Archive for the ‘solar’ Category
advancing solar 2 – more on electrons, holes, dopants and electromagnetic fields
Jacinta: So in the last post we were joking about the horrors of physicists and engineers manipulating innocent electrons and forcing them to work for us, gratis. It comes to mind that there are people who are intelligently dubious about the manipulations of scientists – Bernard Beckett, in his 2007 book Falling for science, comes to mind, as does Yuval Noah Harari in Homo deus. ‘Scientism’ was used for a while as a pejorative, especially during the debates on the values of religion ‘versus’ science…
Canto: Yeah, but – I don’t want to dwell on this issue now, except to say that the critics of science are usually not very literate on the subject. So we were talking about dopants, which are impurities that can be added to the silicon crystal lattice to mess up its fine balance, so to speak. Boron is an example – it has three electrons ready for bonding, leaving a ‘hole’, a p-type space, and presumably a loose electron to carry the charge. And then there’s phosphorus, which has five such electrons – so one to spare after bonding, which they call an n-type situation. Positive charge carriers (p-type) and negative charge carriers (n-type) is how they describe it.
Jacinta: Right, so they layer these two types together: ‘The positive holes and negative electrons migrate towards each other’. The electrons will jump into the p-type and the holes jump into the n-type [they don’t explain how holes can jump]. This causes an imbalance of charge, because now the p-type side has more negative charges, and the n-type side has more positive charges’. This apparently creates an ‘electromagnetic valve’, which allows, or perhaps forces, electrons to pass through in one direction only.
Canto: This isn’t very clear to me, but let’s continue. Maybe you have to do it, and so see it working, to get a full grasp. So, a sufficiently energetic photon enters the p-type side (the boron-doped side) of the solar cell, knocking an electron loose to float within the material. It will either recombine with a hole, and fail to create a current, or it can enter the electromagnetic field – that valve thing between the p-types and n-types, also called a depletion layer for some reason. The effect, apparently, is that it accelerates the electron into the n-type side, which of course tends to lack p-type ‘holes’, but the electromagnetic field most cruelly prevents the electron from passing back to the p-type side.
Jacinta: Yes, it’s still a bit fuzzy, but on the n-type side some ‘holes’ are somehow transported across this electromagnetic field junction, where they recombine with electrons. so one side of this junction or valve becomes negatively charged, the other positive. This creates a ‘potential difference’, aka a voltage!
Canto: Explained neatly for us as ‘The difference in electric potential between two points, which is defined as the work needed per unit of charge to move a test charge between the two points’. Just saying.
Jacinta: So, as our video-maker tells us, we can then add ‘some mental contacts and an external load circuit’ and we have created a current, presumably, as the electrons will ‘pass along the circuit to recombine with the holes on the other side’. And that’s your solar cell, apparently. But I barely understand a word.
Canto: Well, doing and seeing, as I’ve said. But there’s problem with adding this metal to the upper surface as it blocks some of the light needed for the cell to function effectively. So, problems with solutions that create problems. So engineers keep working on new shapes and materials for optimisation. They’re trying to minimise the metal coverage and electron resistance in getting into the circuit. Topology optimisation is one subject of research, using computerised algorithms.
Jacinta: And it’s fascinating but hardly surprising that this sort of research is producing shapes for solar cells that resemble leaves – which after all are like little solar cells resulting from millions of years of evolution.
Canto: Hmmm, not like ours, plants don’t use the sun to make electricity. But this quote from the video is thought-provoking:
Vascular tissue on a leaf does not perform photosynthesis. It instead brings the water that is essential for photosynthesis to the leaf and extracts the useful products, serving a similar purpose as our electric contacts – so of course plants have developed the perfect shape to optimise the energy they can absorb from the sun… However, most solar cells use a simple grid shape, as it is cheap to manufacture.
Inevitably this means an efficiency loss, measured at around 8%. So, in conclusion, a current silicon solar cell has an efficiency, under lab testing, of around 20%. The drop to 18% shortly after operating has resulted in hundreds of scientific papers, and it seems to have to do with the use of boron, as the drop didn’t occur when boron was replaced with gallium. Something to do with a ‘boron oxygen defect’, so there’s been a lot of work done on trying to reduce the ‘concentration of oxygen impurities in the silicon wafers’, caused by the Czochralski process, the standard process for silicon wafer manufacturing. Almost all silicon solar cells are made this way. Recent research using a special imaging technique found that boron oxygen molecules converted to ‘shallow acceptors’ when exposed to light:
In essence they observed the defects transforming into little electron traps that acted as recombination sites, and thus reduced the time and probability of electrons entering the circuit to do work.
It’s something I can almost grasp. And with this knowledge, engineers, whose grasp is way firmer than mine, can find some kind of fix for the problem and get that efficiency up well beyond the 20% mark.
Jacinta: Well, this has indeed been a knowledge-expanding journey. Pour qu’une chose soit interessante, il suffit de la regarder longtemps. You mentioned the depletion layer, which caught my attention. It’s a central feature of semiconductor physics, also called depletion zone, depletion region, junction region and more. The depletion zone is so called because of the depletion of carriers in the region. Charge carriers presumably. Any rate, this region, and understanding it, is key to understanding the physics of semiconductors. The Wikipedia article on what they call the depletion region is a useful supplementary to our discussion. We might explore all this further, or not, depending on our own depletion levels…
References
The mystery flaw in solar panels (video)
https://en.wikipedia.org/wiki/Depletion_region
advancing solar, the photovoltaic effect, p-type semiconductors and the fiendishness of human manipulation
how to enslave electrons – human, all too human – stolen from E4U
Canto: Back to practical stuff for now (not that integral calculus isn’t practical), and the efficiencies in solar panels among other green technologies. Listening to podcasts such as those from SGU and New Scientist while walking the dog isn’t the best idea, what with doggy distractions and noise pollution from ICEs, so we’re going to take some of the following from another blog, Neurologica, which was also summarised on a recent SGU podcast.
Jacinta: Yes it’s all about improvements in solar panels, and the materials used in them, over the past couple of decades. We’re talking about improvements in lifespan and overall efficiency, not to mention cost to the consumer. Your standard silicon solar panels have improved efficiency since the mid 2000s from around 11% to around 28% – something like a 180% improvement. Is that good maths? Anyway, it’s the cheapest form of new energy and will become cheaper. And there’s also perovskite for different solar applications, and the possibility of quantum hi-tech approaches, using advanced AI technology to sort out the most promising. So the future is virtually impossible for we mere humans to predict.
Canto: Steven Novella, high priest of the SGU and author of the Neurologica post, suggests that with all the technological focus in this field today, who knows what may turn up – ‘researchers are doing amazing things with metamaterials’. He takes a close look at organic solar cells in particular, but these could possibly be combined with silicon and perovskite in the future. Organic solar cells are made from carbon-based polymers, essentially forms of plastic, which can be printed on various substrates. They’re potentially very cheap, though their life-span is not up to the silicon crystal level. However, their flexibility will suit applications other than rooftop solar – car roofs for example. They’re also more recyclable than silicon, which kind of solves the life-span problem. Their efficiency isn’t at the silicon level either, but that of course may change with further research. Scaling up production of these flexible organic solar materials has already begun.
Jacinta: So, I’ve mentioned perovskite, and I barely know what I’m talking about. So… some basic research tells me it’s a calcium titanium oxide mineral composed of calcium titanate (chemical formula CaTiO3), though any material with the ‘perovskite structure’ can be so called. It’s found in the earth’s mantle, in some chondritic meteorites, ejected limestone deposits and in various isolated locations such as the Urals, the Kola Peninsula in Russia, and such other far-flung places as Sweden and Arkansas. But I think the key is in the crystalline structure, which can be found in a variety of compounds.
