Is it time we went nuclear?

[homer]

Year probably that one to

lol
i knew its one or the other

The point is that itll be to little to late in this country

[Mikkel]

One farm, just over the hill from Te Apiti, the wind turbine at Wellington, and the one on Bank's Peninsular. so not a lot so far.

No, our current infrastructure does not lend itself to wind generation. That doesn't mean it couldn't nor that it shouldn't.

The main barriers to wind generation are: that wind supplies energy, but not controllable power; and the sites most suited to wind generation are also the poorest ones for transmission.

Because wind is neither fully predictable, nor controllable, wind cannot be counted in assessing peak generation capability. That means that for every MW of wind generation installed a matching MW of fast start / fast ramp generation must also be built. Thus the actual cost of building wind generation is 2 - 3 times the build cost. We are currently facing a possible crisis simply because wind farms have been built without a matching fast start backup.

The planned wind farms in the South Island are inside an already constrained area. If they go ahead then when they generate water will have to be spilled past the Clutha hydro stations.

The solutions are quite simple:
Companies building wind plant should be compelled to match them with fast start plant. Either they could build new plant, buy existing plant, or contract existing plant. Our current market rules do not allow such matching to occur.
Wind generation should be tied to transmission capability. Companies building wind gfarms in areas where there is a transmission constraint should be permitted to build transmission lines to carry the energy. Again, our current laws do not allow that to happen.

I do realise that there's more to introducing wind energy than just chucking up some mills all over the place. And I know that it's not a cheap investment either.

A couple of thoughts:

1. Would you agree that by spreading out wind farms over a large part of the country you would go some way to reducing the likelyhood of "no wind"?

2. Has anyone considered using wind mills to e.g. pump water from the west coast to the east coast side of the main divide seeing as there's usually heaps of rain on the west coast and not so much on the east and that this can cause problems. (Benefit of course being that it doesn't matter too much when the mills operate since they are adding their work to a reservoir that can be tapped into in a controlled manner (hydro))?

I understand the high need for predictable and controlable power generation. But windmills could be used in other applications - some of them actually not even relying on being hooked up to the power grid.
E.g. in a hydrogen based society an off-shore windfarm could be used for producing hydrogen fuel through local electrolysis...

[Robbo]

Mmmmm!!! Amazing the knowledge i have learnt from reading this thread, i could now probably apply for a job as a nuclear scientist.
Still not so sure about the :baked bean" theory but i can see definate posabilities in it.

[steveb64]

Then what are you going to use for spinning reserve?

Simple - use a load following nuke design, rather than base power only. But don't shut down the hydro's - just don't build any more either (though quite where they would/could have been built eludes me). The French seem to have a workable system, where nuke plants are supplying >75% of their energy requirements.

Then there's the Toshiba 4S "nuclear batteries", with a 10MW output for 30 years - no refuelling, using liquid sodium as a coolant. They're being touted as suitable for installation in remote sites - so they must have some form of load control?

[Jantar]

...A couple of thoughts:

1. Would you agree that by spreading out wind farms over a large part of the country you would go some way to reducing the likelyhood of "no wind"?

Yes, I would agree. I would also agree that a geographical spread wouldn't assure us of wind energy, so we would still need matching fast start plant.

2. Has anyone considered using wind mills to e.g. pump water from the west coast to the east coast side of the main divide seeing as there's usually heaps of rain on the west coast and not so much on the east and that this can cause problems. (Benefit of course being that it doesn't matter too much when the mills operate since they are adding their work to a reservoir that can be tapped into in a controlled manner (hydro))?...

Not that I'm aware of. However That would be an interesting one to try and get through the RMA process. The engineering would also be spectacular.

[Jantar]

Simple - use a load following nuke design, rather than base power only. But don't shut down the hydro's - just don't build any more either (though quite where they would/could have been built eludes me). The French seem to have a workable system, where nuke plants are supplying >75% of their energy requirements.

Not as simple as you would believe. Most hydro turbines have a minimum load (usually around 50%) below which they suffer cavitation damage.

The french do have a problem, but not the same one we have. They are tied into the UTCE http://www.ucte.org/ which ties all of Europe together. They only require a miniscule amount of Spinning Reserve of 0.16% of demand. We are in an isolated system and require around 10% of demand depending on the size of the largest unit on the system.

[Mikkel]

Yes, I would agree. I would also agree that a geographical spread wouldn't assure us of wind energy, so we would still need matching fast start plant.

Would it be entirely idiotic to get the windfarms up and running and then use the power generated, when it is generated, to reduce the load on fossil and hydro powerplants?
In that case you could reduce the amount of fast start plants necessary to maintain adequate power.

Not that I'm aware of. However That would be an interesting one to try and get through the RMA process. The engineering would also be spectacular.

Well being an engineer - that's what it's all about isn't it It's no fun if you have to think inside the box all the time!

[Mikkel]

Not as simple as you would believe. Most hydro turbines have a minimum load (usually around 50%) below which they suffer cavitation damage.

The french do have a problem, but not the same one we have. They are tied into the UTCE http://www.ucte.org/ which ties all of Europe together. They only require a miniscule amount of Spinning Reserve of 0.16% of demand. We are in an isolated system and require around 10% of demand depending on the size of the largest unit on the system.

Comparing NZ to Europe in this matter is pretty redundant. A lot of power is transferred across borders from company to company which means that both the market place and the supply is huge!

