by Dreamtwister » Fri 25 Aug 2006, 11:17:26
$this->bbcode_second_pass_quote('Bleep', '')$this->bbcode_second_pass_quote('Dreamtwister', 'I') rank this right up there with railguns: Technically possible, but unlikely to ever see widespread application.
Aside from "because you think so" what specific issues do you see that will inhibit the Pelamis from being widely adopted?
For the same reason that so many other technologies will never be implemented: The energy density is really low.
It's not because the technology is bad, in fact, 30MW/km^2 sounds pretty darn good to me. But a single gas power plant puts out around 400MW. Suddenly, you're talking about 13km^2, not 1 and 520 machines not 40 and £1.04 billion not £6m, just to replace a *single* gas plant that costs around £350m.
Now, consider that Scotland alone is considering adding 30 new natural gas plants in partnership with BP over the next few years.
We're not talking about a couple of sea snakes any more.
The whole of human history is a refutation by experiment of the concept of "moral world order". - Friedrich Nietzsche
by Bleep » Fri 25 Aug 2006, 11:30:30
$this->bbcode_second_pass_quote('Dreamtwister', 'F')or the same reason that so many other technologies will never be implemented: The energy density is really low.
But the energy security is really high.
$this->bbcode_second_pass_quote('Dreamtwister', 'I')t's not because the technology is bad, in fact, 30MW/km^2 sounds pretty darn good to me. But a single gas power plant puts out around 400MW. Suddenly, you're talking about 13km^2, not 1 and 520 machines not 40 and £1.04 billion not £6m, just to replace a *single* gas plant that costs around £350m.
But no amount of gas power plants will help you when you can't get the gas.
by Dreamtwister » Fri 25 Aug 2006, 11:56:03
$this->bbcode_second_pass_quote('Bleep', '')$this->bbcode_second_pass_quote('Dreamtwister', 'F')or the same reason that so many other technologies will never be implemented: The energy density is really low.
But the energy security is really high.
I'm not disagreeing. Well, not completely. At some point, all of those sea snakes are going to start becoming a navigation hazard. All it would take is one broken GPS, and suddenly you have a ship plowing through your wave farm and ripping the snakes off thier moorings. Whether it's an islamic extremist with an explosive vest at the gas plant, or a drunk sea captain, the effect is the same: You're offline, possibly for months.
$this->bbcode_second_pass_quote('Dreamtwister', 'I')t's not because the technology is bad, in fact, 30MW/km^2 sounds pretty darn good to me. But a single gas power plant puts out around 400MW. Suddenly, you're talking about 13km^2, not 1 and 520 machines not 40 and £1.04 billion not £6m, just to replace a *single* gas plant that costs around £350m.
But no amount of gas power plants will help you when you can't get the gas.[/quote]
Again, I'm not disagreeing. But my point wasn't about what "should" be, but what "is". As it stands now, Pelamis power is roughly 3x more expensive than natural gas. Until that changes, Pelamis will remain marginal.
Unfortunately, by the time it *does* change and you "can't get gas" for power plants, you won't be able to get it to fire the natural gas furnaces that are used to forge the steel from which Pelamis is made, either.
The whole of human history is a refutation by experiment of the concept of "moral world order". - Friedrich Nietzsche
by Dreamtwister » Fri 25 Aug 2006, 12:10:06
$this->bbcode_second_pass_quote('Bleep', '')$this->bbcode_second_pass_quote('Dreamtwister', 'I')t's not because the technology is bad, in fact, 30MW/km^2 sounds pretty darn good to me. But a single gas power plant puts out around 400MW. Suddenly, you're talking about 13km^2, not 1 and 520 machines not 40 and £1.04 billion not £6m, just to replace a *single* gas plant that costs around £350m.
Dude, the price of water flowing by the Pelamis machines is free.
You have not factored in the price of the natural gas into your
£350m for one plant equation, have you?
I developed those figures from your own link:
$this->bbcode_second_pass_quote('', 'T')he £6m Pelamis wave energy project will eventually generate 2.25 megawatts - enough for 1,500 households.
...
Four orange-coloured segments for the first of three giant wave energy machines have been completed and are ready for transportation.
£6m for 3 machines = £2m per machine.
400MW target (to compete with 1 NG plant) @ 750kW per machine = 533.33 machines (round to 533)
533 machines * £2m per machine = £1.066 billion
That's just to build the machines and deploy them. I compared that figure to the £350 million figure for constructing a NG plant was calculated from
this article, in which the construction cost was quoted as $600 million.
So no, I did not include the cost of gas to operate the NG plant, just the construction costs. But neither did I include the maintainance costs of the wave farm. How much maintainance is Pelamis going to need? Even if you only go with monthly inspections, there's going to be a substantial dollar value attached.
Again, I'm not suggesting we shouldn't build as many of these as we can. I'm just pointing out that, like other alternatives that have been discussed here, Pelamis won't scale.
Now, if Pelamis can find a way to operate at higher than 10% efficiency, I might re-evaluate...
The whole of human history is a refutation by experiment of the concept of "moral world order". - Friedrich Nietzsche
by Dreamtwister » Fri 25 Aug 2006, 13:32:44
$this->bbcode_second_pass_quote('Bleep', '')$this->bbcode_second_pass_quote('Dreamtwister', 'S')o no, I did not include the cost of gas to operate the NG plant, just the construction costs. But neither did I include the maintainance costs of the wave farm. How much maintainance is Pelamis going to need?
How much maintenance does a NG fired plant require? You can't expect it to operate for free either.
I don't. But we're already looking at construction costs for wave farms being 2-3 times as expensive as natural gas. Regardless of future operating costs (which I will admit I haven't calculated for either), the increased construction costs *all by themselves* will prevent widespread implementation.
$this->bbcode_second_pass_quote('lorenzo', 'W')ave power is (less expensive) too, probably
No, it's not. It's not even close. That's the point I'm trying to make.
1 natural gas plant costs around 350 million euros to construct. An equivelant wave farm would cost
over a billion euros. What investor is going to invest in 1 plant that will have to last 40 years to achieve maximum ROI when he can invest that *same* money in 2 or even *3* NG plants that can each return the same ROI in half the time? The only investors who would do something like that are the ones who already believe in peak oil. A definite minority who are already investing in far more promising alternatives, like the aforementioned wind and solar.
$this->bbcode_second_pass_quote('lorenzo', 't')here is no energy crisis whatsoever and there will never be one.
The whole of human history is a refutation by experiment of the concept of "moral world order". - Friedrich Nietzsche