an autodidact meets a dilettante…

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technomagic – the tellingbone

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weirdly wired – the first telephone

The telephone remains the acme of electrical marvels. No other thing does so much with so little energy. No other thing is more enswathed in the unknown.

Herbert Casson ‘The history of the telephone”, 1910. Quoted in “The Information”, J Gleick

I recently had a conversation with someone of my generation about the technology of our childhoods, and how magical they seemed to us. So let me start with the motor car, or auto-mobile. Our first family car was a Hillman Minx, which was bought in maybe 1964 or so, not too long after we arrived in Australia. The model probably dated from the early or mid-fifties – we certainly weren’t wealthy enough to buy a brand new car. But that didn’t make it any less magical. How was it that you could turn a key and bring an engine to life, and with a bit of footwork and handiwork get the beast to move backward and forward and get its engine to putter or roar? I hadn’t the foggiest.

Next in the mid-sixties came the television box, fired by electrickery. Somehow, due to wires and signals, we could see a more or less fuzzy image of grey figures from faraway, giving us news of Britain and the World Cup, and shows from the USA like Hopalong Cassidy and the Cisco Kid, all made from faraway – even one day from the moon – for our entertainment and enlightenment. Wires and signals, I mean, WTF?

Next we became the first people in the street to have our own tellingbone (or that’s what we proudly told ourselves, actually we had no idea). So people would ring us from the other side of town and then talk to us as if they were standing right next to us!! It was crazy-making, yet people seemed generally to remain as sane as they had been. I would lie in bed trying to work it out. So someone would dial a number, and more or less instantaneously a ringing sound would come out of the phone miles and miles away, and a person there would pick up this bone-shaped piece of plastic with holes in it, and they would talk into one end and listen through the other end, and they could hear this person on the ‘end of the line’ miles away far better than they could hear someone else talking in the next room, all thanks, we were informed, to those wires and signals again.

So, forward to adulthood. One of the most informative books I’ve read in recent years is titled, appropriately enough, The Information, by James Gleick. It’s a history of information processing and communication from tribal drumming to the latest algorithms, and inter alia it tells the story of how the telephone became one of the most rapidly universalised forms of information transfer in human history in the period 1870-1900, approximately. And of course it didn’t come into existence out of nowhere. It replaced the telegraph, the first electrical telecommunications system, itself only a few decades old. Previous to this there were many experiments and developments in the field by the likes of Alessandro Volta, Johann Schweigger and Pavel Schilling. Studying electricity and its potential was the hottest of scientific activities throughout the 19th century, especially the first half.

The telegraph, though, was a transmission-reception system run by experts, making it very unlike the telephone. Gleick puts it thus:

The telegraph demanded literacy; the telephone embraced orality. A message sent by telegraph had first to be written, encoded and tapped out by a trained intermediary. To employ the telephone, one just talked. A child could use it.

Nevertheless the system of poles and wires, the harnessing of electricity, and the concepts of signal and noise (both abstract and exasperatingly practical) had all been dealt with to varying degrees of success well before the telephone came along.

So now let’s get into the basic mechanics. When we talk into a phone we produce patterned sound waves, a form of mechanical energy. Behind the phone’s mouthpiece is a diaphragm of thin metal. It vibrates at various speeds according to the patterned waves striking it. The diaphragm is attached to a microphone, which in the early phones consisted simply of carbon grains in a container attached to an electric current, which were compressed to varying degrees in response to the waves vibrating the diaphragm, modulating the current. That current flows through copper wires to a box outside your home which connects with other wires and cables in a huge telecommunications system.

Of course the miracle to us, or to me, is how a sound wave signal, moving presumably more or less at the speed of sound, and distinctive for every human (not to mention dogs, birds etc), can be converted to an electrical signal, moving presumably at some substantial fraction of the speed of light, then at the end of its journey be converted back to a mechanical signal with such perfect fidelity that you can hear the unmistakeable tones of your grandmother at the other end of the line in real time. The use of terms such as analogue and digitising don’t quite work for me, especially when combined with the word ‘simply’, which is often used. In any case, the process is commonplace enough, and has been used in radio, in recorded music and so forth.

It all bears some relation to the work of the greatest physical theorist of the 19th century, James Clerk Maxwell, who recognised and provided precise relationships between electrical impulses, magnetism and light, bringing the new and future technologies together, to be amplitude-modified by engineers who needed to understand the technicalities of input, output, feedback, multiplexing, and signal preservation. But as the possibilities of the new technology expanded, so did technological expertise, and switchboards and networks became increasingly complex. They eventually required a numbering system to keep track of users and connections, and telephone directories were born, only to grow in size and number, costing acres of forestry, until in the 21st century they didn’t. I won’t go into the development of mobile and smartphones here, those little black boxes of mystery which I might one day try to peer inside, but I think I’ve had enough armchair demystifying of the technomagical for one day.

