set-up will include a 10MW hydrogen-fired gas turbine (the world’s largest) driven by local solar and wind power, and a 5MW hydrogen fuel cell. Parkinson doesn’t describe the underlying technology, so I’ll have a go.
It’s all about electrolysis, the production of hydrogen from H2O by the introduction of an electric current. Much of what follows comes from a 2015 puff piece of sorts from the German company Siemens. It argues, like many, that there’s no universal solution for electrical storage, and, like maybe not so many, that large-scale storage can only be addressed by pumped hydro, compressed air (CAES) and chemical storage media such as hydrogen and methane. Then it proceeds to pour cold water on hydro – ‘the potential to extend its current capacity is very limited’ – and on CAES ‘ – ‘has limitations on operational flexibility and capacity. I know nothing about CAES, but they’re probably right about hydro. Here’s their illustration of the process they have in mind, from generation to application.
Clearly the author of this document is being highly optimistic about the role of hydrogen in end-use applications. Don’t see too many hydrogen cars in the offing, though the Port Lincoln facility, it’s hoped, will produce hydrogen ‘that can be used to power fuel cell vehicles, make ammonia, generate electricity in a turbine or fuel cell, supply industry, or to export around the world’.
So how does electrolysis (of water) actually work? The answer, of course, is this:
- 2 H2O(l) → 2 H2(g) + O2(g); E0 = +1.229 V
Need I say more? On the right of the equation, E0 = +1.229 V, which basically means it takes 1.23 volts to split water. As shown above, Siemens is using PEM (Proton Exchange Membrane, or Polymer Electrolyte Membrane) electrolysis, though alkaline water electrolysis is another effective method. Not sure which which method is being used here.
In any case, it seems to be an approved and robust technology, and it will add to the variety of ‘disruptive’ and innovative plans and processes that are creating more regionalised networks throughout the state. And it gives us all incentives to learn more about how energy can be produced, stored and utilised.
the battery, Snowy Hydro and other stuff
Let’s get back to batteries, clean energy and Australia. Here’s a bit of interesting news to smack our clean-energy-fearing Feds with – you know, Freudenberg, Morrison and co. The Tesla Big Battery successfully installed at the beginning of summer, and lampooned by the Feds, turns out to be doing a far better job than expected, and not just here in South Australia. Giles Parkinson reported on it in Renew Economy on December 19:
The Tesla big battery is having a big impact on Australia’s electricity market, far beyond the South Australia grid where it was expected to time shift a small amount of wind energy and provide network services and emergency back-up in case of a major problem.
Last Thursday, one of the biggest coal units in Australia, Loy Yang A 3, tripped without warning at 1.59am, with the sudden loss of 560MW and causing a slump in frequency on the network.
What happened next has stunned electricity industry insiders and given food for thought over the near to medium term future of the grid, such was the rapid response of the Tesla big battery to an event that happened nearly 1,000km away.
The Loy Yang brown coal fired power station is in south eastern Victoria, so why did South Australia’s pride and joy respond to a problem in our dirty-coal neighbouring state? It surely wouldn’t have been contracted to, or would it? Parkinson also speculates about this. Apparently, when a power station trips, there’s always another unit contracted to provide back-up, officially called FCAS (frequency control and ancillary services). In Loy Yang’s case it’s a coal generator in Gladstone, Queensland. This generator did respond to the problem, within seconds, but the Tesla BB beat it to the punch, responding within milliseconds. That’s an important point; the Tesla BB didn’t avert a blackout, it simply proved its worth, without being asked. And it has been doing so regularly since early December. It seems the Tesla BB has cornered the market for fast frequency control. Don’t hold your breath for the Feds to acknowledge this, but they will have taken note, unless they’re completely stupid. They’ll be finding some way to play it (or downplay it) politically.
As Parkinson notes in another article, the energy industry has been slow to respond, in terms of regulation and accommodation, to the deployment of battery systems and their rapid charge-discharge features. Currently, providing FCAS is financially rewarded, which may have to do with costs involved but the cost/reward relationship appears to be out of kilter. In any case, battery response is much more cost-effective and threatens the antiquated reward system. The AEMC is planning to review frequency control frameworks, but it’ll no doubt be a slow process.
This is an incredibly complex area, combining new, barely-understood (by me) technologies of generation and storage, and the transformation of long-standing energy economies, with a host of vested interests, subsidies and forward plans, but I intend to struggle towards enlightenment, as far as I can.
