News & Discussion: Electricity Infrastructure

[Jaymz]

I would've thought that peak times would be during bitterly cold winter/spring times. Well, for me more likely time to be using the air con.

[rubberman]

Now, while it might be possible that there's an extremely hot day with total cloud cover, over the whole east coast interconnected systems, it's not a hugely likely event, nor a frequent one. When was the last time you recall a hot day with cloud cover so bad that solar wouldn't work, and which covered SA, Vic, and NSW? Or a cold day where the wind wasn't blowing, and there was total cloud cover?

You should do some research on "high pressure gloom". It is a common phenomenon over South eastern Australia in the winter months and is associated with large high pressure systems producing low/no winds and gloomy cloudy conditions sometimes for days at a time over large tracts of the country with large blocking highs. You are correct that peak use is on hot sunny and windy days, but I assume the state would like to have some power also on cold cloudy windless days also.

Fortunately, ANU has done a lot of detailed research on that. You should check it out.

http://energy.anu.edu.au

This reference covers your point specifically:

100% renewable electricity in Australia February 2017. Andrew Blakers, Bin Lu and Matthew Stocks. Australian National University

If you google that reference, you will see how it all fits together.

[PeFe]

And again I have to ask, what provides the power to pump the water on cloudy days? If the answer is that on those days it just doesn't produce power, and we switch over to other sources, then they are not telling the full story.

Well obviously its solar OR wind....or other pumped hydro (yes, if it's cloudy, that usually indicates that it is probably windy) these new pumped hydro schemes would all being doing deals with electricity providers/retailers to get their backup electricity.....probably at vastly reduced rates.....so whilst you're paying 47 cents per kilowatt hour (latest SA electriecity prices I can find) they will probably pay 12 cents per hour, and of course when they start producing electricity they wont need other sources.

Its a bit like the chicken or the egg......which comes first....when a gas or coal fired plant has to shut down for maintenace where do they get their electricity from to start up again?..............

[claybro]

Well obviously its solar OR wind....or other pumped hydro (yes, if it's cloudy, that usually indicates that it is probably windy)

Usually yes. Cloud in SA indicates wind. But Not always. There are several days in any given year usually in late autumn and winter where it is cloudy AND still. As I referred to rubbermans post it is known as anticyclonic or high pressure gloom and can exist over SE Australia for days at a time. At present this renewable generation gap is filled by coal and gas fired generation. Now I know that on probably 360 days per year there is a good chance that somewhere in the grid, it will either be windy, and or sunny, and with battery storage and pumped hydro, and molten salt towers, snowy hydro and Tasmanian hydro it is possible to even exceed the daily requirement of generation in all states, however there will be a handful of days per year, that this will not happen. A large blocking high with no wind and overcast conditions in winter will render all solar and wind generation in SA, Vic and Southern NSW out of action, and in this case it will be necessary to provide a large proportion of power using fossil fuelled generation. So we need to have a backup system in place that can ramp up to provide in one off circumstances almost full generation from fossil fuel-even if only for a handful of days per year. We cant just shut the country down because it is cloudy and still. This seems to be overlooked in all articles from renew as if it is not relevant to the cause, just because it only happens a few times per year. I would just prefer if they were upfront, and stated what the renewable generators were doing to secure power supply on the days when they cannot provide it, and what they are doing to support the supply of backup power generation. There seems to be no requirement for them to guarantee power 24/7/365, and their heavily subsidised operations will eventually squeeze the fossil fuel players out all together, which is surely the point of the exercise. I am apolitical on power, and really would love for renewables to be the answer, but there are still many gaps in the information being provided by the renewable industry, and most other sources of information are split on political lines.

[SBD]

Well obviously its solar OR wind....or other pumped hydro (yes, if it's cloudy, that usually indicates that it is probably windy)

Usually yes. Cloud in SA indicates wind. But Not always. There are several days in any given year usually in late autumn and winter where it is cloudy AND still. As I referred to rubbermans post it is known as anticyclonic or high pressure gloom and can exist over SE Australia for days at a time. At present this renewable generation gap is filled by coal and gas fired generation. Now I know that on probably 360 days per year there is a good chance that somewhere in the grid, it will either be windy, and or sunny, and with battery storage and pumped hydro, and molten salt towers, snowy hydro and Tasmanian hydro it is possible to even exceed the daily requirement of generation in all states, however there will be a handful of days per year, that this will not happen. A large blocking high with no wind and overcast conditions in winter will render all solar and wind generation in SA, Vic and Southern NSW out of action, and in this case it will be necessary to provide a large proportion of power using fossil fuelled generation. So we need to have a backup system in place that can ramp up to provide in one off circumstances almost full generation from fossil fuel-even if only for a handful of days per year. We cant just shut the country down because it is cloudy and still. This seems to be overlooked in all articles from renew as if it is not relevant to the cause, just because it only happens a few times per year. I would just prefer if they were upfront, and stated what the renewable generators were doing to secure power supply on the days when they cannot provide it, and what they are doing to support the supply of backup power generation. There seems to be no requirement for them to guarantee power 24/7/365, and their heavily subsidised operations will eventually squeeze the fossil fuel players out all together, which is surely the point of the exercise. I am apolitical on power, and really would love for renewables to be the answer, but there are still many gaps in the information being provided by the renewable industry, and most other sources of information are split on political lines.