Yet something I didn’t think of as a child was that the telephone was no more technomagical than just speaking and listening to the person beside you. To speak, to make words and sentences out of sounds, first requires a sound-maker (a voice-box, to employ a criminally simplistic term), then a complex set of sound-shapers (the tongue, the soft and hard palates, the teeth and lips) into those words and sentences. Once they leave the speaker’s lips they make waves in the air – complex and variable waves which carry to the hearer’s tympanum, stimulating nerves to send electrical impulses to the auditory cortex. This thinking to speaking to listening to comprehending process is so mundane to us as to breed indifference, but no AI process comes close to matching it.

References

The information, James Gleick, 2011

https://electronics.howstuffworks.com/telephone1.htm

https://www.antiquetelephonehistory.com/telworks.php

https://www.thoughtco.com/how-a-telephone-works-1992551

Written by stewart henderson

March 1, 2019 at 4:31 pm

Useful stuff on extremophiles and their tricks

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A tardigrade or water bear, emblematic creature for extremophile-philes everywhere. Look em up, cause they’re not mentioned in this article

I’ll try to wean myself from the largely thankless task of writing about politics by picking a topic, almost at random, though one that I know will keep me engaged once I get started.

I was reading an article on the geology of the Earth’s crust and upper mantle (aka lithosphere) the other day, which mentioned the possibility of life in the mantle. Little is known for sure about the mantle’s composition and activity, because until recently drilling down to that level has been just a pipe dream, so to speak. The mantle’s distance from the earth’s surface varies considerably from region to region, but the average depth of the crust at its thinnest, ie under the ocean, is about 6 kilometres. In 2011, microscopic nematodes, or roundworms, were found some 4 kilometres below the surface in a gold mine in South Africa. Other single-celled micro-organisms were found in the region, at depths of 5 kms. Since we’ve rarely plumbed such depths, it’s not unreasonable to suppose that life down that far may be commonplace. We already know that life exists under the sea floor, at immense pressures. At the bottom of the Mariana Trench in the western Pacific, bacteria thrive 11 kilometres below sea level, and some bacteria have been tested in the lab as tolerating 1000 atmospheres of pressure.

Of course, the term extremophile, applied to such life forms, is typically anthropocentric, as they would presumably shuffle off their mortal coils tout de suite when subjected to our torturous environment. Then again…

Extremophiles are of course termed as such when found in conditions that are far from what we would term normal. Such conditions include extremely hot or cold environments, highly acidic or alkaline environments, anaerobic environments, and extreme pressure. They include archaea, the earliest living organisms we know of, some of which have been found to be halophilic (thriving in high salt conditions) or hyperthermophilic (lovers of temps around 80°C).

So how far down can these organisms go? What do they live on? What do they look like and how do they relate to other organisms on the bush of life?

This article from National Geographic online suggests the possibility of an ecosystem existing some eight or nine kilometres below the Mariana Trench. The trench is a subduction zone, a region known to provide pro-life environments of sorts. Analysing such regions requires geological as well as microbiological expertise. A geological process known as serpentinisation provides an ecosystem for methane-consuming microbes. Serpentine is a mineral formed deep in the lithosphere ‘when olivine in the upper mantle reacts with water pushed up from within the subduction zone’, according to the article. Hydrogen and methane are by-products of this reaction, and this serpentinisation process is already known to create microbial habitats at oceanic hydrothermal vents. Furthermore, in recent years, serpentinisation has been found ‘everywhere’, at subduction zones and within mountain ranges, suggesting that methane-supported life may be commonplace, and may even exist elsewhere in the solar system where there is tectonic activity, and an abundance of olivine.

Organisms living at great depths, under great pressure, are called piezophiles. So what is it that permits these bacteria, archaea and other unicellular organisms to thrive – or perhaps only just survive – in such conditions? There’s no one-size-fits-all answer, as some, such as xenophyophores, which are found at depth throughout the world’s oceans, are relatively complex creatures that appear to have adapted over time to increased pressure in order to benefit from benthic provender, while others like Halomonas salaria, a proteobacterium, are obligate piezophiles, unable to survive in under 1000 atmospheres. Unsurprisingly the outer membranes of these organisms are necessarily different in structure and composition from your common or garden microbes, but also unsurprisingly, it has proved difficult to analyse the structural features of piezophiles under lab conditions, though it’s clear that regulation of membrane phospholipids is key to maintaining a stable internal environment, which can not only withstand pressure, but also extremes of heat or cold or acidity. Proteins are also modified to maintain function. Although little is yet known about these organisms, the variety of their environments suggest a variety of adaptations independently arrived at. Most are autotrophs, or self-feeders, able to build organic compounds such as proteins through chemosynthesis in the absence of light. Many of them appear able to slow their metabolism and their reproduction rate by many factors.

