Nuclear Renewables

Pumped-hydro energy storage – cost estimates for a feasible system

Guest Post by Peter Lang. Peter is a retired geologist and engineer with 40 years experience on a wide range of energy projects throughout the world, including managing energy R&D and providing policy advice for government and opposition. His experience includes: coal, oil, gas, hydro, geothermal, nuclear power plants, nuclear waste disposal, and a wide range of energy end use management projects.

[Ed: Peter is seeking feedback. Some reviewers comments he has already received are given at the end of this document, for reference.]

Pumped-Hydro Energy Storage – Tantangara-Blowering Cost Estimate


Energy storage is essential for intermittent renewable energy generation and is valuable with coal and nuclear generation too. Pumped-hydro is a mature technology and is generally the least cost option for large scale energy storage.

This paper provides a rough cost estimate for a pumped-hydro energy storage facility that would utilise existing dams and reservoirs in the Australian Snowy Mountains Hydro Electric Scheme.

The paper is in response to questions about the cost of pumped hydro energy storage, especially as a component of a fossil-fuel-free electricity generation scenario for Australia. The paper is the fourth in a series of articles (see here for a listing — search this page for articles authored by Peter Lang).

Figure 1: Conceptual diagram of a pumped-hydro energy storage facility.

Project Description

The proposal is to build a 9 GW pumped-hydro facility by connecting two existing reservoirs with tunnels, pipes, generators and pumps.

The two reservoirs are Tantangara (the upper reservoir) and Blowering (the lower reservoir). The difference in elevation between the water levels in the upper and lower reservoirs is 875m (see Appendix). The tunnels to join the two reservoirs would be 53km long (Figure 2).

Figure 2: Proposed Tunnel Line for Tantangara-Blowering Pumped Hydro Scheme

The facility would generate 9GW peak power, for 3 hours per day from 6 hours of pumping at full pumping rate. It could generate for longer at less than 9GW, or if pumping was for longer than 6 hours per day, or if the pumping rate is greater than assumed in this analysis.

The proposal is to bore three tunnels, each of 12.7m diameter, to link the two reservoirs. The reservoirs would be tapped near their down-stream ends to maximise the volume of water storage available. About 3km of the tunnel at the lower end would be steel lined to prevent leakage. There is just about sufficient ground cover along most of the remainder of the tunnel route to avoid the need for waterproof lining or grouting for most of the remaining 50 km of tunnel.

The rocks to be tunnelled through would be mostly granite and similar strong, hard igneous rocks. There may be some hard sedimentary rocks, possibly including minor amounts of limestone. The rock would be fractured and faulted.

The power station is assumed to be similar to Tumut 3 in that it would have six turbines in a power station of similar size to Tumut 3. The differences are that the power output will be six times that of Tumut 3 (because six time the hydraulic head). There would be six pumps rather than the three at Tumut 3. Another difference is that some 3km of steel lining will be required in the tunnels.

Issue – Francis turbines, which are best for pump storage, currently have a hydraulic head limit of about 600m. Tantangara-Blowering is 875m hydraulic head. The manufacturers are working on increasing the upper limit. I understand manyufacturers are working at the moment to double them up.

Cost Estimate

The table below provides a ball park cost estimate for the scheme. The tunnel costs, the main component, were calculated using costs for rock tunnel excavation from world wide experience. The power station, pumps, etc, were estimated by multiplying the original costs (from 1967) for Tumut 3 by 10 (that is approximately how much inflation between 1967 and 2009), and by doubling the cost of this equipment to allow for the six times greater water pressure and, therefore, power output. The greatest uncertainty is the cost of the steel pipes, tunnel lining, power station and ‘Allowance for Other’.

How realistic is this cost estimate?

World experience is that hydro projects cost about US$2,000/kW to US$4,000/kW. The Electricity Storage Association gives a range of costs for Pumped-Hydro of US$500/kW to US$1500/kW. This project is A$744/kW.

So the proposed Tantangara-Blowering facility is towards the low end of the range (if the figures are correct). The main reason for the lower than average cost is that the reservoirs do not have to be built; they already exist. However, this project requires more tunnelling than is normal for pumped-hydro facilities.


The Tantangara-Blowering pumped hydro scheme would be a high capital cost investment for just 3 hours of peak power generation per day.

This is the most economic of the four projects investigated.

Pumped hydro is often economically viable for providing peak power for a system comprising mostly fossil fuel and/or nuclear generation (France’s system is the ideal example). But pumped hydro is not well suited to intermittent, unscheduled generators.


I would like to acknowledge the help of some friends, all of whom have had a life time of experience working on hydro-electric projects around the world (all but two still are). Our work on hydro sites and our friendship go back 39, 33, 33, 29, and 19 years. I would like to thank Rich Humphries and Dr Derek Martin for their invaluable assistance (and for taking time off from catching neutrinos to help me: they are building a large underground cavern deep below Sudbury, Ontario to catch neutrinos that will be beamed through the rock from Chicago); Tim Little (Canada), Andreas Neumaier (currently in Asia) both of whom have a life-time of experience designing and constructing hydro-electric projects; and David Purcell who was the first boss I had who could influence me. He grew up in Cabramurra, the construction camp for the Tumut 1 and Tumut 2 projects in the Snowy Mountains Scheme. On weekends he would go with his father, a civil engineer, around the scaffolding and walk-ways as he checked out the construction work and instrumentation on the Tumut Pond concrete arch dam, Tumut 2 Dam and the Tumut 1 and Tumut 2 underground power stations. What a way to start a life. Certainly, today’s young can’t get that sort of early experience of the real world.

Pumped hydro is an excellent match for nuclear and for dirty brown coal fired power stations (because they run at full power all the time and produce very cheap power). Consider the 2007 NEM demand: Peak = 33GW, average = 25GW, base-load = 18GW. Option 1 - nuclear only. 33 GW @ $4b/GW = $132b. Option 2 - nuclear + pumped hydro. 25 GW nuclear @ $4b/GW = $100b + 8GW pumped hydro for $15b = $115b. Conclusion: Option 2 (nuclear + pumped hydro) is the lower cost option.

Reviewers’ Comments

Reviewer 1

I had a quick look at your idea of a pumped storage scheme between the Tantangara and Blowering resevoirs in the Snowys. I have only spent a couple of hours looking at your numbers for the assessment of the technical and economic viability of such a scheme. It is my personal view as an individual and not that of the company I am working for.

Ok, here comes the technical side:

1. One would have to assume that the available head is between the minimum operating level at Tangagara, MOL = 1,207 and the full supply level at Blowering, FSL = 380 because any operator would have to guarantee 95% reliability for his peaking power. Thus, the gross head for power generation is MOL – FSL = 827 m

2. Assuming 3 No.s tunnels of diameter D = 12.7 m gives a cross sectional area of Atot = 380 m2.

3. Assuming a maximum flow velocity of v = 3 m/s to keep friction losses within a reasonable range, the total discharge Q = v * Atot = 1,140 m3/s.

4. With that and assuming a local and friction loss factor of η = 0.85, the energy P computes to be P = 7,860 MW using the formula

P = (9.81*η*Q*H)/1000

5. Assuming an operating time of T = 3 hours/day the available energy is E = P * T//1000 = 8.6 GWh/year

6. The discharge volume V = Q * T * 3,600 = 12.3 106 m3.

7. With a reservoir area of Ares = 2,118 ha and assuming vertical reservoir walls, the drawdown over the 3 hour operating period will be Δh = V/Ares = 0.6 m which is acceptable from an environmental and safety point of view, I think.

8. Assuming that the operator can sell peaking power at 4 times the rate as he has to buy the power for pumping during off-peak times, say $0.60 generating vs $0.15 pumping costs, the annual revenue from the scheme would be R = ($0.60 – $0.15) * 8.6 106 = $3.87 billion per year.

9.I am not a mechanical engineer but I believe that at a head of H = 827 m you are pushing the envelope of what turbines can take. I also think that you may need more than 3 units, say 6 or 9 to keep the size of the turbines and pumps and the width of the underground cavern to a reasonable size.

Now comes the project cost sides:

1. The tunnel is by far the most expensive single item so I have focused on that. I do not have a price for a 53 km long, 12, 7 m diameter tunnel excavated by TBM so have used a 8 km long, 3.5 m diameter tunnel and scaled it up to give an approximate figure for the bigger tunnel. Assuming that the tunnel will be mostly unlined and constructed in essentially sound rock, the costs for excavation, support and care of water during construction is $ 7.56 109, which more than double your figure.

2. You have scaled up the 1967 costs of T3 to arrive at the other major cost items. If my tunnel cost figure is correct, I fear that the other cost items may also be higher than what you have estimated.

