Tidal Turbines (vaguely boaty)

[Nick]

I don't think you quite realise the scale of the subsidy.

It was para who quoted the 1% of consumption figure. 4p/kw is a slightly more informative figure, thanks for that - and I am sure you didn't mean to sound patronising

The size of the subsidy is irrelevant though in regard to my previous statement that if the RO covers the cost completely then then that is the cost of producing the electricity. That would seem to imply that the current estimated cost of producing electricity from this system (according to the developers admittedly) is 4p/KWh, which sounds pretty good to me for a small scale nascent technology.

Edit: In fact Lunar Energy quote 5p/KWh on their website, which they claim has good backing by independent authorities - still not too shabby, is it?

A few more thoughts:

In 2004, wind energy cost one-fifth of what it did in the 1980s. Tidal power generation in this country consists of one small unit in Strangford Lough. I see no reason to assume that there will not be similar economies of scale as tidal technology develops.

I would be interested to know the real figure for nuclear subsidy taking into account a few of the following:

• ~ Limited liability to nuclear operators in the case of accident, and at least part provision of security at nuclear sites and whilst waste is in transit.
  
  ~ The failure of the nuclear industry to establish properly managed funds for waste and decommissioning
  
  ~ The large and uncertain public liabilities of up to £5.3bn for failed nuclear operator British Energy

As you say Dave subsidies are essential to encourage the development of renewables, so why this should be used to argue against new technologies - as Para appeared to be - is a bit of a mystery. However, my contention is that the RTT ducted turbine design has all the appearance of a technology that with sufficient research could mature into a system that produces massive quantities of base load renewable energy at a very reasonable price per MW

[Nick]

what in your war footing scenario does massive mean? specifically, what?

Not sure why you want numbers Para, you are obviously hoping I am going to trip myself up in some way so you can pounce with a raft of figures and jargon from the current (pardon the pun) generating scenario.

~ UK Electricity Market £18 billion p.a. (Black & Veatch 2005/Carbon Trust)
~ UK Tidal Energy Resource 6% of total UK market. (Black & Veatch June 2005)
~ ergo UK Tidal Energy Market Value £1.08 billion p.a.

This is extrememly conservative and is based on figures and technology that are now three years old. Other sources, most notably Scottish Enterprise, estimate that 34% of the UK electricity demand could be generated from tidal currents.

Assuming 2MW units running at 50% efficiency you should be able to do the sums easily enough and tell us how many we need for both scenarios (6% and 38%). The answer will be somewhere in between.

Whatever the potential size of the tidal contribution, its huge advantage over wind is that it can be used to provide base load.

[ParaHandy]

]The size of the subsidy is irrelevant though in regard to my previous statement that if the RO covers the cost completely then then that is the cost of producing the electricity.

hmm .. you still haven't got it. The variable cost of producing the electricity *may* be met by the grid revenue; the fixed and residual variable costs are met by the RO. You keep ignoring facts unattractive to your argument which is typical of people of your ilk.

The tax was actually 10% of cost not 1%. In 2001 it was 0.43p/kwh (fixed) when at that time industrial electricity cost 3.5-4.5p/kwh

[Nick]

(Sorry if you have seen some strange things happening in the last ten minutes or so - I somehow managed to overwrite your original post due to a fit of technological incompetence and doing too many things at once. However, I think things are now back to normal - if not then sorry about that and please edit or repost. )

The size of the subsidy is irrelevant though in regard to my previous statement that if the RO covers the cost completely then then that is the cost of producing the electricity.

hmm .. you still haven't got it. The variable cost of producing the electricity *may* be met by the grid revenue; the fixed and residual variable costs are met by the RO. You keep ignoring facts unattractive to your argument which is typical of people of your ilk.

The tax was actually 10% of cost not 1%. In 2001 it was 0.43p/kwh (fixed) when at that time industrial electricity cost 3.5-4.5p/kwh.

You are quoting 2001 figures - what is it now? That was a long time ago. Dave quoted 4p/KWh as the current figure, which suggests that has remainded constant or dropped slightly. I shall be surprised if the cost of industral electricity has remained constant over the same time.

I have no idea how you are breakling down the various costs you claim are associated with generation of electricity - what are 'fixed and residual variable costs' ? You are coming from the position of a person with enormous but highly specialised jargon-infested economic knowledge , and you obviously enjoy putting others ideas down with a raft of figures which, I note, you never provide any sources for. This is the bulldozer style of debate. By then referring to 'people of my ilk' you lower the debate below the standard at which I am prepared to participate. Lift your argument if you wish to continue, or if not just write me off with another disparaging comment which is not worthy of you.