Researchers are becoming increasingly interested in extremophiles in general, as they’ve widened the possibilities of life in environments hitherto dismissed as unviable – in boiling water or under mountains of ice for example – just as we’ve begun to discover or further explore other planets (and moons) within and beyond our solar system. The field of microbiology has also made great strides in recent decades. Don Cowan, a senior researcher at the University of Pretoria, describes the microbiological ‘revolution’ of the eighties:

In less than a decade, a combination of conceptual, scientific and technical developments all came together. These included the ability to purify total environmental DNA, the development of special marker sequences that can identify different microbial species, and the advent of very fast, very cheap DNA sequencing techniques.

Collectively known as metagenomics, these developments hugely stimulated the field of microbiology. They have done so across diverse areas of science, from biological methods for cleaning up environmental pollution and contamination, to human disease.

Researchers are applying these techniques to the examination and possible exploitation of extremophiles, for example to improve drought or temperature tolerance in plant species, for various pharmaceutical applications and possibly for the development of biofuels, as heat-tolerant enzymes enable plant tissues to be broken down more readily. The range of products and processes that can be improved by tapping into the enzyme production of various types of extremophiles is potentially vast, according to James Coker, a researcher at the University of Maryland’s Department of Biotechnology. In a 2016 paper, Coker admits that research in this field is new, but real progress has already been made:

Four success stories are the thermostable DNA polymerases used in the polymerase chain reaction (PCR) 17, various enzymes used in the process of making biofuels 18, organisms used in the mining process 19, and carotenoids used in the food and cosmetic industries 20. Other potential applications include making lactose-free milk 1; the production of antibiotics, anticancer, and antifungal drugs 6; and the production of electricity or, more accurately, the leaching of electrons to generate current that can be used or stored 21

That last-mentioned application is of particular interest (as are all the others), as clean electricity production and storage is a high priority issue for some. Extremophile microbial catalysts can be used to drive microbial electrochemical systems (MES), a new TLA which may or may not catch on. Related TLAs include the MFC (microbial fuel cell) and the MEC (microbial electrolysis cell). Without losing myself in too much detail here, the exploitation of these microbes to help drive reactions at the electrodes has a number of useful applications, such as the remediation of waste-water, desalination, biosensing and ‘generating electrical energy from marine sediment microbial fuel cells at low temperatures’ (Dopson et al, 2016). None of this is, as yet, set to revolutionise the clean energy industry, but these are just some of the largely unsung incremental developments that are, in fact, moving us towards more clever and efficient use of previously untapped renewable resources. I was about to use the metaphor ‘at the coalface’ – which would’ve been appropriately inappropriate.

It’s impossible for we dilettantes to keep up with all these discoveries and developments in a detailed way, but we can at least feel the excitement of work being done and advances being collaboratively made, as well as sensing the many obstacles and unforeseen complexities involved in transforming the viability of these amazing life-forms and their products into something viable and possibly life-transforming for the humans who have discovered them and unlocked their secrets. When politics and our inhumanity to others (human and non-human) lets us down, we can still marvel at our relentless drive and ingenuity.

 

Written by stewart henderson

July 14, 2018 at 8:50 am

the continuing story of South Australia’s energy solutions

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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.

Written by stewart henderson

February 14, 2018 at 4:50 pm

the battle for and against electric vehicles in Australia, among other things

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Toyota Camry hybrid – hybrids are way outselling pure EVs here, probably due to range anxiety and lack of infrastructure and other support

I’ve probably not been paying sufficient attention, but I’ve just learned that the Federal Energy minister, Josh Frydenberg, is advocating, against the naysayers, for government support to the EV industry. An article today (Jan 22) in The Australian has Frydenberg waxing lyrical about the future of EVs, as possibly being to the transport sector ‘what the iPhone has been to the communication sector’. It’s a battle the future-believers will obviously win. A spokesman for the naysayers, federal Liberal Party MP and AGW-denier Craig Kelly, was just on the gogglebox, mocking the idea of an EV plant in Elizabeth here in South Australia (the town I grew up in), sited in the recently abandoned GM Holden plant. His brilliantly incisive view was that since Holdens failed, a future EV plant was sure to fail too. In other words, Australians weren’t up to making cars, improving their practice, learning from international developments and so forth. Not exactly an Elon Musk attitude.

The electric vehicles for Elizabeth idea is being mooted by the British billionaire Sanjeev Gupta, the ‘man of steel’ with big ideas for Whyalla’s steelworks. Gupta has apparently become something of a specialist in corporates rescues, and he has plans for one of the biggest renewables plants in Australia – solar and storage – at Whyalla. His electric vehicle plans are obviously very preliminary at this stage.

Critics are arguing that EVs are no greener than conventional vehicles. Clearly their arguments are based on the dirty coal that currently produces most of the electricity in the Eastern states. Of course this is a problem, but of course there is a solution, which is gradually being implemented. Kiata wind farm in Western Victoria is one of many small-to medium-scale projects popping up in the Eastern states. Victoria’s Minister for Energy, Environment and Climate Change (an impressive mouthful) Lily D’Ambrosio says ‘we’re making Victoria the national leader in renewable energy’. Them’s fightin words to we South Aussies, but we’re not too worried, we’re way ahead at the moment. So clearly the EV revolution is going hand in hand with the renewable energy movement, and this will no doubt be reflected in infrastructure for charging EVs, sometimes assisted by governments, sometimes in spite of them.

