Why are barrages necessary for tidal power? I don't get why it's not possible to build just a few underwater turbines with foundations on a few piles in the sea bed without the need to totally enclose a body of water. Surely any moving water will generate more power than moving air?
Lots of issues to get around. such as bloody harsh environment, sometimes a need to move up and down with the tide to keep in the fastest flowing area, need to work over a range of velocities (during the tidal cycle), need to work in both directions (tide in, tide out etc..). Like wind energy there is also an economy of scale (larger leads to greater efficiency) but of course you only have so much depth of tidal flow... And to add to that.. in many estuarine and marine environments (e.g. Severn, Humber - and places like Menai straights) the bed is mobile - ie its silt and sand, so moves about throughout the year as well as over longer time scales. This means that your impeller/turbine can be swamped by a sand bar (for example) or the fastest area of flow could move to the other side of the estuary - where your turbine is not...
Personally I am strongly in favour of nuclear to fill the gap between weaning ourselves off fossil fuels and getting tidal/ solar/ fusion/ etc up to the required scale.
the only way nuclear is going to get built is by throwing huge amounts of govt money at it.We need to solve this (in reality ten years ago) & nuclear has always proved expensive & slow to construct.
If the cost is comparable & (remember that we have no reliable figures for the cost of nuclear from start to finish as it's never been done) then I'd rather see the money go to a Desertec style project I mentioned earlier.Once done the problem is solved permanently & we gain food production capacity rather than losing it.
Desertec is a lovely idea but exactly the reason why we need new nuclear asap, to replace the fossil fuel base and bridge the gap to such technologies. PV in the desert might be current tech but storing and moving the power long distance is not, nor have we seen too many models of such international cooperation. I doubt the cost would be 'comparable' either.
The government needs to stop looking for private companies to invest and just suck up some more imaginary debt and get some nuclear power plants on line!
Quotethe only way nuclear is going to get built is by throwing huge amounts of govt money at it.We need to solve this (in reality ten years ago) & nuclear has always proved expensive & slow to construct.I'm quite happy for the government to throw loads of money at it - I can think of no better cause. Renewables are hugely important but the country as a whole, and industry in particular, will still need a solid bed of carbon neutral generation capacity that is not weather/ season dependent. Nuclear may be slow but it remains the only available option to replace the current bed of coal-burning power stations.I agree this debate should have been finished ten years ago. I am still in shock at Germany's decision to abandon nuclear. However well their renewables are doing their total power output has gone down, but CO2 production has gone up. All because of scare mongering after Fukushima at which, let's not forget, NO ONE DIED as a result of radiation. (And was caused by a freak natural event. Tsunamis are not a realistic risk to Germany).
Tsunamis are a UK risk, archaeological record for bristol channel and Norfolk prove that.
Quote from: outlawed on August 15, 2013, 04:38:38 pmTsunamis are a UK risk, archaeological record for bristol channel and Norfolk prove that.True; whilst not impossible, they are very highly improbable, and a minimal risk compared to that on the Pacific rim. Just build one at a sheltered spot like Ellesmere Port or Grangemouth it can only improve the look of these places.
I think severn barage and other tidal 'mills' should go ahead. Compare their minimal habitat loss to Chernobyl, 3 mile island, Fukushima, Windscale Irish Sea pollution etc.Because of Hinckley Point and Oldbury nuclear power stations academic papers advise against eating resident fish such as flounder, because of toxic levels of mercury and cadmium in Bristol channel.
Quote from: SA Chris on August 15, 2013, 04:54:57 pmQuote from: outlawed on August 15, 2013, 04:38:38 pmTsunamis are a UK risk, archaeological record for bristol channel and Norfolk prove that.True; whilst not impossible, they are very highly improbable, and a minimal risk compared to that on the Pacific rim. Just build one at a sheltered spot like Ellesmere Port or Grangemouth it can only improve the look of these places.they do happen. That's a fact. The precautionary principle should govern judgement. UK has freak tsunamis every now and then due to plate tectonics. So you're happy to have a nuclear plant in your garden and bury the waste under your house? If not dont wish it on anyone else.
