Thread: Future of the Australian Electricity Market

Beardy

On subsidies holding back further investment I don't really think that is the case. The issue now is that all these companies supplying renewable energy are commercial enterprises and they need to see that they will enjoy a return on their investment. At certain times of the day we have moved towards a situation of over supply and this drives the price down. If a solar company, for example, cannot make sufficient money it goes broke. Until there is a means of storing the electricity by whatever means is devised, I believe that investment in renewables will slow for a while.

Very few companies out there put their hand up to take a loss so they can save the planet. They want to make money. Governments of the past in their wisdom said a competitive market was the way to go. We are now paying the price for that.

Regards
Paul

Found this article

Australian fossil fuel subsidies hit $10.3 billion in 2020-21 - The Australia Institute

Thanks Beardy. You have done well.

Following your link to the media report I found the full report from the the Australia Institute:

Fossil fuel subsidies (australiainstitute.org.au)

I took the following section out:

Fossil fuel subsidies.png

From this you can see that some of the benefits are in the form of "encouragement", facilities and concessions, but it is an awful lot of money. One aspect that troubles me is the granting of monetary assistance for questionable projects. I see the government doing this to patronise certain segments of industry and to make it seem they are supporting and on board with elements of their supporters.

I recently heard the PM touting hydrogen to the Hunter Valley in NSW as if it were the fuel from heaven. he either lies or does not appreciate what it is. It is only green if it is made from renewable electricity. If it is made from coal fired power or gas fired power it is worse than if you had just put coal or gas straight into the vehicles because some efficiency is lost in the process.

I heard Barnaby Joyce in discussion state that electricity price have gone up six fold. Where is this man coming from? Stated simply, it has not. Since 2002 the wholesale price of electricity went from around $25/Mwh to a peak of $75 some time during last year and now is back down to about $50. These are very rounded figures, which will change from day to day, and it is over a period of almost twenty years. During this same time the cost to us as individuals has gone from around 20c/Kwh to nearly 30c/Kwh. Where does six times come from? Why don't people call these statements out as gross misrepresentation (that's political speak for a lie)?

Have a look at the AER statistics on prices.

Wholesale statistics | Australian Energy Regulator (aer.gov.au)

Ask Mr Joyce what price he got for his vealers in 2002. I would suggest about $1.30/Kg. Today he probably gets $4.00! He is complaining about the price of electricity!

Regards
Paul

I chanced on this one:

Queensland moves to call in proposed Clive Palmer coal plant (thenewdaily.com.au)

Unbelievable. It has no economic base and surely has to be considered a voter grab, which of course will never come about, although perhaps the mine will.

Regards
Paul

While driving home this morning I had a good idea for a bumper sticker: -

THE FUTURE HAS BEEN CANCELLED DUE TO LACK OF INTEREST

Just about sums up the state of the world at the moment

Originally Posted by Bushmiller

As far as the coal subsidies are concerned I have often heard that too, but I am uncertain as to exactly what it entails. I believe that some aspects of industry receive concessions on their diesel fuel so that is a subsidy as opposed to a blatant handout, but it is probably quite a significant amount. I am led to believe (by management) that at Millmerran we do not receive much in this line, but truthfully I don't really know. There seems to be the perception that government helps the mates in big business, but is that anecdotal? Again I don't know, but I have to say I am highly suspicious.

Paul
I believe that what you are referring to is a proportion of the Federal Government's fuel excise.
I believe the excise is currently in the order of 60 cents per litre. But I am out of date with the current rate.
The intent of the fuel excise is to fund construction and maintenance of Australia's road system. Part of the excise goes into general revenue from where the dollars can be used to help fund medical services -- it could be argued that Australia's fuel excise covers the externalities of road use.

However, if diesel is used for large mine vehicles -- which never operate on public roads and thus don't need to be registered -- it makes sense for part (the portion intended for road construction and maintenance) or all of the fuel excise to be refunded to those mining companies -- iron ore, coal, minerals.
I wouldn't call it a "subsidy" as diesel used on farm or the fuel used to power reffer boxes is also rebated.

Originally Posted by Bushmiller

I received an email the other day passed on by a friend. The email contained thoughts on coal fired power stations from somebody purporting to have spent twenty five years in the power industry. This was a statement that I picked up on.

"First coal fired power stations do NOT send 60 to 70% of the energy up the chimney. The boilers of modern power station are 96% efficient and the exhaust heat is captured by the economisers and reheaters that heat the air and water before entering the boilers."

The very slight amount exiting the stack is moist as in condensation and CO2. There is virtually no fly ash because this is removed by the precipitators or bagging plant that are 99.98% efficient. The 4% lost is heat through boiler wall convection."

I have to correct some aspects of this statement.