Meanwhile, on the global scale, corporations are slowly shuffling onto the renewables bandwagon. Renew Economy has posted a press release from Bloomberg New Energy Finance, which shows that corporations signed a record volume of power purchase agreements (PPAs) for clean energy in 2017, with the USA shuffling fastest, in spite of, or more likely because of, Trump’s dumbfuckery. The cost-competitiveness of renewables is one of the principal reasons for the uptick, and it looks like 2018 will be another mini-boom year, in spite of obstacles such as reducing or disappearing subsidies, and import tariffs for solar PVs. Anyway, the press release is well worth a read, as it provides a neat sketch of where things are heading in the complex global renewables market.

Getting back to Australia and its sluggish EV market, the naysayers are touting a finding in the Green Vehicle Guide, a federal government website, which suggested that a Tesla powered by a coal-intensive grid emitted more greenhouse gas than a Toyota Corolla. All this is described in a recent SMH article, together with a 2016 report, commissioned by the government, which claimed that cars driven in the Eastern states have a “higher CO2 output than those emitted from the tailpipes of comparative petrol cars”. However, government spokespeople are now admitting that the grid’s emission intensity will continue to fall into the future, and that battery efficiency and EV performance are continuously improving – as is obvious. Still, there’s no sign of subsidies for EVs from this government, or of future penalties for diesel and petrol guzzlers. Meanwhile, the monstrous SUV has become the vehicle of choice for most Australians.

While there are many many honourable exceptions, and so many exciting clean green projects up and running or waiting in the wings, the bulk of Australians aren’t getting the urgency of climate change. CO2 levels are the highest they’ve been in 15 million years (or 3 million, depending on website), and the last two years’ published recordings at Mauna Loa (2015 and 2016) showed increases in atmospheric CO2 of 3PPM for each year, for the first time since recording began in 1960 (when it was under 1PPM). This rate of CO2 growth, apparently increasing – though with variations due largely to ENSO – is phenomenal. There’s always going to be a see-saw in the data, but it’s an ever-rising see-saw. The overall levels of atmospheric CO2 are now well above 400PPM. Climate Central describes these levels as ‘permanent’, as if humans and their effects will be around forever – how short-sighted we all are.

The relationship between atmospheric CO2 and global warming is fiendishly complex, and I’ll try, with no doubt limited success, to tackle it in future posts.

 

Mustn’t forget my update on Trump’s downfall: the Mueller team has very recently interviewed A-G Sessions, who’s been less than honest about his meetings with Russians. Nobody knows what Sessions was asked about in in his lengthy session (haha) with the inquirers, but he’s a key figure when it comes to obstruction of justice as well as conspiracy. Word now is that Trump himself will be questioned within weeks, which could be either the beginning of the end, or just the end. Dare to hope.

 

Written by stewart henderson

January 26, 2018 at 10:26 am

more on Australia’s energy woes and solutions

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the SA Tesla Powerpack, again

Canto: So the new Tesla battery is now in its final testing phase, so South Australia can briefly enjoy some fame as having the biggest battery in the world, though I’m sure it’ll be superseded soon enough with all the activity worldwide in the battery and storage field.

Jacinta: Well I don’t think we need to get caught up with having the biggest X in the world, it’s more important that we’re seen as a place for innovation in energy storage and other matters energetic. So, first, there’s the Tesla battery, associated with the Hornsdale wind farm near Jamestown, and there are two other major battery storage systems well underway, one in Whyalla, designed for Whyalla Steel, to reduce their energy costs, and another smaller system next to AGL’s Wattle Point wind farm on Yorke Peninsula.

Canto: Well, given that the federal government likes to mock our Big Battery, can you tell me how the Tesla battery and the other batteries work to improve the state?

Jacinta: It’s a 100MW/129MWh installation, designed to serve two functions. A large portion of its stored power (70MW/39MWh) is for the state government to stabilise the grid in times of outage. Emergency situations. This will obviously be a temporary solution before other, slower reacting infrastructure can be brought into play. The rest is owned by Neoen, Tesla’s partner company and owner of the wind farm. They’ll use it to export at a profit when required – storing at low prices, exporting at higher prices. As to the Whyalla Steel battery, that’s privately owned, but it’s an obvious example, along with the AGL battery, of how energy can be produced and stored cleanly (Whyalla Steel relies on solar and hydro). They point the way forward.

Canto: Okay here’s a horrible question, because I doubt if there’s any quick ‘for dummies’ answer. What’s the difference between megawatts and megawatt-hours?

Jacinta: A megawatt, or a watt, is a measure of power, which is the rate of energy transfer. One watt equals one joule per second, and a megawatt is 1,000,000 watts, or 1,000 kilowatts. A megawatt-hour is one megawatt of power flowing for one hour.

Canto: Mmmm, I’m trying to work out whether I understand that.