Canto: Yes, worth watching perovskite developments in the future. I’m currently watching a video from Real Engineering called ‘the mystery flaw of solar panels’, which argues that this flaw has been analysed and solutions are being found. So, it starts with describing the problem – light-induced degradation, and explaining the photovoltaic effect:
The photovoltaic effect is the generation of voltage and electric current in a material upon exposure to light. It is a physical and chemical phenomenon.
Jacinta: Okay can we get clear again about the difference between voltage and current? I know that one is measured in volts and the other in amps but that explains nout.
Canto: Well, here’s one explanation – voltage, or emf, is the difference in electric potential between one point and another. Current is the rate of flow of an electric charge at any particular point. Check the references for more detail on that. Anyway we really are in the middle of a solar revolution, but the flaw in current solar panels is that newly manufactured solar cells are being tested at a little over 20% efficiency, that’s to say, 20% of the energy input from the sun is being converted into electric current. But within hours of operation the efficiency drops to 18% or so. That’s a 10% drop in generation, which becomes quite substantial on a large scale, with solar farms and such. So this is the problem of light-induced degradation, as mentioned. So, to quote the engineering video, ‘[the photovoltaic effect] is where photons of a particular threshold frequency, striking a material, can cause electrons to gain enough energy to free them from their atomic orbits and move freely in the material’. Semiconductors, which are sort of halfway between conductors and insulators, are the best materials for making this happen.
Jacinta: That’s strange, or counter-intuitive. Wouldn’t conductors be the best for getting electrons moving? Isn’t that why we use copper in electric wiring?
Canto: That’s a good question, which we might come back to. The first semiconducting material used, back in the 1880s, was (very expensive) selenium, which managed to create a continuous current with up to 1% efficiency. And so, silicon.
Jacinta: Which is essentially what we use, in inedible chip form, in all our electronic devices. Pretty versatile stuff. Will we always have enough of it?
Canto: Later. So when light hits this silicon crystal material, it can either be reflected, absorbed or neither – it may pass through without effect. Only absorption creates the photovoltaic effect. So, to improve efficiency we need to enhance absorption. Currently 30% of light is reflected from untreated silicon panels. If this wasn’t improved, maximum efficiency could only reach 70%. So we treat the panels with a layer of silicon monoxide reducing reflection to 10%. Add to that a layer of titanium dioxide, taking reflection to as low as 3%. A textured surface further enhances light absorption – for example light might be reflected sideways and hit another bump, where it’s absorbed. Very clever. But even absorbed light only has the potential to bring about the photovoltaic effect.
Jacinta: Yes, in order to create the effect, that is, to get electrons shifted, the photon has to be above a certain energy level, which is interesting, as photons aren’t considered to have mass, at least not when they’re at rest, but I’m not sure if photons ever rest… As the video says, ‘a photon’s energy is defined by multiplying Planck’s constant by its frequency’. That’s E = h.f, where h is Planck’s constant, which has been worked out by illustrious predecessors as 6.62607015 × 10−34 joule-seconds, according to the International System of Units (SI). And with silicon, the photons need an electromotive force of 1.1 electron volts to produce the photovoltaic effect, which can be converted, apparently, to a wavelength of 1,110 nanometres. That’s in the infrared, on the electromagnetic spectrum, near visible light. Any lower, in terms of energy (the lower the energy, the lower the frequency, the longer the wavelength, I believe), will just create heat and little light, a bit like my brain.
Canto: I couldn’t possibly comment on that, but the video goes on to explain that the solar energy we get from the sun, shown on a graph, is partially absorbed by our atmosphere before it reaches our panels. About 4% of the energy reaching us is in the ultraviolet, 44% is in the visible spectrum and 52% is in the infrared, surprisingly enough. Infrared red light has lower energy than visible light but it has a wider spectrum so the total energy emitted is greater. Now, silicon cannot use light above 1,110 nms in wavelength, meaning that some 19% of the sun’s energy can’t be used by our panels.
Jacinta: Yes, and another thing we’re supposed to note is that higher energy light doesn’t release more electrons, just higher energy electrons…
Canto: And presumably they’re talking about the electrons in the silicon structure?
Jacinta: Uhh, must be? So blue light – that’s at the short-wavelength end of the visible spectrum – blue light has about twice the energy of red light, ‘but the electrons that blue light releases simply lose their extra energy in the form of heat, producing no extra electricity. This energy loss results in about 33% of sunlight’s energy being lost.’ So add that 33% to the 19% lost at the long-wavelength end, that’s 52% of potential energy being lost. These are described as ‘spectrum losses’.
Canto: Which all sounds bad, but silicon, or its reaction with photons, has a threshold frequency that ‘balances these two frequency losses’. So, it captures enough of the low-energy wavelengths (the long wavelengths beyond the infra-red), while not losing too much efficiency due to heat. The heat problem can be serious, though, requiring active cooling in some climates, thus reducing efficiency in a vicious circle of sorts. Still, silicon is the best of threshold materials we have, presumably.
Jacinta: So, onto the next piece of physics, which is that there’s more to creating an electric current than knocking an electron free from its place in ye olde lattice, or whatever. For starters, ye olde electron just floats about like a lost lamb.
Canto: No use to anyone.
Jacinta: Yeah, it needs to be forced into doing work for us.
Canto: Because humans are arseholes who make slaves of everything that moves. Free the electrons!
Jacinta: You’ve got it. They need to be forced to work an electric circuit. And interestingly, the hole left when we’ve knocked an electron out of its happy home, that hole is also let loose to roam about like a lost thing. Free electrons, free holes, when they meet, they’re happy but the circuit is dead before it starts.
Canto: This sounds like a tragicomedy.
Jacinta: So we have to reduce the opportunities for electrons and holes to meet. Such is the cruelty of progress. For of course, we must needs use force, taking advantage of silicon’s unique properties. The most excellent crystal structure of the element is due to its having 4 electrons in its outer shell. So it bonds covalently with 4 other silicon atoms. And each of those bonds with 3 others and so on. A very stable balance. So the trick that we manipulative humans use to mess up this divine balance is to introduce impurities called dopants into the mix. If we add boron, which has 3 outer electrons, into the crystal lattice, this creates 3 covalent bonds with silicon, leaving – a hole!
Canto: How fiendishly clever!
Jacinta: It’s called a p-type trick, as it has this ‘positive’ hole just waiting for an electron to fill it. Sounds kind of sexy really.
Canto: Manipulation can be sexy in a perverse way. Stockholm syndrome for electrons?
Jacinta: Okay, there’s a lot more to this, but we’ve gone on long enough. I’ve had complaints that our blog posts are too long. Well, one complaint, because only one or two people read our stuff…
Canto: No matter – at least we’ve learned something. Let’s continue to rise above ourselves and grasp the world!
Jacinta: Okay, to be continued….
References
https://www.theskepticsguide.org/podcasts
https://news.mit.edu/2022/perovskites-solar-cells-explained-0715
The Mystery Flaw of Solar Panels (Real Engineering video)
https://byjus.com/physics/difference-between-voltage-and-current/
Amazing internet, female science communicators and fighting global warming: an interminable conversation 4
from Renew Economy – SA doing quite well
Jacinta: As I’ve said many times – or at least I’ve thought many times – the internet is surely the greatest development in human history for those interested in self-education. Can you think of anything to compare?
Canto: Not really. The printing press was important, but literacy rates were much lower when that came out – which makes me think that universal education, which includes literacy of course, must be up there. But of course it was never really universal, and I suppose neither is the internet, but it appears to have penetrated further and wider, and much faster than any previous technology…
Jacinta: Universal education was more or less compulsory, and so very top-down. Not self-education at all. The internet gives every individual more control…
Canto: And most choose to stay within their own social media bubble. But for those keen to learn, yes the internet just gets more and more fantastic.
