You need to estmate the cost of your proposal, and provide the basis of your estimate so we can understand it, or it is measningless. Look at the lead article on this thread and the twoo hundred comments on the thread to get some background as to how to approach that.

Without costs, your idea has about as much credibility as a proposal to pipe hydrogen from the Sun.

There have been many comments on this thread about using Australia’s pumped hydro facilities to help make wind and solar power more viable.

A recent paper “100% renewable electricity for Australia’s NEM” by Elliston, Diesendorf and MacGilll http://www.ies.unsw.edu.au/docs/Solar2011-100percent.pdf demonstrates clearly that Australia’s pumped hydro plants could not help renewable energy much at the time it is most needed. (As explained in a number of comments up-thread there are also a number of reasons why the existing hydro facilities’ role and function in the NEM could not be diverted for the use envisaged by the wind and solar power advocates).

The objective of the paper is to show that a 100% renewable electricity system could reliably meet all of the NEM’s demand. In fact, it demonstrates the opposite.

Look at slide 12 in this slide presentation of the simulation study http://www.ceem.unsw.edu.au/content/userDocs/Solar2011-slides.pdf . There is no pumped hydro generation on 1, 2, 5 and 6 July, 2010. Those are the days where Wind + CST + PV could not provide sufficient energy to store energy at the CST plants, let alone in the pumped hydro plants.

This slide reveals much more too. For the period 1 to 6 July, the simulation would need gas generating capacity about equal to the winter peak demand. Ignore the hydo; it is wrong. Contrary to assumptions in the simulation, Australia’s total hydro capacity cannot be run at full power for days and weeks at a time (outside sun hours).

http://physics.ucsd.edu/do-the-math/2011/11/pump-up-the-storage/#comment-1655

Contrary to your statement that Kops II has a vertical shaft and the underground power station is located below the upper reservoir, this is not correct. Kops II is conventional layout [1]. The power station is located near the down stream end. There is a high level pressure tunnel, sloping pressure shaft, surge chambers, underground power station and tailrace tunnel. This is usually the least cost option and would probably be the least cost option for Tantangara-Blowering (if such a scheme with 53 km of headrace tunnel could ever be viable).

Just for interest, I’ve compared Kops II [1], [2]] and Tantangar-Blowering:

Capital cost; $ m;$545;$12,000
Power; MW; 450; 9,000
Capital cost; $/W; $1.21; $1.33
Generation p.a.; MWh; 614,000;
Capacity factory;; 16%;

Pressure tunnel:
length m 5552 53,000
diameter m 4.9 3 x 12.7
Water weight t 104,696 20,141,622

Note: In changing from generating to pumping mode, Kop II has to stop and reverse the flow of 100,000 tonnes and Tantangara-Blowering 20 million tonnes of water.

References:

[1] http://www.kopswerk2.at/downloads/Folder_061006_englisch.pdf
[2] http://www.hydroworld.com/index/display/article-display/0159389604/articles/hrhrw/hydroindustrynews/pumpedstoragehydro/austria_s-450-mw_kopswerk.html

You are correct that the power station has to be sited underground. This was discussed up thread. I explained than that my original analysis was intended as a simple analysis making use of the Tumut 3 costs and engineering features which I had access to and could scale up. I did not have any way to do a rough calculation of the cost of the underground siting.

The cost of high pressure surface pipes is far too expensive. Also, surface pipes are more vulnerable to environmental threats, such as land slides. At higher elevations there is the threat of freezing in winter if there is a period when the water is not flowing in the pipes.

You suggest the shaft should be located at the upstream end rather than near the downstream end. The choices are:

1. Long, high level pressure tunnel to shaft above the power station and short low pressure tailrace tunnel. In this case the tunnel would begin a little belo Tantangara’s minimum supply level and decline at about 2% slope to the top of the shaft. A surge tower would be above the shaft.

2. Short high pressure tunnel, shaft to deep underground power station, and long tailrace tunnel.

3. sloping tunnel from Tantangara to the underground power station and then a short tailrace tunnel. The power station would be as close to Blowering as is practicable. It must at about 300m depth below surface so there is sufficient weight of rock above to contain the 925 m of static water pressure plus dynamic pressure.

Which option is selected would be based on engineering design and costs of the various options. (the surface pipe option would also be considered in early options analysis, but I suspect would be ruled out at the prefeasibility stage).

Here are some issues that would be considered in the options analyses:

1. Geology, rock conditions, tunnel stability, tunnel support and leakage along the various possible routes.

2. Location and cost of the surge chambers

3. Tunnel length

4. Length of access tunnels to the tunnels (for construction and removal of the excavated rock). The longer and steeper the access tunnels the higher the cost of the project.

5. Length and gradient of the access tunnels to the underground power station. (these tunnels have be used to get the huge turbines, generators, transformers and other large equipment into the power station and for operation and maintenance for 60 to 100 years.

6. Hydraulic head loss in the low pressure tailrace tunnels. The tailrace tunnel must slope down from the Minimum Supply Level of Blowering Reservoir. So the power station would have to be located deeper if it is located far from the downstream end. This means the shaft must be longer. Long tailrace tunnels have to be larger diameter or more of them.

I would expect the cost difference between the highest and lowest cost underground option would be no more than 20%. Surface option would be probably 5 to 10 times higher than the underground options.