3. If this is the case, the construction costs may be closer to $15 billion than $7 billion as you have estimated, which will bring the cost per installed kW back into the range of $2,000/kW which is about what pumped storage schemes cost these days.

I do not mean to discourage you but the capital expenditure for a pumped storage scheme between Tantangara and Blowering seems prohibitive because of the scale of the investment, the high up-front costs and the long period for investors to recover their money. Unfortunately, politicians and banks take a much shorter view of life when it comes to political or financial gains and it seems to me that your idea, as much as I like hydro, seems to be condemned to the ‘not economical’ basket.

Reviewer 2

I took a quick look at your costs and determined that it would take more time than I have to review those adequately.  We have had a lot of challenges with cost escalation over the last several years (until the last year or so) and I would not want to give you a misleading opinion.  That said, I do have some quick comments on your proposal:

— The proposed capacity of 9GW (9000 MW) is huge.  Compare to Itaipu (12,600 MW), previously the world’s largest hydro plant and now Three Gorges (ultimately about 22,000 MW) or Revelstoke (2000 MW, soon to be 2500 MW when Unit 5 is completed).

The proposed number of turbines is 6, which translates to 1500 MW each.  I believe the world’s largest turbine capacity to date is about 750MW. (e.g. the turbines at the Sayano-Shushenskaya dam in Siberia which recently experienced the world’s worst hydro plant disaster to date – check it out on Google if you are not familiar already).

The head is very high as you note.  I believe Francis turbines have been built for heads as high as about 800m, but probably not for large capacity.

Your overall cost looks quite low at less than $800/kW; as you note, world experience is typically several times that today.

Your stated uncertainty of 25% is too optimistic.  When we do a conceptual level estimate by a qualified estimator, we state that the uncertainty on the upper end is as high as 100%. The uncertainty goes down as more design is done, and we would not claim 25% uncertainty until we were into final design.

Steel lining is one of the more critical cost factors.  For many high head projects, the cost of steel lining is the factor that determines whether the project is economic or not. You need to know in situ stresses etc to do a proper analysis.

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By Barry Brook

Barry Brook is an ARC Laureate Fellow and Chair of Environmental Sustainability at the University of Tasmania. He researches global change, ecology and energy.

238 replies on “Pumped-hydro energy storage – cost estimates for a feasible system”

Thanks Peter, that’s similar to the 1,200 GWh I estimated in the post before yours — my estimate is lower because I used a figure of 30 GWe of installed wind instead of 48 GWe. Scaling mine up, i.e. 48/30 * 1,200 = 1920 GWh, which is a little more than your figure, but I did it on daily averages rather than the overall 6-day average CF.



On the cost estimates, first the U.S. projects: the published documents associated with the permitting of several U.S. projects with the FERC indicate costs of $970/kW for one (Eagle Mountain) – which uses mine pits for reservoirs, and Lake Elsinore Advanced Pumped Storage (LEAPS) – at about $1450/kW; neither include transmission. For European projects and projects in Asia, you need to hunt around for cost figures on a project-by-project basis, as I have, and there’s also the September, 2009 article from University College Cork (Ireland) titled “Techno-Economic Review of Pumped Hydro Energy Storage Plants” (available online) that shows the range of figures for mostly European projects. Also, the figures published for the newest South African projects both come in at well under $1,000/kW. Part of it certainly must be related to the cost of doing business in a given country (e.g., Japanese projects tend to be on the expensive side).



If it’s any interest here is my neighbour’s newly connected microhydro. Head 21m through 30cm pipe. Average turbine speed 1500 rpm connected to an asynchronous 230v three phase generator. Max output 14 kwe. Metering is 26.5c per kwh which was the pre-existing tariff at the adjoining farmhouse. There is no special feed in tariff or credit for RECs.

The turbine room a stone hut.
Water exits below the hut.

The owner is under no illusions it makes any difference at all. It just suits his property.



Thank you for this. I love these micro hydro hydro schemes, but for interest not for economic reasons. I had a small part to ply in a very similar scheme in Canada, From memory it was about 80kW and it generated that power all year. When the power generated was excess to demand (it was off grid), the excess power heated water in the tailrace.

The really valuable pieces of information you could give us, if your friend will release them, are:

1. The total cost of the system (all costs inlcluded)
2. Energy generated per year from the 14kW plant


Matthew Shapiro,

Thank you for the cost info for some pumped storage sites.

Australia is not average with hydro or pumped hydro because we have relative low topographic relief and less water when compared with USA, Europe and Japan.

Here is a list of some recent pumped-hydro schemes including costs.


What I find interesting about the figures above is that even if one were to use the least cost figures above ($970 per Kwh, as opposed to the $2000 Peter Lang has used) is that the six days of coverage would have implied a spend well in excess of $1.5 trillion dollars, even assuming the capaicty to build and connect at that cost were available.

Then of course you have an empty reservoir, which is utterly useless until enough surplus wind (or fossil fuels) is used to replenish it. You actually have to do that pretty quickly otherwise you have no spare capacity at all if there’s even a brief dip in wiond capacity.

Realistically you’d be switching your fossil fuel sources on well before you got near exhaustion of the pumped storage and since it was such a substantial task you’d probably choose your cheapest source — in this case coal, probably brown coal.

So at the end of the day you have a lot of expensive wind, a hideously large and expensive pumped storage capacity standing by for wind you expect to be no use and finally you have to have fossil fuels in at worst black start readiness anyway.

Yet if you just went with a purely CCGT-based system you could just use the existing pumped storage to manage slews and run the CCGT at optimal efficiency and have no major outlays outside of the new gas capacity. Total CO2 abated per dollar of outlay would be far smaller and if you really did want to spend more you could cut deeper into emissions without the wind for still a fraction of the price.



I agree with the point you are making but you are confusing the unit cost of power (kW) and unit cost of energy (kWh). Have a look at the chart in the lead article (the one full of coloured rectangles just before the Conclusions). The chart plots Capital Cost Per Unit Energy versus Capital Cost Per Unit Power. Capital Cost per unit energy fror Pumped hydro is around $50 – $150/kWh. Note the log scale on both axes.



I calculate a rough cost for sufficient pumped hydro storage capacity to allow wind power to meet the NEM’s demand for power at all times as follows:

1,728 GWh (from above) for sufficient storage for the 6 days 17 to 22 May 2010
= 1,728,000,000 kWh
@$100/kWh for storage capacity (ref. figure in lead article)
= $172.8 billion

How much storage capacity would we need for 6 months of low wind conditions for an average year? Say 10 times this amount? And how much for a worst case, low wind period? Say 20 times?

Estimated cost for sufficient pumped hydro energy storage capacity to last through a worst case low wind year:

= $172.8 billion x 20

= $3,460 billion

No problem! Put it on credit? Worry about it tomorrow! Let the next generation worry about it! And all future generations !! :)


Look at it on an annual average basis. Taking a purist point of view on who’s using the storage facility is not helpful; rather, attempt to work the ratios between wind capacity, storage generating and pumping capacity, and storage volume such that you minimize the need for the latter to maintain a given amount of supply to the grid. You won’t be getting 100% of your charging energy from wind. Throughout the year, there will be times when much of it is coming from wind, and you are firming wind with wind. At other times, you will be using more off-peak baseload resource to maintain the required reserves. The end goal is to maximize the amount of non-polluting, flexible supply in the system while maintaining reliability at the lowest cost. Wind and solar can be part of that.


Peter Lang re microhydro economics; the owner claims it cost around $40k as a result of using second hand hardware and mates to do the trade work, though fully certified. Since this years rainfall is nothing like last year it will be tuned to earn around $250 pw giving a payback period of about 4 years. Tuning involves setting the nozzles to produce a target output with the least water flow, say
40 L/s (flow) X 20m (head) X 9.8 ( g) X 0.7 (efficiency)
= 5.5 kw

It will only produce 14 kw if the big rains come like last year. The annual average output will probably be in the range 5-10 kw X 8,760 h = 44 – 88 Mwh.


Thank you John. For an analysis to be of much value we’d need to do the calculations on the basis of the commercial cost of such a system. We’d also need to have a cost for operation and maintenance. You’ve just mentioned it needs an operator to tune the nozzles from time to time. I wonder what the true operation and maintenance cost would be on a fully commercial basis.


Matthew Shapiro,
@ 2 June 2010 at 0.18

I strongly disagree with your approach. What you are proposing is what the RE advocates attempt to do all the time. That is to muddy the waters so much that no one can see the reality.

Do not use averages. They hide the reality. We need to be able to provide power that is demanded at every point in time.

If you follow through the analysis in the lead article, in the comments, and on the other threads I and others have posted on BNC, you can see that the cost of storage for renewables is exceedingly high.