Jacinta: And the trend now is for spoken presentations, with bells and whistles, rather than reams of writing, which can be off-putting…
Canto: Well, our stuff is pretend-speak. We don’t do videos because we’re both extremely ugly, and even our voices are hideous, and we haven’t a clue about bells and whistles.
Jacinta: Sigh. Consigned to obscurity, but we must perforce mumble on into the vacuum of our little internet space. Even so, I’d like to enthuse, however impotently, about the many excellent female science presenters out there, with their vodcasts or vlogs or whatever, such as Australia’s Engineering with Rosie, as well as Kathy loves physics and history, Sabine Hossenfelder and Dr Becky. And I’ll keep an eye out for more.
Canto: But of course we still love books. The most recent read has been Saul Griffith’s The Big Switch, a call to action on renewables, particularly here in Australia.
Jacinta: So with a change of government, Australia is now going to try and catch up with the leading nations re renewable energy and generally changing the energy landscape. So it’s time to turn to the Renew Economy website, the best Australian site for what’s happening with renewables. First stop is the bar graph that’s long featured on the site. It shows that the eastern states, Queensland, NSW and Victoria, are the problem states, still heavily reliant on coal. Victoria is arguably worst as it relies on brown coal for about two thirds of its supply.
Canto: And the other two states use black coal, but they’ve developed a lot more solar than Victoria. They are, of course, a lot sunnier than Victoria. What’s the difference between the two coals, in environmental terms?
Jacinta: Black coal, aka anthracite, is generally regarded as a superior fuel. It contains less water than brown coal, aka lignite, and more carbon. You have to use quite a lot more brown coal – maybe 3 times as much – to extract the same amount of energy as anthracite. According to Environment Victoria,
Brown coal is pulverised and then burned in large-scale boilers. The heat is used to boil water and the steam is used to drive turbines that generate electricity. When brown coal is burnt it releases a long list of poisonous heavy metals and toxic chemicals like sulphur dioxide, mercury, particulate matter and nitrogen oxides. By world standards these pollutants are poorly monitored & controlled, and they impose a staggering health cost of up to $800 million every year.
I’ve left in the links, which are to other Environment Victoria articles. Clearly this website isn’t government controlled, as it castigates heavily subsidised ‘boondoggle’ projects intended to keep the brown coal afloat (very problematic for mining). These projects have apparently gone nowhere. However the site does mention the ‘recent’ announcement of an electric vehicle manufacturing plant in the Latrobe Valley, providing at least 500 jobs. But since the article isn’t dated, I don’t know how recent it is. PLEASE DATE YOUR ARTICLES.
Canto: Yeah, and please do your research Jazz. That plant, announced in 2018, was scrapped last November. Apparently it was announced ahead of the 2018 election. And over-hyped, as it was never guaranteed that the ‘promised’ 500 jobs would be created. Politics.
Jacinta: Sad. Manufacturing has been in a sorry state in Australia for years. As Saul Griffith points out, we rely largely on the raw materials – crushed rocks – we export to keep our economy going, but if we could switch to other crushed rocks for the growing renewable energy economy we would be even better off. Further, if we added value through processing this material at home, we might be even better off financially, and we wouldn’t have to import those processed materials as we do now. Our two biggest imports are petrol and cars. If we could produce that stuff here we wouldn’t be paying for another country’s production costs, according to Griffith. Though I’m not quite sure if it’s that simple.
Canto: So you’re talking essentially about manufacturing in Australia. The Reserve Bank (RBA) has an interesting article on this topic, and here’s a quote from the opening summary:
Manufacturing output and employment have fallen steadily as a share of the Australian economy for the past three decades… the increase in the supply of manufactured goods from low-cost sources abroad, exacerbated by the appreciation of the Australian dollar during the period of rising commodity prices, impaired the viability of many domestic manufacturers and precipitated the closure of some manufacturing production over the past decade. While the recent exchange rate depreciation has helped to improve competitiveness of Australian producers, so far there is only limited evidence of a recovery in manufacturing output and investment.
Economics isn’t my strong suit, but I think I understand what ‘exchange rate depreciation’ means. Something like the exchange rate has swung a bit more in our favour (for home-grown manufacturing) than it was before..
Jacinta: But wouldn’t the exchange rate between us and other countries vary greatly from country to country? Or maybe they take an average, that’s to say of the countries we tend to trade with?
Canto: I suppose so. The article goes on to say that manufacturing hasn’t declined so much as commodity exports have increased. Commodities being raw materials, mostly. And by the way, this article is from the June quarter of 2016, and I suspect things have gotten worse for this gap between manufacturing and commodities. So, not so out-of date re trends. It claims that ‘over the 2000s, strong Asian demand for Australian commodities led to a sharp increase in the terms of trade and an appreciation of the Australian dollar’.
Jacinta: Well, we all appreciate the Aussie dollar…
Canto: Appreciation just means a rise in value. An increase in the terms of trade means an increase in the trading price agreed by any two countries, for example Australia and China, our big bogey man trading partner. Here it might mean beneficial terms of trade for Australia specifically. So basically, manufacturing has stagnated, and declined as a percentage of total output, which includes commodities. Manufacturing industries as an employer have declined quite sharply – as I can personally attest to. I’ve worked in five different factories in my life, all of which have since closed down – for which I take no responsibility.
Jacinta: So there would be a lack of skilled workers in manufacturing, unless… do we make solar panels here? And what about the old car factories we had here – Mitsubishis and Holdens, remember? Though I presume making EVs would require a whole different skill-set, and besides, wouldn’t it be largely automated?
Canto: Well, in February – that’s 2022 – the Australia Institute posted a highly optimistic media release entitled ‘Australia ready to become sustainable EV-making powerhouse: new research’. And with the new federal government elected in May, this hope, expressed in a report from the AI’s Carmichael Centre, Rebuilding Vehicle Manufacturing in Australia: Industrial Opportunities in an Electrified Future, may actually be realised, at least partially. But before I explore that report – solar photovoltaic manufacturing in Australia. A recent (early July) Guardian article reports that ‘China controls over 80% of the global photovoltaic (PV) solar supply chain, with one out of every seven panels produced worldwide being manufactured by a single factory’. And China is actually increasing production, so as to dominate the market. Diversification is urgently required. Meanwhile, Australia is suffering a labour shortage in the field. The International Energy Agency (IEA) has found that ‘one in three installation jobs in Australia – including electricians and installers – were unfilled and at risk of remaining unfilled in 2023’. Tindo Solar is our only home-grown PV manufacturer, and is expanding its output, but clearly this is dwarfed by China’s production. Also there’s a problem with expending production here because, currently, it actually creates more carbon emissions. We need to ‘create renewables with renewables’, which local experts are saying is now more cost-effective than ever. So, back to the report on vehicle manufacturing in Australia. It’s a job trying to access the full report, so I’ll rely on the media release. It describes our country as ‘uniquely blessed’ to rebuild our car manufacturing capabilities, retooled to EVs, but this will require essential government input – a view very much consistent with Griffith’s. Here are some of the recommendations from the report:
- Establishing an EV Manufacturing Industry Commission
- Using tax incentives to encourage firms involved in the extraction of key minerals – primarily lithium and rare earths – with local manufacturing capabilities, especially emerging Australian EV battery industries
- Introducing a long-term strategy for vocational training, ensuring the establishment of skills to service major EV manufacturers looking to set up operations Australia
- Offering major global manufacturers incentives (tax incentives, access to infrastructure, potential public capital participation, etc) to set up – especially in Australian regions undergoing transition from carbon-intensive industries
- Introducing local procurement laws for the rapid electrification of government vehicle fleets
Jacinta: So, as Griffith points out, we need to do some lobbying for this ourselves. Here in SA, we have a sympathetic state government as well as a federal government keen to make up for lost time, or at least saying all the right things. Where do we start?
