Earl Bardsley explains what the Government investigating his idea for a pumped hydro scheme could mean for NZ's electricity market

Alas, the Greenies do not like hydro.

My husband's father was an engineer working on construction of the Manapouri scheme all those many years ago.  Like this scheme, I suspect folks back then thought it bigger and more complex than anything done before.  They way I look at it - Megaprojects - are better done earlier, rather than later.  I guess what could happen to this one, if started could be disrupted through total collapse of the monetary/exchange system as we know it today.  But, I suppose the last thing we should give up on is ambition.

Sorry Kate - Transmission Gully is to facilitate cars, and is presumably paved with bitumen.

I don't call that an asset - from our grandchildren's perspective, I call it a liability. Why did all those folk think they needed to squander energy on a daily basis, to do what, exactly? They'll think us nuts.

Make some time to listen to Nate Hagen's The Great Simplification.

Go well

They went cheap and the surface has already had to be repaired twice I think and still no sign of asphalt.

The kapiti bit of road was a total fiasco as National instructed that it would be operational before the election

As much as you won't like it, Dino juice needs to remain on the menu for the next 100 years. 

CS -  think it through; energy underwrites money, 100%. No energy = no work. No work = nothing done, nothing produced. And money would then be worth? Nothing (well, you could trade existing stuff for ever-bigger numbers, but you couldn't buy anything new).

Thus we should be counting in calories or joules, not dollars.

But I tell you what (and I've been off-grid longer than anyone here, I'm guessing); renewable energy will never build renewable energy (the EROEI is too bad), so don't expect them to be 'cheaper'. They're more correctly rebuildables, than renewables.

And we've burnt the best half of the fossil energy; it's gone already.

It's fossil fuels that keep energy prices high.  Incorrect.  No it is the lack of fossil fuels.  Environment is better for fossil fuels.  Environment is better the more we consume, the better our environment. 

KH, have you worked out the cost per kwh for wear on your battery ?

Onslow is a much more price effective battery that whatever you have.

The storage of Onslow is equivalent to something like 30 Tesla power walls per house in NZ, and would cost $1 trillion dollars to replicate with power walls. 

Your idea is reasonable, but much easier if we centralise the battery in Onslow. 

Unless you can show the numbers this is likely to be far higher cost than grid connected. Perhaps you can publish something with financial and technical information and let the interest readers know they can obtain or view the report.

For this to work, it needs everyone to invest in a battery (home or car). This is a hugely expensive exercise for the amount of energy returned. To use li-ion instead of pumped hydro increases the cost 1000x for the same level of output.

If you want to use your EV for this, then then wear on the battery will cost more than you make selling the electricity.

"Most folk will be involved in local food-production."

How far away do you think that reality is? 20yrs? 60yrs? 

Not all and if you are generating enough for your neighbours too then you have a lot of roof and are likely facing the right direction without shade.  I would hazard a guess that there aren't that many houses that fulfill all these criteria.  I am a big fan of solar and want to put it on a new house we are building, but after talking to the installers, it isn't for every house and even ours is going to be marginal.

Then even if everyone can generate enough for themselves, they also need a battery (max load is after the sun goes down during winter and even during summer at poor generating hours). But do they also have the means to pay for a solar and battery installation too? And then what happens when we have a winter like we just had? They all need to take power from the grid as their solar isn't cutting it, which means the grid still needs to be able to handle peak load from all households.  And if the grid is to handle peak load, then you may as well build a peak loader or a shared battery, which would support all forms of renewable, not just rooftop solar. It would be simpler to operate for a small country rather than a few thousand different interchanges for electricity to be shuttled around the country, we could more predictably use the green energy and pump or drain the pumped hydro lake. And it's probably as efficient (if not more so) than all the households having inverter/battery combinations, given the losses and complexity.

ok what do you do after 12 years when the batteries are totally dead?

why do you think Onslow would be hardly ever used?  I imagine it will be used constantly.  It will take midday solar and deliver it in the evening peak.  It will take excess wind and deliver it when the wind aint' blowing, and it will massively arbitrage day/night rates.   Depending on the generating capacity they install at the bottom, it could even eliminate the generation cost contribution to peak day/night rates (You'd still have transmission/distribution network peak charges).