Quote from: outlawed on August 15, 2013, 05:09:14 pmQuote from: SA Chris on August 15, 2013, 04:54:57 pmQuote from: outlawed on August 15, 2013, 04:38:38 pmTsunamis are a UK risk, archaeological record for bristol channel and Norfolk prove that.True; whilst not impossible, they are very highly improbable, and a minimal risk compared to that on the Pacific rim. Just build one at a sheltered spot like Ellesmere Port or Grangemouth it can only improve the look of these places.they do happen. That's a fact. The precautionary principle should govern judgement. UK has freak tsunamis every now and then due to plate tectonics. So you're happy to have a nuclear plant in your garden and bury the waste under your house? If not dont wish it on anyone else.I thought the recorded ones were believed to be due to massive landslides on the Canaries (somewhere) and Norway? Given that arecheological records and supposition are the only knowledge about them, shows the remoteness of the risk.And just because I'm saying your concerns regarding tsunamis are poorly grounded doesn't mean all of a sudden I want waste buried under my house, or indeed anyone's. Stop making suppositions.
Outlawed - I like your passion for the debate..But Tsunami risk in the UK is tiny - and those that historically have struck were small (1-2m) - their impact was probably much greater as there were effectively no coastal flood defences in that time.. Most of the East coast is protected against surge tide heights, so it would be unlucky for the very rare tsunami to hit at the same time as a king tide... (I'm not sure how you'd get one from the east coast..). Chris - the Canaries mega tsunami theories have recently been debunked my Tusnami/Landslide/Volcanologist colleague tells me (there were mega landslides, but earlier studies cocked up the tsunami estimation)..I used to set my first year tutees (I'm an academic if you hadn't guessed) a 'get them warmed up' type essay on 'compare the impact of nuclear vs coal power on humans'. If you do a straight body count - then surprisingly (to them usually) you find that a few dozen people have died immediately after nuclear incidents (direct result) and c.5-50 000 total (make up your own numbers really in this range - that seems to be what the journal articles do) from shortened life expectancy from the accidents (mainly Chernobyll). When you look at coal - there are hundreds to low thousands of people every year who die in the extraction process (mining incidents etc..) - and several thousand to 10 thousand (per year) who have die prematurely due to the pollution of burning the stuff.. Its easily if not more 10:1 Coal to Nuclear in the body count... thats before you start factoring in any global warming effects which will start to come in at some point.. I appreciate the jist of this thread debate is more towards RE vs Fracking/Fossil fuels - but I think we need to consider that Nuclear power is possibly the lesser of several evils. Put it another way - I've done some work at this place: ranger uranium mine in Australia. Its not an especially big pit (its tiny in the open cast mining scheme of things) but at one point in the early 90's, uranium from this mine was generating 10% of the WORLDS electricity... thats just one small (comparatively) sized hole compared to the huge tracts of the earth being removed for coal open cast mines... (see edits on tsunamis made a couple of in after the OP)
they do happen. That's a fact. The precautionary principle should govern judgement.
So you're happy to have a nuclear plant in your garden and bury the waste under your house? If not dont wish it on anyone else.
No radiation deaths due to Fukushima? You gotta be kidding? http://m.huffpost.com/us/entry/1790423
Which coming from climbers, whose hobby involves assessing risk, is disappointing.
but if UK can be RE energy self sufficient, we should challenge nuclear and fossil fuel lobbies. Not just sit back and take their crap? We've sat back long enough, and paid for the privilege of not questioning their hegemony.
Quote from: Johnny Brown on August 15, 2013, 06:00:49 pmWhich coming from climbers, whose hobby involves assessing risk, is disappointing.Very different scales of risk though, skills in one may not be directly transferable to the other.