Canto: The Clean Energy Council has a website that encourages everyone to get educated (they cite a number of resources such as Renew Economy and ARENA), to spread the word, and of course to actually invest in renewable energy, which we, as impoverished public housing renters, aren’t in a great position to do, though we are trying to get our Housing Association to explore renewable options, and to lobby the government in our name.
Jacinta: I think I’m starting to feel more optimistic…
References
Saul Griffith, The big switch: Australia’s electric future. 2022
Difference Between Black and Brown coal
Nem Watch
Australia ready to become sustainable EV-making powerhouse: new research
https://www.carmichaelcentre.org.au/rebuilding_vehicle_manufacture_in_australia
all renewable energy by 2050? Hang on a tick
Sir David McKay, who died in 2016 of stomach cancer, aged 49. A great loss.
The late Sir David McKay, physicist, engineer, sustainable energy expert, Cambridge professor and Royal Society Fellow, has just become known to me through his 2012 TED talk and a lengthier exposition of the same ideas presented at Harvard. These talks were designed, to ‘cut through some of the greenwash’ and provide a realistic account of what can be done, on both the supply and the demand side, to reduce fossil fuel consumption and transform our energy economy.
As I need to keep saying, I’m far from an expert on this stuff, and I’m always impressed by the ingenious developments in the field and the promise of new technology, in batteries and other storage systems – like the compressed air underwater energy storage system being trialled in Lake Ontario, Toronto. But McKay’s contributions are helping me to think more realistically about the enormity of the problem of weaning ourselves from fossil fuels as well as to think more practically about my own domestic usage and the demand side more generally.
While McKay was no renewable energy sceptic or climate change denier, his ‘arithmetical’ view of the future poured a lot of cold hydro on the rosy idea that we’d be living in an all-renewables-powered biosphere within x decades. So I want to take a closer look at some aspects of what he was saying (he also wrote a highly-regarded book, Sustainable energy – without the hot air, available free online).
I particularly want to look at two forms of renewable energy that he talked about; wind and solar. He also talked at some length about two other energy sources, biofuels and nuclear, but I’ve never been much keen on biofuels, which in any case seem to have been largely taken off the menu in recent years, and nuclear, as McKay admits, has a popularity problem – a massive one here in Australia, unfortunately. What I say here about wind and solar will be gleaned largely fromMackay’s Harvard talk, but I’ve downloaded and plan to read his book in the near future.
Mackay has calculated that the current energy production of wind turbines in windy Britain is about 2.5 watts per square metre, and by multiplying per capita energy consumption by population density, you get power consumed per unit area, which for Britain is about 1.25 watts per square metre. This suggests that to cover the consumption of Britain solely by wind, you’d need an area, on land or sea, half the area of Britain. This is clearly not feasible, though of course nobody in Britain, I hope, was ever expecting to have all their energy needs provided by wind. The situation is vastly different for South Australia, two thirds of which is currently powered by wind. SA has vastly more land than Britain and vastly less people.
Though I’m sure it’s possible to quibble with Mckay’s figures and calculations, what he brings to the issues, I think, is a global, as well as a particular perspective that can be lost when you focus, as I have, on local success. For example, South Australia has been very successful in its deployment of wind power over a short period of time, and it’s easy to get carried away and think, if we can do it, why not state x or country y? But SA is a state with a small population and a very large area, and plenty of wind to capture. This just can’t be replicated in, say, Massachussetts, with more than three times the population, a thirtieth of the area, and little wind.
So McKay wasn’t offering global solutions, nor was he dismissing local ones. He was simply pointing out the complexity of the problem in physical and arithmetical terms of weaning ourselves from fossil fuels, as well as getting us thinking about our personal responsibilities on the demand side. Solar isn’t much of a national solution in Britain, though it could be in Australia, which could be a net exporter of renewables, as Elon Musk has suggested, but to which countries, and how exactly do you export solar energy? You’d need conversion and transmission and bilateral agreements. All of this while fighting entrenched interests and upsetting long-standing arrangements. Having said this, more people are hopping on the renewables bus and it’s almost becoming unfashionable, in most western countries outside of Australia, to be dismissive of them, a noticeable change in the last decade.
So what’s the point of this post? It’s to heed McKay’s advice that we need to recognise the complexity of the problem, to keep all possible reasonable solutions on the table, to become more aware, as individuals, communities and states, of our energy consumption, and to recognise that there’s never going to be a one-type-fits-all fix. Environments and needs vary widely, so we need to find particular solutions and we also need to find ways of joining and mixing those solutions together in effective networks. It all sounds pretty daunting, but the fact is, we’re already moving in the right direction, and there’s much to be positive about. Technology and engineering are international, and those in the business are hunting out solutions across the globe and thinking of harnessing and adapting them to their own region, in the process building communication, sharing information and expertise and raising consciousness about energy supply and consumption. And another positive is the endless innovation that comes with thinking about energy solutions in new ways, like small, cheap solar panels to provide energy in developing regions, backyard or small-scale wind-turbines in suitable locations, processing waste to fuel, new developments in batteries and EVs, and so on. So, while there aren’t major, mind-blowing solutions to our fossil-fuel dependence in the offing, we are making progress, incrementally, and the effects of climate change, as they become more impactful, will no doubt accelerate our progress and innovation. We have no option but to think and act positively.
portable solar panels can be surprisingly useful, and cheap
In a future post I’ll look at the demand side, following McKay and many others. Having just moved house, and sadly leaving solar panels behind, it’s time to find out where my meter is, and check our consumption.
On Trump’s downfall: Fire and Fury, the overly-discussed tell-all book about Trump and the White House, is unlikely to affect Trump’s base though it will hopefully toughen the opposition. Trump’s rating remains below 40% and nothing much has happened so far this year. There’s talk of Oprah Winfrey standing for the Presidency in 2020 – please no! – but Trump will be in jail by then and Americans will have lost their appetite for ‘celebrity’ candidates. I’m looking out for Elizabeth Warren.
more on Australia’s energy woes and solutions
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.
the strange world of the self-described ‘open-minded’ part two
- That such a huge number of people could seriously believe that the Moon landings were faked by a NASA conspiracy raises interesting questions – maybe more about how people think than anything about the Moon landings themselves. But still, the most obvious question is the matter of evidence.
Philip Plait, from ‘Appalled at Apollo’, Chapter 17 of Bad Astronomy
the shadows of astronauts Dave Scott and Jim Irwin on the Moon during the 1971 Apollo 15 mission – with thanks to NASA, which recently made thousands of Apollo photos available to the public through Flickr
So as I wrote in part one of this article, I remember well the day of the first Moon landing. I had just turned 13, and our school, presumably along with most others, was given a half-day off to watch it. At the time I was even more amazed that I was watching the event as it happened on TV, so I’m going to start this post by exploring how this was achieved, though I’m not sure that this was part of the conspiracy theorists’ ‘issues’ about the missions. There’s a good explanation of the 1969 telecast here, but I’ll try to put it in my own words, to get my own head around it.
I also remember being confused at the time, as I watched Armstrong making his painfully slow descent down the small ladder from the lunar module, that he was being recorded doing so, sort of side-on (don’t trust my memory!), as if someone was already there on the Moon’s surface waiting for him. I knew of course that Aldrin was accompanying him, but if Aldrin had descended first, why all this drama about ‘one small step…’? – it seemed a bit anti-climactic. What I didn’t know was that the whole thing had been painstakingly planned, and that the camera recording Armstrong was lowered mechanically, operated by Armstrong himself. Wade Schmaltz gives the low-down on Quora:
The TV camera recording Neil’s first small step was mounted in the LEM [Lunar Excursion Module, aka Lunar Module]. Neil released it from its cocoon by pulling a cable to open a trap door prior to exiting the LEM that first time down the ladder.