Jacinta: Let’s take kilowatts. A kilowatt (KW) is 1,000 times the rate of energy transfer of a watt. In other words, 1000 joules/sec. One KWh is one hour at that rate of energy transfer. So you multiply the 1000 by 3,600, the number of seconds in an hour. That’s a big number, so you can express it in megajoules – the answer is 3.6Mj. One megajoule equals 1,000,000 joules of course.

Canto: Of course. So how is this working for South Australia’s leadership on renewables and shifting the whole country in that direction?

Genex Power site in far north Queensland – Australia’s largest solar farm together with a pumped hydro storage plant

Jacinta: Believe me it’s not all South Australia. There are all sorts of developments happening around the country, mostly non-government stuff, which I suppose our rightist, private enterprise feds would be very happy with. For example there’s the Genex Power solar, hydro and storage project in North Queensland, situated in an old gold mine. Apparently pumped hydro storage is a competitor with, or complementary to, battery storage. Simon Kidston, the Genex manager, argues that many other sites can be repurposed in this way.

Canto: And the cost of wind generation and solar PV is declining at a rate far exceeding expectations, especially those of government, precisely because of private enterprise activity.

Jacinta: Well, mainly because it’s a global market, with far bigger players than Australia. Inputs into renewables from states around the world – India, Mexico, even the Middle East – are causing prices to spiral down.

Canto: And almost as we speak the Tesla gridscale battery has become operational, and we’ve gained a tiny place in history. But what about this National Energy Guarantee from the feds, which everyone seems to be taking a swing at. What’s it all about?

Jacinta: This was announced a little over a month ago, as a rejection of our chief scientist’s Clean Energy Target. Note how the Feds again avoid using such terms as ‘clean’ and ‘renewable’ when it talks or presents energy policy. Anyway, it may or may not be a good thing – there’s a summary of what some experts are saying about it online, but most are saying it’s short on detail. It’s meant to guarantee a reliable stream of energy/electricity from retailers, never mind how the energy is generated – so the government can say it’s neither advocating nor poo-pooing renewables, it’s getting out of the way and letting retailers, some of whom are also generators, deliver the energy from whatever source they like, or can.

Canto: So they’re putting the onus on retailers. How so?

Jacinta: The Feds are saying retailers will have to make a certain amount of dispatchable power available, but there is one ridiculously modest stipulation – greenhouse emissions from the sector must be reduced by 26% by 2030. The sector can and must do much better than that. The electricity sector makes up about a third of emissions, and considering the slow movement on EVs and on emissions reductions generally, we’re unlikely to hold up our end of the Paris Agreement, considering the progressively increasing targets.

Canto: But that’s where they leave it up to the private sector. To go much further than their modest target. They would argue that they’re more interested in energy security.

Jacinta: They have a responsibility for providing security but not for reducing emissions? But it’s governments that signed up to Paris, not private enterprises. The experts are pointing this out with regard to other sectors. More government-driven vehicle emission standards, environmental building regulations, energy efficient industries and so forth.

Canto: And the Feds actually still have a renewable energy agency (ARENA), in spite of the former Abbott government’s attempt to scrap it, and a plan was announced last month to set up a ‘demand response’ trial, involving ARENA, AEMO (the energy market operator) and various retailers and other entities. This is about providing temporary supply during peak periods – do you have any more detail?

Jacinta: There’s a gloss on the demand response concept on a Feds website:

From Texas to Taiwan, demand response is commonly used overseas to avoid unplanned or involuntary outages, ease electricity price spikes and provide grid support services. In other countries, up to 15 per cent of peak demand is met with demand response.

Canto: So what exactly does it have to do with renewables?

Jacinta: Well get ready for a long story. It’s called demand response because it focuses on the play of demand rather than supply. It’s also called demand management, a better name I think. It’s partly about educating people about energy not being a finite commodity available at all times in equal measure…

Canto: Sounds like it’s more about energy conservation than about the type of energy being consumed.

Jacinta: That’s true. So on extreme temperature days, hot or cold – but mostly hot days in Australia – electricity demand can jump by 50% or so. To cope with these occasional demand surges we’ve traditionally built expensive gas-based generators that lie idle for most of the year. For reasons I’m not quite able to fathom, at such extreme demand times the ‘spot price’ for wholesale electricity goes through the roof – or more accurately it hits the ceiling, set by the National Energy Market at $14,000 per MWh. That’s just a bit more than the usual wholesale price, about $100/MWh. Demand management is an attempt to have agreements with large commercial/industrial users to reduce usage at certain times, or the agreements could be with energy retailers who then do deals with customers. Of course, bonuses could be handed out to compliant customers. The details of how this offsets peak demand usage and pricing are still a bit of a mystery to me, however.

Written by stewart henderson

December 9, 2017 at 9:07 pm

on electrickery, part 2 – the beginnings

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William Gilbert, author of De Magnete, 1600

Canto: So let’s now start at the beginning. What we now call electricity, or even electromagnetism, has been observed and questioned since antiquity. People would’ve wondered about lightning and electrostatic shocks and so forth.