It's not clear to me who "they" are in the last part of your post...?

There are quite a few gas-fired "peaking" plants of various kinds around the place. They will last quite a long time if they are only needed for five days a year, plus turned on a few times to make sure the fuel is fresh and the bearings don't seize. They will certainly last for long enough to gather empirical evidence about what the actual demand for different kinds of generation and storage are, and how much of it. There are already contracts in NSW and Vic (not sure about SA) to turn off
certain power-hungry consumers on days of electricity shortage. As far as balancing supply and demand, that is just as valid a strategy as paying to turn on a big coal-fired boiler.

If coal turns out to be needed for a few days a year, then someone who owns one of the last few might decide that the maintenance costs of keeping it available for those few days (on which they will be paid a premium for the electricity it generates) are actually quite a pleasant outcome on their balance sheet when compared to the cost of demolishing and disposing of it.

[claybro]

There are quite a few gas-fired "peaking" plants of various kinds around the place. They will last quite a long time if they are only needed for five days a year, plus turned on a few times to make sure the fuel is fresh and the bearings don't seize. They will certainly last for long enough to gather empirical evidence about what the actual demand for different kinds of generation and storage are, and how much of it. There are already contracts in NSW and Vic (not sure about SA) to turn off
certain power-hungry consumers on days of electricity shortage. As far as balancing supply and demand, that is just as valid a strategy as paying to turn on a big coal-fired boiler.

If coal turns out to be needed for a few days a year, then someone who owns one of the last few might decide that the maintenance costs of keeping it available for those few days (on which they will be paid a premium for the electricity it generates) are actually quite a pleasant outcome on their balance sheet when compared to the cost of demolishing and disposing of it.

We currently survive the few days per year of negligible renewable generation, because of the still sizable amount of generation from the various coal fired generators, and some new gas generators. At the current rate, coal might be around another 20 odd years, with some in Qld maybe 30-40 as they are newer. The current small gas plants will not be able to supply a large chunk of power once coal is gone and on days where most of SE Australia has little wind and no sun-even if it is only a handful of days per year. Just building more solar and wind generation while fine for most days of the year, will still all be idle on just a handful of days per year. My question is, why are the renewable companies not accountable for the building of small backup plants at each of their sites to cater for these days. It would be a more honest indication of their overall cost and accountability, both in the critical service they provide, and the emissions generated because of their overall operation.
On another point you talk about "load management" , turning off hungry consumers, so we now have a power system that has a built in requirement to cut off power to industry when there is lack of supply. You all do realise we are competing for manufacturing with India, China and soon Indonesia, who by the way are currently constructing hundreds of new coal fired power stations, as are some European countries.

[PD2/20]

We currently survive the few days per year of negligible renewable generation, because of the still sizable amount of generation from the various coal fired generators, and some new gas generators. At the current rate, coal might be around another 20 odd years, with some in Qld maybe 30-40 as they are newer. The current small gas plants will not be able to supply a large chunk of power once coal is gone and on days where most of SE Australia has little wind and no sun-even if it is only a handful of days per year. Just building more solar and wind generation while fine for most days of the year, will still all be idle on just a handful of days per year. My question is, why are the renewable companies not accountable for the building of small backup plants at each of their sites to cater for these days. It would be a more honest indication of their overall cost and accountability, both in the critical service they provide, and the emissions generated because of their overall operation.

Surely the same accountability for backup plants should also then be imposed on the fossil generators to cover for outages, planned or otherwise. An unexpected trip of a large fossil plant can have a considerably greater impact on power system operation than the loss of output from a wind farm on a calm day which can be predicted by weather forecasting.

On another point you talk about "load management" , turning off hungry consumers, so we now have a power system that has a built in requirement to cut off power to industry when there is lack of supply. You all do realise we are competing for manufacturing with India, China and soon Indonesia, who by the way are currently constructing hundreds of new coal fired power stations, as are some European countries.

When peak demand can be several times the average demand, isn't it prudent to consider ways of managing demand to even out the load requirements over the day or year rather than necessarily building additional generation capacity to cater for occasional peak demand. Load management doesn't just equate to blackouts. It can exploit technology in controlled and intellegent ways to reduce peaks in demand.

