Southerly: New Zealand's Wave Energy Technology programme
41 Responses
First ←Older Page 1 2 Newer→ Last
-
"I don't really enjoy sand in my underwear"
Put on swimwear when you go to the beach. Please?
Interesting transcript - my immediate questions are... is the 100kW figure correct? That's the output of an average car engine if it's right. Expected a bit more.
Second, these seem like fairly major structures. What's the "resource cost" in terms of energy and material to build wave generators, and to transport and maintain them? Is it worth it, basically?
-
Juha Saarinen wrote:
... is the 100kW figure correct? That's the output of an average car engine if it's right. Expected a bit more.
Yes, that's for the first commercial-scale device that they're working on. They expect to be able to increase this to around 1 MW for later devices.
To put this figure into perspective, the Brooklyn wind turbine in Wellington is rated at 225 kW.
Comparisons with car engines are always a little unfair. A hundred kilowatts is actually a lot of power -- about 5000 energy-efficient light bulbs worth, or the maximum continuous power output of around 350 fit human beings.
In automotive terms, note that 100 kW would be the maximum output for a (large-ish) car, and the engine would wear out after only a few dozen hours at this output. A wind turbine or wave device can keep generating this power output for years on end -- and you never have to fill up the tank with petrol!
Note also that they expect to operate these devices in large "arrays" with a common electrical feed back to land. If you have an array of 100 x 1 MW devices then you're talking about a very sizable total power output.
Juha Saarinen wrote:
Second, these seem like fairly major structures. What's the "resource cost" in terms of energy and material to build wave generators, and to transport and maintain them? Is it worth it, basically?
The power density in waves is much higher than that from wind -- so the devices should theoretically be smaller than comparable wind turbines (note that wind turbines have large concrete foundations), and therefore would require less energy and material to build/transport. The energy pay-back period is expected to be only a couple of months.
So, yes, if you can build a cost-efficient and reliable wave energy device then it is definitely worth it.
-
So, yes, if you can build a cost-efficient and reliable wave energy device then it is definitely worth it.
Which is easier said then done. There are a number of broken marine energy devices around the world that just could not stand up to the rigors of the environment.
As the oil industry has shown we can build structures that can survive in the sea under the worse conditions, but they do not move, while a marine energy device must move in order to generate electricity...
With NZ's abundant wave resources, which can do nasty things to a frigate on the bottom of Wellington harbour, any device will need to prove it can last it's design lifetime before it gets supported by commercial interests.
Investment in large scale infrastructure projects like this (lots of $ up front, cash flow over a long time) needs certainty. One of the main reasons why wind farms were delayed was the life of the turbines was not known in the field. Until this was established , costs for operation known and the best of breed systems determined, the risks were to great for investment.
It doesn't matter how wonderful a widget is, its got to prove itself for 10 to 20 years before serious money gets invested and larger scale operations commence. -
That was my third question, reliability.
What happens if one of the large arrays break up?
-
What happens if one of the large arrays break up?
Stuff gets washed up on the beach or floats around being a danger to shipping.
The investors lose money and future consenting gets more difficult - meaning expensive and risky - so the whole industry is delayed. -
I was hoping environmental protesters would cement and weld themselves to wave generator components to act as human shields in case something goes wrong...
-
Will they be protesting for, or against, the arrays? (The bananas will be out in force no doubt)
Much as you would hope for this kind of behaviour, it is more likley protesting will be done from the arm chairs
-
Andrew Stevenson wrote:
Which is easier said then done...
Sure... if it was easy to do then it would have been done years ago...
Andrew Stevenson wrote:
It doesn't matter how wonderful a widget is, its got to prove itself for 10 to 20 years before serious money gets invested and larger scale operations commence.
Sure... that's extremely well understood by everyone involved. But that's no reason not to try to develop this sort of technology. (Do you work as an accountant for an electricity company, by the way -- this is exactly the sort of conversations I used to have with them when I was an energy engineer!).
The early wave energy research (in the 1950s and 1960s) was incredibly costly. Japan put itself off wave energy by building a few super-expensive systems that only survived a few days/weeks at sea.
But with recent advances in computer modelling this sort of expensive suck-it-and-see engineering has been greatly reduced. IRL have been 'testing' and optimizing their wave energy device for the last two years in a virtual environment based on real wave conditions.
Pelamis underwent similar development -- although they came up with a very different solution. Their device then passed extensive sea-trials in the North Sea.
At the moment, unfortunately, the cost of electricity produced by Pelamis would be far too high for New Zealand, but it is already economic in some countries. Portugal, for example, is in the final stages of constructing the world's first wave energy farm (based on Pelamis). Further wave farms (also based on Pelamis) are in the early stages of construction in Scotland and England.
Juha Saarinen wrote:
What happens if one of the large arrays break up?
You have, as Andrew suggests, a big problem. But I should emphasize here, that really -- engineers aren't a bunch of complete fuckwits. They have thought hard about these issues for many years. If a wave array breaks up they won't throw up their hands and say: "Oh, I never considered the possibility of that happening". They design in safety systems (quadruple redundancy, warning beacons, scuttling systems) that make this possibility as remote as possible, and -- if it occurs -- to have a safe failure option.