Jacinta: And by an electrostatic shock, you mean the sort we get sometimes when we touch a metal door handle? How does that work, and why do we call it electrostatic?

Canto: Well we could do a whole post on static electricity, and maybe we should, but it happens when electrons – excess electrons if you like – move from your hand to the conductive metal. This is a kind of electrical discharge. For it to have happened you need to have built up electric charge in your body. Static electricity is charge that builds up through contact with clothing, carpet etc. It’s called static because it has nowhere to go unless it comes into contact with a positive conductor.

Jacinta: Yes and it’s more common on dry days, because water molecules in the atmosphere help to dissipate electrons, reducing the charge in your body.

Canto: So the action of your shoes when walking on carpet – and rubber soles are worst for this – creates a transfer of electrons, as does rubbing a plastic rod with wooden cloth. In fact amber, a plastic-like tree resin, was called ‘elektron’ in ancient Greek. It was noticed in those days that jewellery made from amber often stuck to clothing, like a magnet, causing much wonderment no doubt.

Jacinta: But there’s this idea of ‘earthing’, can you explain that?

Canto: It’s not an idea, it’s a thing. It’s also called grounding, though probably earthing is better because it refers to the physical/electrical properties of the Earth. I can’t go into too much detail on this, its complexity is way above my head, but generally earthing an electrical current means dissipating it for safety purposes – though the Earth can also be used as an electrical conductor, if a rather unreliable one. I won’t go any further as I’m sure to get it wrong if I haven’t already.

Jacinta: Okay, so looking at the ‘modern’ history of our understanding of electricity and magnetism, Elizabethan England might be a good place to start. In the 1570s mathematically minded seamen and navigators such as William Borough and Robert Norman were noting certain magnetic properties of the Earth, and Norman worked out a way of measuring magnetic inclination in 1581. That’s the angle made with the horizon, which can be positive or negative depending on position. It all has to do with the Earth’s magnetic field lines, which don’t run parallel to the surface. Norman’s work was a major inspiration for William Gilbert, physician to Elizabeth I and a tireless experimenter, who published De Magnete (On the Magnet – the short title) in 1600. He rightly concluded that the Earth was itself a magnet, and correctly proposed that it had an iron core. He was the first to use the term ‘electric force’, through studying the electrostatic properties of amber.

Canto: Yes, Gilbert’s work was a milestone in modern physics, greatly influencing Kepler and Galileo. He collected under one head just about everything that was known about magnetism at the time, though he considered it a separate phenomenon from electricity. Easier for me to talk in these historical terms than in physics terms, where I get lost in the complexities within a few sentences.

Jacinta: I know the feeling, but here’s a relatively simple explanation of earthing/grounding from a ‘physics stack exchange’ which I hope is accurate:

Grounding a charged rod means neutralizing that rod. If the rod contains excess positive charge, once grounded the electrons from the ground neutralize the positive charge on the rod. If the rod is having an excess of negative charge, the excess charge flows to the ground. So the ground behaves like an infinite reservoir of electrons.

So the ground’s a sink for electrons but also a source of them.

Canto: Okay, so if we go the historical route we should mention a Chinese savant of the 11th century, Shen Kuo, who wrote about magnetism, compasses and navigation. Chinese navigators were regularly using the lodestone in the 12th century. But moving into the European renaissance, the great mathematician and polymath Gerolamo Cardano can’t be passed by. He was one of the era’s true originals, and he wrote about electricity and magnetism in the mid-16th century, describing them as separate entities.

Jacinta: But William Gilbert’s experiments advanced our knowledge much further. He found that heat and moisture negatively affected the ‘electrification’ of materials, of which there were many besides amber. Still, progress in this era, when idle curiosity was frowned upon, was slow, and nothing much else happened in the field until the work of Otto von Guericke and Robert Boyle in the mid-17th century. They were both interested particularly in the properties, electrical and otherwise, of vacuums.

Canto: But the electrical properties of vacuum tubes weren’t really explored until well into the 18th century. Certain practical developments had occurred though. The ‘electrostatic machine’ was first developed, in primitive form, by von Guericke, and improved throughout the 17th and 18th centuries, but they were often seen as little more than a sparky curiosity. There were some theoretical postulations about electrics and non-electrics, including a duel-fluid theory, all of which anticipated the concept of conductors and insulators. Breakthroughs occurred in the 1740s with the invention of the Leyden Jar, and with experiments in electrical signalling. For example, an ingenious experiment of 1746, conducted by Jean-Antoine Nollet, which connected 200 monks by wires to form a 1.6 kilometre circle, showed that the speed of electrical transmission was very high! Experiments in ‘electrotherapy’ were also carried out on plants, with mixed results.

Jacinta: And in the US, from around this time, Benjamin Franklin carried out his experiments with lightning and kites, and he’s generally credited with the idea of positive to negative electrical flow, though theories of what electricity actually is remained vague. But it seems that Franklin’s fame provided impetus to the field. Franklin’s experiments connected lightning and electricity once and for all, though similar work, both experimental and theoretical, was being conducted in France, England and elsewhere.