[SBD]

There are quite a few gas-fired "peaking" plants of various kinds around the place. They will last quite a long time if they are only needed for five days a year, plus turned on a few times to make sure the fuel is fresh and the bearings don't seize. They will certainly last for long enough to gather empirical evidence about what the actual demand for different kinds of generation and storage are, and how much of it. There are already contracts in NSW and Vic (not sure about SA) to turn off
certain power-hungry consumers on days of electricity shortage. As far as balancing supply and demand, that is just as valid a strategy as paying to turn on a big coal-fired boiler.

If coal turns out to be needed for a few days a year, then someone who owns one of the last few might decide that the maintenance costs of keeping it available for those few days (on which they will be paid a premium for the electricity it generates) are actually quite a pleasant outcome on their balance sheet when compared to the cost of demolishing and disposing of it.

We currently survive the few days per year of negligible renewable generation, because of the still sizable amount of generation from the various coal fired generators, and some new gas generators. At the current rate, coal might be around another 20 odd years, with some in Qld maybe 30-40 as they are newer. The current small gas plants will not be able to supply a large chunk of power once coal is gone and on days where most of SE Australia has little wind and no sun-even if it is only a handful of days per year. Just building more solar and wind generation while fine for most days of the year, will still all be idle on just a handful of days per year. My question is, why are the renewable companies not accountable for the building of small backup plants at each of their sites to cater for these days. It would be a more honest indication of their overall cost and accountability, both in the critical service they provide, and the emissions generated because of their overall operation.
On another point you talk about "load management" , turning off hungry consumers, so we now have a power system that has a built in requirement to cut off power to industry when there is lack of supply. You all do realise we are competing for manufacturing with India, China and soon Indonesia, who by the way are currently constructing hundreds of new coal fired power stations, as are some European countries.

According to the spreadsheet linked from https://www.aemo.com.au/Electricity/Nat ... nformation , SA currently has a total of 2661MW of gas-powered electricity generation (not counting Torrens island A to be mothballed soon nor Barker Inlet which will partially replace it), probably a bit less on really hot days when many of them cannot operate at full capacity. I don't know of a source for peak demand. Typical daily peak is around 1800MW at present. That is looking at SA as an island, unable to import or export electricity.

Yes, I mentioned load management, which is different to load shedding. Load management means that the business in question has negotiated and contracted to reduce demand on request, as distinct from load shedding which is the grid needing to cut customers off involuntarily. If I worked in a smelter or refinery, I might be quite happy to find that the boss has negotiated to make just as much money on a few extremely hot days by shutting down and letting me work in a cool 35 degree area doing maintenance instead of working on the heat sources I usually work on.

I have no significant concern if the backup generators are owned and operated by different people than the primary generators, nor if they happen to not be co-located. The skill sets to operate them and the financial profile is quite possibly different. So far, SA's batteries are next to wind farms (Hornsdale and Wattle Point) but pumped hydro might not make sense to be next to a wind farm if the right kinds of hills are in different places. Snowy Hydro has gas reciprocating engines in SA, but no renewable energy yet. Several of the newer wind and solar farms have included provision to add batteries, and at least one proposal includes pumped hydro.

If the market works properly and has the right kinds of price signals in it, then someone will likely respond to the demand to meet the few days of unusual demand. The "right" technology to run economically for five days a year could well be something quite different to providing "base" (i.e. near-constant) power. I wonder if that is what has led to pumped hydro proposals.

[rubberman]

The material point though is that it's almost impossible for coal fired plants to get finance for construction. In order to make a financial case, a coal fired plant needs to have a 40 year life to pay off loans/provide a dividend stream. Anything less than that risks a loss, a big loss. Private finance will not bet on coal being cheaper than renewables in five years, let alone forty.

That leaves coal fired plants viable IF and only IF taxpayers guarantee their profit.

It would be an interesting exercise seeing a pro-privatisation Federal Government trying to justify multi-billion subsidies to private companies for technology the private sector won't touch any more.

[claybro]

That leaves coal fired plants viable IF and only IF taxpayers guarantee their profit.

It would be an interesting exercise seeing a pro-privatisation Federal Government trying to justify multi-billion subsidies to private companies for technology the private sector won't touch any more.

But aren't taxpayers guaranteeing profits for the renewable companies via their subsidies? And it still does not answer the question, who is going to pay for the fossil fuel standby plants once all coal is closed down. Who is going to construct the multiples of gas fired plants required to cover baseload for the few days per year that that renewables will not be able to supply power over SE Australia. Probably again the taxpayer. The more renewables in the system, the less opportunity there will be for a fossil fuel generator to sell power, until it becomes unviable as they cannot compete, except on a handful of days per year-not a good business model. Who is going to pay for the replacement of all the wind turbines and solar panels in 20-30 years?-probably the taxpayer, so why aren't the renewable companies, via their large subsidies at least required to guarantee power from their plant 365 days per year 24/7?

