Thread: Water, Water..It's not everywhere.

Originally Posted by Bushmiller

Remember that just at the moment there is a distinct shortage of water. I agree that being able to pump water back to a "head" dam in effect becomes stored energy and could power a hydro electric power station and this could be the solution to storage batteries. which still are not at an economic point right now. I heard recently that solar power has become as cheap as any other form. I believe that is correct and incorrect. For a given megawatt that may be true (I don't really know exactly but I am prepared to concede it is close enough) but to keep the sums simple I work on a maximum of eight hours that our solar panels or solar thermal is operable. Ian has suggested it is closer to five hours. It will depend on the time of year and country of origin

Let's assume Australia during the summer as a best scenario. If we only produce power for a third of the day we need to be able to produce three times that amount for it to be the equivalent of a thermal station and we have to have a place to store it. Consequently for the cost of solar power to equate to other electricity production it has to have at least three times the capacity (probably more like four times when averaged through the year) and a a storage facility. This is where a dam could substitute for batteries, which is probably the first image that comes to mind when electricity storage is mentioned.

Problems:

1. Dams are not necessarily where the transmission lines already exist.
2. There has to be sufficient water (The DC link between Tasmania and the Mainland was put in for Tasmania not the other way around: It was in case Tasmania ran out of water)
3. Who is going to put these installations in place? The various governments have moved towards privatisation. At least solar allows smaller enterprises to be considered.
4. Solar farms have recently cried foul because there were no transmission lines provided for them. Who did they think was going to do this? What part of private enterprise did they not understand?

I don't really agree with privatisation of major utilities, but this is what successive governments have done in the quest for a quick buck and an attractive looking bottom line. It was the agricultural equivalent of selling off your breeding herd.

Regards
Paul

Problems 1 & 2 are non issues - often trotted out the the fossil fuel apologists.

Problem 3 requires some political action - it should be either fully funded or at lest underwritten by public sector - but at the very least they should stop subsidising fossil fuels &provide some regulatory certainty to allow any private investment to start. This is in part where the fat arses can help!!

Problem 4 really requires a complete reversal of the idiocy in privatizing the poles & wires. The national grid should be federal infrastructure, and the reticulation within a state the state government. These are natural monopolies and NOT suited to private enterprise on s many, many levels. However that does NOT stop the implementation of pumped hydro, as there a re many sites suitably located close to the grid.

While those sites may be potentially able to generate energy, to say that they are all potential pumped hydro sites is drawing a long bow. The summary in the link makes no mention of the flow or storage available at those sites. It's probably not realistic to build storages above and below each turbine site, and there would almost certainly be justified environmental objections to most.
There is an inherent conflict in operating a river system for pumped hydro and irrigation, and almost every river in Australia has some irrigation extraction from it. To operate a pumped hydro system efficiently, you need to keep the water as high up in the system as possible, while irrigation water is usually required at the bottom of the system. Who decides which gets priority? To paraphrase Paul Keating, never get between an irrigator and a bucket of water.

Originally Posted by AlexS

To paraphrase Paul Keating, never get between an irrigator and a bucket of water.

too true

Originally Posted by RossM

Problems 1 & 2 are non issues - often trotted out the the fossil fuel apologists.

Problem 3 requires some political action - it should be either fully funded or at lest underwritten by public sector - but at the very least they should stop subsidising fossil fuels &provide some regulatory certainty to allow any private investment to start. This is in part where the fat arses can help!!

Problem 4 really requires a complete reversal of the idiocy in privatizing the poles & wires. The national grid should be federal infrastructure, and the reticulation within a state the state government. These are natural monopolies and NOT suited to private enterprise on s many, many levels. However that does NOT stop the implementation of pumped hydro, as there a re many sites suitably located close to the grid.

Ross

While I agree with much of what you say and in particular the concept of a major utility not being in private hands, the fact is that all the states embarked on a policy some years ago to sell off the various components of electrical generation and distribution and to a large extent that is exactly what has happened. I suspect that even if they wanted to, and I don't believe they do, they would not have the money to buy back. It was at the time a once off sale for easy gain.