Canto: Yes, there’s a giant roll-call of eighteenth century researchers and investigators – among them Luigi Galvani, Jean Jallabert, John Canton, Ebenezer Kinnersley, Giovanni Beccaria, Joseph Priestley, Mathias Bose, Franz Aepinus, Henry Cavendish, Charles-Augustin Coulomb and Alessandro Volta, who progressed our understanding of electrical and magnetic phenomena, so that modern concepts like electric potential, charge, capacitance, current and the like, were being formalised by the end of that century.

Jacinta: Yes, for example Coulomb discovered, or published, a very important inverse-square law in 1784, which I don’t have the wherewithal to put here mathematically, but it states that:

The magnitude of the electrostatic force of attraction between two point charges is directly proportional to the product of the magnitudes of charges and inversely proportional to the square of the distance between them.

This law was an essential first step in the theory of electromagnetism, and it was anticipated by other researchers, including Priestley, Aepinus and Cavendish.

get it?

Canto: And Volta produced the first electric battery, which he demonstrated before Napoleon at the beginning of the 19th century.

Jacinta: And of course this led to further experimentation – almost impossible to trace the different pathways and directions opened up. In England, Humphrey Davy and later Faraday conducted experiments in electrochemistry, and Davy invented the first form of electric light in 1809. Scientists, mathematicians, experimenters and inventors of the early nineteenth century who made valuable contributions include Hans Christian Orsted, Andre-Marie Ampere, Georg Simon Ohm and Joseph Henry, though there were many others. Probably the most important experimenter of the period, in both electricity and magnetism, was Michael Faraday, though his knowledge of mathematics was very limited. It was James Clerk Maxwell, one of the century’s most gifted mathematicians, who was able to use Faraday’s findings into mathematical equations, and more importantly, to conceive of the relationship between electricity, magnetism and light in a profoundly different way, to some extent anticipating the work of Einstein.

Canto: And we should leave it there, because we really hardly know what we’re talking about.

Jacinta: Too right – my reading up on this stuff brings my own ignorance to mind with the force of a very large electrostatic discharge….

now try these..

Written by stewart henderson

October 22, 2017 at 10:09 am

On electrickery, part 1 – the discovery of electrons

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Canto: This could be the first of a thousand-odd parts, because speaking for myself it will take me several lifetimes to get my head around this stuff, which is as basic as can be. Matter and charge and why is it so and all that.

Jacinta: so let’s start at random and go in any direction we like.

Canto: Great plan. Do you know what a cathode ray is?

Jacinta: No. I’ve heard of cathodes and anodes, which are positive and negative terminals of batteries and such, but I can’t recall which is which.

Canto: Don’t panic, Positive is Anode, Negative ICathode. Though I’ve read somewhere that the reverse can sometimes be true. The essential thing is they’re polar opposites.

Jacinta: Good, so a cathode ray is some kind of negative ray? Of electrons?

Canto: A cathode ray is defined as a beam of electrons emitted from the cathode of a high-vacuum tube.

Jacinta: That’s a pretty shitty definition, why would a tube, vacuum or otherwise, have a cathode in it? And what kind of tube? Rubber, plastic, cardboard?

Canto: Well let’s not get too picky. I’m talking about a cathode ray tube. It’s a sealed tube, obviously, made of glass, and evacuated as far as possible. Sciencey types have been playing around with vacuums since the mid seventeenth century – basically since the vacuum pump was invented in 1654, and electrical experiments in the nineteenth century, with vacuum tubes fitted with cathodes and anodes, led to the discovery of the electron by J J Thomson in 1897.

Jacinta: So what do you mean by a beam of electrons and how is it emitted, and can you give more detail on the cathode, and is there an anode involved? Are there such things as anode rays?

Canto: I’ll get there. Early experiments found that electrostatic sparks travelled further through a near vacuum than through normal air, which raised the question of whether you could get a ‘charge’, or a current, to travel between two relatively distant points in an airless tube. That’s to say, between a cathode and an anode, or two electrodes of opposite polarity. The cathode is of a conducting material such as copper, and yes there’s an anode at the other end – I’m talking about the early forms, because in modern times it starts to get very complicated. Faraday in the 1830s noted a light arc could be created between the two electrodes, and later Heinrich Geissler, who invented a better vacuum, was able to get the whole tube to glow – an early form of ‘neon light’. They used an induction coil, an early form of transformer, to create high voltages. They’re still used in ignition systems today, as part of the infernal combustion engine

Jacinta: So do you want to explain what a transformer is in more detail? I’ve certainly heard of them. They ‘create high voltages’ you say. Qu’est-ce que ça veux dire?

Canto: Do you want me to explain an induction coil, a transformer, or both?

Jacinta: Well, since we’re talking about the 19th century, explain an induction coil.