One has to spend money to see if one needs to spend money. My concern is the report would be engineered via models to show a goer. Any report on it would need to be carefully reviewed and not by politicians. Too easy to pull the technical wool over their eyes. I don't know what Nationals view is but I suspect Labour are using dry years because of their belief in man made CC and so the need to justify Onslow on that basis. I'm sure there are alternatives to Onslow that haven't been examined nearly to the extent that Onslow is being investigated.

Also look at the composition of the board . At least two political appointments. Amanda Larsson, Lead Climate and Energy Campaigner, Greenpeace (2017 – present).

Isla Day Member, Wellington City Council Environmental Reference Group (2019 – present) Founding member, School Strike 4 Climate New Zealand (2019).

Hoani Langsbury Ngāi Tahu and Te Rūnanga ō Ōtākou Former Chair, Otago Conservation Board (2005 – 2010)

for the pedants out there... electric smelters where the electricity is generated predominantly from coal (or other non-renewables) vs 100% hydro for Tiwai

Hydrogen conversion of what? 

Yes ... as Stuart Mason says , below ... we need to unshackle ourselves from the 1980's anti nuke ideology , and discuss constructing a nuclear power plant in the north island  ... France has shown the way for 50 years  ....it's time to learn from them ...

Using it on a daily basis doesn't affect it's capacity.  pump up off peak,  generate on peak, at the end of the day the water level is where it was at the start.

The capacity could fluctuate a fraction day to day and week to week depending on wind and solar production, but across a whole season that should even out leaving you most of the capacity for dry year insurance.

It's likely once we get to that point, the load across the electric car fleet will be managed, much like hot water is at the moment.

the one in the middle of the day, between the morning and evening peak.  The one that is going to get worse if we add allot of solar.

And the one between 1am and 6am, after everyones cars have charged from their average 12kms of commute.

The trough when the wind isn't blowing that night and the hydro lakes are low because it's been a dry year. And to top it off more and more EVs are plugged in for charging.

And no I would never allow my EV to put electricity back into the grid to smooth short demand peaks because it would cost more for wearing out the battery than they would likely pay.

Every night when the wind is blowing and every day when the sun is shining. You can also safely install more baseload e.g. geothermal knowing that it will be used.

Onslow would allow us to massively overbuild our cheapest generation options of wind and solar, and manage their main drawback of intermittent generation. 

The added benefit is Onslow will provide a willing buyer of electricity even when all the generation is pumping - at the moment when wind is generating too much, the price paid is lower due to basic supply and demand. Onslow will put in a floor price (and a corresponding ceiling price as it will step in and generate when needed)

Also a good case for just bringing on more renewable energy sooner, spending money on this rather than huge amounts on pumping water uphill.Total demand for energy is unlikely to decrease, so spare electricity to pump water uphill may be rarer than you think, especially in prolonged droughts.

It's really, really high, that's why it's a good place for a battery. Aqueducts basically wouldn't be possible to it, unless we also do the Manorburn Dam in the same range which is nearby (and I think in a better position than Onslow, closer to Lake Roxburgh), or the Loganburn on the other side (which is more of a shallow pond when I have been up there).  Both would require a lot more work up there.

Rainfall at Lake Onslow is about 0.6 metres per year and lake evaporation will be a little more. We estimated an upper bound of 1.5 cubic metres per second for additional water that would need to be introduced to an expanded Lake Onslow to maintain the mean flow of the Teviot River flowing out of the lake. This would come from pumping a little more water up than comes back down, with perhaps some winter water being diverted by gravity flow through a short tunnel linking to the Taieri River. Our paper was published earlier this year. 

They need to get all those geothermal stations cranking to try and cool the Taupo volcano enough so it doesn't get any funny ideas.

MBIE have evaluated the need for a dry year buffer of 5 TWh of additional hydro power energy storage capacity. That is, 5 TWh in addition to the  (about) 4.5 TWh that we now have. Lake Tekapo cannot be considered as a 5 TWh alternative to Onslow because it would require raising the lake 50 metres above its present upper operating level. This would flood Lake Tekapo township and impose an operating range in excess of 50 metres on one of our most scenic lakes. It would not be a pretty picture at maximum drawdown. Lake Hawea would be even worse because the lake would have to be raised more than 100 metres. This would flood the Lake Hawea township and impose a lake operating range in excess of 100 metres.