Consequently, where the old state owned networks were formed to provide continuity of supply, the current system is a commercial operation including the few state owned stations, who are bound by the same rules. When it was first established just before 2000 the general consensus was that while continuity of supply had been the prime objective now there were only three things that mattered: Price, Price and Price. It is a business. Pure and simple.

While in principle it allows new players to enter the market, in practice they can only do this if they can see it as a viable enterprise. You have to appreciate that we are talking about what we have got and no longer about an ideal situation. It is true to say that the government of the day could re-enter the market with their own competitive business, but I don't believe that either of the two major parties have an interest in doing this and I certainly have not heard any noises from either side reflecting a desire to get back in. Even the current government, who have advocated the building of one or more coal fired power stations have shown no interest in building it themselves. It is just the liberal government mouthing off to appease their buddies in the coal industry.

Just on the issue of where dams and solar farms are placed I'm afraid that is very far from being a non issue. To my mind it is probably the largest single impediment always assuming that the commercial sums stacked up in the first place.

Before I get into that and quote some examples from our local situation let me state my personal situation again. I work as a control room operator at Millmerran , which is a supercritical coal fired power station and the second last station to be built in Australia having been commissioned in 2003. (Kogan Creek was the last station in 2007 and is in fact government owned by CS Energy.) I have made no secret of where I work and my involvement in the fossil fired industry. However I have no axe to grind and my aim is to make people aware of aspects to which they would not ordinarily be privy (without divulging discrete information privy to the Millmerran operation). I am a big fan of solar power. I have solar panels on the house. My overall position is that there needs to be a transition from fossil fired power to renewable energy and I despair at the amounts of CO2 that are being placed into the atmosphere without sufficient trees to act as a carbon sink .

Coal fired power stations traditionally had a life expectancy around fifty years. That would take our station to 2053 and Kogan to 2057. However that was while newer more efficient installations were being continually being produced. Under the circumstances I would expect a few selected stations to remain open far longer on emergency standy by much in the same way as we keep diesel generators on standy today.

OK, back to the infrastructure for any station. When Millmerran PS was built the owners had to construct a new road to bypass the town, they had to construct an 80Km pipeline to take recycled water from Toowoomba, they had to build a substation and they had to put in place a 330KV transmission line. Back around the turn of the century it coast $1.4billion. It was done on the absolute cheap. A similar station today would cost around $4billion or more and it is a small station. This is why nobody is going to put their hand up for a new thermal station that will not be allowed to go for it's full life cycle. So you can relax on that count.

Nearby, but in almost the opposite direction there is a site that has approval for a 2000MW solar farm. Absolutely nothing has happened because they think that somebody else should supply the transmission lines.

Actually, that is not the whole story. Remember I mentioned that all these projects have to be commercially viable and the influx of solar power has indeed dropped the price during the day. So now at times (certainly not all the time) the wholesale price drops to zero dollars and sometimes it goes negative. Of course if it goes negative the solar is just shut off, but it means they can't make any money. Yes, I hear the chorus of the government should intervene, but that is not their philosophy.

If I can comment on the pumped hydro, as with all the other forms of power generation, it has to be commercially viable. In other words competitive. In articular with hydro it has to meet the environmental criteria too. Remember that the primary reason for the Snowy Mountain scheme was irrigation. Electricity generation was a secondary consideration. Neither do all the generators in that scheme have the ability to pump back up to the top dam.

As we are on the subject of hydro, this article on Snowy 2.0 may be of interest: It coincidentally mentions the issue of transmission lines, but also the reality of what can really be produced as opposed to a theoretical maximum.

Snowy 2.0 will not produce nearly as much electricity as claimed. We must hit the pause button

Unfortunately nothing in life is simple. As I have mentioned before in other threads, particularly on power generation, there is no power source today that does not have a fundamental flaw: None.