A thermal fired generating plant comprises three main components: The boiler, the turbine and the generator. The boiler and the generator are very efficient with figures certainly in the high nineties (it doesn't really matter exactly what it is, but it is good), but the turbine or more precisely the condenser is not so efficient and brings the overall efficiency of the power plant down to somewhere between 30% for the older designs and approaching 40% for the most modern installations. This means that 60% or more of the energy produced by the boiler does indeed go up the chimney as it is not converted to electricity. Compare this to the 25% efficiency of you house's slow combustion heater (not that it produces electricity) and a diabolical % of an open fire. In the power plant this loss of efficiency comes from the requirement to condense the steam back to water to be reused. The heat loss occurs in the transition from steam to water (technically referred to as the "latent heat of evaporation", although in this instance it is the reverse process back to water).

Modern power stations attempt to minimise these losses by a number of techniques. The air heater, which is a slow rotating device to warm incoming air to the boiler, is sited in the flue gas path as is the economiser, which pre heats the water entering the boiler. At our plant in Millmerran, water entering the boiler at this point is already about 300°C (still water because it is under high pressure) immediately after the economiser.

Modern plants also incorporate feed heaters where steam is bled off from the turbine at different points and used to pre heat water on it's way to the economiser and subsequently the boiler. All this heating takes place before the water enters the boiler. This takes advantage of the heat without the need to cool it in the condenser. However, there is a limit to how much of this you can do as our primary objective is to drive the turbine. I believe at Millmerran, which has a supercritical boiler, the efficiency is around 38%.

The Reheater, mentioned in the statement above, takes the steam from the exhaust of the HP (high pressure) cylinder of the turbine and returns it to the boiler to gain further heat (at a lower pressure of course) before continuing it's journey through the IP (intermediate pressure) and LP (low pressure) cylinders. Consequently with an efficiency of 38%, 62% of the generated energy is indeed "wasted" in going up the chimney.

Hi Paul

dragging the following info from the recesses of my memory of studying thermodynamics 45 or so years ago.

The efficiency of all thermal processes can be described by a four (?) sided curve called the Carnot cycle. Essentially the larger the difference in absolute temperature between the "hot" and the "cold" side of a exothermic process determines the process' efficiency.

From my long ago memory, the maximum theoretical thermal efficiency of a steam generator is around 42% -- the other 58% of the coal or natural gas's energy is wasted, latent heat lost when the steam used in the generator is condensed back into water to be fed back into the boiler.
Those billowing clouds of stuff the media loves to display as examples of pollution from burning coal are actually the steam issuing from the power plant's cooling towers.

The latent heat of evaporation represents the energy gained by the cooling water (and visible as atmospheric steam) as the super hot steam is condensed back into boiler feed water.

I believe -- but it is a very long time ago -- that issues like hydrogen embrittlement of the pressurised steam pipework puts a limit to how close to the theoretical maximum efficiency any given electricity generator can achieve.


The Carnot cycle efficiency of a gas turbine -- think jet engine powered generator -- is significantly more than 40 percent. I think as high as 60% ?
But again, a large amount of the gas turbine fuel's inherent energy is lost as waste heat.

Originally Posted by ian

But again, a large amount of the gas turbine fuel's inherent energy is lost as waste heat.

That's why they have combined cycle plants, that use that waste heat for a boiler & steam turbine and co-generation plants that then pipe that used steam off for industrial processing etc. This is what we should have been building as a transition from coal to renewables until someone develops a way to store large amounts of energy from the renewables (apart from pumped hydro)

Originally Posted by ian

Hi Paul



From my long ago memory, the maximum theoretical thermal efficiency of a steam generator is around 42% -- the other 58% of the coal or natural gas's energy is wasted, latent heat lost when the steam used in the generator is condensed back into water to be fed back into the boiler.
Those billowing clouds of stuff the media loves to display as examples of pollution from burning coal are actually the steam issuing from the power plant's cooling towers.

The latent heat of evaporation represents the energy gained by the cooling water (and visible as atmospheric steam) as the super hot steam is condensed back into boiler feed water.

I believe -- but it is a very long time ago -- that issues like hydrogen embrittlement of the pressurised steam pipework puts a limit to how close to the theoretical maximum efficiency any given electricity generator can achieve.

Ian

We tend to use the Rankine cycle in power stations and I have to say I have only "heard" of the Carnot cycle. However, it comes to the same thing..I think . That is that the most efficient stations are around that 40% mark and the other 60% is indeed wasted as it goes up the chimney, but is inescapable. The person who was quoting in the email I referenced clearly was not aware of the difference between his ass and his elbow I'm afraid.

One of my favourite hates is the media depicting the power stations as polluting because of their cooling towers. Technically it is not even steam but water vapour pouring out of those hyperbolic towers. Even for a chimney stack I pointed out for many years that it is not any visible particles that you may see (only occasionally nowadays because of the use of baghouse filters) which should worry you. It is the invisible gases: Namely CO2 (and NOX and SOX)

Just back on efficiency, supercritical stations have been around for quite a while, but the increased pressures (around 24,000KPa compared to conventional stations at 15,800KPa) for a long while placed too great a stress on the pipework and associated components and they fell from favour. Developments in metallurgy improved the reliability and new feasibility allowed the supercritical plants to rise up again. The last six coal fired units built in Australia were all supercritical and all in Queensland.

