Labour attacking plans to sell power plant

[BMWST?]

The old Whirinaki station was completely sold off in 2001, just before the electricity crisis of that year.

good planning eh!.We need the capacity and as Jantar has pointed out its a fast reaction station.You cant have solar and wind as backup cos it might be dark and or not windy when something happens to another generatiing plant.Dismantle it and move it to where there are still gas reserves(or NZ diesel supplies)

[Mully]

IIRC, they were talking about doing that up North of Auckland way (Rodney-ish). The local iwi told 'em to fuck off cos it's hapu or tapu or some such gobbledygook. Nothing that a fat cheque couldn't fix, I suspect.

i'm still hopeing to see the day when the Kaipara harbour is tapped.
there is a lot of water moving there,22-23hrs/day

KAIPARA!!! That's where it was proposed.

I do recall one of the Maori Party troublemakers was one of the main shitstirrers.

Well the first one was supposed to working last year. So far no-one has been able to produce anything that will work in Cook Straight.

Here's the Kaipara link - Crest Energy

And here's lots of locals - (not just Iwi - I guess I recalled wrong) getting snaky - true Kiwi NIMBYs.

Almost exactly a year ago now. Just over.

http://www.northernadvocate.co.nz/lo...s-nod/3908523/

[Jantar]

....Here's the Kaipara link - ...

That is for tidal power which is a bit different to deep current power which was proposed for Cook Straight. To say that they would be completely submerged isn't quite correct either. The turbines would be submerged, but the remainder of the plant and switchgear is still above water. Gilkes in Scotland build the best tidal turbines, but even theirs are only marginally economic with a 6 m tide. Tidal turbines work best where the tides are high, and around New Zealand our tides are quite small, around 2 m.

[piston broke]

That is for tidal power which is a bit different to deep current power which was proposed for Cook Straight. To say that they would be completely submerged isn't quite correct either. The turbines would be submerged, but the remainder of the plant and switchgear is still above water. Gilkes in Scotland build the best tidal turbines, but even theirs are only marginally economic with a 6 m tide. Tidal turbines work best where the tides are high, and around New Zealand our tides are quite small, around 2 m.

wouldn't it be more about the amount of water rather than tide hieghts?
isn't the Kaipara one of the larger inland harbours in the southern hemisphere?

[piston broke]

does anyone have any idea why there aren't solar panels set up under the windmills?
surely they could do it and fully use the sites.
i mean the lines e.t.c are already there to move the power.

[Jantar]

wouldn't it be more about the amount of water rather than tide hieghts?
isn't the Kaipara one of the larger inland harbours in the southern hemisphere?

The formula for getting power from water is:

P = GQHe
where P is power in kW
G is gravity (9.81 m/s^2)
Q is the flow of water in cumecs
H is the head (height) or equivilent head of water in m
e is the turbine efficiency.

In tidal, or instream situations where there is no or very little actual head then the equivilent head must be calculated from the speed of water.
H = V^2/2G

and the flow Q is calculated from
Q = Va
where a is the cross sectioanl area of the flow path through the turbine in m^2.
e in the power formula is highest when a is minimised.

So it is obvious that unless you have a large head, or high velocity of water then it is impossible to get meaningful amounts of power.

[puddytat]

Sell it...its an outdated concept thats prone to the fluctuations of Diesel prices & will be no doubt a CO2 emitting monster that we'll also have to pay for.
With the money we get for it, we can give every household in the country a hot water cylinder wrap & save damn near as much. Any money left over should the go into planning a large net work of mini hydro run of the river schemes, the kind that dont require a large impact on the river & so consequently the conservationist AND the rednecked Joe Average river user can see the sense of...

But in saying that, I do see the emergency backup side of it. But I can also see the possibilty of some politicians buying it back in the future, after its been run down & you & I will pay yet again to update it before we sell it & go thru it all again....
Like the Railways?

[Swoop]

just look at wellington,the beehive

all that gas , hot air and the unbelivable piles of Shyte ,,,,

I was thinking exactly the same thing. A wind turbine mounted horizontally across the debating chamber would produce sufficient energy to power the greater Wellington area!

isn't the Kaipara one of the larger inland harbours in the southern hemisphere?

It is the largest. Tidal flow out at the graveyard is staggering!

[Jantar]

.....

It is the largest. Tidal flow out at the graveyard is staggering!

It is also one of the places in New Zealand with the highest mean tide.

[Ocean1]

It is also one of the places in New Zealand with the highest mean tide.

Mean tide?

As in... half way between average high and low tides?

Or greatest mean difference?

[Jantar]

Mean tide?

As in... half way between average high and low tides?

Or greatest mean difference?

Greatest mean difference. Sorry, I should have been clearer.

[Ocean1]

Greatest mean difference. Sorry, I should have been clearer.

So it is obvious that unless you have a large head, or high velocity of water then it is impossible to get meaningful amounts of power.

I recall the cook straight numbers looked very promising. IIRC the mean peak flow is >4 knots. If you consider the displaced volume the potential is very encouraging.

Need turbines over quite a wide cross section, though, and there's some impressively deep flows out there...

[Jantar]

....I recall the cook straight numbers looked very promising. IIRC the mean peak flow is >4 knots. If you consider the displaced volume the potential is very encouraging.......

Thats only 2 m/s which is equivilent to a head of 0.7m.

[Ocean1]

Thats only 2 m/s which is equivilent to a head of 0.7m.

Yup. Lots of it though.

Bit of disparity in the early proposals...

The company claims there is enough tidal movement in Cook Strait to generate 12 GW of power

...has applied for resource consent to install up to 10 marine turbines, each able to produce up to 1.2 MW, near the Cook Strait entrance to Tory Channel. They claim Tory Channel is an optimal site with a tidal current speed of 3.6 metres a second and the best combination of bathymetry and accessibility to the electricity network

Looking for cumecs/day. Saw a flow graphic a couple of years ago...

[Jantar]

...Looking for cumecs/day. Saw a flow graphic a couple of years ago...

Um, no such animal as cumecs per day. One cumec is one cubic meter of water per second. Cumecs per day is a bit like km/hr per day.