seven_tech

seven_tech t1_j1kn3ts wrote

The last coal plant in Australia is due to close in 2038. It's moved forward closure an entire decade in the last 3 years and they're talking about moving it forward again. LNG has shot themselves in the foot here, as they tried to game the federal electrical system during a lack of 'gas availability' (they chose to export it for higher prices) in June. They've just had their prices capped and a super profits tax is on the cards in early '23. LNG will be summer peaking only by mid-2030s. They'll be lucky if they're being used more than a month year.

I'm afraid you don't seem to see what's happening in the renewable space. Regulation globally is decimating fossil fuels because people are sick of them determining prices based on their profits. This isn't the 2000s anymore. The world is moving quickly and inexorablly to renewables. The war in Ukraine has galvanised Europe on it even more. Yes, in the short term (2-4 years) they will be more dependant. But they are spending hundreds of billions to get off it now because they're no longer prepared to have it used as a weapon a la Russia. America is the only major Western country now lagging in their ambition.

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seven_tech t1_j1jwo8c wrote

Australia went from 5% to 20% in 15 years. South Australia had blackouts during the 2016 summer due to fossil fuel (particularly gas) companies poor maintenance shutting them down during high heat scenarios. Their state government decided enough was enough and poured money into renewables. They got the very first Tesla grid scale battery from Musk in 2017, which saved their grid $48m last year. In October this year, their grid ran 100% renewable for 6 days. They are officially planning a regular 100% renewable grid in 2025.

Australia changed national government this year and altered their targets substantially. They injected $25b into renewable sources directly and received $85b on top in private investment as a result. Their energy regulator is now planning (not predicting, actively planning pole and wire infrastructure requirements, new regulation to control Rooftop solar and forcing fossil fuel, particularly coal, to stay idle) for 80% renewables in 2030.

It's attitudes like yours which are holding us back. Labour and private investment are waiting for strong targets.

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seven_tech t1_j1h7rpb wrote

Ok there's 3 reasons this is simply not true, and is regularly used as an argument as to 'crashing the economy' :

1- Renewable energy creates jobs, while being cheaper to produce electricity AND cheaper to build than building out more fossil fuels

2- The more renewables there are, the more expensive mining new fossil fuel is, while conversely being less likely to get investment because renewable energy puts downward pressure on energy prices. This in turn makes building new or maintaining existing fossil fuel plants bad investments and therefore, more expensive

2- The world disagrees with you regardless: https://en.m.wikipedia.org/wiki/Mandatory_renewable_energy_target

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seven_tech t1_j1gxnlj wrote

Yeah, nah mate. Sorry, this line has been parroted by the fossil fuel industry since the 90s. We're still waiting for a broad scale fossil fuel carbon capture plant to achieve its emissions capture targets. None have gotten anywhere near even half let alone full capture goals.

We have the resources, money, tools and labour to go to 100% renewable, with battery and other storage backing, within 15 years if we wanted. But while ideas like this continue to be pushed, we never will.

Carbon Capture for fossil fuels is just another way of sweating assets and getting governments to pay for it. Direct air/water Carbon Capture is what we need. There is a successful one in Iceland running at capacity day in day out right now.

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seven_tech t1_j1coweo wrote

Mmm, kind of? 2 stroke has its place though. It's reliable, cheap to build and easy to maintain vs 4 stroke. Which makes it perfect for simple engines like lawn mowers and yard trimmers.

Gas-gas refrigeration doesn't really have any advantages over liquid-gas. So we don't really use it since perfecting the gas-liquid version. They used to use air refrigeration cycles. But not really anymore because it's so bulky due to the sheer amount of space/gas needed.

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seven_tech t1_j1asa41 wrote

Haha, thanks. Yes, this was my whole point. I was never taught 'latent heat of fusion'. Nor were my colleagues. So we never had that ambiguity. Hence why I started the argument.

But hey, it's the internet. You'll get dragged for calling water wet...

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seven_tech t1_j1apyhr wrote

Yes, I've had this argument several times.

We don't use that term in Australia. Because it's ambiguous. Fusion (more specifically nuclear fusion) is a specific physical process and its use in science is replacing fusion as in 'melting', which is a term dating back several hundred years. So we use melting now, because it's unambiguous otherwise.

You could argue, and many people would still agree, gay means happy. Yet you also wouldn't be unsurprised if people thought they were homosexual if you said 'I thought he was very gay' and many young people would never have heard gay used in any other context. Language changes and it's ambiguous. And science when speaking of fusion, doesn't like ambiguity.

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seven_tech t1_j1aozpx wrote

Mmm, I get what you're saying, but I don't agree.

