Thread: Future of the Australian Electricity Market

Originally Posted by havabeer69

yeah my terminology is probably a bit muddled up. Everything we put over the fence into the switch yard is defined as Megawatts. A quick google also says you've got your definition around the wrong was as well

Yeh thanks for the correction - starting to get things the wrong way round - must be another sign of old age.

Energy is in Joules,

Energy per unit time is Power
So one Joule per second is one Watt,

One Watthr brings it back to energy, or 3600 Joules.
One kWh is 3600000 Joules of energy
But not many people think of energy in Joules.

Originally Posted by BobL

But not many people think of energy in Joules.

Joules singular, no. But in the coal seam gas industry we calculate production in terajoules; trillions of the little burgers. Currently my workplace is expected to churn out about 660tj today out of a 1350tj total for the company.

That's going to boil a lot of kettles.... in China.

Originally Posted by Chief Tiff

Joules singular, no. But in the coal seam gas industry we calculate production in terajoules; trillions of the little burgers. Currently my workplace is expected to churn out about 660tj today out of a 1350tj total for the company.

That's going to boil a lot of kettles.... in China.

our site still goes off coals "calorific" value

I suppose it is inevitable that until renewable energy becomes 100% sufficient, debate will centre around the ability to generate when the sun does not shine and the wind doesn't blow and if you remove all the thermal sources of producing electricity which are coal, gas and oil, you are only left with nuclear. So, not surprising really that Sky News are resurrecting the debate.

'Very few good options' for renewable energy without nuclear power (msn.com)

Now they did not address all the old bug bears of the nukes, with the primary issues being safety (arguably much improved over early designs), the potential for targeted attacks, the issue of spent waste disposal (the perennial bug bear), the difficulty of siting such an installation (who is going to put up their hand for one in the back yard) and the cost of decommissioning at end of life. However, they opened up pointing out that there could be some potential for SMRs (Small Modular Reactors). I don't think there are any operational units around yet so this is once again pie in the sky (no intentional pun there).

Cost and generating potential are still going to be governing factors. A small installation may be very costly on a MW/hr basis and with renewables becoming increasingly able to supply ALL the demand during the day it will require the more expensive forms of electricity generation to shut down for hours at a time. Australia is currently experiencing more of this trend even with existing fossil fuelled plants. This trend will be a warning to future generators that they may not be required to generate for sufficiently long periods of the day and the incentive for a new player to enter the market may be too small even if the problem issues I mentioned above are satisfactorily addressed.

Reference was made to the UK and the fact they have they have virtually no coal fired stations left, but they did not mention that they have gas fired stations instead. I believe gas fired (still fossil fuel of course) stations represent around 36% of their generation. They already had some nuclear power plants. Around 17% is generated by nuclear with some plants having received extensions to their operating life.

It appears to me that even with all the problem issues resolved, atomic power will be too expensive for insufficient profit in a market of reduced demand and diminishing returns. Who will put up their well healed hand?

Regards
Paul

Sooner or later the people who manage our electricity supply will work out that it is inefficient to run the grid to small towns when they can have local stand alone sources of power using batteries and solar/wind generation.

Originally Posted by Chris Parks

Sooner or later the people who manage our electricity supply will work out that it is inefficient to run the grid to small towns when they can have local stand alone sources of power using batteries and solar/wind generation.

I'm not so sure this will be a problem.

Just so happened I saw this not so long ago.... King Island and Brunny Island down in the Bass installed solar to replace their diesel generators. The cost of the solar+battery install was the same as they paid in fuel for ONE YEAR.

There was a thing on landline that profiled them after 3 years. They've both added a windmill and looking to install a second turbine.

They generate so much power they are looking to export it!

So, from an enormous cost, to a revenue stream..... They seemed very chuffed indeed!

Here is a bit of a read: Whole towns to be taken off the grid and powered by stand-alone renewables

Also, these blokes don't buggerise around, they are getting very serious Indeed:

Rio Tinto plans massive 7GW wind and solar for smelters and iron ore mines

Maybe I spoke too soon and the management is starting to work it out finally. There are other micro grids in WA but the old ones are powered by diesel gen sets from memory.

'Micro' Snowy Hydro: Renewable energy fix to tackle town's power problems (msn.com)

Chris

I am not really familiar with the WA grid, but I suspect the area is so vast that there are many communities that have no option but to be self sufficient by whatever means is available to them. The town of Walpole is apparently about 500 people.

A family member used to live in the similar sized town of Tyalgum in Northern NSW. Way back they were destined to go off the grid. This is from Wikipedia, but I first heard it from the family member.

"As of 2016 Tyalgum plans to disconnect from the electricity grid, and produce renewable power locally, primarily using solar power and battery storage.^[3]"

Based on that information she did not go ahead with a solar installation. However, the disconnection never happened.

I think the scale of WA lends itself to isolated systems far better than the East Coast grid. Having said that, we should remember that there are still "islands," but they are generally further inland such as Mt Isa etc. probably they are don't qualify as East Coast.

The grid is not all embracing and this diagram shows the extent of the problem:

Australian Electricity grid.png

I don't recall the exact percentage of people that live on the coast (not sure how far inland is still classified as the coast), but it is huge: maybe >95%.

