I was having a chat with my mate Tim earlier at Uni (mostly about Astronomy), and he told me an interesting tale from Brazil and a tidal-based power station there.

Basically, they set the thing up, it collected loads of water over a vast area in huge reservoirs when there was plenty of water, and used this water as a "green" way of generating power, i'm sure you've heard of this before!

Anyway, the huge drawback with this one was that, every time the water drained back towards the sea, it dragged virtually ALL the vegatation with it too (over a vast area, bigger than planned) and actually takes this material to the bottom of the ocean, where it decomposes and generates a lot of methane, thus causing about as much damage to the environment as a power station! Apparently it was in the Independant last week, I find it unbelievable! roflmao


It made my mind boggle though. Is it just the case that all methods of generating vast amounts of power are going to be harmful to the environment in some way we may not yet know? Before all the coal, gasetc. started to get burnt, worldwide energy needs were miinute in comparison with todays demand. Is it possibly just a case that whatever we use to generate power, there will always be a payback? :shrug:

To be honest, that sounds like a bogus story to me. One of the concerns about "tidal power plants" is the effect they might have on marine life and vegetation, but the story above sounds fictional. It's actually more likely that such a plant would redirect water away from land that is normally flooded by the tides, affecting those ecosystems, not flooding them with a rush of water that drags everything into the sea.

It does sound a bit farfetched....

Whether or not this story is true, there are two interesting points.

a) I do not think that there is some "law of conservation of pollution" which means we cannot come up with cleaner energy sources. It is likely that any technology has some dangers and drawbacks, but it is in our hands to be in a position where we can judge what exactly these drawbacks are, how we can minimize them, and which are more dramatic than others.

B) Unfortunately, we seem to have a tendency to rush into using technology without actually knowing the consequences. (The theme of the 'Terminator' films, by the way ...) People rushed into civil uses of nuclear power without really knowing the possible dangers, or how to control things etc., which not only led to Chernobyl, but to quite a few near-misses in the western world as well. I think we are seeing the same happening with GM foods ... there seems to be a general unwillingness to at least wait and try to figure out whether we are not making an irreversible mistake. I think it is part of human nature, but it is certainly accelerated by the open market, and the fact that governments are scared to but too tough restrictions on new technologies in the fear that the expertise will go elsewhere ... Yet another problematic consequence of the fact that business has globalized, while government hasn't.

Overall, it would seem to be a really good idea if we first worked out what energy we can afford to spend, and then spending that energy (rather than more than we can afford). But we aren't too good at that (see e.g. credit card debt on the smaller scale, or national deficits). So I guess we're always going to be likely to scramble and try to pay the debts we've racked up before it too late ... seems like a reasonable metaphor for the climate scenario, I think.


I would like to see nuclear fusion working ... I've heard some rather well-known physicists state that "nuclear fusion is the technology of the future ... and it will always be so", reflecting the fact that they've thought for decades now that they're close, but now they still reckon it might take another 50 years. I'm also doubtful whether it will really be as harmless as it's often made out to be. It may yet be our best bet at producing a lot of energy with little cost to the planet, but it is something that will have to be carefully evaluated.

I don't believe it is fictional Nick - the guy who told me this is very straight talking, you should see him in our astronomy project!

I can't actually remember if it was the sea or a deep part of the reservoir where the vegetation went to rot - but the same end result whatever!

Nuclear fusion will have to be well bloody controlled, otherwise we may as well be on the surface of the sun roflmao

Well, no.

If you do astronomy, you'll know that it's the mass of the sun that makes the fusion work inside it. The point seems to be that, if a fusion reactor was to be breached, this would simply mean that the fusion wouldn't be sustained, and the process would just shut down. However, that doesn't mean that there wouldn't be finer points which could pose a risk. (People didn't really know the risks when they started building nuclear reactors either, did they.)

And, actually, there already are fusion reactors, as far as I know; the point is that the energy put in his higher than the energy that's coming out, which isn't much good. :P However, the theory seems to indicate that the main problem is the *scale* of the reactor: if you are able to make one which is big enough, the energy output should outweigh the energy needed considerably. Europe recently started a project to build such a prototype reactor, iirc.