Apologies to the OP for the small digression. Heck that was me. I'll allow it .

Regards
Paul

Originally Posted by Bushmiller

Coal fired power stations traditionally had a life expectancy around fifty years. That would take our station to 2053 and Kogan to 2057. However that was while newer more efficient installations were being continually being produced. Under the circumstances I would expect a few selected [coal fired] stations to remain open far longer on emergency standby by much in the same way as we keep diesel generators on standby today.

Methinks that scenario -- keeping a coal fired plant as an emergency standby -- is very unlikely.
without divulging trade secrets, realistically how long would it take to get a coal fired power station from stone motherless cold up and running?

I've seen estimates that just varying the station output takes around 24 hours. Starting a station from stone motherless cold would take much much longer than a month. First off you'd have to locate and possibly train the operators.

Not something you can do as an emergency standby.

Originally Posted by ian

Methinks that scenario -- keeping a coal fired plant as an emergency standby -- is very unlikely.
without divulging trade secrets, realistically how long would it take to get a coal fired power station from stone motherless cold up and running?

I've seen estimates that just varying the station output takes around 24 hours. Starting a station from stone motherless cold would take much much longer than a month. First off you'd have to locate and possibly train the operators.

Not something you can do as an emergency standby.

Sorry Ian.

I misled everybody there with the diesel gen analogy. I meant to say hot standby (actually back in NSW we used to refer to it as "rolling reserve. although I have not heard it called this for a long time, possibly because there has been precious little of it.) In other words, the station is generating it's absolute minimum load ready to step up if needed. The only real scenario I can imagine for this would be that such a station would be paid a retainer as it certainly would not be economic to run at that level. This also is my personal supposition and not based on anything factual and I envisage it only for a brief period in the final transition to other forms of electrical generation.

Your assumption as to time taken to get up and running is on the right track, but does vary hugely from station to station. Kogan creek for example can go from a unit trip back up to full load in four to six hours (assuming the trip was a simple fix and not a catastrophe) while we at millmerran are.....well, quite a bit slower . We just caint go no faster, no sirree!

As to starting up from a mothball situation, we could be talking months depending on what the rats have eaten and what was plundered while it was "stored."

Regards
Paul

My understanding is that back when governments owned the generators, the definition used to be "spinning reserve" -- meaning a generator that was spinning but not generating power. A unit that could be brought on line relatively quickly. Certainly within about 15 minutes.

With the NEM "spinning reserve" has been replaced by the generator bidding process -- I undertake to supply x MW for a period of y (in 30 minute units) at a cost of z dollars. And everyone is paid at the the last rate accepted -- which around lunch time can be a negative dollar amount.


Looking on line, Kogan Creek is a single boiler / single generator (Millerman has 2 generators?). So a system trip at Kogan Creek -- presumably a situation that equates to a hot restart -- requires 4 to 6 hours to get back to full capacity.


I'll go out on a limb and suggest that keeping a coal fired power station as an emergency reserve is not something that even a coal loving government would find the money for. Paying wages and overhead for a fully staffed station to sit idle for 5 years during the transition to "clean energy" would cost far too much.

Originally Posted by ian

My understanding is that back when governments owned the generators, the definition used to be "spinning reserve" -- meaning a generator that was spinning but not generating power. A unit that could be brought on line relatively quickly. Certainly within about 15 minutes.

With the NEM "spinning reserve" has been replaced by the generator bidding process -- I undertake to supply x MW for a period of y (in 30 minute units) at a cost of z dollars. And everyone is paid at the the last rate accepted -- which around lunch time can be a negative dollar amount.


Looking on line, Kogan Creek is a single boiler / single generator (Millerman has 2 generators?). So a system trip at Kogan Creek -- presumably a situation that equates to a hot restart -- requires 4 to 6 hours to get back to full capacity.