You need to separate out the components to understand the cost. Otherwise you fall into the trap of burying the true costs of renewables in a system such that the true extra cost caused by renewable energy is not visible.



Are you genuinely interested in finding a viable solution, or are you more interested in trying to promote a belief in renewable energy?

If you are genuinely interested in finding viable solutions to address a problem, can I suggest you define the problem then dispesne with the adjectives. Crunch the numbers and estimate the cost of your proposals. Then we can have a serious discusion. Otherwise we are simply discussing a belief – “renewable energy is good because it is good”.


I’m simply an advocate of living in a manner that leaves as little trace of damage in the long run as possible. Any long-term thinker will consider renewables seriously, even if they are more expensive at the moment.

As for averages, demand at any given moment is based on averages. Even conventional plant outputs have “average” reliabilities of a given number, and can be forced out unpredictably. Wind happens to be quite variable – but it is okay to use averages for it, too, so long as we have a means (the storage system) that helps fit the overall energy flow with the demand at a given point in time.

For for illustration’s sake, a 200 MW storage plant, with a reasonable amount of storage, coupled with a 300 or 400 MW wind plant can – over the long term – operate as an integrated entity with firm output; one that can (under circumstances of a good wind resource and a well-chose storage site) compete directly against conventional sources. So the addition of storage is incremental, not on a par. You don’t need to add the cost of wind/MW plus a MW of storage (that would indeed be expensive). And different types of sites or wind patterns and demand patterns will require different types of configurations. And as I mentioned previously, there is a role for other baseload sources to play in there as well. Even with half or so of the charging energy used to maintain the reserve coming from a non-wind source, you still end up with a product that is mostly renewable in nature.

Now, as I tried to point out, in extended wind lull periods, the lion’s share of charging energy will come from off-peak baseload sources; in extended high wind periods, the lion’s share of charging energy will come from wind. That is okay, and that is why using averages is okay. You just need to look ahead at the seasonal and diurnal patterns based on historical information to determine where it’s safest to set your basic thresholds of firm capacity commitment for the integrated product.



I’m simply an advocate of living in a manner that leaves as little trace of damage in the long run as possible. Any long-term thinker will consider renewables seriously, even if they are more expensive at the moment.

What you either don’t realise or are ignoring is that “renewables” are not renewable. Only the fuel is renewable. Renewables require 10 times more concrete, 15 times more steel, and tens of times more of other non-renewable material. So they require far more mining, far more area disturbed for mining, and far more area for the actual plants. Renewables are not as sustainable as nuclear energy, not even close. So the reason you should look more closely into your belief is not just about cost. Renewables are less sustainable than nuclear. There are several other threads on the BNC web site where this has been covered and discussed at length in the comments.



I’m simply an advocate of living in a manner that leaves as little trace of damage in the long run as possible. Any long-term thinker will consider renewables seriously, even if they are more expensive at the moment.

What you either don’t realise or are ignoring is that “renewables” are not renewable. Only the fuel is renewable. Renewables require 10 times more concrete, 15 times more steel, and tens of times more of other non-renewable material. So they require far more mining, far more area disturbed for mining, and far more area for the actual plants. Renewables are not as sustainable as nuclear energy, not even close. So the reason you should look more closely into your belief is not just about cost. Renewables are less sustainable than nuclear. There are several other threads on the BNC web site where this has been covered and discussed at length in the comments.



We can’t even begin to sidsucc something like your example when you make statements like this:

with a reasonable amount of storage

I retort: most pumped storage sites have a few hours of storage at full power. So what on earth oare we talking about? The whole post is so loaded with adjectives we can’r discuss it in any meaningful way. Could I urge you to consider the pdf paper linked from here:
Even though this article is about solar and pumped hydro storage, it will give you the gist of what is required for pumped hydro to provide sufficent storage to make intermittent renewables viable. Note the costs. The discussion in the comments covers many of the points you are making.


@Mathew …

I’m simply an advocate of living in a manner that leaves as little trace of damage in the long run as possible. Any long-term thinker will consider renewables seriously, even if they are more expensive at the moment.

I agree completely. I share your desire to leave a small footprint and spent most of the first part of my life as an adult considering renewables seriously, even though I knew they would be more expensive. I put a significant value on treading lightly.

What I found though was that I’d grossly underestimated just how much more expensive RE would be in practice. When I began investigating I discovered that others who had considered renewables seriously and had solid expertise in the field found that they simply couldn’t do the most important job most RE advocates, me included, wanted them to do — the job now being done with fossil fuels, except at an unrealistic premium and maybe not even then. It suddenly became very clear why what had seemed obvious to me — renewables were the way to go — was being ignored by almost everyone with the dollars to invest. They weren’t stupid or ignorant or greedy (well they were but that was beside the point). They simply could not see any way they could break turn a profit on the deal, even with a state subsidy. Sad but true. After all, if you could sell “clean energy” for only a modest premium on coal or gas (and thus for the same price with a modest subsidy), why would you not do so? A dollar is a dollar, however you get it.

I also found out that nuclear power was a lot less polluting and dangerous than I’d thought. As Peter points out, it involves a far smaller footprint in practice than renewables.

The problem is the numbers. If you are going to supply an industrial scale energy system you must have despatchable output i.e you must be able to promise to deliver exactly so much power to the grid at a given moment in time. If you can’t do that what you can produce at random times is simply not commercially useful.

The point Peter makes is that it is not the average output of windfarms that is key. It is the minimum output that is critical in assessing storage needs. If there are times when you are only producing 5% of what you could produce at best or of what you would produce on average then one of these has to be the benchmark for your storage or your fossil fuel cover. It you expect, for example, on on average to supply the grid with 400MW then you must have the shortfall from 400MW at any given time in storage perpetually or a fully despatchable source able to fill the gap on the same notice you have of the shortfall. Either solution is very expensive unless the average and the minimum are very similar. They aren’t , so “reasonable storage” doesn’t cover it. The question is how far into deficit will you go before your average power output recovers to that you predicted? Nobody can say that with certainty. It is politically unacceptable for any government to load shed in circumstances where they ought to have been able to avoid it and so no government will take that risk.

As Peter demonstrates in the Hazelwood thread, trying to use wind with gas shadowing costs a lot but at the margin, doesn’t produce significant reductions either in emissions of reductions in fossil fuel usage and yet it is very expensive.


[…] Hydro Power Storage is quite expensive with estimates ranging from $500-$1500/KwH which is comparable to the most expensive forms of Energy Storage like Lithium Batteries.This form of Energy Storage also leads to losses of between 15 – 30%.There are also minor problems of environmental impact of large hydro plants and availability of  favorable sites. The main advantages are that it uses existing infrastructure of Hydro Power which has a large global installed base.In the 1930s technology was developed for building Turbines which could generate Electricity and also serve as Motors allowing Storage of Hydro Power.Also Pumped Hydro Storage has High Reliability of >99% and  relatively Long Cycle times which means that the stored electricity can be used in a few hours to a few days. […]


There is an important error in the previous post. It highlights the frequent confusion between power, energy, and energy storage capacity.

Hydro Power Storage is quite expensive with estimates ranging from $500-$1500/KwH which is comparable to the most expensive forms of Energy Storage like Lithium Batteries.

This should be restated as follows:

Hydro Power Storage is the cheapest electrcity storage technology with estimates ranging from $500-$1500/kW power and $50-$150/kWh energy storage capacity which is about 1/10th the cost of forms of energy storage like Lithium Batteries


Neil Howes @

Tantangara Reservoir is a component of the Snowy Mountains Hydro Electric Scheme. Its purpose in the scheme is to divert water from the upper catchment of the Murrumbidgee River to Eucumbene Reservoir for long term storage. Eucumbene Reservoir is the large central storage reservoir for the Snowy Mountains Scheme.

Tanatangara operates between empty and full. Seasonal waters flow into the reservoir and are diverted to Ecumbene Reservoir as fast as the tunnel can move the water. Sometimes Tantangara Reservoir fills faster then the water can be diverted. When this happens Tantangara Dam overflows and water is discharged down the Murrumbidgee River. This water is lost from use for hydro electricity generation. It generates no electricity. So overflowing is a loss of potential stored hydro energy.

If we were to use Tantangara Reservoir for pumped hydro, then the proportion of the reservoir’s volume we use for pumped hydro storage is storage removed from use for Tantangara’s intended purpose. If we wanted to use all of Tantangara Reservoir for pumped hydro storage in the way envisaged by Neil Howes – that is, using 526GWh of potential storage to back up for intermittent wind power – then Tantangara Reservoir would need to be kept full throughout the year so it is ready to generate at high power for days at a time. To do that would mean Tantangara Reservoir could not do its job of capturing the seasonal inflows from the upper Murrumbidgee River and diverting them to the central storage (Eucumbene Reservoir) for future use in generating electricity. So the capacity factor of the Snowy Mountains Hydro Electric scheme would be reduced forever. It would produce less hydro electricity forever more.

