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

Peter:

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).

Regards,
Matthew

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John,

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

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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.

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Ewen,

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 !! :)

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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.

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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.

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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.

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Matthew,

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.

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@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.

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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

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Neil Howes @ https://bravenewclimate.com/2010/07/14/zca2020/#comment-85915

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.

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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.

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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.

http://www.cnnc.com.cn/tabid/168/Default.aspx

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.

http://nextbigfuture.com/2010/08/china-leverages-learning-curve-cost.html

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.

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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

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

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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.

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Dirk,

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.

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

Goldisthal versus Tantantangara-Blowering;
item;units;Goldisthal;Tantangara-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

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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.

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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. http://www.environmentalfisherman.com The Tripe (track-pipe) System report. 11 pages illustrated.

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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.

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MickH,

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: https://bravenewclimate.com/2010/04/05/pumped-hydro-system-cost/#comment-133008 . 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.

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MickH,

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: https://bravenewclimate.com/2010/04/05/pumped-hydro-system-cost/#comment-86108. So it totally uneconomic

Some important reasons why pump hydro storage is not suitable for intermittent renewables is summarised here: https://bravenewclimate.com/2010/04/05/pumped-hydro-system-cost/#comment-133008

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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
http://transmission.bpa.gov/business/operations/wind/baltwg.aspx

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@ 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.

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@ 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.

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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
http://www.themercury.com.au/article/2011/08/30/257231_tasmania-news.html
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.

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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
http://transmission.bpa.gov/business/operations/wind/baltwg.aspx

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Neil to my knowledge recovery of water pumped uphill in Tasmania adds up to a mere 1.7 MW http://www.hydro.com.au/system/files/documents/PS_Factsheets/TodsCorner_Power_Station-Fact-Sheets.pdf
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.
http://www.transend.com.au/ournetworks/electricity/planning/windpower/
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.

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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.

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Neil,
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?

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Surface pipes are far more costly that tunnels.

Really?

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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.

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@ 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.

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“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.

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“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.

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Zvyozdochka,

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: https://bravenewclimate.com/2010/04/05/pumped-hydro-system-cost/#comment-133008

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 https://bravenewclimate.com/2010/04/05/pumped-hydro-system-cost/#comment-86108 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.

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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.

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

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Z@Z, do you have any links for the WA solar system referred to above?

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@ John Morgan

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

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

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

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Zvyozdochka @ 12 September 2011 at 1:38 PM

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

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

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@ Peter Lang

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

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

What is your definition of “low”?

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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.

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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.

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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.

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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 http://www.sekisuichemical.com/eslon/index.html).

We have the required turbine, pump and tank estimates.

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

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

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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: https://bravenewclimate.com/2010/04/05/pumped-hydro-system-cost/#comment-86108 )

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

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This “Do the Maths” article on Pumped Hydro Energy Storage covers many bases and explains the key issues in easy to understand language.

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

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