Regards
Paul

Originally Posted by Bushmiller

Reference was made to the UK and the fact they have they have virtually no coal fired stations left, but they did not mention that they have gas fired stations instead. I believe gas fired (still fossil fuel of course) stations represent around 36% of their generation. They already had some nuclear power plants. Around 17% is generated by nuclear with some plants having received extensions to their operating life.

It appears to me that even with all the problem issues resolved, atomic power will be too expensive for insufficient profit in a market of reduced demand and diminishing returns. Who will put up their well healed hand?

I wouldn't be too sure about that
as it stands, the UK currently imports 4GW from France, all of which is nuclear generated, or so I understand. Well the UK did import 4GW from France till a fire on September 15 in one of the main DC to AC converter halls caused an unscheduled shut down of 1GW till sometime in mid-2023. At the time of the fire, a further 1GW was out for scheduled maintenance.

The UK also imports electricity from the Netherlands (1GW) and Belgium (also 1GW). I'm not sure if the import links from The Netherlands and Belgium are from nuclear or renewable sources or a mixture of both.
I understand that the link with Norway (1.4GW) which came on line in late October will allow the import of hydro power or the export of excess wind energy from the UK. Will hydro in Norway become the UK's "national battery"?

Quoting this source Britain hits power imports record "Two new interconnectors to Germany and Denmark, which are currently under construction, will add another 2.8GW of capacity by 2023-24." As I understand it, Danish and German electricial generation is largely renewable.
also quoting from the same source: "EnAppSys data shows that Britain remained Europe’s second biggest net importer in the first half of 2021, recording net imports of 12.3TWh." I think these imports represent around 25% of the UK's total electricity demand.



In regards to the nuclear option -- I have little confidence that "the market" will step in and provide a reliable supply of nuclear generated electricity. Given that, as far as I know, we have yet to be told what blow torch the Nationals held to the Liberal's belly when they agreed to the Liberal's net zero "plan" I would not be at all surprised if one of the "sweeteners" is the Australian tax payer stumping up the cash (and assuming the risk) for a large nuclear power station or four.

BTW, I may have mentioned this earlier in this thread, but somewhere I have seen an estimate that for Australia to be totally renewable when it comes to electricity, there needs to be enough pumped hydro (or tidal power) to power the grid for around 72 hours. I don't recall if the estimate assumed no solar, no wind for those three days, or if the assumption included daylight solar generation. But at an annual electricity consumption of 265TWh, three days is equivalent to 2.2TWh -- which is one hell of a lot of lithium in an exceedingly large battery.

This news today would go some way to answering Ian's most excellent comment:

NSW flooded by 11GW of pumped hydro proposals for big flip to renewables | RenewEconomy

I had no idea electricity was sold to England in such a manner. Man, I'd reckon those DC/AC facilities would be a marvel to tour.

(If I may add a political comment... It seems that the Liberals are utterly unaware of the enormous shift in people's thinking about renewables. The average Joe is super keen on every aspect of this tech. The Libs seem to be fundamentally stuck in the 1950s)

Originally Posted by ian

BTW, I may have mentioned this earlier in this thread, but somewhere I have seen an estimate that for Australia to be totally renewable when it comes to electricity, there needs to be enough pumped hydro (or tidal power) to power the grid for around 72 hours. I don't recall if the estimate assumed no solar, no wind for those three days, or if the assumption included daylight solar generation. . . . .

Thats what the Walpole pumped hydro microgrid in south West WA is being set up for. Their average power outage is only a few hours but occasionally its more than 24 hours.

This CCS project has been on the books at Millmerran for two or three years. It is a joint venture. As it is at my workplace I am unable to comment specifically other than to draw your attention to the media release for information:

Carbon capture storage trial in Queensland to demonstrate Morrison's promise to reduce emissions via 'technology' (msn.com)

The only additional information I can add is that one of Millmerran Power Station's joint owners already has two of these Carbon Capture and Storage plants in China.

Regards
Paul

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.

Ahem! A lot goes up the stack in terms of gases. Tons of the bloody stuff. Primarily CO2. Hopefully there is very little moisture as that would be indicative of a tube leak. One statement made in the email is fundamentally true as the baghouse collection systems, when fitted to modern power plants, do collect the majority of the visible particles. I would question the whether precipitators can achieve such a good result. Liddell used to have "precips" and my memory is that they caught about 75% of the dust, but that was only on a good day. We did not call it "old smokey" for nothing. They subsequently installed a baghouse and completely fixed the visible dust issue.

My point in relating this story is to make us wary of what we read. I don't know if the email I received is deliberately mis-leading or there is just a lack of understanding. The general thrust of the email was to say that we cannot go directly to renewables and is probably reasonable, but incorrect information should not be put out there to justify the argument.

Regards
Paul

Interesting reading, your last statement about incorrect/ misleading information equally happens on the renewable side as well.

I would rather everyone just called it as it is, acknowledge we don’t have all the pieces of the puzzle yet but are working on it.

Bushmiller I don’t know if you can answer this question or not but you often hear how renewables are being held back because of the heavily subsidised coal industry ( looking after their mates is often touted as well) so there is a reluctance to invest in renewables.

How accurate is that line of conversation?