With the above-average wave energy crashing on their shores, perhaps the West Coast would also suit LIMPET
http://www.wavegen.co.uk/

Trevor.

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An area served by long transmission lines with a peaky power demand and some local generation – sounds like the sort of place that could benefit from a vanadium redox battery system.

http://www.vrbpower.com/

Trevor.

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Two lakes, one above the other, with a hydro generator linking them…

That just about describes a pumped hydro storage system!

I wonder if it has occurred to them? It probably wouldn’t store a lot – perhaps 100MWH – but it would reduce the transmission losses and allow us to make use of the “must-run” generation available.

Trevor.

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Why is the Stockton Plateau Hydro Project being set up to generate baseload energy – 25MW 24/7? The area has 50% transmission losses at times of peak demand so it needs generation that can help meet peak demand. The Stockton scheme has 78 hectares of reservoir storage and they are talking of 50MW peak generation in times of flooding. Surely they should aim to run closer to 50MW at times of high demand and under 25MW at other times?

Trevor.

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Kevyn – the geothermal idea isn’t a workable option. Geothermal sources are only a few hundred degrees. Cement requires 1200-1400 degrees C:
http://www.nzic.org.nz/ChemProcesses/inorganic/9B.pdf

I don’t see why concentrated solar wouldn’t work.

Trevor.

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Shunda, It’s only ridiculous if you don’t understand the persistence of CO2 in the atmosphere. Methane is bit more complex. Bur as BJ pointed out changing the way cement is cooked can eliminate the carbon emissions from that source. In fact that might be a more cost-effrctive way of utilising the world’s abundant low temperature geothermal and concentrated solar potential instead of converting it to electricity.

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From what I understand you are pretty much on the button there Trevor. West Coast rivers are considered to be “flashy” rivers, in reference to the potential rapid rise in water after heavy rain that occurs regularly.
We also experience some massive peak flood flows on the larger rivers, the Buller being the largest river in NZ for peak flood discharge at a massive 8000 cumecs (50 year flood) and the Grey not far behind at 6100 cumecs. 100 year floods are even bigger!!.
No doubt this would pose some difficult engineering for hydro schemes to spill such a massive amount of water, even the Clutha and Waikato rivers never get near that peak flood discharge in a 100 year event.

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Everyone knows that the West Coast gets a lot of rain. However this does not necessarily mean that hydro power stations there will be cheap. I suspect that the costs mount up. I can believe that one power company might avoid investing there even if it was a cheap option. I find it harder to believe that NZE and all the power companies formed since NZE was split up would have avoided hydro schemes there if they were very cheap.

I can think of several reasons why they might be more expensive than alternatives:

One possibility is that the river flows there tend to be low most of the time, but with frequent high peaks. Without storage lakes to even out this flow, most of the water would need to be diverted down spillways.

Related to this would be the possibility that a significant amount of rocks and stones are washed down – that could cause all sorts of problems.

I don’t know. I’m not that sort of engineer and I’m not really familiar with the area. Still I’m glad that the power company engineers are now considering the possibilities.

Trevor.

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Frog

If the emissions for the concrete to build a dam that prevents emissions for 100 years are too much for the planet to bear then we’re finished before we start and any OTHER measures are completely irrelevant.

I don’t think this is the case.

The concrete is being made, currently made in places that use fossil fuels to cook it. We could make it using electrical ovens. Heck, if the Aussies wanted they could concentrate solar to cook the stuff.

Concrete=Bad is not an equation of necessity. It is a perception of the current system and true as long as the material is made in coal fired ovens. Not necessarily true, just true now.

Moreover, concrete is going to be made anyway. It’ll just be put to less productive (from a deep green perspective) uses.

respectfully
BJ

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“Very much an AGW Catch 22. Big emissions now when we can least afford, small emissions later when it may be too late.”

That is rediculous.

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Sorry Trevor, I didn’t realise that. Does that mean most power to the West Coast first goes up the east coast, across to Nelson and then down to the West coast?
If true that is an incredible transmission length!!

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http://www.gridnewzealand.co.nz/f70,3566/3566_transmission-map-si.pdf

shows a 50 or 66kV line from Hororata to Kumara but 110kV and 220kV lines from Dobson through Inangahua and Kikiwa and down to Islington. Kikiwa is South-West of Stoke, so I was a little out saying it went through Stoke – only the Nelson circuit goes through Stoke.

I stand by my comment that the MAIN feed is not over the alps.