The Tantangara-Blowering pumped hydro scheme I envisage is a traditional pumped hydro plant that would pump the water up every night at the times of least demand on the grid. At this time power is cheap and is supplied by the least cost baseload power stations. I envisage these being nuclear power stations in the future. If we used Tantangara-Blowering as I envisage we would use only up to about 40GWh of storage. That would amount to less than 10% of the total storage of Tantangara. So we would effectively lose only 10% of Tantangara’s capacity to capture water for traditional hydro electric generation in the years when Tantangara overflows.

If Tantangara-Blowering is developed as a traditional pumped hydro scheme for use with low cost baseload power in the early ours of the morning it can provide 8GW or peak power (high value power) every day for 80 odd years. That would avoid the equivalent of eight nuclear power stations. It would cost about $15 billion and save about $32 billion in nuclear power stations (the nuclear power stations to do the same job, in a fossil fuel free world, would be load following and used at a capacity factor of about 20%). That is the really great value of pumped hydro if we do not waste it on propping up renewable energy.

However, if the site was used for supporting wind, we’d need to use all Tantangara’s capacity for pumped hydro and would lose its use for conventional hydro. Tantangara Reservoir would need to be kept full so it is able to provide essential power in the infrequent events where the wind isn’t blowing and there is insufficient energy stored in the molten salt at the solar power stations. This would be an enormously expensive way to ensure a secure supply of electricity. It is totally ludicrous suggestion when you really think about it. The $15 billion investment would be for a plant that is required rarely but then is essential to keep our electricity system running.

It would be irrational to use our limited hydro resources and any other potential sites for the purpose of supporting wind power.

I’ve answered the other points in your post before on this thread and several others.

Neil Howes, your advocacy of wind power is irrational.


Compare the cost of wind power and nuclear power on the basis that they must be able to provide baseload power:


Power is available whenever we demand it – every instant of every day and all through the night.

Cost of nuclear power


1. the first nuclear power station would cost the same or less than the first nuclear power station to be built in United Arab Republic (contract for four APR1400 units awarded to a Korean consortium a few months ago); i.e.

2. The cost of further units would decrease over time, to say
$3,000/kW for the sixth unit.

Cost of wind power (to provide reliable, on demand power)

$2,600/kW for the Wind farms.
$1,000/kW cost for transmission and grid enhancements to manage the peak and fluctuating wind power
$1,000/kW for gas generators to provide the power when the wind is not blowing at full power
$4,600/kW total

But wind power delivers, on average, only about 1/3 the energy of a nuclear power station of the same capacity. So we need 3 wind farms to produce the same energy per year (or average power) as a nuclear power station. So the cost of the wind farms to provide the same energy as a nuclear power station would be:
$7,800/kWy/y of average power for the wind farms
$3,000/kWy/y of average power for the transmission and grid upgrades
$1,000/kWy/y for gas generation for backup when there is no wind
$11,800/kWy/y total

An alternative to back-up with gas generators is to use energy storage, such as pumped hydro, compressed air or batteries. Pumped hydro is the cheapest option where the appropriate topographic and geological conditions are available (Australia does not have much economic hydro potential near our major demand centres).
If we did have economic pumped hydro sites available the cost might be something like this:
$7,800/kWy/y of average power for the wind farms
$3,000/kWy/y of average power for the transmission and grid upgrades
$1,500/kWy/y for pumped hydro generating capacity
$100/kWh for energy storage capacity and we’d need say 50 days energy storage to get us through the low wind season; 50d x 24h/d = 1200h x 1kW @ $100/kWh =
$120,000/kWy/y of average power
$132,300/kWy/y total (cost per kW average power)


Peter Lang,
Neil Howes, your advocacy of wind power is irrational.
Possibly the way you are advocating that pumped hydro would be used to support wind and solar power is irrational. I was pointing out that you stated only 40GWh of pumped hydro was available in the Tantangara/Blowering scheme when you had earlier stated 525 Gwh “potential”. I was not proposing that Tantangara be kept full. By linking Tantangara, Eucumbene and Blowering with a least one tunnel each, about 600,000ML of the 1,600,000ML active storage could be used (1200GWh) without compromising long term storage.In fact it could ensure no water was lost from Tantangara as all would end up in Blowering or Eucumbene. During each high wind event( <48h) in SE Australia, up to 8GW surplus wind power would be used
to pump (4,000ML/h) or 200GWh storage( 18% of working pumped storage), and save up to 700GWh of CSP thermal storage. As well no hydro would be used for peak demand( saving 80GWh/2days). During lower wind periods( in SE) some of the thermal storage would be used, and most of the 200GWh pumped hydro used saving additional hydro and some CSP and wind from outside the SE would be imported(up to 8GW).
During really low wind events in SE( generally <24h but sometimes up to 120h) 8GW of long term pumped hydro, 5GW( 2.3GW in Snowy, 2.2GW in TAS) would be used generally for <24h but for about 12-24 days per year in total. Running Snowy at 10.3GW for even 5 days is only going to use <1300GWh storage, with <10% lost via Murray. TAS hydro would be using 280GWh (<2weeks average consumption and 2% of storage). After the first 24h of low wind or when CSP storage was low could start up existing 4GW NG fired power(mainly May to July), generating another 380GWh in 4days, but at a very low annual capacity factor or using NG to top up CSP storage.
Longer seasonal balancing could be mainly achieved by adjusting TAS hydro storage(at a maximum rate of 25-50GWh/day or 6,000GWh over 3-6 months.), with no annual change to storage except in very wet years when more hydro would be used.


At a time when we need an energy common denominator, pumped storage of water may be efficient on site if the conditions are right, but pumped storage of water, as opposed to compressed air, can’t be portable.

I believe in wind to compressed air to the pipes, as a portable energy solution. The compressed air can easily be produced offshore, as dragging air down to depth compresses it. The beauty of the compressed air is that it can be used with any fossil fuel. The new compressed air vehicles that also use gasoline are efficient.

check out the Tripe System Report on It is a system converting wind to compressed air, wind to Hydrogen, and wind to ORCA, or oxygen rich compressed air. Steven J. Scannell


If you google, the FortisBC Resource Plan you will get the detail of a $510M pumped hydro plan for Nicola lake.

The project has an maximum output 770 MW of 2250 floding 25 ha max 8 hectare min, and will pump a huge recreational water body up and down 6 inches every day with associated massive methane emissions. There is zero chance the enviro’s will let this one through. Maybe if they used sea water they might have a chance.

With full utilization the project would output 2250 GWH annual into the grid in peak hours after sucking 3000 GWH into its pumps at night – 75% efficiency.

If we only look at the power input as if it was a power plant the cost per GW avg is $2B/Gw (.510/(2250/(365*24)))

By comparison the last Candu 6 build in at Qinshan was $2B a GW and somewhat less than the $2.5B/Gw currently quoted for first of kind Candu ACR-1000 builds in Canada.

It is more than the current and twice the predicted cost for mass produced nuclear power based on the massive builds of American designed nukes built by American engineers in China today.

We can build better airplanes cheaper than the Chinese in the most highly regulated industry on earth. We should be able to compete on nukes after America’s major cost and delay factor the NRC is upgraded to an OECD standard regulator like Canada’s CNRC. We invented the damn things nukes after all.

So like at lot of things stupid greenie attorney politicians come up with the idea is idiocy. Better to build the nukes and use them off peak for off peak power would be used for hydrogen/methane fuel production, COGEN, desalinization, heat storage and cooling ice storage and charging of electric vehicles.



Thank you for that info. It is really interesting for several reasons. It shows:

1. It is the same cost per kW as a CANDU6 nuclear power plant.

2. It generates 38% the energy of a CANDU6 per year

3. So electricity would be, roughly, 2.5 times the cost of energy from a CANDU6 (Both have O&M costs but nuclear would be a little higher)

4. It generates for about 8 hours per day (during day time and evening peak)

5. It sucks power from the grid that is generated by coal power stations for about 12 hours per day (during the night).

6. Because of the 75% efficiency, the electricity generated i, in effect, emitting 133% of the normal emissions from a coal fired power station.

7. The 770MW pumped hydro plant, if paired with three CANDU6 plants, would provide peak power up to 33% above the baseload and allow the CANDU6’s to run at full power full time (apart from during mainenance). That happens to be exactly the ratio we have in the NEM (in 2007). Our baseload was 25GW, minimum was 17 to 20GW depending on the season, and peak was 33GW.