Neil Armstrong, touching down on the Moon – an image I’ll never forget
the camera used to capture Neil Armstrong’s descent
As for the telecast, Australia played a large role. Here my information comes from Space Exploration Stack Exchange, a Q and A site for specialists as well as amateur space flight enthusiasts.
Australia was one of three continents involved in the transmissions, but it was the most essential. Australia had two tracking stations, one near Canberra and the other at the Parkes Radio Observatory west of Sydney. The others were in the Mojave Desert, California, and in Madrid, Spain. The tracking stations in Australia had a direct line on Apollo’s signal. My source quotes directly from NASA:
The 200-foot-diameter radio dish at the Parkes facility managed to withstand freak 70 mph gusts of wind and successfully captured the footage, which was converted and relayed to Houston.
Needless to say, the depictions of Canberra and Sydney aren’t geographically accurate here!
And it really was pretty much ‘as it happened’, the delay being less than a minute. The Moon is only about a light-second away, but there were other small delays in relaying the signal to TV networks for us all to see.
So now to the missions and the hoax conspiracy. But really, I won’t be dealing with the hoax stuff directly, because frankly it’s boring. I want to write about the good stuff. Most of the following comes from the ever-more reliable Wikipedia – available to all!
The ‘space race’ between the Soviet Union and the USA can be dated quite precisely. It began in July 1956, when the USA announced plans to launch a satellite – a craft that would orbit the Earth. Two days later, the Soviet Union announced identical plans, and was able to carry them out a little over a year later. The world was stunned when Sputnik 1 was launched on October 4 1957. Only a month later, Laika the Muscovite street-dog was sent into orbit in Sputnik 2 – a certain-death mission. The USA got its first satellite, Explorer 1, into orbit at the end of January 1958, and later that year the National Aeronautics and Space Administraion (NASA) was established under Eisenhower to encourage peaceful civilian developments in space science and technology. However the Soviet Union retained the initiative, launching its Luna program in late 1958, with the specific purpose of studying the Moon. The whole program, which lasted until 1976, cost some $4.5 billion and its many failures were, unsurprisingly, shrouded in secrecy. The first three Luna rockets, intended to land, or crash, on the Moon’s surface, failed on launch, and the fourth, later known as Luna 1, was given the wrong trajectory and sailed past the Moon, becoming the first human-made satellite to take up an independent heliocentric orbit. That was in early January 1959 – so the space race, with its focus on the Moon, began much earlier than many people realise, and though so much of it was about macho one-upmanship, important technological developments resulted, and vital observations were made, including measurements of energetic particles in the outer Van Allen belt. Luna 1 was the first spaceship to achieve escape velocity, the principle barrier to landing a vessel on the Moon.
After another launch failure in June 1959, the Soviets successfully launched the rocket later known as Luna 2 in September that year. Its crash landing on the Moon was a great success, which the ‘communist’ leader Khrushchev was quick to ‘capitalise’ on during his only visit to the USA immediately after the mission. He handed Eisenhower replicas of the pennants left on the Moon by Luna 2. And there’s no doubt this was an important event, the first planned impact of a human-built craft on an extra-terrestrial object, almost 10 years before the Apollo 11 landing.
The Luna 2 success was immediately followed only a month later by the tiny probe Luna 3‘s flyby of the far side of the Moon, which provided the first-ever pictures of its more mountainous terrain. However, these two missions formed the apex of the Luna enterprise, which experienced a number of years of failure until the mid-sixties. International espionage perhaps? I note that James Bond began his activities around this time.
the Luna 3 space probe (or is it H G Wells’ time machine?)
The Luna Program wasn’t the only only one being financed by the Soviets at the time, and the Americans were also developing programs. Six months after Laika’s flight, the Soviets successfully launched Sputnik 3, the fourth successful satellite after Sputnik 1 & 2 and Explorer 1. The important point to be made here is that the space race, with all its ingenious technical developments, began years before the famous Vostok 1 flight that carried a human being, Yuri Gagarin, into space for the first time, so the idea that the technology wasn’t sufficiently advanced for a moon landing many years later becomes increasingly doubtful.
the first Dalek? Sputnik 3
https://en.wikipedia.org/wiki/Tsiolkovsky_State_Museum_of_the_History_of_Cosmonautics
Of course the successful Vostok flight in April 1961 was another public relations coup for the Soviets, and it doubtless prompted Kennedy’s speech to the US Congress a month later, in which he proposed that “this nation should commit itself to achieving the goal, before this decade is out, of landing a man on the Moon and returning him safely to the Earth.”
So from here on in I’ll focus solely on the USA’s moon exploration program. It really began with the Ranger missions, which were conceived (well before Kennedy’s speech and Gagarin’s flight) in three phases or ‘blocks’, each with different objectives and with increasingly sophisticated system design. However, as with the Luna missions, these met with many failures and setbacks. Ranger 1 and Ranger 2 failed on launch in the second half of 1961, and Ranger 3, the first ‘block 2 rocket’, launched in late January 1962, missed the Moon due to various malfunctions, and became the second human craft to take up a heliocentric orbit. The plan had been to ‘rough-land’ on the Moon, emulating Luna 2 but with a more sophisticated system of retrorockets to cushion the landing somewhat. The Wikipedia article on this and other missions provides far more detail than I can provide here, but the intensive development of new flight design features, as well as the use of solar cell technology, advanced telemetry and communications systems and the like really makes clear to me that both competitors in the space race were well on their way to having the right stuff for a manned moon landing.
I haven’t even started on the Apollo missions, and I try to give myself a 1500-word or so limit on posts, so I’ll have to write a part 3! Comment excitant!
The Ranger 4 spacecraft was more or less identical in design to Ranger 3, with the same impact-limiter – made of balsa wood! – atop the lunar capsule. Ranger 4 went through preliminary testing with flying colours, the first of the Rangers to do so. However the mission itself was a disaster, as the on-board computer failed, and no useful data was returned and none of the preprogrammed actions, such as solar power deployment and high-gain antenna utilisation, took place. Ranger 4 finally impacted the far side of the Moon on 26 April 1962, becoming the first US craft to land on another celestial body. Ranger 5 was launched in October 1962 at a time when NASA was under pressure due to the many failures and technical problems, not only with the Ranger missions, but with the Mariner missions, Mariner 1 (designed for a flyby mission to Venus) having been a conspicuous disaster. Unfortunately Ranger 5 didn’t improve matters, with a series of on-board and on-ground malfunctions. The craft missed the Moon by a mere 700 kilometres. Ranger 6, launched well over a year later, was another conspicuous failure, as its sole mission was to send high-quality photos of the Moon’s surface before impact. Impact occurred, and overall the flight was the smoothest one yet, but the camera system failed completely.
There were three more Ranger missions. Ranger 7, launched in July 1964, was the first completely successful mission of the series. Its mission was the same as that of Ranger 6, but this time over 4,300 photos were transmitted during the final 17 minutes of flight. These photos were subjected to much scrutiny and discussion, in terms of the feasibility of a soft landing, and the general consensus was that some areas looked suitable, though the actual hardness of the surface couldn’t be determined for sure. Miraculously enough, Ranger 8, launched in February 1965, was also completely successful. Again its sole mission was to photograph the Moon’s surface, as NASA was beginning to ready itself for the Apollo missions. Over 7,000 good quality photos were transmitted in the final 23 minutes of flight. The overall performance of the spacecraft was hailed as ‘excellent’, and its impact crater was photographed two years later by Lunar Orbiter 4. And finally Ranger 9 made it three successes in a row, and this time the camera’s 6,000 images were broadcast live to viewers across the United States. The date was March 24, 1965. The next step would be that giant one.