The best option will not be decided until well into the design stage. However, the difference between the various underground options will be small compared with big issues that you, Neil, are concerned about. The cost difference between the various underground options doesn’t make the slightest difference to the fact that a large pumped hydro scheme like this is totally uneconomic now, even for storing energy from cheap baseload power stations. When we get to the point that nuclear generates at least 50% of our baseload, it is cheap electricity, and is available every night during low demand periods, then a project like this may start becoming attractive. It will only be attractive if the cost of electricity with pumped hydro is cheaper than from load following nuclear. Pumped hydro may become a viable option sometime after 2030 at the earliest, IMO.

One thing for sure, as I’ve made clear many times before, pumped hydro will not be viable as back up for intermittent renewable energy in Australia. Wind and pumped hydro will be some 30 times more expensive than nuclear (ref: http://bravenewclimate.com/2010/04/05/pumped-hydro-system-cost/#comment-86108 )

If you want to argue that wind power can be a fully dispatchable electricity supplier, like fossil fuels, hydro and nuclear, then I suggest you cost wind generators with energy storage at site. That should be your starting point. Then you can get a good estimate of the true cost of wind generation.

http://www.hydroworld.com/index/display/article-display/0159389604/articles/hrhrw/hydroindustrynews/pumpedstoragehydro/austria_s-450-mw_kopswerk.html

My international colleagues (in their wisdom) have decided to make this a fully fledged project and estimate it ‘properly’.

Requests have gone out for the tunnelling component (RFQ to Grow Tunnelling and Skanska JV).

Current discussion revolves around the possibility of using composite pipes which are up to 40% cheaper than steel. (RFQ to Sekisui Chemical http://www.sekisuichemical.com/eslon/index.html).

We have the required turbine, pump and tank estimates.

Obviously our greatest unknown is the surface path and profile for works.

Will we get a credit for longer system life?? (Joking).

Now for an example. A relatively speaking nearby 30 MW [nameplate] wind farm contracted with Idaho Power for an LCOE of US$0.091/kWh. Assuming 100% financing at US rates (15 years @ 8%), maximum CF of 26%, standard O&M (US$30/kW-yr), standard integration fee of US$0.005/kWh, and assuming Idaho production credit is the same as Washington state’s US$0.021/kWh, the project just breaks even at US$1800/kW.

Sources please. Total project cost divided by kW, for all US projects completed over the past 12 months. Doing that for Australia the average cost id $2750/kW. I doubt Australia’s costs are that much higher than US costs.

The capital cost for the whole renewable energy scheme is US$4450/kW (does not include the desalination component)

It seems unlikely that 11 MW of wind capacity costs only $16 million Euro (US$22 million) which is $1450/kW. That is about half what I would expect it to be.

I expect the the capital cost for the whole renewable energy scheme is more likely to be around US$5,000 to $6,000/kW.

Here http://bravenewclimate.com/2010/04/05/pumped-hydro-system-cost/#comment-135527 I did a rough ‘back-of-an-envelope’ calculation of the cost of your suggested alterative to the Tantangara Blowering Pumped Hydro scheme.

My rough estimate for your suggested alternative was $141 billion

My estimate for Tantangara-Blowering (8GW minimum, 9GW average power) is about $12 to $15 billion.

I’ve done another very rough, calculation of your proposal by scaling up the cost of El Hiero from 11 MW to 9 GW (based on the El Hierro figures – $38 million for the pumped hydro component – given here: http://gotpowered.com/2010/el-hierro-an-island-powered-entirely-by-renewables/ (thanks John Newlands for that link).

This very rough estimate is $42 billion for a surface scheme. This is much lower than my first ball park estimate but still about three times the estimated cost of the underground alternative.

I look forward to your cost estimates for the two options: underground versus surface.

Just for interest:
The capital cost for the pumped hydro component is US$3450/kW.
The capital cost for the whole renewable energy scheme is US$4450/kW (does not include the desalination component)

I look forward to your cost estimates you said you will do for an 8GW Tantangara-Blowering pumped hydro scheme comparing all tunnel option with an option with tunnels for generating and surface pipes for pumping.

“11 MW, low head cannot be compared with 8 GW and 900 m head.”

The El Hierro head appears to be ~700m (http://en.wikipedia.org/wiki/El_Hierro#Energy).

What is your definition of “low”?

Could you please change the link to “worldwide rock experience” in the lead article. It is under the sub heading “Cost Estimate”.

The last three letters “pdf” have been changed to “PDF”. The revised link is: http://www.rocscience.com/hoek/references/H2001b.PDF

Your “worldwide rock experience” reference does not link to a page so no-one can see what you were referring to.

I don’t know which link you are referring to. Is it this one?
http://www.solarserver.com/solar-magazine/solar-energy-system-of-the-month/hydraulic-hydro-storage.html
It is working fine for me.

It’s fully commercial unfortunately, but here is one item of coverage;

http://www.energybusinessnews.com.au/2011/08/23/investec-banks-on-solar/

This report’s timings are slightly out and the project is already proceeding. Last I’d heard, full details will be available before year end as orders have been placed for the tracking CPV systems. It looks highly likely that the overall cost will be significantly lower than reported as well.