8. This would allow three CANDU6 units to run at full power, full time, and thus at least cost. This would be the ideal situation.

9. Also note, that wind power could not provide the power for pumping because wind power is not reliable and not cheap.

Point to note: BC has some of the best hydro and pumped hydro potential of anywhere in the world. Yet even in BC, the cost is $2/W.

Thanks again Seth, really interesting. Consistent with everything we’ve been saying in this thread and others.


Very interesting discussion !

The concept to build a pumped-hydro facility by connecting two existing reservoir with a tunnel and with a cavern power plant is applicated in Europe for several pumped storage projects recently.

For instance, projects in realisation:

– Nant De Drance, Switzerland, first step 600 MW, final 1000 MW

– Vianden 11, Luxembourg, 120 MW

Project under investigation:

Lago Bianco, Switzerland, 1000 MW


[…]             Because wind is so fitful, and because power providers have to supply load on demand, back-up generators are required to fill in the gaps when the wind gusts or fails. Hydro power is best for this, but in Australia that resource is already fully utilised, so any new windfarm capacity will require the building of additional generators. In practice the solution is to add a gas turbine generator of the same capacity as the windfarm. This back-up must be running at all times so that wind fluctuations can immediately be compensated, otherwise blackouts will occur. The costs of construction of the back-up generator should be counted when assessing the capital cost of the windfarm. The running costs and carbon generation of the back-up should  be counted when assessing the cost of power and the carbon emissions of the windfarm. For a rough cost comparison see this comment: […]


Dear Mr Peter Lang would you be so kind to give your opinion about this method show on google :
since you are an expert Eng in this HYDRO field we would like to have your opinion in this specific field


Tantangara-Blowering Pumped Hydro – suitability for energy storage for renewable energy generators

The Tantangara-Blowering pumped hydro project would not be suitable for energy storage for intermittent renewable energy generation.

First, to be viable, the sell price of electricity from the pumped hydro scheme needs to be about four times the buy price – so the electricity needs to be generated by low-cost, baseload power stations.

Second, the pumped hydro scheme needs to generate for around 8 to 12 hours every day to earn enough revenue to pay for the capital cost. So it needs a reliable, constant supply of power for about 6 to 8 hours every night when demand is low and electricity is cheap. Intermittent generation throughout the year would not earn enough revenue to pay for the plant. (see Reviewer 1’s comments in the article at the top of this thread).

Third, it is not possible to frequently reverse the direction of the water flow in the tunnels, as would be required if used to store energy from intermittent renewable generators. The tunnels contain 20 million tonnes of water. The flow rate at full power is 3 m/s. Consider the power required to stop 20 million tonnes of water flowing at 3 m/s and pump it back in the opposite direction.

Fourth, for intermittent renewables we’d need much greater storage capacity. The storage required for 5 hours of generation at full power (8 GW) is 40 GWh. That is what is needed to allow the pumped hydro to pump every night and generate every day at peak times for the life of the project. Contrast this with the situation if we wanted to use intermittent renewable energy generators instead of reliable baseload generators. The plant would need enormous storage to allow it to generate during long periods when the renewable energy plants are generating insufficient power. We’d need sufficient storage to cover for days, months and decades of below average generation.

Fifth, we cannot use the full storage capacity of Tantangara Reservoir for pumped hydro. Tantangara’s main purpose is to capture spring run off and divert it to Eucumbene Reservoir for long term water storage (to ensure water for hydro and irrigation during decade-long droughts). I suggested using about 0.6m height of Tantangara’s water (at full supply level, more at lower levels) for pumped hydro storage. This gives 40 GWh of energy storage. The other water in the reservoir could be used for emergency if required and when Tantangara is full the scheme could generate up to 500 GWh, in an emergency situation.

The proposed Tantangara-Blowering pumped hydro scheme is unsuited to intermittent renewables.


Peter a possible solution to the flow reversal problem is to have separate water circuits. Rather than reversible motor-generators that need to be built into the hillside merely keep the existing generators (if they have spare capacity) and build a separate water lifting system as an add-on. How the cost compares I don’t know but it wouldn’t require tunnelling or much concrete.

With climate change some once mighty dams may be chronically low (e.g. Hoover Dam USA) therefore they could generate more power with their existing turbines with increased water flow. Assuming there is a cheap enough external power source some of the outlet water could simply pumped back up to the lake with the dedicated pump. If that pumping is irregular the large volume of existing water smooths out the fluctuations.

As you say logically this suits excess baseload. I believe many people now have a psychological need for wind and solar so this could help give them the reassurance they need.


“I understand manyufacturers are working at the moment to double them up.”

In Nestil, Switzerland, VA Tech Hydro have installed a Francis machine with 4 runners in series. They can deliver over 1000 m head. The quadro-runner unit is primed with a Pelton machine.



Thank you for that information. Can you provide a link?

Is that 1000 m head being used for pumped hydro or just hydro?

What is the maximum power output per generator?

The concept in the lead article is for 923 m static head and maximum total generating capacity of 9,018 MW (at maximum static head). If we assume twelve turbine-generator-pump sets, the maximum power output per generator is 750 MW.

So, the Tantangara-Blowering Pumped Hydro concept needs reversible Francis turbines for pumping and generating, with maximum static head of 923 m, and suited for generating 750 MW power output. Is the state of the art here yet? If not, how long until we get there?

By the way, I suspect there would be no need for such a scheme until well into the 2030’s. It would not be viable until at least 50% of our baseload power is being produced by nuclear power.


Goldisthal Pumped-Storage Plant: More than Power Production

Some points of interest:

1. The time it takes for large capital projects like hydro to go from initial concept to completion. This one started in 1965 and was competed in 2004. That is 40 years.

2. The story of the interrupted progress through investigation, delays, deferments, financial and political interference is common. It’s worst with nuclear, but happens with all technologies.

3. The information about the variable speed turbines is interesting. They are used for controlling fluctuations in grid power. This is definitely not a plant designed for or useable with the variable power output from intermittent renewable energy generators like solar and wind power.

This link is interesting and contains the key engineering features on the last page. I’ve compared some key figures for Goldisthal and Tantangara-Blowering. These highlight what a huge scheme Tantangara-Blowering would be by today’s standards. The Goldisthal plant is tiny in every respect in comparison

Goldisthal versus Tantantangara-Blowering

head (maximum static) m 325 924
Maximum power output MW 1,060 9,018
Max power per generator MW 265 750
Flow rate
– generating m3/s 412 1,133
– pumping m3/s 320 595
Storage m3 12,000,000 238,800,000
Headrace tunnels
– number 2 3
– length m 825 53,000
– diameter m 6.2 12.7


Here is the table with columns separated by semicolons. Copy to Excel and pars with “:” to display in columns.

Goldisthal versus Tantantangara-Blowering;
head (maximum static);m;325;924
Maximum power output;MW;1,060;9,018
Max power per generator;MW;265;750
Flow rate;;;
– generating;m3/s;412;1,133
– pumping;m3/s;320;595
Headrace tunnels;;;
– number;;2;3
– length;m;825;53,000
– diameter;m;6.2;12.7


Would the correlation of nuclear and pumped storage have anything to do with the problems of integrating inflexible nuclear power stations into the grid?
The inflexibility of nuclear and the need to find demand in off-peak times is something that often seems to be ignored in the nuclear debate.



The economics drives the choice of technologies. The least cost option is to make nuclear baseload only (get the most electricity for the capital cost invested) and build pumped hydro storage (where practicable) to provide the flexibility. Where sufficient pumped hydro storage is not available, economically, then we find the least cost alternative way to provide the needed flexibility from other options such as load-following nuclear, gas and/or coal.

The key point to understand is that pumped hydro is far too expensive to be viable as a support for expensive, intermittent, unreliable unscheduled renewable energy. The reason is explained in my comment @ 14 August 2011 at 8:43 PM.

If you are genuinely seeking a better understanding, you may find the lead article and comments on this thread valuable.


Storage of the sustainable such as wind and wave, geothermal, solar, remote locations is best done using pumped hydro’s first cousin compressed air. The second cousin, hydrogen, would also use pipes. Over time, pipe costs will not be too expensive, especially when we interface the energy pipes with mono rail and other needs. Consider a compare and contrast, that pushing water up, and then pushing air down (under water at sea to pressurize), are very similar in concept. The Tripe (track-pipe) System report. 11 pages illustrated.