I'll go out on a limb and suggest that keeping a coal fired power station as an emergency reserve is not something that even a coal loving government would find the money for. Paying wages and overhead for a fully staffed station to sit idle for 5 years during the transition to "clean energy" would cost far too much.

ian

Your memory is better than mine and it was indeed called "spinning reserve." That's a measure of how long it is since the term was used (or a measure of my memory). However, the units would no sit spinning but not generating as they overheat. If a 500MW unit is running at 250MW it has 250MW of spinning reserve.

The NSW system when I first joined it used to aim to have 2000MW of spinning reserve. That probably has not happened for a long time now. It has to be said that the grid is now interconnected in part so that does partially negate the need for spinning reserve. Gas Turbines with their quick response times also satisfy that need as do the Hydro stations with the fastest response of all.

Kogan Creek is a better designed plant than Millmerran and more automated, which is why it would take us four to five times as long to reach full load on a hot restart.

I think you are right about keeping a station in reserve. Time will tell there.

Regards
Paul

Well it looks like we are in for some rain in Sydney over the next few days.
Ive cleaned the leaves and dirt out the front and rear gutters on the house and pulled up the down pipes into the stormwater and hooked up some pvc pipes to spread the water over the yards.
I don’t expect we’ll get much so I’m not letting it go into the harbour.
Ive also a 3000 litre corro tank plus one of those 1000 litre plastic square tanks as an over flow on the Shed.
Unfortunately it’s on the uphill side of the Shed so will only be getting about 20% of the 240 square metre roof until I rehang the gutters out there.
Anyone else in the big smoke got a tank?
When our neighbor redid his yard I missed the chance to put 2 x 10,000 litre tanks in a dead space next to the Shed. I even had a hydraulic ram pump to pump up to the 1000 in the peak of the Shed internally.
Id really prefer a windmill, that would really get up some noses in this rapidly gentrifying burb.
When he did it we were in Canada so the only way to get tanks in that spot now is to roll them over 10 metres of corro roof on the leanto annex. That could be interesting but maybe possible.
H.

Originally Posted by Bushmiller

Ross

...Just on the issue of where dams and solar farms are placed I'm afraid that is very far from being a non issue. To my mind it is probably the largest single impediment always assuming that the commercial sums stacked up in the first place...

... So now at times (certainly not all the time) the wholesale price drops to zero dollars and sometimes it goes negative. Of course if it goes negative the solar is just shut off, but it means they can't make any money...

...If I can comment on the pumped hydro, as with all the other forms of power generation, it has to be commercially viable. In other words competitive...

...Unfortunately nothing in life is simple. As I have mentioned before in other threads, particularly on power generation, there is no power source today that does not have a fundamental flaw: None...

Hi Paul - sorry for delayed response - off the air (caused by another bloody right wing government screw up - the NBN intervention to "fix" something that never needed fixing - another story!)

I was being somewhat flippant & should have explained my earlier response:

"1. Dams are not necessarily where the transmission lines already exist."This is not an issue as:
a) so many sites have been identified that there are many that are more than suitable from all possible criteria. There has been cost modelling done by a number of players, including the AEMO, ARENA and others; and all that I have seen include the costs of building transmission lines interconnecting pumped hydro to the grid. Note that the sites are not in-stream, but propose construction of off-river systems such as turkeys nest or dry gully reservoirs (with the exception of Snowy 2, which is an outlier & in part driven by political optics).
b) I'm not commenting on the location of any proposed renewable generation facility (and these do not need to be co-resident with the pumped hydro facility.) To bring this up as an objection is a straw-man fallacy.

"2. There has to be sufficient water "
a) Pumped hydro is a closed loop system, and requires a comparatively small volume of water. You could truck water in at full commercial rates and you would not notice it in the capital cost of the system.
b) Operational losses overall are small (for example evaporation losses are controlled by various means and can keep evaporation rates below average rainfall).
c) Overall water use is fractional in comparison to fossil fuel systems. Design for these systems show less than a quarter of the water use.
d) There are suitable sites that can use salt water rather than fresh.