Trevor.

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Source for the above is
http://www.wcrc.govt.nz/river_level_rainfall/about/

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Kahikatea asked: > The fact is, with the abundant rainfall on the West Coast there should be a nett export of hydro power to the national grid.

I would have thought so, too. Any idea why it isn’t?

The simple answer is in this comparison of one rainfall monitoring site on the west coast and seven on the West Coast. Please note that West Coast sites that receive more rain than the Auckland site are all located on the Great Alpine Fault. The title Great is reserved for faults with a history of generating M8+ quakes.

Waitakere Ranges records a mean annual rainfall of 2030mm.

Karamea River at Gorge records a mean annual rainfall of 2760mm and daily falls of up to 140mm.

Inangahua River at Landing records a mean annual rainfall of 2460mm and daily falls of up to 170mm.

Ahaura River at Gorge records a mean annual rainfall of 2450mm and daily falls of up to 140mm.

Hokitika River at Colliers Creek records a mean annual rainfall of 7600mm and daily falls of up to 600mm.

Whataroa at State Highway 6 Bridge records a mean annual rainfall of 5690mm and daily falls of up to 320mm.

Waiho at Franz Josef records a mean annual rainfall of approximately 5500mm and daily falls of up to 400mm.

Haast River at Roaring Billy records a mean annual rainfall of 5750mm and daily falls of up to 400mm.

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Trevor, I never let the facts get in the way of a good link teaser. However, in this case my only defense to your response is to provide the link to the original post from The Oil Drum that led to the PDF link that I gave. That post discusses the very issues you mention – or more precisely the newer more efficient technology that is being considered to increase the generating capacity:
http://anz.theoildrum.com/node/4802#more

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Shunda asked “Hydro is not emissions free either, yet considered renewable” Where do the emissions come from, farting trustpower technicians?

There are two sources of significant GHG emissions from all new dams. The CO2 emitted during the manyfacture of the cement, unless it is an earth dam of course.
The methane emitted by the anaerobic decomposition of the flora inundated by the dam.

Very much an AGW Catch 22. Big emissions now when we can least afford, small emissions later when it may be too late.

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” The rugged nature of the Southern Alps discourages building power lines across from Canterbury.”

Actually the main power line comes through from Canterbury, I remember it being threatened by a wild fire near Mt horrible a few years back.
The transmission distance from the West coast to Christchurch is still close enough to export power from west to east without too much transmission loss.
The future of hydro may be with a larger number of smaller schemes like the stockton option Frog blogged on above. This scheme could generate 25MW of power from just 4-9 cumecs of water going through the system, with a peak output of 50MW during heavy rain, this is a remarkable amount of power for such a low water requirement.
The West coast terrain is suitable for a number of similar schemes and they have very low environmental impact. Hydro is miles in front as far as the most cost effective method for sustainable power generation.

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The West Coast is not the only area with good wave energy potential – the South Island’s South Coast is another, and handy to the Aluminium smelter and the transmission lines linking it and Manapouri to the rest of teh South Island. The West Coast lacks infrastructure – the main power feed is via Stoke, near Nelson! The rugged nature of the Southern Alps discourages building power lines across from Canterbury.

Exporting power (e.g. in the form of Urea or other fertilizers) isn’t something I had thought of for the West Coast. (I think that was what BJ was suggesting.)

Methane generation for local consumption on the West Coast may not be economical because of the small scale, but would certainly tie in with balancing the amount of local generation with demand. Having said that, it might be a good place to build a trial plant? (Once more generation is installed of course.)

I’m largely in agreement with you BJ – we should be building more generation using our renewable resources. We just disagree a little on where and what.

Trevor.

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With regard to the type of thinking behind the notion that continual economic growth is possible/ desirable I found this article has some relevance:

The era that defined Wall Street is finally, officially over. Michael Lewis, who chronicled its excess in Liar’s Poker, returns to his old haunt to figure out what went wrong.
http://tinyurl.com/64mm8l
ht the visible hand

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Trevor

I don’t agree. Generate as much as we can and power there is cheap. We can use it to make methane, or we can price it according to the surplus. It will necessarily be a matter of exporting power as much as importing energy intensive industry from places where power is generated from coal or oil.

Displacement of carbon generation takes place due to the economics of the resource. Whether we build massive transmission lines or not.

One has to think it through to the other side… the construction of hydro resources (and all renewable resources) inevitably makes us better off.

BJ

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