A Ranger 9 image showing rilles – long narrow depressions – on the Moon’s surface
on the preliminary report into the future of the NEM – part 2
Chapter 5 of the report focuses on the challenges to NEM system reliability caused by increasing VRE penetration, and on possible reforms to the system to accommodate these changes. Price signals, bidding, and market cap prices and floors, as well as many other terms dealt with in this chapter, are definitely outside my sphere of knowledge or interest, but I feel duty bound to try and make sense of them. For a useful beginner’s guide to the NEM, check out this ABC site, though it dates from 2010, and it’s fascinating to note how things have changed since then. The AEMO was only established in 2009.
The NEM is an ‘energy-only’ market, rather than a capacity market. An energy-only market is one in which the companies generating energy are paid for the electricity they sell. In a capacity market they would be paid for keeping generation capacity available to cover what might be a fluctuating demand. With an energy-only market, producers would presumably be focused on demand, not wishing to provide more of something they can’t sell when demand is down, as it has been in recent times. However, base load demand, which is intermittent and unpredictable, becomes a particular problem when investment in the kind of generators that provide base load power is low. The report has this to say on the matter:
The NEM relies on price signals (subject to market price caps and floors), performance standards and market information to incentivise the development and retirement of generation infrastructure. When there is sufficient baseload supply, average prices tend to be low, signalling that no new investment in base load generation is needed. When base load supply tightens, average prices increase, signalling that investment in base load generation is needed. Peaking generators respond to similar patterns but look to higher price periods associated with peak demand.
I don’t really understand this, especially the bit about peaking generators, which sounds as if there are separate generators for peak demand, but that can’t be right. In any case, what this chapter tells me is that the economics of electricity generation in a transforming and uncertain market are fiendishly difficult to comprehend and control. The review ends the chapter, and all other chapters, with consultation questions which help concentrate the mind on the issues at stake. These include questions about the NEM’s reliability settings, liquidity in the market for forward contracts to ensure supply for business and commercial enterprises (and the effect of increasing levels of VRE on forward contracts, and how this can be catered for), and other questions about creating or ensuring future investment.
Chapter 6 deals with the problem of the seemingly ever-increasing cost of electricity to the consumer. The chapter divides itself into sections on wholesale costs and retail pricing. It seems Australia no longer experiences low electricity costs by OECD standards. Network investments have recently driven prices up, and further rises are expected due to generator closures, the international price of gas, and constraints on gas supply. Again the report emphasises the role of gas, at least in the interim:
Gas has the potential to smooth the transition to a lower emissions electricity sector. Gas generation provides the synchronous operation that is key to maintaining technical operability with increased renewable generation until new technologies are available and cost-effective. Furthermore, gas is dispatchable when required.
It seems there’s an intergovernmental understanding that reform is desperately needed to develop and incentivise the local gas market. There are many roadblocks to successful reform, which are currently affecting wholesale costs which will lead to higher retail prices.
Some 43% of current residential electricity prices are made up of network charges, mostly for distribution. Many network renovations were necessary to meet revised standards. A 2013 Productivity Commission inquiry criticised ‘inefficiencies in the industry and flaws in the regulatory environment’ in respect of the planning of large transmission investments and management of demand. Consumer concern about rising prices is driving reform in this area, but we’re yet to see any clear results. Also, there is a difficult balance to be struck between system reliability and cost. A significant proportion of consumers have expressed a willingness to live with reduced reliability for reduced cost.
There has been a difficulty also in forecasting demand, and therefore the spread of cost. Reduced peak demand in the period 2008 to 2013 wasn’t foreseen. The reduction, likely driven increasing electricity costs, was a result of many factors, such as solar installations, energy efficiencies and reduced consumption. There’s a plan to introduce ‘cost reflective pricing’, which means ‘charging prices that accurately reflect the cost of providing network services to different consumer groups’. This is expected to reduce peak demand overall, as will increasing use of solar and, in the future, battery storage.
Retail pricing is another matter, and according to the report there is a lack of transparency in the retail market. Retailing electricity is obviously complex and involves covering wholesale costs as well as billing, connections, customer service, managing bad debts, marketing, return on investment, inter alia. We can only determine whether the retail market is operating fairly when these costs are open to scrutiny.
Chapter 7 deals with energy market governance from a national, whole-of-system perspective. The report stresses urgency on this, though given the complexity of the system and the divided views of policy-makers, it’s unlikely that decisions on integrating the system and making it more flexible will be forthcoming in the immediate future. The governance of the NEM is divided between policy-maker (the COAG Energy Council), rule-maker (AEMC), operator (AEMO) and regulator (AER, the Australian Energy Regulator). None of these bodies, the report notes, are integrated with bodies advising on emissions reduction. Again, the report doesn’t advance a plan for an improved governance system, but posts consultation questions for how improvements might be made. These include amendments to various rules and guidelines, methods for improving accountability and transparency, and expedited decision-making in a rapidly transforming market.
The report includes a number of appendices, the first and most important being a comparison of the NEM with other energy systems and markets worldwide, including those with a large market share of VRE, such as Denmark and Ireland. It is noted that the transformation of these markets, as well as larger markets in Spain and Germany, is being managed apparently without compromising energy security. However, the variety and complexity of many overseas markets and systems makes comparisons well-nigh impossible for someone as uninitiated as myself. Suffice to say that the role of interconnectors for system security is very important in many European regions, and support from governments for a more flexible system to accommodate VRE is more widespread.
South Australia and electricity revisited
Canto: So what’s the latest on SA’s statewide blackout of September 28 last year, who’s to blame, who’s blaming who, and what solutions are in the offing, if any?
Jacinta: Well the preliminary report on the NEM, which we’ve been reading and writing about, has a few things to say about this, and they’re based on the findings of the Australian Energy Market Operator (AEMO) in its own preliminary report.
Canto: He said she said.
Jacinta: Well maybe sort of. So the SA blackout is presented as a case study. Here in SA we have a very high proportion of VRE (variable renewable energy) generation – one of the highest in the world. Our peak demand as a region is 3300 MW, and our supply capacity is almost 2900 MW of gas, almost 1600 MW of wind, and 700 MW of installed solar. We’re connected to the rest of the NEM by two interconnectors, an AC connector with a capacity of 600-650 MW, and a DC connector with a capacity of 220 MW. With electricity demand here declining, or at least not growing, synchronous generation and supply have reduced, with a resultant reduction in system inertia.
Canto: I presume by system inertia you mean the tendency for a machine, a vehicle, or a generator, whatever, a system to keep going once the power’s switched off. Like the QE2 has a lot of system inertia.
Jacinta: Right, but it’s a particularly important term in reference to power generation. There are some neat explanations of this online, but I’ll give a summary here. Coal-fired power stations work through the burning of coal which generates steam to turn a turbine, putting energy into the grid, and being massive, it has a lot of spinning inertia. Slow to fire up, slow to wind down. Solar, though, doesn’t work that way. It has no spinning or even moving parts. When the sun’s off, it’s off, but when it’s on it’s on. There’s really no inertia at all in a conventional solar PV system.
Canto: And wind? That’s the principal renewable energy here.