With regard to the effects of trading on electricity price & cost efficiencies - by using a storage solution for renewables much of this is eliminated. Instead of selling to the grid at zero dollars, the excess capacity can be stored & sold as demand picks up. I know this is a very complicated issue; it is another area where government really needs to intervene to reduce the gaming of the trading system. Again, this requires some political courage that favours consumers (both institutional as well as residential)

Commercially viable & competitive - the ability to supply low cost instantly dispatchable / ‘peaking’ energy at an LCOE of less than 14c/kWh seems pretty competitive. And the benefit of grid stabilization also helps. Capital costs of about $500M for a 250MW plant (including transmission!) also seems to stack up well.

I agree - nothing in life is simple & there are no silver bullets. However something needs to be done. PHES can be deployed relatively quickly (systems could be commissioned within 3 years) and can serve an immediate need. I have used POGE (the Principle Of Good Enough) throughout my career; or in other words don't let perfection get in the way of progress. So, flaws or not, we need to make progress. PHES may not be the perfect solution, but as far as I can see given the current state of technology, it is the most pragmatic one to help with a rapid transition to renewables.

To put another slant on this - its a risk mitigation game. Sadly, procrastinating with the status quo has much more risk than moving forward with current alternatives.

Originally Posted by RossM

"2. There has to be sufficient water "
a) Pumped hydro is a closed loop system, and requires a comparatively small volume of water. You could truck water in at full commercial rates and you would not notice it in the capital cost of the system.

Ross, I'm going to have to call you on this one.
The Dinorwig scheme in Wales is perhaps the best example of pumped hydro in the world.
The Dinorwig hydro "battery" has a capacity of 9.1 GWh -- equivalent to around six hours of running at a flow rate of 390 cubic metres per second. 390 cubic metres is equivalent to 26 Army Mack tankers each second. ,
Six hours contain 21600 seconds, which roughly translates to 560,000 Mack tanker trucks of water.
At $2 per tonne km and assuming an 80 km one-way trip, that equates to about $1.3 B -- I'd think even Government would notice $1.3 B.

Thanks Ross for a well thought out post.

It is a pity that people in a position to implement remedies seem not to be either thinking or implementing. I would caution that there can be quite a deal of hype over ideas that all too frequently does not translate into viability in the real world. However, that is not an excuse to ignore possibilities. All too often the political agenda of those seeking re-election gets in the way.

You mentioned $500m for a 250MW pumped hydro plant. I don't know where that figure came from or who conducted the estimate, but I would suggest that if it was commercially viable companies would be crawling over each others backs to put up their hands. That would be competitive with Millmerran nearly twenty years ago and that was built on an absolute budget. There are many reasons why it is not being taken up and at least one of them can be laid fairly and squarely at government doors as they have no plans and consequently no assurance of continuity into the future for a wouldbe player entering the electricity market.

I think your last statement sums up the situation for new entrants to the market"

"To put another slant on this - its a risk mitigation game. Sadly, procrastinating with the status quo has much more risk than moving forward with current alternatives."

I have to say it is very easy for me to see pitfalls in new technologies (actually I see even more pitfalls in old technologies), but I have to be critical bearing in mind nobody is going to take up something that is not viable. Today we just cannot go past the first premise of commercial viability and we can thank both major parties for that. In NSW the Labour government kicked off the first moves towards privatisation under barry Unsworth in 1986. Ironically Unsworth was an electrician and and electrical trades union official before entering politics!

For example, as far as throwing up barriers is concerned, I quite like the thought of using sea water for pumped hydro, but then I thought that it has to go through a turbine. I don't think there is any way you could do that. Coastal thermal stations use sea water but only for cooling purposes. I think we both agree, there is not goingto be a simple solution and I suspect neither major party really wants to stick it's neck out.If that were the case labour would have already boasted and promised what it would do if elected next time around. Having said that, they may well get in purely by allowing Scomo to continue alternating with the right and left foot in his mouth.