I think too that hydrogen, expensive and difficult as it may be has enormous potential to be our miracle fuel. If we can think of hydrogen potentially as frozen electricity, transmitted by pipe, not wires, this may help us to justify working more diligently on hydrogen system proposals, and get us out of the bad habit of defaulting back to the fossil fuels. When we crack water we get hydrogen and oxygen, both usable fuels. ORCA, (oxygen rich compressed air) can be very helpful in hybrid gasoline and compressed air hybrid cars. We have a need for higher quality brainstorming, along with a willingness to push technologies forward. We haven’t maxed out on fossil fuel efficiency either, so I’m not saying give that a rest, but the directed need is for practical storage or conversions delivery etc. for our many good sustainable energy systems. Let’s look for the common denominators, non electrical, for future energy systems. What, or how does compressed air, (CAES) (ORCA), and hydrogen, and or other generated gases and liquids, or even pipe ready pellets, …. What do these have in common, and how do we invent the interfaces with the existing fossil fuels based and smart electrical grid based systems?
This is the wiser question rather than putting all hope and research into the electrical grid systems.


Hawkmoon, on 23 August 2011 at 1:29 PM — Gen II nuclear reactors were originally designed to provide nearly constant power. In fact, those units can be (and are) cycled for load-following; most of the data is from France.

The newest Gen III+ designs are prefectly capable of load following although even these newer units will operate to provide lower cost electricity if run nearly flat out. However, as I see the economics, while there may be a few locations where pumped hydro is economic, in most regions using the newer NPPs for load following is the most economic alternative.


@Peter Lang,

In point 3 on 23 August 2011 at 10:54 AM you said:

“The information about the variable speed turbines is interesting. They are used for controlling fluctuations in grid power. This is definitely not a plant designed for or useable with the variable power output from intermittent renewable energy generators like solar and wind power.”

Having read the article, I think it’s ambiguous at best. The following comment from the article:

“Asynchronous machines make it possible to regulate power not only in turbine mode but also in pumping mode. The range of control at Goldisthal amounts to 190 mw to 290 mw.”

and further reading of this article:

Click to access asamihppaiaftegs.pdf

suggest to me that variable speed units, whilst unable to vary all the way down to zero active power, have a broader operating power range in both pumping and generating mode than their synchronous counter-parts. They also, as you say, seem to have a few more strings to their bow with regard to providing ancillary services.

I’m still getting my head around the power issues with sync and async machines, and indeed active and reactive power (my AC theory is very weak), but it does seem to me that variable speed pumped hydro units have some distinct advantages in a grid environment with strong fluctuations.



Thank you for your comment and the link you provided. My comment you replied to is necessarily simplified for posting on a web site like this. It also assumes a lot of background from previous posts on BNC, the lead article on this thread and my previous comment here: . In response to your comment I’d make the following points:

While intermittent renewables, like wind, are a small proportion of total generation, during pumping hours, the variability can be accommodated by the variability of the variable speed pump turbines. However, when the wind penetration is high, as is advocated by renewable energy advocates, the variability cannot be handled by variable speed pumped hydro units. This is one reason it is wrong to argue that projects like Tantangara-Blowering could be used to make wind power viable at high wind penetration (as Beyond Zero Emissions advocates).

Solar power is generated during the day. At this time hydro is generating or on standby, not pumping, so solar energy will not be stored. Furthermore, it is very high cost electricity so unsuitable for pumping (see comment linked above).

Wind power is high cost, so the economics are not favourable for pump storage. You wouldn’t consider building wind power or pumped hydro storage unless wind power is mandated. It wouldn’t make economic sense.

Furthermore, wind power is highly variable. That imposes additional costs on the system.

The most important point I can make is that there is little value in discussing possible technological solutions without looking at the overall economics and financing aspects.


Another trick I learned with variable speed water pumping (on a pond system) was to replace impeller type pumps with positive displacement types eg helical rotor for large volumes. Impeller pumps don’t like changes in intake water level (causing cavitation) or low near stalling speeds when the water flows backwards. Helical pumps can go fast or slow though I understand they are less efficient.

My neighbour has an asynchronous or 3-phase squirrel cage generator on his mini hydro. I don’t fully understand the theory yet but I know some electrical settings have to be tuned for a particular water flow. I imagine that applies to pumping as well.



Further to the last paragraph of my reply to you, “there is little value in discussing possible technological solutions without looking at the overall economics and financing aspects“, the cost of wind with pumped hydro as a means to provide reliable dispatchable power would cost roughly thirty times as much as conventional power generation: So it totally uneconomic

Some important reasons why pump hydro storage is not suitable for intermittent renewables is summarised here:


I get it; if the nuclear proponents need-it/want-it that’s OK, but if the renewable proponents propose a solution it’s too expensive or not technically possible.

My father-in-law’s farm submersible wind/solar bore pumps a head of over 120m (I believe it go do 200m). Maybe the wide-diametre tunnel is the wrong approach; above ground pipes to covered/smaller reservoirs.


Zvyozdochka (@Zvyozdochka), on 29 August 2011 at 8:05 AM — Peter Lang has been looking at one particular proposed pumped hydro project. Some power stations stations, already in operation, are more versatile. The usual difficulty for gengizing by wind power is the lack of large storage; almost all existing pumped hydro stations are only appropriate for diurnal operation. Lack of wind power for an even moderately extended perior would put such a station out of business for the interim.

Follow the green line on


@ David B. Benson

I understand what you say but perhaps misreading what Peter is implying; are you Peter Lang, implying that pumps that can operate with a constantly variable input of energy (ie from wind) are not available?

As a technical challenge, why approach it with a massive diameter tunnel? Why not use tanks (like a lock) to raise the water step-by-step. I’d suggest it’s likely that the tanks themselves wouldn’t have to be huge, but perhaps large enough to stablise the next pump’s input draw.


Zvyozdochka (@Zvyozdochka), on 29 August 2011 at 1:23 PM — I’m not Peter Lang. It is standard practice to use variable rate pumps; done locally to pump groundwater. However, pumped hydro almost always uses a special king of pump/generator about which I know no more than such exist.

But even with a setup which can reverse every 15 minutes (as in a Franch pumped hydro facility), if you are out of overnight power you are out of business. Which is why nobody is seriously looking into such schemes.


@ David B. Benson

I apologise for accusing you of being Peter….

I thought the idea was to pump water from Blowering (lower) to Tantangara (upper) and then just let it run through Tumut 3. Why is it necessary to use 3-massively expensive new bored shafts forward/reverse to be the both the pumping path and power generation?

Obviously I’m missing something, but I can’t see why you wouldn’t just connect the two reservoirs over ground and drain through Tumut.


Zvyozdochka (@Zvyozdochka), on 30 August 2011 at 2:05 PM — You’ll have to ask Peter Lang. We don’t seem to have anything remotely comperable here in the USA.


Suggestions by Neil Howes and others that Tasmanian hydro stores excess energy generated on the mainland seem to be off the agenda. See the 4th paragraph in
The present underwater HVDC cable is normally limited to 500 MW either way with minimum periods between flow reversals. The converter station on the Tasmanian end is close to an aluminium smelter and two gas fired power stations. The Victorian end is Loy Yang brown coal fired station, a candidate for replacement by combined cycle gas with the contract to be drawn by June 2012. Slight problem being lack of gas.

Clearly Tas dams have capacity for increased generation. The photogenic Strathgordon dam whose narrow ravine features in TV ads and sometimes on BNC has vacant mounting slots for two 150 MW Francis turbines. Evidently 3-4m rainfall the last couple of years is still below expectations. Another power source could easily pump outfall water back up to the lake to be recovered by existing or updated turbines.


John Newlands, on 30 August 2011 at 2:50 PM said:

Suggestions by Neil Howes and others that Tasmanian hydro stores excess energy generated on the mainland seem to be off the agenda. See the 4th paragraph in……

The data suggests that Tasmanian hydro already stores excess energy generated on the mainland, however presently most of that excess is off-peak coal -fired, returned during peak demand. Since TAS peak demand is about 500MW lower than present TAS hydro capacity, no need at present for additional HVDC links, but with more TAS wind capacity and more hydro capacity that could change. Of course future excess mainland electricity may be from wind, solar or nuclear rather than coal-fired.


David B. Benson, on 29 August 2011 at 8:29 AM said:

The usual difficulty for gengizing by wind power is the lack of large storage; almost all existing pumped hydro stations are only appropriate for diurnal operation. Lack of wind power for an even moderately extended perior would put such a station out of business for the interim.
Since most pumped hydro was built to even out diurnal fluctuations its not surprising. For BPA however, there is clearly enough hydro capacity and hydro storage for wind ( see the daily range in hydro). The problem is the transmission capacity for exporting surplus wind plus hydro in periods of high precipitation.