Onslow would have an operating range in the order of 60 metres but, unlike Hawea and Tekapo, this would be over a bedrock shoreline. Hawea and Tekapo would be dustbowls at maximum drawdown if they were used for dry year backup.

Evaluating the energy storage potential of the Onslow basin does indeed require nothing more than elevation data pasted into a spreadsheet.

Simulating Onslow pumped storage operation is a larger task and was carried out in the Majeed PhD thesis. As the supervisor of that thesis, I guess I know its contents fairly well. The small Hawea / Wanaka pumped storage option was never a possibility for a dry year buffer, which is why it appears only as an Appendix in the thesis. Also, Onslow was not proposed as an alternative to the existing hydro storage capacity in New Zealand, which would certainly be a bizarre concept. Nor could there be any possibility of power being somehow shifted backwards and forwards between Onslow and distant locations. Rather, the thesis simulated how Onslow operation might enable better management of existing hydro lakes by avoiding both high levels (flood and spill risk) and low levels (unsightly mudflats). To do this properly would have required simulating the complex NZ electricity market. What we did instead was to impose a hypothetical rule such that the hydro lake levels were simulated as operating consistently toward always seeking a target level around the mid-point of their respective operating ranges. The simulations indicated significant spill reduction, sufficient to enable Onslow to make a net mean positive energy contribution. That is, effectively becoming a small power station as far as the national electricity energy balance in concerned.

Onslow operating in the electricity market would have a similar effect to our target levels. High lake levels mean lower electricity prices and lake water would be released to provide the power for Onslow pumping. For low levels, Onslow generation would take advantage of the high prices for generating so the levels would tend to rise.

Perhaps some of the readers of this post were impacted by the 1998 Taupo / Waikato flood. I suspect that they would have preferred not to have had that impact, despite being that told the flood was well-managed. The point is taken though with respect to the plotting of the Waikato River discharge data for Cambridge. We should check that data but the conclusions remain unchanged.

Far from costing millions to pump water up to the Onslow operating level, the Lake Onslow initial fill operation is most likely to return a profit to the Onslow operators. This is because it will not be a one-way water level rise. There will be times during the fill process when high electricity prices make it profitable for some of the water to be released back for generation. There will still be a net rise in the fill process but will be interspersed with falls to generate net income over the period of filling. The fact that Onslow is in a dry part of the country is irrelevant to this process.

It is true that most of the pumped storage schemes in the world operate over short time scales. For example, to cover daily fluctuating power demand in association with constant-rate thermal stations. However seasonal and longer term operation is not unknown. The pumped storage schemes in Norway operate largely in seasonal mode.

There is nothing inherently bad about pumped storage schemes operating in open loop mode (not using the same water twice). Water released from Onslow is not "wasted" any more than water flowing through the Benmore dam is wasted. In fact, the open loop nature of Onslow is an environmental advantage because low Clutha River flows (high power prices) will be augmented by water released from Onslow. Similarly, high Clutha River flows (low power prices) will be reduced a little by Onslow pumping.

The concern about northward transmission line capacity is no longer an issue. With the threat of closure of the Tiwai aluminium smelter, Transpower moved quickly to upgrade line capacity. The Roxburgh-Livingston upgrade was completed earlier this year.

The small streams flowing into Lake Onslow are certainly different to the large river inflows to the main South Island hydro lakes. That is, Onslow would be a "pure" pumped storage scheme as opposed to a pumped storage / hydro hybrid scheme. This is an advantage. Given the construction cost of Onslow, we would wish it to be operative for a very long time without the risk of silt accumulation from a large river inflow - as is occurring presently with Lake Dunstan.

1.  Alpine fault is encountered no matter where the tunnel is - er - Tunneled.  And it's  due to pop.

2. Snails.

Most of the changes needed are certainly possible , and I would say , make for a better way of life. 