Most fossil fired power stations use large quantities of cooling water for their condensers. Something that I don't believe I have mentioned in the past when talking about Millmerran PS is that we have air cooled condensers (huge fans) and while we do use an amount of water for cooling (it is a small fraction of the traditional water cooling methods) that water is recycled effluent from Toowoomba.

In summary I like the concept of water storage as a substitute for a battery, but I doubt there are very many suitable sites. I would also draw your attention to the Snowy 2 link in post #20 where there are serious doubts cast on the ability to pump back suitable quantities of water. Again was the Turnbull government of the day trotting out election pleasers?

Regards
Paul

Originally Posted by ian

Ross, I'm going to have to call you on this one.
The Dinorwig scheme in Wales is perhaps the best example of pumped hydro in the world.
The Dinorwig hydro "battery" has a capacity of 9.1 GWh -- equivalent to around six hours of running at a flow rate of 390 cubic metres per second. 390 cubic metres is equivalent to 26 Army Mack tankers each second. ,
Six hours contain 21600 seconds, which roughly translates to 560,000 Mack tanker trucks of water.
At $2 per tonne km and assuming an 80 km one-way trip, that equates to about $1.3 B -- I'd think even Government would notice $1.3 B.

We are not talking PHES at that scale, we only require short term off river storage systems. A 200MW project requires about 2 GigaLitres of water. Just before xmas the Qld government started to truck about 2 MegaLitres of water per day to a drought affected dam. Based on their costs it would be around $50M to provide the needed water for a 200MW facility. However this is really moot and I apologise; I probably should not have mentioned trucking above, as it really is a distraction. There are so many potential sites and we need so few to secure the required energy that we can afford to select sites with good local water availability.

Originally Posted by Bushmiller

Thanks Ross for a well thought out post.

...You mentioned $500m for a 250MW pumped hydro plant. I don't know where that figure came from or who conducted the estimate, but I would suggest that if it was commercially viable companies would be crawling over each others backs to put up their hands...

... I quite like the thought of using sea water for pumped hydro, but then I thought that it has to go through a turbine. I don't think there is any way you could do that. Coastal thermal stations use sea water but only for cooling purposes...

...In summary I like the concept of water storage as a substitute for a battery, but I doubt there are very many suitable sites...

Hi Paul

There are many recent studies that put capital costs at around $2M/MW - for example the recent Entyra report commissioned by ARENA says "$1.48m/MW for 6 hours storage, $1.70m/MW for 12 hours, $2.11m/MW for 24 hours storage and$2.75m/MW for 48 hours storage. The high cost of 48 hour storage projects is mainly due to a low number of such projects." This is in line with many other benchmarks I have read.

With regards to seawater - Energy Australia is hoping to proceed with the Cultana Pumped Hydro Project in South Australia.
https://www.energyaustralia.com.au/s...ust%202017.pdf
(This is a 225MW plant with an estimated cost of around $470M - in line with my estimates earlier)

Okinawa Yanbaru Seawater PHES was the first plant in the world to use seawater as the energy source. It was decommissioned after about 15 yrs of operation due to cheaper power availability in Japan and lower than expected demand. The technology has advanced since the 1990s.

With regard to the number of sites in Australia, over 22,000 have been identified (thought I had mentioned that, but maybe in Brett's thread on Katoomba Temp records?) - you can check the ANU study. The following is interesting reading & has links to the ANU study and other info:
Pumped hydro energy storage: What are the opportunities for the water sector? - Water Source
ARENA has a summary of the ANU study here:
Study identifies 22,000 potential pumped hydro sites

Of course we don't even need water - Deep shaft kinetic systems can also be used in a similar manner:
https://www.researchgate.net/publica...ed_mine_shafts
and being commercialised already:
UK startup eyes abandoned mine shafts for energy storage The Engineer
https://www.bbc.com/news/uk-scotland...iness-50146801