Follow the green line on


Neil Howes, on 30 August 2011 at 7:04 PM — I’ve followed the BPA situation quite closely. (1) Isn’t enough storage capacity. (2) Wind has to be curtailed in June. The problem has been partially resolved by almost 1 GW [nameplate] wind turbines shiftling from BPA balancing authority to the baancing authority to the south.

All this, of course, is off-topic on this pumped hydro threaed.


Neil to my knowledge recovery of water pumped uphill in Tasmania adds up to a mere 1.7 MW
The Hydro plays the NEM spot market by selling hydro at peak times and re-importing coal power. You’d think carbon tax will make it preferable to conserve water in the dams. The other technique I believe is hydro balancing of wind so that hydro is throttled back when the wind is strong and vice versa.
Despite claims that Australia has boundless gas I believe it will be unaffordable by 2050 so we’ll have to find some other way to balance windpower.


John Newlands, on 31 August 2011 at 6:08 AM said:

Neil to my knowledge recovery of water pumped uphill in Tasmania adds up to a mere 1.7 MW
I was not referring to pumped hydro but storing off-peak power from mainland by not using as much hydro locally during off-peak times.

The Hydro plays the NEM spot market by selling hydro at peak times and re-importing coal power. You’d think carbon tax will make it preferable to conserve water in the dams
A carbon tax isnt relevant while excess off-peak power is available. TAS hydro is going to generate the same number of kWhs/year it just makes more by selling at high peak prices.


Neil it’s alleged that the Comalco aluminium smelter and Nyrstar zinc smelter pay some 3-4c per kwhe, a subsidy against market rates claimed to be worth $133,000 per employee. If Loy Yang Vic produces 1.4 kg CO2 per kwh then 1.4 X 2.3c = 3.2c carbon tax, doubling the energy cost to the smelter if sourced this way.

What I don’t know is if there will be is enough local electricity in dry times to cover all Tasmania’s needs and whether there are escalator clauses in big supply contracts. A proposal for a silicon smelter near Burnie was nixed when carbon tax was first mentioned. I think several dams would suit pumping with minor modification but the Hydro seems uninterested.


John Newlands,
Off-peak prices on the NEM grid drop to $130( about the price that OCGT starts to come on-line). TAS off-peak demand is 6-800MW while TAS peak demand is usually 500MW less than hydro capacity so importing cheap off-peak mainland power and storing hydro to export at peak prices makes sense. The CO2 price is irrelevant because its a MWh/MWh swap, both off-peak and peak rates will rise. If TAS hydro is using the Bass-link at full capacity(500MW) pumped hydro adds no value, because they already have full flexibility.


Is that a retail price? Data from AEMO suggests (in 2011) that the average wholesale price for the cheapest 7.5 hours of electricity each day is about $20 for VIC and about $21.60 for TAS. Are we talking about different things?


Zvyozdochka (@Zvyozdochka),
@ 29 August 2011 at 1:23 PM

I understand what you say but perhaps misreading what Peter is implying; are you Peter Lang, implying that pumps that can operate with a constantly variable input of energy (ie from wind) are not available?

No. I am saying you cannot change the flow direction and velocity of 20 million tonnes of water to suit the wind. Did you see this comment:

@ 30 August 2011 at 2:05 PM,

I thought the idea was to pump water from Blowering (lower) to Tantangara (upper) and then just let it run through Tumut 3. Why is it necessary to use 3-massively expensive new bored shafts forward/reverse to be the both the pumping path and power generation?

Obviously I’m missing something, but I can’t see why you wouldn’t just connect the two reservoirs over ground and drain through Tumut.

Read the lead article. The water is pumped up through the tunnels and runs back down through the tunnels to generate. Pumping is from about midnight to 6 am and geneation and standby is during the day, with maximum power output at peak times and in emergency.

The wter would not be released through Eucumbene reservoir, long tuinnels and three dams and power stations (Tumut 1, 2 and 3) on the Tumut River because around half the power would be lost in head loss.

The large diameter tunnels are needed to move the volume of water needed to generate the power. Power = hydraulic head x flow rate.

Surface pipes are far more costly that tunnels.


John Morgan,

Yes. The reasons are:

1. longer distance,

2. pumping needed to push water over elevations above the lowest level of the upper reservoir

3. Pipe has to be strong enough to resist negative internal pressure at high points.

4. Pipes have to be strong enough to withstand 10 MPa internal static pressure plus dynamic pressure at the lowest level. Conversely, the tunnel needs no lining except near the power station and in fault zones.

Refer to the discussions upthread about the cost of the steel liner for the surface power station option.


John Morgan, to see some comparative costs look at Table 1 in the lead article.

Surface pipes, at the lower levels (full pressure), cost about $1,000,000 a metre.

The tunnels cost about $65,000 a metre.

The steel pipe cost/metre is probably too low by at least a factor of two.

The pipes would be longer than the tunnels (probably 50% or more longer).

The tunnels need no lining for most of their length.


@ Peter Lang

Why not raise the water over the surface in a series of elevations, to tanks, like a ship lock? The pipes need only be strong enough to get to the next head. A college believes you could operate the pumping with a much wider range of power consumption as well (spare kWs to spare MWs).

Then you could have one drain/power tunnel that only ever operates in one direction.



Engineers look at all options and cost them. They select the least cost option that meets all the requirements. The fact that the vast majority of large pumped hydro schemes, especially high head schemes like this, use tunnels rather than surface pipes should be sufficent to convince you.

However, if you are not convinced, I’d suggest doing some simple calculations yourself. You can use the information in the lead article of this thread as a guide.

You might also ponder how you would transport the pipes to site and weld them on site. How do you weld steel pipes with 700mm wall thickness?

It is easy for people to pose all sorts of ideas but they need to be checked out before they are posted. Here is an example of one of the silliest ideas around at the moment:

A quick check with anyone who knows anything about rock would have made them aware that this idea is totally impracticable. This is one of many such schemes being proposed by people who sit in front of computer screens but have no practical engineering experience.

I hope this reply will enable you to understand why I do not engage with you in depth on your various comments on this or the other threads.


“How do you weld steel pipes with 700mm wall thickness?”

Why would you distort what I say like that? If the pipes that raise the water in steps are NOT used as the power path (ie use one bored tunnel rather than three, one flow direction for drainage), the surface pipes that raise the water (in steps with smaller heads) don’t need to be 700mm thick.



Get someone to design and do the cost calculations for your proposed scheme. It is not in the ball park of being viable. There is no point in me wasting my time on totally hare-brained schemes. It’s just as hare brained as the one I linked to above.

Just think about it. This discussion started by arguing you want to be able to provide storage for wind power. You argued you could use reverseable pump-turbines so you could reverse the flow each time the wind changed. That is reverse the direction of 20 million tonnes of water flowing at up to 3 m/s.

Now you want to be able to pump up in one direction (in surface pipes) and let water down in the other (in tunnels). So you need all three tunnels for the flow in the down direction PLUS you want pipes, pumps and storage tanks for the upstream direction. You want thin walled steel pipes, pumps, and storage tanks at what vertical spacing? Say every 100m of vertical spacing. So you need say six pipes like the ones pictured in the Tumut 3 photo at the top of this thread. Each is about 80 km long, total 480 km of pipes plus the tunnels. And fifty four pumps and reservoirs.

Your proposed scheme is at least ten times the cost of the proposed conventional scheme. And this is being proposed to try and make wind power viable. This should be a wake up call about the sanity of those who promote wind energy and renewable energy.

Have you considered piping hydrogen from the Sun to Earth?


“You argued you could use reverseable pump-turbines so you could reverse the flow each time the wind changed.”

I made no such suggestion. I initially queried whether you were claiming that no pump existed that could operate with a variable/intermittent energy source.

After-that, I simply observed that it should be possible to use lightweight piping/tanks on the way “up” reserving a single large(r) tunnel on the way down.

Such a system could be capturing grid excess wind contributions continuously.


@ Peter Lang

“There is no point in me wasting my time on totally hare-brained schemes.”

Might I say that while you are good with your calculator and that is a plus, you are a magnitude of minuses on your advocacy.

Nuclear proponents need storage too, unless there is to be a massive overbuild of NPPs to meet the peak demand. This was the motivation behind the examination of a number of pumped storage schemes in the first place; capture the unused excess generation during the demand lows and use them during the peaks.

The alternative is to use some other low CF but high availability source during peaks, which usually turns out to be fossil fuelled.

The fact that proponents of renewables might wish to utilise such pumping storage schemes as well appears to irritate you endlessly. What a shame.



The problem is you just don’t take notice of what you are told if it doesn’;t agree with your preconceived ideas. You have little understanding of the subject matter and and seem unable to recognise the difference between 10% and 10 times difference between two options.