You may not 'believe' in renewables and may believe that it is a load of tree-hugging nonsense - fair enough, all I can say is that to me your 'arguments' make no sense at all and your position appears to be purely negative. Where do you think future energy provision should come from? Nuclear electricity is the most heavily subsidised of all the technologies, even though it has been around for forty years. Coal is filthy and has high (carbon) transport costs associated with it. Carbon capture is very limited and expensive.

Tell us your answer.

In the meantime, can I remind others of the reason this thread was started - if you would like to find out more about the current state of tidal power technologies in the UK there is a mini-site at TIDESTREAM

And - as Ash would remark - THIS IS A SAILING FORUM . . . carry on here if you wish, but there is an environmental website with a forum at GREENPHASE

- Nick

[DaveS]

Nick,

I entirely take your point about not wanting to pursue non-saily topics, and as I said earlier, I happen to be strongly in favour of tidal stream generation anyway (provided it does not interfere significantly with sailing - see, it is a saily topic! ). However, in the interests of accuracy, statements like this cannot be left unchallenged.

Nuclear electricity is the most heavily subsidised of all the technologies, even though it has been around for forty years.
- Nick

Taking the ball park figures of the previous discussion, onshore wind currently receives subsidies in the order of twice the value of the electricity produced, and something similar may happen for tidal. Nuclear is, as you point out, a mature technology and has been producing around 20% of the UK's electricity for a fair number of years. In aggregate, that's a lot of electricity. 81.6TWh in 2005 to be precise, according to the most recent EU energy statistics.

Let's assume for the moment that a "nuclear subsidy" exists. For nuclear to be "most heavily subsidised" that subsidy would have to beat wind, i.e. be more than twice the value of the electricity. I don't have an accurate current wholesale figure for nuclear - perhaps Para could oblige? - but let's take £35/MWh (3.5p/kWh). Twice that would be £70/MWh, requiring for 2005 a total subsidy of over £5 billion. Now there is no equivalent to the ROCs mechanism to transfer money from consumers to the nuclear generators: they simply sell in the market at whatever they can get - a process which, when prices were low, did indeed give British Energy real difficulties. So the postulated "subsidy" would have to come from elsewhere - presumably government. They claim there is no subsidy, and I would have thought that a covert spend of £5,000,000,000 per annum a bit difficult to hide.

In my view, if the true objective is to generate sufficient electricity while reducing, (or, ultimately, eliminating) production of CO2, then nuclear and renewables should, certainly at this stage in the game, be seen not as competitors, but as on the same side. Once generation of CO2 is eliminated then, if renewables fulfill their potential, there could be a sensible discussion about their gradual substitution for nuclear.

[Nick]

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Sorry Dave, I didn't include wind - I was talking about the big providers. For what its worth I think wind has been grossly overhyped and oversubsidised - and have said so before - while tidal has been overlooked. Too many wind power firms have their snouts in the trough for tidal to get a look in.

I see the Scotsman has jumped on the tidal bandwagon today with a fairly meaningless article about the tidal potential of the Pentland Firth, complete with many column inches devoted to an 'expert' who says it won't work. Why? Well, Tony Trapp spent a lot of public money building over-complex inefficient flapping wing device (the Stingray) which gave disappointing results, so obviously if Mr. Trapp can't do it no-one can!

I don;t think tidal power will require anything like the subsidy wind has been receiveing to cover the r&d and kick start it, but if it does so be it - I still see it as a far more satisfactory technology - once fully developed - from the point of view of reliability, scalability and cost.

Anyway, back to nukes. I know you favour them and speak with considerable knowledge, but I am not entirely convinced that anyone has correctly calculated the nuclear subsidy in terms of the items I enumerated in an earlier post - or even if it is possible to accurately quantify some of them, eg long term waste storage, as a solution doesn't exist yet.

A limited short term nuke programme may be the only way to keep the lights on over the next half century if we are unprepared to reduce energy consumption, but that should be it - they should then be shut down forever as we move to to 100% renewables. What I am very much afraid will happen is we will build new nukes then sit back and not bother pouring resources into renewables because we don't need them. Nukes don't use a renewable energy source, uranium supplies are finite. When the new generation of nukes come to the end of their service life we could easily be in a much worse position than we are now, with a big pile of radiocative sh1te, uranium scarce and no alternative in place.