Frankly, the possibility of such an event is not a reason to give up on attempts to develop this sort of technology.
Yes, the development of wave energy devices is an extremely difficult engineering problem. But that means that it is also a huge opportunity.
-
It's not the engineers I worry about, it's the managers holding the purse strings.
I hope this doesn't mean clean and green nookolea powa isn't out of the question, incidentally.
-
David Haywood wrote:
Do you work as an accountant for an electricity company, by the way -- this is exactly the sort of conversations I used to have with them when I was an energy engineer!
Ahhh no, not an accountant, actually I'm an energy engineer...
Juha - stop stirring!
-
Moi? Never...
We have to align ourselves with Australia!
-
Ok, I'll bite
Why do we have to align ourselves with Australia?
-
Andrew Stevenson wrote:
Ahhh no, not an accountant, actually I'm an energy engineer...
Oops... A thousand apologies for that, Andrew.
Why do we have to align ourselves with Australia?
For the same reason, obviously, that Finland has always been so keen to align herself with Russia...
-
clean and green nookolea powa
Shouldn't that be nookolea paua?
-
David Haywood: "For the same reason, obviously, that Finland has always been so keen to align herself with Russia..."
And I'm being accused of stirring...
-
So why do we have to align ourselves with Australia?
They have uranium, we don't
They have places to store the waste, we don't
They use lignite to provide baseload, we don't
They have larger power demands suited to current nuclear plant, we don'tI must confess I'm not seeing your logic here Juha
-
Who said anything about logic? But anyway, the above conditions don't apply to every country that has nuclear power plants.
I'm pretty sure nothing will be done on time though, so all the talk about new power generation is academic (not a dig at David that).
Related tangent: what's the longest you can run an underseas power cable?
-
But anyway, the above conditions don't apply to every country that has nuclear power plants
No, but they are the sort of thing you think about before spending a couple of billion setting up an industry in NZ.
Related tangent: what's the longest you can run an underseas power cable?
As long as you like - might not get any energy out the other end though...
Before you even think about running a cable from Australia, work out the cost of the conductor metal alone, probably be cheaper to ship charged batteries over, particulary at the rates they would charge us for power. Anyway, they will need it all the power to run desalination plants and pumps.
-
Oh well, we're pretty stuffed then. Better learn how to become the world's most energy-miserly nation by a massive margin.
-
I once spoke to David Bellamy about this. He was against tidal generators but not wave generators. He's gone a little balmy about wind generation though, so I'm not sure if its an endorsement or not.
As a strictly non-serious end-of-the-day question, where does Mexico stand on this issue? Surely there'd be a big push for Mexican Wave Power (snigger).
-
Juha Saarinen wrote:
Oh well, we're pretty stuffed then. Better learn how to become the world's most energy-miserly nation by a massive margin.
Dude, we're the luckiest country in the world in terms of renewable energy: hydro, wind, wave, solar, tidal, geothermal, biomass, etc. we have all in abundance. There's every reason to be very optimistic about our energy future...
Hadyn Green wrote:
I once spoke to David Bellamy about this. He was against tidal generators but not wave generators.
Having some familiarity with Dr Belamy's energy 'expertise' I imagine that this is because he doesn't realize the difference between tidal stream and tidal barrage systems.
Tidal stream is where you use underwater tidal turbines to capture the tidal energy. It's just like a windfarm, but with smaller turbines (since water is more dense). This is the method that you could most easily use in New Zealand.
Tidal barrage is where you essentially build a dam across the mouth of an inlet. As the tide rises the water flows into the dam via a turbine/generator. And then, as the tide falls, the water flows out of the dam via the turbine/generator. It's kind of like a normal hydro dam that can work in both directions.
Environmentalists are (probably fair enough) very anti the tidal barrage approach because it causes a major impact on the ecosystem. So (in my experience) when some of them hear the word 'tidal' they tend to just shout "No, no!" and don't bother to listen to whether you're talking tidal stream or tidal barrage.
Either that, or Dr Bellamy believes the myth about tidal stream turbines chopping up fish. This operates on the same principle as all those birds which are sliced and diced by wind turbines (don't worry, bird lovers, there basically aren't any).
We hope to do a programme on tidal energy before the end of the series.
-
if you had wind turbines out in the sea, you could use the turbine base as the monolith, and have swingarms and floats poking out each side. so for every turbine you'd have four wave generators. and you'd save money on power cables. brilliant. i don't know why no-one's thought of this before! :-)
david bellamy's part of augie auer's NZ climate science coalition. make of that what you will
-
Oh well, I'll readily admit that I haven't been following the issue beyond feeling annoyed that electricity prices are rising fast and regularly. Good to hear that it's all under control then.
-
Off topic (broadly on perhaps). Maybe a suggestion for a future - because I want a windmill - either for power, or pumping water from a bore, both would be useful - I've been wondering why we aren't being encouraged to all install small generating devices on our properties, where it is possible.
How feasible are small turbines, either wind or water driven? And can they generate enough to provide relief for the family power? Enough to feed back to the grid? And how feasible is THAT, anyway?
-
An organic nookolea paua farm sounds a better idea... but here's an Aussie one mentioned that costs A$10,000 and spins at 100 rpm which makes it less bird-chopping prone apparently.
Post your response…
This topic is closed.