  1. Fusion is a word to describes a process, in both cases. It's not a noun made up of multiple words like hot dog. And 2) Science terms in the 21st century are coined to be unambiguous. That's the point of defining something in science.

If we want to get technical, it's nuclear fusion. But that still leaves the idea you could be discussing 'nuclear' melting, which is again, ambiguous. Science doesn't like ambiguity.

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seven_tech t1_j1anx4r wrote

That's kind of like asking why don't we try and get to the theoretical efficiency of an internal combustion engine - what does it solve? Liquid to gas refrigeration systems are inherently more efficient, so it doesn't serve any real purpose to try. Same as we know we can't keep using petrol, so there's no longer a point to try in ICEs.

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seven_tech t1_j18u41q wrote

An ideal Carnot cycle is Isentropic. The real world isn't ideal. Entropy is increased in the real world because of loss of energy through friction, intra-molecular force in gas and other similar processes.

And again, liquid is a much better transfer medium for heat than gas inherently.

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seven_tech t1_j18rv46 wrote

But CBD doesn't get you high....so they have nothing to gain by doing that here.

Edit: nevermind- I read 'cannabis oil' as 'CBD oil'.

For disclosure - I use CBD oil. It doesn't 'help me sleep' but does reduce my anxiety and anxious thoughts, which is what keeps me awake often.

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seven_tech t1_j18ozp2 wrote

Again, not saying it isn't used anywhere. It isn't used here anymore. Because it's no longer specific.

We use enthalpy instead of latent heat, and we use desublimation instead of fusion. Because latent heat is also a material property and fusion is an atomic process.

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seven_tech t1_j18mlkb wrote

It's not in Australian university physics. It would be enthalpy of desublimation crossed conversations-enthalpy of melting. I did high school physics and 2 years of physics at uni. I never once heard it called latent heat of or fusion.

Also, type fusion into Google. Which page number do you have to go to before you find it being referred to as the process of liquid to solid? It may have been used as a standard reference to that process. It isn't anymore, because fusion (the atomic process) was discovered.

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seven_tech t1_j18l0vk wrote

Again, widely used where? We don't use them here in Australia. We use simply heat of or, more correctly and usually, enthalpy of. Latent heat is a property of a material to me (specific latent heat). We don't use latent heat to describe a process, because it's confusing vs the material property called specific latent heat. That's how we were taught in High school and Uni. In fact I remember a lecture our year 12 physics teacher gave about not using latent heat to describe a process, because of the confusion with the material property, so use enthalpy.

Also, we no longer use fusion to refer to melting. That's an old terminology that's being replaced as fusion has very specific meaning now in physics/chemistry since we discovered the process in the early 20th century. Fusion meaning melting was coined well before this.

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seven_tech t1_j18jtxf wrote

Yes, I've never heard it called that, though the internet says it's a thing. At Uni here, it's called enthalpy of phase transition (or enthalpy of melting). Fusion is only the literal atomic process of fusing 2 atoms. I have a feeling heat of fusion is a very antiquated version that's being replaced, because fusion has such a specific chemical meaning. Sublimation, evaporation, melting and condensation are the only phase change phrases we have ever referred to at Uni.

But also, still not relevant here. Almost all commercial (and most industrial) refrigeration uses gas and liquid, not solid and liquid.

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seven_tech t1_j18j4up wrote

I've literally never heard it called that. Enthalpy of fusion, yes. But not latent heat of fusion. Though it does appear it can be called that. Still referring to a process that doesn't happen in commercial refrigerators (solid-liquid or vice versa).

At uni here, latent heat refers to the amount of heat a substance can absorb before changing state. If you are talking about the heat absorbtion of a process (like state change) that's the 'heat of' or 'enthalpy of', not latent heat of. Not sure if maybe it's a difference of country thing.

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seven_tech t1_j18cb0w wrote

Because phase changes using compressor/condensor/evaporator refrigerator systems are, in the real world (non-ideal), very efficient ways of transferring huge amounts of heat from one place to another, for low amounts of work. Phase changing liquid to gas enables it to absorb large amounts of heat, that's pumped out from the heat exchanger. It then fully evaporates to gas, expelling some heat, before being compressed and condensed to pure liquid and the heat of this change also dumped out by a heat exchanger and fan and the cycle starts again. Liquids transfer heat better in the heat exchangers than gases due to molecular density and surface area effects.

Also we've spent the better part of 150 years making heat pumps on the premise of electric motors running compressors for changing phases of gas and liquid, making those motors extremely efficient. We can input up to 3 times less electric energy for the same transfer of 'heat' energy in a very efficient heat pump.

TL;DR- Phase changes (liquid-gas-liquid) in the real world, with compression and evaporation, is much more efficient in work input terms, than using just gas.

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