Neoen’s Hornsdale Wind Farm
Regardless of regulation and grid problems, renewable energy projects keep on popping up, or at least popping into my consciousness through my desultory reading (NY resolution: inform myself much more on what’s going on, here and elsewhere, in clean energy). For example, the Murra Warra wind farm’s first stage will have an output of 226MW, which has already been sold to a consortium of Australian corporations including Telstra and ANZ. The farm is near Horsham in western Victoria, and will finally have a capacity of up to 429MW, making it one of the biggest in the Southern Hemisphere. And of course there are many other projects underway. Back in August, the Renewable Energy Index, a monthly account of the renewable energy sector, was launched. Its first publication, by Green Energy Markets, was a benchmark report for 2016-7, all very glossy and positive. The latest publication, the November index, shows that rooftop solar installations for that month broke the monthly record set in June 2012 when subsidies were twice to three times what they are today. The publication’s headline is that the 2020 RET will be exceeded and that there are ‘enough renewable energy projects now under development to deliver half of Australia’s electricity by 2030’. The Clean Energy Council, the peak body for Australian dean energy businesses, also produces an annual report, so it will be interesting to compare its 2017 version with the Renewable Energy Index.
Hydro is in fact the biggest clean energy provider, with 42.3% of the nation’s renewable energy according to the 2016 Clean Energy Australia Report. Wind, however, is the fastest growing provider. This brings me to a topic I’ve so far avoided: The $4 billion Snowy Hydro 2 scheme.
Here’s what I’m garnering from various experts. It’s a storage scheme and that’s all to the good. As a major project it will have a long lead time, and that’s not so good, especially considering the fast growing and relatively unpredictable future for energy storage. As a storage system it will be a peak load provider, so can’t be compared to the Hazelwood dirty coal station, which is a 24/7 base load supplier. There’s a lot of misinformation from the Feds about the benefits, eg to South Australia, which won’t benefit and doesn’t need it, it’s sorting its own problems very nicely thanks. There’s a question about using water as an electricity supplier, due to water shortages, climate change and the real possibility of more droughts in the future. There are also environmental considerations – the development is located in Kosciuszko National Park. There’s some doubt too about the 2000MW figure being touted by the Feds, an increase of 50% to the existing scheme. However, many of these experts, mostly academics, favour the scheme as a boost to renewable energy investment which should be applied along with the other renewables to transform the market. In saying this, most experts agree that there’s been a singular lack of leadership and common-sense consensus on dealing with this process of transformation. It has been left mostly to the states and private enterprise to provide the initiative.
With each post I’ll add something on the projected Trump downfall.
Just watched a CNN special report: The Trump Russia Investigation. It suggests to me that the notorious Trump Tower meeting, while nothing much in itself, is but a small piece of the growing case against Trump. It filled me in muchly on the much-discussed ‘dossier’ released just before Trump’s inauguration, the commandeering of Facebook by Russian operatives for a disinformation campaign, stirring up issues on immigration, gays, guns, etc, and much more. I still maintain that he won’t be in office by year’s end.
an assortment of new technology palaver
I like the inset pic – very useful for the Chinese
Western Australia lithium mining boom
I’m hearing, better late than never, that lithium carbonate from Western Australia is in big demand. The state already provides most of the world’s lithium for all those batteries used to run smart devices, electric vehicles, and large-scale storage batteries such as South Australia’s Tesla-Neoen thingy at Jamestown (now 80% complete, apparently). Emissions legislation around the world will only add to the demand, with the French and British governments planning to ban the sale of petrol and diesel vehicles by 2040, following similar plans by India and Norway, and the major investments in EVs in China. Australia’s government, of course, is at the other end of the spectrum re EVs, but I’ve no doubt we’ll get there eventually (we’ll have to!). Tesla, Volvo, Nissan, Renault, Volkswagen and Mercedes are all pushing more EVs into the marketplace. So now’s the time, according to Money Boffins Inc, to buy shares in lithium and other battery minerals (I’ve never bought a share in my life). This lithium mining boom has been quite sudden and surprising to many pundits. In January of this year, only one WA mine was producing lithium, but by mid-2018 there will be eight, according to this article. The battery explosion, so to speak, is bringing increased demand for other minerals too, including cobalt, nickel, vanadium and graphite. Australia’s well-positioned to take advantage. Having said that, the amount of lithium we’re talking about is a tiny fraction of what WA exports in iron ore annually, but it’s already proving to be a big boost to the WA economy, and a big provider of jobs.