There was a very interesting article in one of the recent papers published by the danish engineers labour union (they send them down here free of charge ) about how there's been some controversy lately.

Denmark is trying to establish an image as a forerunner in the environmental debate - low carbon foot print, use of renewable energy sources, state of the art fossil fuel plants with low emission, use of super conductors in the high current segment of the grid, etc. Anyway, we buy a lot of power from Sweden produced by nuclear and hydro plants - which of course have low carbon footprints - especially when it's cheap. Same goes for trading with Germany and Norway...

Anyway, the controversy is that Denmark, like NZ, is an idiot hippie country with a big NO THANKS TO NUCLEAR POWER banner that has been flying since some socialistic politicians in the early 70s got carried away by the mood. And apparently there's noone who's willing to rock that boat. However, our dear neighbour Sweden rightfully yell hypocrisy - which is understandable since Denmark for decades have applied diplomatic pressure to have a perfectly well functioning nuclear power plant closed down because it was a bit to close to our border. Oh, the amount of propaganda that has been circled around about this

So yeah, it's a bigger market - but there are other issues that might factor in as well.

[Jantar]

Would it be entirely idiotic to get the windfarms up and running and then use the power generated, when it is generated, to reduce the load on fossil and hydro powerplants?
In that case you could reduce the amount of fast start plants necessary to maintain adequate power...

That is what happens now. But when the amount of wind generation exceeds the swing on connected plant then something must shutdown. If its hydro that shuts down we lose spinning reserve. If its thermal that shuts down it can take hours or even days to bring the plant back on line when the wind stops.

[Mikkel]

That is what happens now. But when the amount of wind generation exceeds the swing on connected plant then something must shutdown. If its hydro that shuts down we lose spinning reserve. If its thermal that shuts down it can take hours or even days to bring the plant back on line when the wind stops.

Hmmm, I can't help thinking that a power plant that can not graduate their output better than that must be designed pretty poorly. Or is the swing the amount of power graduation available in a given part of the grid?

What do you mean by spinning reserve?

[Jantar]

Hmmm, I can't help thinking that a power plant that can not graduate their output better than that must be designed pretty poorly. Or is the swing the amount of power graduation available in a given part of the grid?

What do you mean by spinning reserve?

Second question first:

Spinning reserve is the amount of standby power that is avaible almost instantly. It is obtained usually from hydro plant as hydro can change its load very rapidly. At the moment I have a single generator running at Clyde Power Station on 95MW. It is capable of 116 MW, and can ramp up there in 6 seconds. So at the moment it is providing 21 MW of spinning reserve.

In each island the amount of spinning reserve available must be equal to or greater than the single largest plant connected to the system. This is to cover any unplanned event without the lights going out. Right now the largest plant connected is the combined cycle plant at Huntly generating 383 MW. So in the north Island we need to have 383 MW of spinning reserve, and to cover that we need at least 766 MW of other fast ramp plant connected. Thermal stations are slow ramping, Geothermal cannot ramp at all, so it is almost all hydro.

[Jantar]

Your other point: I'm not sure just what you mean about "a power plant that can not graduate their output better than that must be designed pretty poorly". All power turbines, whether hydro Gas Turbine, or thermal have different operating characteristics. Generally the more efficient a turbine is then the narrower will be its operating band.

[steveb64]

Not as simple as you would believe. Most hydro turbines have a minimum load (usually around 50%) below which they suffer cavitation damage.

The french do have a problem, but not the same one we have. They are tied into the UTCE http://www.ucte.org/ which ties all of Europe together. They only require a miniscule amount of Spinning Reserve of 0.16% of demand. We are in an isolated system and require around 10% of demand depending on the size of the largest unit on the system.

Hmm - but I know that turbines can be simply shut down by closing the headstock(?) gates, cutting the water flow - I was under the impression that startup from this point is still quite rapid?

I think miniscule is a relative term - the French grid is producing in excess of 500TWh - so 0.16% of that is still going to be a hell of a lot of power... But I can also see that the huge grid formed by the UTCE has got to be of benefit too.

Err - I don't quite understand the "size of the largest unit on the system."? Is that generating unit or load unit? (My head is starting to hurt...)

[Jantar]

Hmm - but I know that turbines can be simply shut down by closing the headstock(?) gates, cutting the water flow - I was under the impression that startup from this point is still quite rapid?

That is correct for hydro plant, but not for thermal plant. I can get a hydro machine from complete shutdown to on load in around 2 minutes. Thermal plant has to warm through to get correct temperatures and pressures and to maintain correct blade clearances. That can take many hours, and if the shaft vibration levels, blade clearances etc aren't correct it can take days.

I think miniscule is a relative term - the French grid is producing in excess of 500TWh - so 0.16% of that is still going to be a hell of a lot of power... But I can also see that the huge grid formed by the UTCE has got to be of benefit too.

You are confusing Power and Energy. The French do not have to supply all of their own reserve as they can sure a proportion with the rest of UTCE. The total amount required from France is less than we need in the South Island, and only a quarter of what we need in the North Island.

Err - I don't quite understand the "size of the largest unit on the system."? Is that generating unit or load unit? (My head is starting to hurt...)

That is the largest generation unit, or the load on the largest single transmission component like the HVDC.

[steveb64]

Hmm - answered the question while I was still working out how to ask it...