Yes, nuclear is cheaper if you use some storage for peak generation (every day). It is not essential, it is just cheaper to do it this way. But that is not the case for intermittent renewables. I explained why here:

After-that, I simply observed that it should be possible to use lightweight piping/tanks on the way “up” reserving a single large(r) tunnel on the way down.

That statement reveals you have no understanding of what is involved, and worse still you have not even bothered to try to understand the article at the top of the thread. If you have only one tunnel instead of three, you reduce the power by two-thirds, from 8 GW to 2.6 GW. Your lack of understanding or willingness to understand what you are being told, is why it is a waste of time trying to explain anything to you. You simply do not want to know. You just want to believe that wind must be good because …

Here I did a rough calculation showing that the cost of wind with pumped hydro storage to make it capable of meeting our energy demand would cost about 30 times the cost of nuclear. The scheme you propose would cost at least 300 times the cost of nuclear.

Your proposed pumped hydro scheme would cost:

$12 billion for the generating component (tunnels, power station, etc), Plus:
100 pump stations (6 pipes the size of Tumut 3 pipes and 12 lifts because we have to get over hills above the top reservoir level and there will be multiple ups and downs) . Each pump station will cost say $7 million. Total = $700 million for pumps.

Reservoirs: say $100 million

Pipes: Tumut 3 pipes are 500 m long and cost roughly $80 million in todays dollars; i.e. $160 million per km. We’d need say 80 km. Therefore, total cost of pipes = $128,000,000,000

Total cost of the pumping up component is $128,900,000,000 (say $129 billion.
Generating component = $12 billion
Total = $141 billion

Compared with about $12 billion for the proposed pumped hydro scheme (which is suitable for coal and nuclear but not for intermittent renewables for the reasons outlined in the link provided above)

This cost estimate is very rough (back of an envelope), but sufficient to show it is pointless investigating such ideas any further.

By the way, the Tantangara-Blowering scheme is unlikely to ever be viable, even for nuclear. The Tantangara-Talbingo scheme at about 6 GW may be more viable. However, none of these schemes would be considered until at least 50 % of our electricity was being supplied by nuclear.

I hope this clarifies this for you. I hope you will do your own rough cost calculations in future before posting your ideas.


“I hope you will do your own rough cost calculations in future before posting your ideas.”

Happy to. We will cost;

– 1 only bored tunnel w/equiv flow to 3x 12.7m tunnels

– required lightweight surface pipes to create 12 lifts to tanks using submersible pumps* over 12-18 hr period

It is my understanding that the Ludington Pumped Storage facility upgrades (Michigan) will use surface based piping in the manner I describe. It increases the plant flexibility.

* A recent project my US collegues consulted on uses some of the largest submersibles to lift 44-100m into tanks for stormwater control in Mexico City. They are sized for enormous and very sudden volumes. The pumps/piping/tanking per unit of pumping capability cost nothing like your statements.


How can you estimate the cost for a tunnel that is larger than the largest tunnel boring machine?

When I did the analysis I looked at combinations of two three and four tunnels and different tunnel diameters for each so I considered 9 options. If you reduce the total corss sectional area you increase the water velocity; this increases the head loss which means less power is generated and less revenue over the plant life. I used the least cost option. You can’t build one tunnel because there is no tunnel boring machine large enough to bore it (read the references in the article and learn a little background). You seem to think no one considers options.

You can’t use light weight steel if you want to raise water 100 m. And the steel thickness must be thicker as pipe diameter increases.

The costs I gave you would show any engineer that you are totally wasting your time. It shows me that you do not check out anything properly. You are running on belief that renewables are a good thing. just because they are! I’d urge you to get rational. You and those of suimilar ilk, such those who follow Climate Spectator, are doing Australia enormous damage.

I await your design that you claim will be cheaper than three tunnel option. By the way, just to cover my backside, I agree with comments up thread that the powerstation would have to be underground and the 6 GW Tantangara-Talbingo option may be more economic than Tantangara-Blowering.


@ Peter Lang

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

Robbins Company have a 14.4m hard rock machine in use now for the Niagara Hydro Tunnel Project. They claim their design can go to 22-24m, recently discussed in the Berring Straight Tunnel speculation.

I see you choose to ignore my reference to a recent project undertaking by our company. Complete pump/pipe/tank costs on a cubic metre basis of head raised are nothing like your estimates.

“You and those of suimilar ilk, such those who follow Climate Spectator, are doing Australia enormous damage.”

Ilk? Our company is doing active work worldwide reducing emissions NOW on many projects, matching clients, investors and technology;

A project that has recently been given the go-ahead here in WA is a 50MW solar PV system (with diesel backup) via a fully commercial tendered PPA with audited emissions reduction claim for peak power production. It will be installed outside of Geraldton and be operating for 2013’s summer. The operator has options to supply a further 250MW.

How do you feel about that? Are we “damaging Australia”? Please.



Write up your proposed design and cost estimate. Then we can discuss it. Until then, further discussion is pointless.

How do you feel about that? Are we “damaging Australia”? Please.

In my opinion those advocating renewable energy, and blocking nuclear, are damaging Australia. In my opinion they are not being objective or rational. Your advocacy of a project that is totally uneconomic just because you want it to work is a typical example. People advocating renewables generally ignore the economic facts. I doubt you have even looked back at the references I gave in my earlier comments.

Those advocating renewables are usually the same people as those blocking nuclear. 50 years of blocking nuclear has caused it to be more expensive than it would be if progress had been allowed as in other industries. It also means that world emissions now are about 10% to 20% higher than they would be if nuclear development had not been thwarted. And we’d be on a much faster trajectory achieve low emisisons.

Your lack of ability to provide even the most basic cost estimates for what you advocate is common amongst renewable energy advocates, but demostrates how scary such irrational beliefs (such as in renewable energy) can be.

So my answer to your question is “yes”.


@ John Morgan

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

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.


My mistake on the head for El Hierro.

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.


Volcanic islands that rise straight up out of the sea offer better elevation therefore need smaller volume upper reservoirs for the same stored energy. Thus pumped seawater hydro has been proposed for Hawaii and Reunion Island. In Australia we might be lucky to get 100-200m coastal elevation close to transmission. If I recall John Bennetts suggests the escarpment near Wollongong NSW. Fleurieu Peninsula near Adelaide might be OK but that area is NIMBY central.



Here 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: (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)


Woops, this statement in my previous comment looks wrong:

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.


Current US wind farm installations are running around US$1725/kW capital costs, but I don’t know by how much that is lowered by various incentive schemes. Nor does that include the cost of new, long transmission lines.


David Benson,

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.


Overnight cost from

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.


Peter, thank you for that update.

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

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).


Zvyozdochka (@Zvyozdochka), on 14 September 2011 at 1:39 PM
Its worth considering a different option of a vertical shaft from Tantangara to an underground turbine room and a low pressure low incline tunnel to Blowering similar to the Kopswerk pumped hydro that is designed to handle variable wind power. This would eliminate the use of steel lined tunnels/pipelines.


Neil Howes,

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: )

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.


Neil Howes,

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.




Australia’s pumped hydro not for renewables

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 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 . 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).


Retooling to green energy is proving to be a daunting task. If only we could figure out how to both store and ship energy … feasibly. I think I may have the answer, but my research is seat of the pants. My thinking is that we can plumb our energy, rather than depend on the fossil fuel related electrical transmission lines, entirely. CAES has major advantages in storage and shipment, using pipe. So once pipes are in place the location of CAES and hydrogen is not a factor. In fact using plenty of pipe, we gain storage, and we gain equilibrium, so transmission pumping energy drops to virtually zero. High pressures are a must to achieve these lofty goals, and also larger diameters than we’re used to. These pipes can also serve, and must serve other utility needs as well, just to justify the expense. That’s not a problem. We need a good monorail system. We could also do with a modernization of our rail systems, which can be augmented with this plumbing. My designs for track-pipe rail systems use steel to ground for most of the weight, but have two gauges of steel track and the wide pipe gauge would be for outriggers or light weight land yachts on rail, increasing tourism. Conduit pipe is a good idea in many respects in spite of naysayers who can’t fathom how the air gets compressed or can’t fathom how pumping or use conversions would work. These conduits are a super system which carries any and almost all of our major infrastructure needs: Water, Sewage, Natural Gas, Broadband, Granulated Plastics, and of course CAES and Hydrogen. So I have a feeling in addition to the major transportation infrastructure rebuild, these utilities would be carried by such a system, and financially carry it indeed. So many uses for a pipe. It’s the Track+Pipe concept, or TRIPE for short. CAES I’m sure could augment pumped hydro, and add to its viability. High pressure hydraulic systems tied to CAES are up and coming technologies, and a company SustainX is working on this. Peter, have a look please.


Steven Jf Scannell,

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.


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