[rubberman]

That leaves coal fired plants viable IF and only IF taxpayers guarantee their profit.

It would be an interesting exercise seeing a pro-privatisation Federal Government trying to justify multi-billion subsidies to private companies for technology the private sector won't touch any more.

But aren't taxpayers guaranteeing profits for the renewable companies via their subsidies? And it still does not answer the question, who is going to pay for the fossil fuel standby plants once all coal is closed down. Who is going to construct the multiples of gas fired plants required to cover baseload for the few days per year that that renewables will not be able to supply power over SE Australia. Probably again the taxpayer. The more renewables in the system, the less opportunity there will be for a fossil fuel generator to sell power, until it becomes unviable as they cannot compete, except on a handful of days per year-not a good business model. Who is going to pay for the replacement of all the wind turbines and solar panels in 20-30 years?-probably the taxpayer, so why aren't the renewable companies, via their large subsidies at least required to guarantee power from their plant 365 days per year 24/7?

Well, it's almost like a Federal Government should have an energy policy.

As for renewable subsidies. If private financiers will not finance coal plants, and it looks like the unsubsidised renewables price is going down, here's the choices:

Don't subsidise renewables, then when the coal plants are decommissioned with no replacement because nobody will finance them, there's a sudden huge gap between supply and demand.

Or.

Subsidise renewables and when coal fired plants are decommissioned, there's at least some capacity to meet demand.

Or.

Subsidise coal, and then have high prices for the next 40 years. Noting that present coal generating proces are based on fully depreciated plant. New plants will carry a very high depreciation cost, boosting prices.

Choose one.

[PeFe]

Coal fire power generation in this country is a "dead man walking"......most of the existing plants will be retired 2022-2035...

And new coal fired power construction is a "future dead loss". Current comparison prices between coal ($72 mw wholesale) wind and solar ($45-55)

If you started to build a new coal power station tomorrow, it would not open until 2024 (at the earliest, typical construction time is 6-8 years) meanwhile the price of wind and solar and storeage continues to fall.....and most people have bought batteries to add to their solar panels, so they can sell their excess electricity in time of need.
And of course Australia is now awash with large solar farms and South Australia gets it daytime electricity needs exclusively from renewables, some days solar does it all, other days its the wind and other occasions "storeage" is brought in to fill the gap. South Australia will still have gas plants but they are increasingly only being used at night or summer, but even this is getting less as more storeage comes online...........yes 2024.

[claybro]

PeFe, probably without realising you have summed up my concern entirely. If gas is being used less and less and mainly at night as more storage comes online, even the gas plants will become uneconomical. Coal is gone, it's a given. We do not have the storage technology for anywhere near enough, nor is it currently possible to store enough power to make up for these night time " outages" by renewables. Coal may be gone, I agree.. but soon the renewables will also price gas out if only required intermittently. Again I have to ask, why the renewable companies are not required to provide their own gas backup as part of their generation mix, AT THIER COST, both in co2 emulsions and money.

[Goodsy]

PeFe, probably without realising you have summed up my concern entirely. If gas is being used less and less and mainly at night as more storage comes online, even the gas plants will become uneconomical. Coal is gone, it's a given. We do not have the storage technology for anywhere near enough, nor is it currently possible to store enough power to make up for these night time " outages" by renewables. Coal may be gone, I agree.. but soon the renewables will also price gas out if only required intermittently. Again I have to ask, why the renewable companies are not required to provide their own gas backup as part of their generation mix, AT THIER COST, both in co2 emulsions and money.

The future is pumped hydro

http://www.abc.net.au/news/2017-06-16/p ... sa/8623758

"About 400 hectares of reservoir is required to support a 100 per cent renewable energy grid for South Australia, which is four parts per million of the state's land mass," he explained.

At 24,000MWh the largest in the world would just about cover our entire energy needs for 12 hours

https://en.wikipedia.org/wiki/Bath_Coun ... ge_Station

[rhino]

PeFe, probably without realising you have summed up my concern entirely. If gas is being used less and less and mainly at night as more storage comes online, even the gas plants will become uneconomical. Coal is gone, it's a given. We do not have the storage technology for anywhere near enough, nor is it currently possible to store enough power to make up for these night time " outages" by renewables. Coal may be gone, I agree.. but soon the renewables will also price gas out if only required intermittently. Again I have to ask, why the renewable companies are not required to provide their own gas backup as part of their generation mix, AT THIER COST, both in co2 emulsions and money.

Isn't that the gap where Pumped Hydro comes in? I know there are no pumped hydro plants up and running yet, but reading the info on the Baroota Plant posted earlier this week, that was the impression I got.