Good post. I was unsurprised that Earl avoided answering my question (I always fish to check, but techno-optimism tends to avoid).

The reality is that - as Dr Krumdieck used to point out - by 2100 we will be running on real-time solar (hydro being a solar derivative).

The reality is that we won't be making hight-tech renewable energy infrastructure, using renewable energy infrastructure (actually, they're both rebuildable, rather than renewable).

So we won't be 'doing' much of what were were doing, when there was so much surplus energy around. As you agree; triage.

We will be food production first, water obviously, and other-than-food energy next. How much culture we manage to keep/keep alive, is moot. 

So what are we powering with in 2100? Is Auckland still intact? Could we maintain the grid (Benmore/Heywards/Otahuhu)? The problem is that thiat is a Systems question, and the Bardsleys of this world need to be meshed into a Systemic debate. For which we are probably too late...

We have to ask the same question of tertiary education; churning out ever-more debt-encumbered siloed complexity-believers, may not be optimal...

https://www.goodreads.com/en/book/show/3014984-approaching-the-benign-e…

Go well.

I am all for ambition Kate.  But there are alternative ambitious projects which are alternatives to Onslow.  Lets investigate those.

Nowadays , You can post anything, and at least on social media,it becomes fact.

What i would like to see from Chris , who is  knowledgeable and experienced, is a alternative solution , other than BAU.

Brendon - Chris is introducing a diversion in proposing a private enterprise framework for Onslow evaluation. The NZ Battery group has been tasked with finding the best option, or combination of options, for taking us through a dry year without the use of fossil fuels for power supply. "Best" is in terms of national good measured against national cost, taking all aspects into account. None of the considered options would pass an evaluation in narrow private enterprise terms. Measured in national terms, Onslow pumped storage may or may not be determined to have sufficient merit to be part of the solution. It does have some nice multi-use advantages but we have to await the final decisions. It should all be clear by this time next year. The good thing is that Onslow is being given proper evaluation. It is at some expense but it is better to spend millions on evaluation now rather than risk spending billions on too quickly moving to construct a scheme that we come to regret later.

I did better than that Brendon. I gave you the actual assumptions I used. Use bond rate 5%, DR 8% and depreciation 3%. Build your own model. It is easy enough. Then you can vary the assumptions to see what the effect is.

Sure we do it on roads, but the CBA on Transmission Gully, for example, if I recall correctly, never did stack up (it was done time and time again and a necessary project delayed as a result). I made a habit of writing to the DomPost editor everytime we had a death on the old SH1 route between Pukerua Bay and Paekakariki.

The need to build safety and resilience won out eventually.

And it's not a matter of what I would pay in addition, or you would pay (or even our grandchildren would pay) in addition for our electricity/energy. 

Instead it is a matter of whether our current generation wishes to work toward future generations having access to a secure, reliable energy supply.  Have we forgotten what our ancestors who fought in two World Wars did for us - and all those to come 

I find it hard to believe so few people are willing to invest in intergenerational equity these days - when it was such a feature in our ancestors past. $1 dollar a week per household - it's an embarrassingly small sacrifice in comparison.

And the government reduced the duty on petrol because they are weak, in combination with having made poor decisions/commitment to public transport expenditure in the past.

No matter what happens, I suspect energy costs are going to be high in the future - much higher. And energy conservation will become the norm. Some government may well need to reverse the industry privatization of the past as well in the future. 

You seem to be saying it is a solution looking for a problem. And it isn't a production dam. It is pumped storage. There are big differences

Most of the capital cost of the project would be in the powerhouse and tunnels - that won't change. As an aside, lot more concrete will be needed in there than they budgeted for.  Whether usable storage is 50GWh or 5000, the capital cost doesn't scale similarly. And you forget the 3000GWh worth of dead water needed to fill the lake up to a usable level. 

For sure Chris, we all would like cheap, reliable (and sustainable) power. I guess the issue is how it could be achieved.

Belated apologies for some of my original wording Chris - which might have been taken to mean that you were part of the coal industry. A good thing about Interest posts is that they can be edited - now tidied up. I'm sure many would be interested in your thoughts about how NZ would best achieve a cheap reliable stable electricity system.