It's not fictional - New Scientist happens to agree with your mate Tim.....

New Scientist Article

Sounds like maybe Sam's mate just had a bogus story that was loosely based on real events. The above story is about a traditional hydroelectric dam project, and has nothing to do with tidal power or with vegetation being swept out to sea. So don't misunderstand me. I was just saying the story sounded bogus, not that the concept of tidal power having adverse environmental effects sounded bogus.

Id agree with Nick there. The article is talking about damming fresh water as opposed to using tidal power to generate electricity. And the tidal water obviously is likely to be salty which would have a big effect on what type of vegetation will grow if any .

Right, i was in the middle of saying that the only reason i posted that link is that it was the closest thing i could find to what Sam was saying......that was about when my boss walked in!!!! :blink: I didn't actually have time to read the article either, so didn't know how close it was to what Sam was arguing - although I got it off a link from Wikipedia on tidal power.

I couldn't find anything about this brazilian power station though - other than the fact that it's the biggest in the world! I wasn't trying to say anyone was wrong or right, just trying to find some actual evidence as to what the thread was about! Would probably have helped if i were a scientist and knew anything about this subject :P

What this episode does say is that are the environmentalists really that sure their ideas will work? Most of them are designed to moan it seems, let's see if their bright ideas work! roflmao

Politicians always have bright ideas in opposition - but usually can't back it up if elected!

I'm not quite sure what you are implying here.

I would consider myself an 'environmentalist' (in a positive sense of the word), and I certainly never had the idea that water plants were particularly good for the environment :blink:.

I also consider myself a fairly rational human being, and I certainly don't think that there is going to be a simple, straightforward solution (as some politicians would like us to believe, in the government *and* in the opposition), but it is also clear that we have to do something. So we need to look at what options we have in producing energy, what are their advantages and drawbacks, where can we invest in cleaner technology, etc. It's not about being dogmatic, it's about working out what is the best way to keep our world in a reasonable condition.

Or are you saying that there's nothing we can do anyway, so we may as well fiddle while the world burns? I don't think that would be a very mature and sensible attitude. I also don't think it's true.

:shrug:

Btw, since I was talking about market forces before ...

http://www.geocities.com/mmemym/bits1/fal0034.htm

:)

I'm rational about it too - but the 'partisan' environmentalists actually have slowed the reaction down I reckon. Because of how partisan some have been over the last few years about global warming (you know what I mean, the "We know we are right and you're all wrong and idiots brigade"), people haven't taken their point seriously.

I'd like these people to now not hide away, like they invariably will, but lead the building of new sites. Put their heads on the block, not those of governments. So many people are going to moan if any of these "green" ideas went wrong, so surely it should be put at the door of activists?

It's not easy to type what I am thinking on this, I hope it makes some sort of sense roflmao

It seems odd to blame the people who have warned about global warming for a lack of response to it. Do you think if no-one had said anything, something would have happened? I don't think you can blame Cassandra for the fall of Troy.

I don't much care for dogmatism in any form, and you will certainly find people with strong views in any camp. But I much prefer people who are passionate (and perhaps somewhat over the top) about an issue which they are basically right about to those who basically couldn't care less and are looking for excuses not to do anything.

At least 'the environmentalists' tend to do their own part, trying to save energy, recycling, taking public transport/walking/cycling rather than driving, etc. If everyone did that, it would already be likely to make a difference.

And I still fail to see what this has to do with water plants. Do you have any evidence of environmental organizations advertising this as a way of tackling climate change, or as a particularly clean way to produce energy?

What I think is that from the start the environmentalists were a little too robust, so that people thought to dislike and distrust them. When you look on it bluntly I suppose the facts have to stack up for global warming happening - but I think many more would have come to that conclusion has the activists had not tried to go blaise from the off - people obviously look to knock them down and it has wasted time with the reaction.