Canto: Search for it on google images. It consists of a magnetic iron core, round which are wound two coils of insulated copper, a primary and secondary winding. The primary is of coarse wire, wound round a few times. The secondary is of much finer wire, wound many many more times. Now as I’ve said, it’s basically a transformer, and I don’t know what a transformer is, but I’m hoping to find out soon. Its purpose is to ‘produce high-voltage pulses from a low-voltage direct current (DC) supply’, according to Wikipedia.

Jacinta: All of this’ll come clear in the end, right?

Canto: I’m hoping so. When a current – presumably from that low-volage DC supply – is passed through the primary, a magnetic field is created.

Jacinta: Ahh, electromagnetism…

Canto: And since the secondary shares the core, the magnetic field is also shared. Here’s how Wikipedia describes it, and I think we’ll need to do further reading or video-watching to get it clear in our heads:

The primary behaves as an inductor, storing energy in the associated magnetic field. When the primary current is suddenly interrupted, the magnetic field rapidly collapses. This causes a high voltage pulse to be developed across the secondary terminals through electromagnetic induction. Because of the large number of turns in the secondary coil, the secondary voltage pulse is typically many thousands of volts. This voltage is often sufficient to cause an electric spark, to jump across an air gap (G) separating the secondary’s output terminals. For this reason, induction coils were called spark coils.

Jacinta: Okay, so much for an induction coil, to which we shall no doubt return, as well as to inductors and electromagnetic radiation. Let’s go back to the cathode ray tube and the discovery of the electron.

Canto: No, I need to continue this, as I’m hoping it’ll help us when we come to explaining transformers. Maybe. A key component of the induction coil was/is the interruptor. To have the coil functioning continuously, you have to repeatedly connect and disconnect the DC current. So a magnetically activated device called an interruptor or a break is mounted beside the iron core. It has an armature mechanism which is attracted by the increasing magnetic field created by the DC current. It moves towards the core, disconnecting the current, the magnetic field collapses, creating a spark, and the armature springs back to its original position. The current is reconnected and the process is repeated, cycling through many times per second.

A Crookes tube showing green fluorescence. The shadow of the metal cross on the glass showed that electrons travelled in straight lines

Jacinta: Right so now I’ll take us back to the cathode ray tube, starting with the Crookes tube, developed around 1870. When we’re talking about cathode rays, they’re just electron beams. But they certainly didn’t know that in the 1870s. The Crookes tube, simply a partially evacuated glass tube with cathode and anode at either end, was what Rontgen used to discover X-rays.

Canto: What are X-rays?

Jacinta: Electromagnetic radiation within a specific range of wavelengths. So the Crookes tube was an instrument for exploring the properties of these cathode rays. They applied a high DC voltage to the tube, via an induction coil, which ionised the small amount of air left in the tube – that’s to say it accelerated the motions of the small number of ions and free electrons, creating greater ionisation.

x-rays and the electromagnetic spectrum, taken from an article on the Chandra X-ray observatory

Canto: A rapid multiplication effect called a Townsend discharge.

Jacinta: An effect which can be analysed mathematically. The first ionisation event produces an ion pair, accelerating the positive ion towards the cathode and the freed electron toward the anode. Given a sufficiently strong electric field, the electron will have enough energy to free another electron in the next collision. The  two freed electrons will in turn free electrons, and so on, with the collisions and freed electrons growing exponentially, though the growth has a limit, called the Raether limit. But all of that was worked out much later. In the days of Crookes tubes, atoms were the smallest particles known, though they really only hypothesised, particularly through the work of the chemist John Dalton in the early nineteenth century. And of course they were thought to be indivisible, as the name implies.

Canto: We had no way of ‘seeing’ atoms in those days, and cathode rays themselves were invisible. What experimenters saw was a fluorescence, because many of the highly energised electrons, though aiming for the anode, would fly past, strike the back of the glass tube, where they excited orbital electrons to glow at higher energies. Experimenters were able to enhance this fluorescence through, for example, painting the inside walls of the tube with zinc sulphide.

Jacinta: So the point is, though electrical experiments had been carried out since the days of Benjamin Franklin in the mid-eighteenth century, and before, nobody knew how an electric current was transmitted. Without going into much detail, some thought they were carried by particles (like radiant atoms), others thought they were waves. J J Thomson, an outstanding theoretical and mathematical physicist, who had already done significant work on the particulate nature of matter, turned his attention to cathode rays and found that their velocity indicated a much lighter ‘element’ than the lightest element known, hydrogen. He also found that their velocity was uniform with respect to the current applied to them, regardless of the (atomic) nature of the gas being ionised. His experiments suggested that these ‘corpuscles’, as they were initially called, were 1000 times lighter than  hydrogen atoms. His work was clearly very important in the development of atomic theory – which in large measure he initiated – and he developed his own ‘plum pudding’ theory of atomic structure.

Canto: So that was all very interesting – next time we’ll have a look at electricity from another angle, shall we?

 

Written by stewart henderson

October 1, 2017 at 8:14 pm