There is another level of boiler with Ultracritical power plants where the steam pressures are around 30,000KPa.

However I have shied away from getting too technical in this thread as it is something that probably only really appeals to those in the industry and other technical types. I don't want to frighten everybody off from a subject that should be ever present in their minds and cause a distraction from the realities of the electricity situation and climate change.

We only really need to know the bones of why something is good or bad unless people try to mislead us with incorrect information.

Regards
Paul

Originally Posted by Bushmiller

One of my favourite hates is the media depicting the power stations as polluting because of their cooling towers. Technically it is not even steam but water vapour pouring out of those hyperbolic towers. Even for a chimney stack I pointed out for many years that it is not any visible particles that you may see (only occasionally nowadays because of the use of baghouse filters) which should worry you. It is the invisible gases: Namely CO2 (and NOX and SOX)

I agree about the cooling towers.

Uniortunately the bag filters don't trap all the invisible particles, and other thing that gets released is some radioactive material. Coal is a magnet for naturally radioactive elements so over the formation of coal deposits it tends to concentration radioactive elements some of which which cannot be filtered out. The amount varies but in a study done a few years back it was found that some coal fired plants emitted more radiation than nuclear power plants. The other issue is the use of fly ash containing radioactive materials in concrete, thus recommending that fly ash concrete not be used for dwellings but is OK for things like bridges etc.

It's a bit like cigarettes causing cancer. It has been estimated that radioactive dust trapped on tobacco leaves causes about 30% of cigarette smoking cancers. It turns out that tobacco has tiny hairs that trap ordinary dust particles that does it. Tobacco companies knew about this as far back as the 1950's and (secretly) spent many millions on hair removal and washing techniques to no avail. In the 1960s they embarked on an extensive selective breeding and rudimentary genetic engineering to remove the hairs still nothing worked. I wonder if they could do it today with the new genetic engineering tools like CRISPER.

Originally Posted by BobL

I agree about the cooling towers.

Uniortunately the bag filters don't trap all the invisible particles, and other thing that gets released is some radioactive material. Coal is a magnet for naturally radioactive elements so over the formation of coal deposits it tends to concentration radioactive elements some of which which cannot be filtered out. The amount varies but in a study done a few years back it was found that some coal fired plants emitted more radiation than nuclear power plants. The other issue is the use of fly ash containing radioactive materials in concrete, thus recommending that fly ash concrete not be used for dwellings but is OK for things like bridges etc.

It's a bit like cigarettes causing cancer. It has been estimated that radioactive dust trapped on tobacco leaves causes about 30% of cigarette smoking cancers. It turns out that tobacco has tiny hairs that trap ordinary dust particles that does it. Tobacco companies knew about this as far back as the 1950's and (secretly) spent many millions on hair removal and washing techniques to no avail. In the 1960s they embarked on an extensive selective breeding and rudimentary genetic engineering to remove the hairs still nothing worked. I wonder if they could do it today with the new genetic engineering tools like CRISPER.

Bob

I may not have explained myself clearly. The baghouse filters only trap most of the visible particles. They do not trap any of the invisible particles, which are primarily the gases. I did not know about the radioactive component of flyash. Power stations sell the fly ash to the concrete companies. I think about thirty trucks a day would cart ash from us at Millmerran.

I have surmised that the price of concrete will increase as the supply of fly ash diminishes as it is used as a bulking agent.

I can't comment on the tobacco industry: I gave up smoking when I was eleven.

Regards
Paul

Originally Posted by Bushmiller

Bob

I may not have explained myself clearly. The baghouse filters only trap most of the visible particles. They do not trap any of the invisible particles, which are primarily the gases.

Sure I understand this. Bag filters will also trap some invisible particles <10 microns during the self clogging process of filtration. CO2 does not represent an immediate health issue but fine (PM2.5) particulate matter does represent a more serious risk to health.

I did not know about the radioactive component of flyash. Power stations sell the fly ash to the concrete companies. I think about thirty trucks a day would cart ash from us at Millmerran.

The radioactivity levels in the fly ash will depend on the levels in the coal which can vary as much as a fact or of 100. Some of my students checked out the background radioactivity levels with distance downwind from the Kwinana power station and the sorts of numbers they got was around 5 to 10 higher than natural background radioactivity compared to the upwind side. They also checked out the natural radioactivity in the Perth hills (~5x higher than Perth coastal plain) and in salt lakes in the wheat belt where it was up to 25x higher.

Originally Posted by BobL

.... In the 1960s they embarked on an extensive selective breeding and rudimentary genetic engineering to remove the hairs still nothing worked. I wonder if they could do it today with the new genetic engineering tools like CRISPER.

I would shudder to consider what these foul creatures would be doing, or have done.

When one reads of their history, they are as profane as slavers, pedos and torturers. They have no moral base.

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