battery recycling
Of course all of this also poses a problem, as mentioned in my last post, and it’s a problem that the renewable energy sector should be at least ideologically driven to deal with: waste and recycling. Considering the increasing importance of battery technology in our world, and considering the many toxic components of modern batteries, such as nickel, lead acid, cadmium and mercury, it’s yet another disappointment that there’s no national recycling scheme for non-rechargeable batteries. Currently only lead acid batteries can be recycled, and the rest usually end up in landfill or are sent to be recycled overseas. So it’s been left to the industry to develop an Australian Battery Recycling Initiative (ABRI), which has an interesting website where you can learn about global recycling and many other things batterial – including, of course, how to recycle your batteries. Also, an organisation called Clean Up Australia has a useful battery recycling factsheet, which, for my own educational purposes I’m going to recycle here, at least partly. Battery types can be divided into primary, or single-use, and secondary, or rechargeable. The primary batteries generally use zinc and manganese in converting chemical to electrical energy. Rechargeable batteries use a variety of materials, including nickel cadmium, nickel metal hydride and of course lithium ion chemistry. Batteries in general are the most hazardous of waste materials, but there are also environmental impacts from battery production (mining mostly) and distribution (transport and packaging). As mentioned, Australian batteries are sent overseas for recycling – ABRI and other groups are trying to set up local recycling facilities. Currently a whopping 97% of these totally recyclable battery units end up in landfill, and – another depressing factoid – Australia’s e-waste is growing at 3 times the rate of general household waste. So the public is advised to use rechargeable batteries wherever possible, and to take their spent batteries to a proper recycling service (a list is given on the fact sheet). The ABRI website provides a more comprehensive list of drop-of services.
2015 registrations: Australia’s bar would be barely visible on this chart
EVs in Australia – a very long way to go
I recently gave a very brief overview of the depressing electric vehicle situation in Australia. Thinking of buying one? Good luck with that. However, almost all motorists are much richer than I am, so there’s hope for them. They’re Australia’s early adopters of course, so they need all the encouragement we can give them. Journalist Timna Jacks has written an article for the Sydney Morning Herald recently, trying to explain why electric vehicles have hit a dead end in Australia. High import duties, a luxury car tax and a lack of subsidies and infrastructure for electric vehicles aren’t exactly helping the situation. The world’s most popular electric car, the Nissan Leaf, is much more expensive here than in Europe or the US. And so on. So it’s hardly surprising that only 0.1% of all cars sold in Australia in 2015 were electric cars (compared with 23% and rising in EV heaven, aka Norway, 1.4% in France and 0.7% in the US). Of course Australia’s landscape’s more or less the opposite of compact, dense and highly urbanised Europe, and range anxiety might be a perennial excuse here. We have such a long way to go. I expect we’ll have to wait until shame at being the world’s laughing-stock is enough of a motivation.
Adelaide’s Tindo
I’ve been vaguely aware of Adelaide’s ‘green bus’ for some years but, mea culpa, haven’t informed myself in any depth up until now. The bus is called Tindo, which is a Kaurna aboriginal word meaning the sun. Apparently it’s the world’s first and only completely solar powered electric bus, which is quite amazing. The bus has no solar panels itself, but is charged from the solar panels at the Franklin Street bus station in the city centre. It’s been running for over four years now and I’m planning to take a trip on it in the very near future. I was going to say that it’ll be the first time I’ve been on a completely electric vehicle with no internal combustion engine but I was forgetting that I take tram trips almost every day. Silly me. Still, to take a trip on a bus with no noisy engine and no exhaust fumes will be a bit of a thrill for me. Presumably there will be no gear system either, and of course it’ll have regenerative braking – I’m still getting my head around this stuff – so the ride will be much less jerky than usual.
So here are some of the ‘specs’ I’ve learned about Tindo. It has a range of over 200 kilometres (and presumably this is assisted by the fact that its route is fixed and totally urban, so the regen braking system will be charging it up regularly). It uses 11 Swiss-made Zebra battery modules which are based on sodium nickel chloride, a type of molten salt technology. They have higher energy density, they’re lightweight and virtually maintenance free. According to the City of Adelaide website the solar PV system on the roof of the bus station is (or was – the website is annoyingly undated) ‘Adelaide’s largest grid-connected system, generating almost 70,000 kWh of electricity a year’. No connection to the ‘carbon-intensive South Australian electricity grid’ is another plus, though to be fair our grid is far less carbon intensive than Victoria’s which is almost all brown coal. South Australia’s grid runs on around half gas and half renewables, mostly wind. The regen braking, I must remind myself, means that when decelerating the bus uses no energy at all, and the motor electronically converts into an electrical generator, which generates electricity with the continued forward motion of the bus. There are many more specs and other bits of info on this Tindo factsheet.