Jacinta: Yes that has inertia, certainly, but it’s variable and not as significant as perhaps it could be. So anyway on the morning of the blackout weather forecasts were grim, but not enough for AEMO to put out alerts for a ‘credible contingency event’. As it turned out there were at least seven tornadoes in the north of the state that day, as well as numerous lightning strikes and high winds which caused structural damage to transmission lines. At blackout time electricity demand in the state was a little over 1800 MW, with nearly half of it being supplied by wind farms, and of the rest about a third came from gas-fired generators, and the other 600 or so megawatts came through the interconnectors from Victoria. The main Heywood connector was approaching its operating limit. Short circuits to the transmission lines, caused by lightning, were the probable proximal cause of the blackout. Thirteen wind farms were in operation at the time, and eleven of them experienced ‘voltage dips’. What happens in these circumstances is that ‘fault ride-though’ responses are invoked. However, nine of the eleven farms had a lower pre-set limit for the ride-through response to proceed, and after a number of dips those nine wind farms cut their connection. The other two had higher pre-set limits and continued operation.
Canto: Ahh, so those preset limits were set too low?
Jacinta: Maybe – that’s one for further investigation. So the lack of generation from the wind farms caused an overload on the Heywood interconnector, and it was disconnected as per protection systems, resulting in frequency failure on the grid, and blackness fell upon all the land.
Canto: Right, so how did things get restarted? What’s the normal procedure?
Jacinta: Well, there’s this contracted service, called the System Restart Ancillary Service, which in SA is contracted to two major electricity generators (unnamed in the report), who can supposedly restart regardless of the grid situation, and provide power to the transmission network, but these servers failed for unexplained reasons, and power was finally restored through the Heywood interconnector together with the Torrens Island power station.
Canto: Okay, so now the fallout. How could things have been done differently?
Jacinta: Some near-term fixes have been implemented already. Firstly, having to do with frequency rates which I won’t go into here, and secondly in relation to wind farms. Five of them have made changes to their fault ride-through settings, and AEMO is looking at this issue for wind farms across the NEM. The Australian Energy Regulator, another bureaucratic body, will have completed a full analysis of the blackout by early next year to determine if there were any breaches of regulations. Obviously it’ll be looking at the conduct of AEMO throughout, as well as that of the transmission operator, ElectaNet. It’ll also look at these fault ride-though settings of wind farms and the failures of the System Restart Ancillary Service. It all sounds as if everything’s being done that can be done, but the major problem is that grid security as it stands can only be provided by large generators. The report again mentions gas-fired generators as the best solution, at least in the short to medium term.
Canto: So, as the grid, and the general provision of electricity, undergo these transformations, we’ll no doubt experience a few more of these hopefully minor setbacks, which we can learn from as we develop security for a more diverse but more integrated system…
Jacinta: Greater integration might require less squabbling about the future of energy. I can’t see that happening in the near future, unfortunately.
on the preliminary report into the future of the NEM – part 1
Australia’s Chief Scientist, Alan Finkel, who also happens to be a regular columnist for Cosmos, Australia’s premier science magazine, of which I’m a regular reader, has released his panel’s preliminary report on our national electricity market (NEM), and it has naturally received criticism from within the ranks of Australia’s conservative government, which is under pressure from its most conservative elements, led by Tony Abbott amongst others, who are implacably opposed to renewable energy.
The report confirms that the NEM is experiencing declining demand due to a range of factors, such as the development of new technologies, improved energy efficiency and a decline in industrial energy consumption. It makes a fairly reasonable assumption, but one unwelcome to many conservatives, that our electricity market is experiencing an unprecedented and irreversible phase of transition, and that this transition should be managed appropriately.
The NEM has been in operation for over 20 years, and the recent blackout here in South Australia (late September 2016) was its first real crisis. The issue as identified in the report is that variable renewable energy (VRE) sources are entering and complicating the market, which heretofore has been based on the synchronous generation of AC electricity at a standard system frequency. VRE generation is multiform and intermittent, and as such doesn’t sit well with the traditional system.
There are a number of other complicating issues. Improvements in building design and greater public awareness regarding emissions reduction have led to a decrease in overall energy consumption, while high peak demand on occasion remains a problem. Also the cost of electricity for the consumer has risen sharply in recent years, largely due to network investment (poles and wires). It’s expected that prices will continue to climb due to the closure of coal-fired power stations and the rising cost of gas. Interestingly, the report promotes gas as a vital energy source for this transitional period. It expresses concern about our overseas sales of gas, our low exploration rates, and negative attitudes to the fuel from certain states and territories. Rooftop solar systems, numbering more than 1.5 million, have further complicated the market, as the Australian Energy Market Operator (AEMO) understandably finds it difficult to measure their impact. System integration, which takes solar and wind energy system contributions into account, is clearly key to a successful NEM into the future.
The report also stresses Australia’s commitment to emissions reductions of 26-28% by 2030. It points out that business investors are turning away from fossil fuels, or what they call ’emission intensive power stations’, and financial institutions are also reluctant to back such investments. Given these clear signals, the report argues that a nationally integrated approach to a system which encourages and plans for a market for renewables is essential. This is clearly not what a backward-looking conservative government wants to hear.
So the report describes an ‘energy trilemma’: provision of high level energy security and reliability; affordable energy services for all; reduced emissions. More succinctly – security, affordability and the environment.
In its first chapter, the report looks at new technology. The costs of zero-emission wind turbines and solar PVs are falling, and this will maintain their appeal at least in the short term. Other such technologies, e.g. ‘concentrated solar thermal, geothermal, ocean, wave and tidal, and low emission electricity generation technologies such as biomass combustion and coal or gas-fired generation with carbon capture and storage’ (p13), are mentioned as likely technologies of the future, but the report largely focuses on wind and solar PV in terms of VRE generation. The effect of this technology, especially in the case of rooftop solar, is that consumers are engaging with the market in new ways. The penetration of rooftop solar in Australia is already the highest in the world, though most of our PV systems have low capacity. Battery storage systems, a developing technology which is seeing cost decreases, will surely be an attractive proposition for future solar PV purchasers. Electric vehicles haven’t really taken off yet in Australia, but they are making an impact in Europe, and the AEMO has projected that 10% of cars will be electric by 2030, presenting another challenge to an electricity system based largely on the fossil fuels such vehicles are designed to do without.
The management of these new and variable technologies and generators may involve the evolution of micro-grids as local resources become aggregated. Distributed, two-way energy systems are the likely way of the future, and an Electricity Network Transformation Roadmap has been developed by CSIRO and the Energy Networks Association to help anticipate and manage these changes.
In chapter 2 the report focuses on consumers, who are becoming increasingly active in the electricity market, which was formerly very much a one way system – you take your electricity from the national grid, you pay your quarterly bill. With distributed systems on the rise, consumers are becoming traders and investors in new forms of generation. The most obvious change is with rooftop PV. The national investment in these systems has amounted to several million dollars, with the expectation that individual households will be generating electricity more cleanly, more efficiently, and also more cheaply, notwithstanding the traditional electricity grid. Developments in battery storage and other technologies will inevitably lead to consumers moving off-grid, likely creating financial stress for those who remain. The possibilities for developing micro-grids to reduce costs will further complicate this evolving situation. Digital (smart) metering and new energy management software empower consumers to control usage. And while this is currently occurring mostly at the individual level, industrial consumers will also be keen to curb usage, creating added pressure for a more flexible and diverse two-way market. The report emphasises that the focus should shift more towards demand management in terms of grid security. One of the obvious problems from the point of view of consumers is that those on low incomes, or renters, who have little capacity to move off-grid (or desire in the case of passive users), may bear the burden of grid maintenance costs at increasing rates.
Chapter 3 deals with emissions. In reference to the Paris Agreement of 2015, which has been ratified by Australia, the report makes this comment which has been picked up by the media:
While the electricity sector must play an important role in reducing emissions, current policy settings do not provide a clear pathway to the level of reduction required to meet Australia’s Paris commitments.