What an incredibly short-sighted species we are . . .

[Nick]

a covert spend of £5,000,000,000 per annum a bit difficult to hide

That's 5bn in our convenient modern shorthand, isn't it? And 5bn isn't hard to hide these days.

In January this year , the National Audit Office said that the cost of decommissioning ageing nuclear power sites had risen from £12bn to £73bn. CLICKY.Other estimates say it is going to rise even further.

If aggregated over - say - the last 15 years, that would be erm . . . 5bn per annum.

OK, so it might be fairer to aggregate it over the last 40 years, but even so that is nearly 2bn per annum - and this is just decommissioning, long term storage remains an unsolved problem. That's a fair old subsidy I would say.

[DaveS]

A number of points. Firstly, moneys were set aside during operation of the now-closed nuclear stations to pay for their decommissioning. Was it sufficient? I don't know, but probably not. The political decision to set up the NDA with its arms length relationship with assorted contractors was, however, a sure method of increasing costs: think of the railway, where a similarly complex structure means that costs are now triple what they were under BR. Secondly, the point made by one of those interviewed in your reference is quite correct: the early stations were not really designed with decommissioning in mind, and much is having to be learnt as work procedes.

Lessons are, however, sometimes learned. A new nuclear fleet would have ease of decommissioning designed into it, and with certainty of what that would involve, the operators could (and would be required to) set aside sufficient funds to pay for it.

Regarding long term waste storage, this is by no means "unsolved". What is required is construction of a secure underground repository. Some countries, e.g. Finland, have already built one, others including the UK intend to, the only big outstanding issue is where. The requirement for this is not greatly influenced by whether or not there is any new nuclear build: a new nuclear fleet to replace the currently operating stations would add less than 10% to the volume of stored waste. If this seems surprisingly low, consider that the historic power reactor designs produced more waste than would a current model, and the inventory of radioactive waste requiring long term storage also includes military and medical materials.

On uranium stocks: I had a useful reference document for this but can't find it. From memory, annual extraction (mainly from Australia and Canada) is running at a low %age of known reserves, with some mines shut and little prospecting activity due to low prices. Rising prices will change this, but in essence we're looking at centuries rather than decades of supply. If the price rises sufficiently then re-processing will become economically attractive, and using breeder reactors to create new fissile material would make the available fuel supply effectively unlimited.

Interestingly, one cause of the currently low uranium price is the increasing use of ex-warhead material as part of the mix of power reactor feedstock. (Some 30% of the EU's nuclear fuel is currently ex-military from Russia.) This is an aspect of nuclear power that is rarely mentioned: it provides a safe and useful disposal route for nuclear weapons. Swords to ploughshares indeed!

[philiph]

We sailed past the Strangford Lough turbine yesterday morning at about 0800 (tide due to turn about 0900) and the rotors were raised for inspection with some guys working on it. If I knew how to post photos then I would upload the couple we took.

[Nick]

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Pic posting tutorial please.

Re. the Strangford turbines - I am not convinced that adapting wind technology by putting in a few 'o' rings and sticking it underwater is the best way forward - shrouded turbines as per the RTT and the (operating) Race Rocks turbine look like a much more sensible idea to my offshore eyes . . .

[sahona]

http://www.bluemoment.co.uk/phpBB2/viewtopic.php?t=3743

[Silkie]

If I knew how to post photos then I would upload the couple we took.

I've added a post to the FAQ thread.

[Alcyone]

An interesting idea

http://news.bbc.co.uk/1/hi/wales/south_east/7748431.stm

[sarabande]

these people seem to have got another solution worth consideration, and which doesn't rely on diurnal variations of tide height.

http://www.ocees.com/mainpages/otec.html

[Nick]

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Heat pump technology has been around a long time, but no-one appears to be able to scale it up to provide Gigawatt electricity generation. This organisation's proposed power stations are very small-scale:

OCEES International, Inc. utilizes integrated OTEC systems power cycle designs which are scalable and modular for implementation into nearly every tropical island application with suitable access to cold, deep seawater.

Interesting, but probably not a contender in the UK in the forseeable future.

One thing I found puzzling about your post - what is wrong with relying on diurnal variations of tide height, do you know something we don't?