The current Renewable Energy Target does not go beyond 2020 and national policy vis-à-vis emissions extends only to 2030, causing uncertainty for investors in an already volatile market. Clearly the report is being critical of government here as it has already argued for the primary role of government in developing policy settings to provide clarity for investment. The report also makes suggestions about shifting from coal to gas to reduce emissions at least in the short term. The report discussed three emissions reduction strategies assessed by AEMO and AEMC (Australian Energy Market Commission): an emissions intensity scheme, an extended large-scale renewable energy target, and the regulated closure of fossil-fuelled power stations. The first strategy is basically a carbon credits scheme, which was assessed as being the least costly and impactful, while an extended RET would provide greater policy stability for non-synchronous generation, so adding pressure to the existing grid system. Closure of coal-fired power stations would reduce low-cost supply in the short to medium term. Base load supply would be problematic in that scenario, so management of closures would be the key issue.
Chapter 4 looks at how VRE might be integrated into the system. It gets a bit technical here, but the issues are clear enough – VRE will be an increasing part of the energy mix, considerably so if Australia’s Large-scale renewable energy target is to be met, along with our international commitment vis-a-vis the Paris Agreement. However, VRE cannot provide spinning inertia or frequency control, according to the report. Basically this means that they cannot provide base load power, at a time when coal-fired power stations are closing down (nine have closed since 2012) and eastern states gas is being largely exported. The Hazelwood brown coal power station, Australia’s largest, and one of the most carbon intensive power stations in the world, will cease operation by April next year.
The difficulty with non-synchronous, distributed, intermittent and variable energy generation (e.g. wind and solar PV) is that these terms seem to be euphemisms for ‘not effing reliable’ in terms of base load, a problem currently being encountered in South Australia and likely to spread to other regions. The report identifies frequency control as a high priority challenge.
Frequency is a measure of the instantaneous balance of power supply and demand. To avoid damage to or failure of the power system the frequency may only deviate within a narrow range below or above 50 Hertz, as prescribed in the frequency operating standards for the NEM.
It’s likely that this narrow range of frequency proved a problem for South Australia when it suffered a blackout in September. I’ll look at what the report has to say about that blackout next time.
national electricity consumption – apparently on the rise again?
our recent power outage – how to prevent a recurrence. part 2
dispatchable solar energy to local areas – a possible solution
Jacinta: So the problem is, or was, that the whole state of South Australia was left without power for a long period of time – more than 24 hours in some places, it varied between regions. This affected some 1.7 million people, endangering lives in some instances.
Canto: And how did it come to be a problem? First because of storm conditions, particularly north of Adelaide, described as unprecedented. This might be seen as the proximate cause, with many describing the ultimate cause as anthropogenic global warming, which will see conditions such as these arising more often.
Jacinta: Well another cause, whether proximate or ultimate, might be degraded transmission infrastructure – the big towers. The transmission network, which is operated and managed by ElectraNet, is the long-distance network, carrying power to the distribution network – the poles and wires – which connects homes and businesses. The distribution network is owned and managed by SA Power Networks, which is 51% owned by Cheung Kong Infrastructure/Power Assets (CKI), a Hong Kong Chinese company. But it’s ElecraNet that we need to focus on. It’s apparently owned by a consortium of companies, but the largest share is 46.5%, owned by China’s State Grid Corporation (SGCC), the largest electric utility company in the world. I’ve heard rumours that there were complaints by technicians regarding rusty and poorly-maintained towers, complaints dating back over five years, but I’ve found nothing as yet to confirm those rumours.
Canto: So overseas ownership may feature in answering the question of how this came to be a problem. Another factor might be the interconnectors.
Jacinta: Yes, to be clear, there are two interconnectors between SA and Victoria, with some speculation about a third being built connecting us to NSW, and allowing us to export our renewables-based energy to that state from time to time…
Canto: Can you describe what an interconnector actually is, and how it works? I’ve heard that they actually work as surge protectors, among other things, shutting down the system when it’s overloaded or in crisis.
Jacinta: It connects transmission systems between different states, or different countries, allowing states to import or export power according to differential capabilities at different times, which helps stabilise or standardise the power available to interconnected states or regions. I should point out that SA imports far more power than it exports, so we are reliant on the national electricity grid, as we always have been I think, for regular, stable supply. Apparently, in terms of area, this is the largest electricity grid in the world. In 2013-2014 SA’s import to export ratio was 6 to 1. If you look at the chart on the SA government website, you’ll notice that SA generates less power within its borders than any other state, including Tasmania, which gets most of its power from hydro. But this varies – not long ago, when Tasmanian dams were low, that state was the least productive. The two interconnectors to Victoria are the Heywood interconnector, with a 460MW capacity, and the smaller Murray Link, which was not operational at the time of the storm. An ABC article quotes the SA Premier as saying the interconnector ‘played no role in the blackout’, but the same article quotes Paul Roberts of SA Power Networks: “We believe — and this is only early information — that there may have been some issue with the interconnector but the state’s power system is shut down I think possibly as a protection”. This statement is vague – it tends to contradict the Premier, but it doesn’t say that the interconnector had a direct role in the statewide shut-down.
Canto: Sounds like people are being cagey and defensive right from the start.
Jacinta: Well, of course – avoiding blame here is a big thing, in terms of money as well as reputation. It’s probably being overly naive to assume that nobody really knows whether the shut-down was caused by the interconnector, or whether that shut-down, if caused by the interconnector, was absolutely necessary. But it looks like nobody’s going to admit knowledge.
Canto: So the problem may or may not have been related to the interconnector, but it was definitely caused by a major storm north of Adelaide, which may or may not have been due to anthropogenic global warming, and it caused damage to infrastructure which may or may not have been avoided if that infrastructure was being upgraded effectively by ElectraNet. Sounds like we’re getting nowhere fast.
Jacinta: What about this idea that the state’s relying too much on renewables. What evidence is there about that?
Canto: Well, unsurprisingly, the state’s opposition leaders and their fellow-travellers are lining up to score points out of this event. SA’s conservative party leader Steven Marshall says there should be an investigation into the state’s ‘lack of base-load power generation’, the Prime Minister, Malcolm Turnbull, who now heads a conservative government in spite of having been a long-time advocate of renewables, has ‘rebuked’ state labor governments for having ‘ideological’ renewable energy targets, and the populist MP Nick Xenophon has expressed a rather vague but passionate outrage.
Jacinta: Okay so let’s look first at SA’s lack of base-load power generation. Hasn’t this been a perennial problem for SA? As I’ve already said, we’ve been importing a lot of power from interstate, on a variable basis, really since the year dot. Or since we’ve been able to do so, via the interconnectors.
Canto: Well there’s something of a new mantra among the renewable advocates that the base-load concept is out-dated, but I’d rather not get into that now, I’m really a novice about electricity markets and grids and such. The fact is that SA is running neck-and-neck with Tasmania as the state that produces the least electricity in the nation, though of course SA is a much bigger state. It’s just that now we’re generating more from wind, so we’ve shut off our coal generators. So the argument will be that renewables had nothing to do with the outage, which damaged transmission lines and initiated a shut-down of our only operating interconnector. This would’ve happened regardless of the power source, though there may be questions about the interconnector, and about the maintenance of the transmission lines.
Jacinta: Okay, that’ll do, though I’d like us to discuss the whole topic of renewable energy, in SA and elsewhere, on an ongoing basis in the future. It’s a hot topic, with a lot of people implacably opposed to it, particularly readers of the rather reactionary Australian newspaper, apparently. All very amusing. And perhaps we can educate ourselves a bit more about the National Electricity Market (NEM), the Australian Energy Market Operator (AEMO) and the future of grids and off-grid electricity supply.
For more interesting articles on this issue: