Combined Power Plant: 100 % power from renewable energy - including base load

probe

German experimental electric power plant uses wind, solar, biogas and hydro storage combination to provide 100% renewable energy solution.

http://www.solarserver.de/solarmagazin/anlagejanuar2008_e.html

SeanW

This is old news and I'm sorry to say, not very encouraging. This experiment started some years ago in the University of Kassel. It demonstrated (and perhaps its still running) via a "Virtual Power Plant" controlling wind farms, solar photovaltaic sites, biomass power plants and pumped storage, that they could provide exactly 1/100th of 1% of Germany's electricity requirements at any given time. This would suggest that it was possible to provide exactly 100% of Germany's electricity requirements via renewables at any given time with further investment in renewables.

Unfortunately, such inference avoids some obvious and pertinent questions, regarding the reliability of weather-dependent renewables and energy storage. In the first instance a video about the Kassel experiment, it was claimed that if the sun stopped shining on the solar power plants in one part of Germany, the wind might pick up in another. That's fallacious however, unless there's a causal relationship between increased production in one facility and reduced production in another, (or vice versa) you still have to have alternative provisions to deal with times of oversupply and undersupply from your renewable power plants.

So what happens when the weather doesn't co-operate? There are two planks in the strategy (and this is where the Kassel experiment shows its achilles heel), biomass power and pumped hydro storage. The biomass plank of the plan requires growing corn on a farm adjacent to the biomass processing and burning facility, the Virtual Power Plant can bring the machinery online with the click of a mouse if the grid controller tell V.P.P. crew that it requires more electricity than they're currently providing.
The second plank is pumped hydro. This deals with the problem of oversupply (where the grid has too much power coming in and tells the generators to turn it down before the grid collapses as a result) by using surplus electricity to pump water into a dammed valley. As and when the renewables fall back into undersupply, the water flows from the flooded valley through a generator, providing electricity.

The problem with these plans should by now be obvious - the biomass portion requires a load of farmland to be committed solely to providing electricity, while the pumped hydro requires the country to have some spare mountain valleys which can be flooded.

Now, lets assume that by some miracle, Germany did in fact have all the farmland and unpopulated mountain valleys required for this to be expanded 10000 fold - and the chances of this are so low as to be effectively discarded - the question of "opportunity cost" comes into play. That is, if you commit the land and valleys required to acting as backups and storage for weather based renewables, you lose the opportunity to use the resources for something better. I.E. in the nuclear or fossil fuels scenario, you could use the farmland to grow biofuels for transport (transport is a much more difficult question) and you could set aside the mountain valleys as nature reserves, which, as a (sort of) environmentalist myself) I would be very happy with

In short, there's no avoiding that weather based renewables cannot be relied on. There is no avoiding the fact that complimentary storage is not up to the challenge of acting as a backup. There is no avoiding the fact that for a certain amount of our electricity needs the choice is limited to nuclear vs. fossil fuels.

With that in mind, if I were running Germany here's what I would do - in no particular order:

• Build a bunch of nuclear power plants with fast breeder and reprocessing facilities as required.
• Kick this pathetic experiment out the window and tell the proponents to come back when they have something that works and wouldn't do more harm than good
• Find all the valleys the promoters had scoped out for pumped hydro and declare them Wildlife Refuges (if they are not already).
• Introduce (or expand and refine) a biodiesel energy-crop programme.

probe

>>>if I were running Germany here's what I would do

Fortunately Germany is a relatively democratic country. While it, and the EU, have a long way to go to catch up with the Swiss Confederation in terms of democracy, one suspects that they have had enough of “der Führer” nuclear types like yourself with their nuke agenda to peddle at every opportunity! :-)

Google is probably the largest super computer in the world at the moment. It runs on zillions of networked PCs processors. In the distant past a typical airline would have a big expensive mainframe computer (eg an IBM 360 / 370) to run its reservations system and related operational transaction processing work. Ditto for banks, utilities, and virtually any big company. The mainframe computer reminds me of one of your nuclear power stations. Big and centralised requiring lots of support specialists and very vulnerable to all sorts of risks. Well past its sell-by date.

Energy production is rapidly moving in the same direction. Zillions of small power generation and storage units in peoples’ homes, factories, office buildings, farms, and offshore – all inter-connected in an island and Continent-wide grid stretching from Scandinavia to North Africa.

Even coal has a longer shelf-life (in terms of reserves, if you ignore the issue of paying people to mine it and the pollution impact – CO2 etc) compared with uranium. Nuclear is the worst solution because it is the only non-renewable energy source on the planet (new hydrocarbon sources will most likely form over the next million years or so). Uranium is finite, and requires increasing amounts of energy to refine as good quality reserves get depleted. Nuclear has a short term shelf life, with a protracted installation timeframe, and creates a long terms waste tail that has to be managed for perhaps 100,000 years+ - depending on the isotope in question.

The network diversity of weather conditions between the hot sunshine in the Med / North Africa area, and the wind and wave energy along Europe’s coastline – particularly in Northern Europe, combined with energy storage technologies ranging from updating hydro-power (from a one-way street of conventional hydro-power to the pumped storage two-way street) in mountainous regions like Norway, the Alps (which run from the Cote d’Azur over to Slovenia and up to Switzerland and Austria), the Pyrenees, and other regions. Electric car fleets will provide zillions of GWh of energy storage using capacitors and conventional batteries.

Add to this the increases in energy efficiency of appliances. Eg a 3W LED has about the same light output as a 50W conventional halogen lamp. An SSD (solid state hard drive) in a PC uses a fraction of the electricity of a traditional hard disk. It generates almost no heat (less energy required to cool it and less fan noise). And is several times faster than an HD – Linux, OSX or even Windows is ready to use within 10 to 15 seconds of powering up an SSD equipped PC. SSD encourages the user to power off their PC when they are not using it, instead of leaving it on – because it is so fast to boot up. The same SSD technology can be used in server farms. One example among several thousand of technology improvements that will lead to greater energy efficiency. Not to mention better thermal insulation of buildings and energy management generally.

Switzerland is working towards the objective of becoming a 2,000 W per day society* (they currently consume about 4,900 W pppd). Americans use 10,300 W pppd. The Canadians are even worse with 11,000 W. Japan uses 5,300 W pppd. UAE consumes 14,000 W pppd. Iceland consumes 15,000 W pppd – at least most of it is renewable geothermal energy powering high energy consuming aluminium smelter plants and similar.

*http://www.uvek.admin.ch/dokumentation/00476/00477/01300/index.html?lang=en

SeanW

Fortunately Germany is a relatively democratic country. While it, and the EU, have a long way to go to catch up with the Swiss Confederation in terms of democracy, one suspects that they have had enough of “der Führer” nuclear types like yourself with their nuke agenda to peddle at every opportunity! :-)

Ja Wohl !!!!

The mainframe computer reminds me of one of your nuclear power stations. Big and centralised requiring lots of support specialists and very vulnerable to all sorts of risks.

Not sure if you've ever read any of my posts if you had, you'd know that for Ireland, I advocate the use of Pebble Bed reactors and Toshiba 4S reactors. The "Mainframe" approach is only a good idea in huge market like France where it seems to working OK.

Zillions of small power generation and storage units in peoples’ homes, factories, office buildings, farms, and offshore – all inter-connected in an island and Continent-wide grid stretching from Scandinavia to North Africa.

So where are they? And why, for example, is eco-concious Germany deciding to replace its nuclear plants with the biggest coal fired plant building spree this side of China? What's going on?

in mountainous regions like Norway, the Alps (which run from the Cote d’Azur over to Slovenia and up to Switzerland and Austria), the Pyrenees, and other regions.

Ok, so it's possible that the surplus of mountain valleys do in fact exist. Great. Two problems - 1, the cost of building these things would be insane, and 2, since we assume that there are few/no people living in the god knows how many acres of mountainside land you'd have to flood, it's safe to say that these valleys are currently in use as wildlife habitats. To flood them would kill and/or displace large numbers of animals.

Can you accept the logic of doing this when an alternative plan doesn't require flooding up to 10% of your national landmass, but gives you most of the benefits of doing so?

I also notice that you didn't try to refute my claim that the land required for a large biomass power programme doesn't exist. Do you accept that this is so, and that in any case such lands could be better employed doing things like growing biodiesel crops (the internal combustion engine isn't going anywhere in the near term at least), or again as a wildlife reserve?

Electric car fleets will provide zillions of GWh of energy storage using capacitors and conventional batteries.

Umm ... have a look at the state of the electric car market. The only half decent ones out there are the €100,000 cars, like the Venturi Fetish and the Tesla. Why? I assume it's because they're simply pushing the available technologies, Lithium Ion, to the limit. Li-Ion technology is expensive and extremely filthy, and if I had to guess I'd say there's a hard limit to how much of the stuff is available.

As for alternatives, remember that the closest thing we have to an efficient battery (right now) is the Vanadium Redux Battery. Such implementations are usually in the X number of hudred kilowatt-hours range. There was a proposal to build one capable of holding 12Mw/h (about 10 seconds of Irelands energy needs in peak time) but it was so expensive it would have required an increase in Ireland's already sky high electricity rates. The company making the thing has also had at least a passing relationship with bankruptcy protection.

dahak

probe wrote: »

Even coal has a longer shelf-life (in terms of reserves, if you ignore the issue of paying people to mine it and the pollution impact – CO2 etc) compared with uranium. Nuclear is the worst solution because it is the only non-renewable energy source on the planet (new hydrocarbon sources will most likely form over the next million years or so). Uranium is finite, and requires increasing amounts of energy to refine as good quality reserves get depleted. Nuclear has a short term shelf life, with a protracted installation timeframe, and creates a long terms waste tail that has to be managed for perhaps 100,000 years+ - depending on the isotope in question.

Saying that nuclear is the worst solution because hydrocarbons will naturally form over the very long term and uranium won't is a fairly weak argument.

According to Wikipedia, there are current economic reserves of 100 years at 2006 usage rates. Note that these are reserves at the current economic value of uranium.

From the Wikipedia article:

It is estimated that 5.5 million tonnes of uranium ore reserves are economically viable at US$59/lb, while 35 million tonnes are classed as mineral resources (reasonable prospects for eventual economic extraction). An additional 4.6 billion tonnes of uranium are estimated to be in sea water (Japanese scientists in the 1980s showed that extraction of uranium from sea water using ion exchangers was technically feasible)

Also from the Wikipeda article:

Some claim that production of uranium will peak similar to peak oil. Kenneth S. Deffeyes and Ian D. MacGregor point out that uranium deposits seem to be log-normal distributed. There is a 300-fold increase in the amount of uranium recoverable for each tenfold decrease in ore grade." In other words, there is little high grade ore and proportionately much more low grade ore available.

This also totally ignores breeder reactors, which recycle and reuse uranium and other nuclear materials such as plutonium and Thorium. Thorium itself is much more common than uranium, and is distributed well across the world. The thorium fuel cycle starts with Th232 and converts it to U233.

There are good reasons to not like Nuclear energy, the potential of running out of fuel in the medium term is not one of them.

Shiny

I don't see why people even bother arguing the case for Nuclear in
Ireland. As our wind penetration increases, what use will a nuclear
power plant be when it takes hours/days to lower its output?

SeanW

Shiny wrote: »

I don't see why people even bother arguing the case for Nuclear in
Ireland. As our wind penetration increases, what use will a nuclear
power plant be when it takes hours/days to lower its output?

I mean no disrespect Shiny, but do you know anything about wind power? Or nuclear power for that matter?

Because you should know that the wind is not constant, and thus output from any give group of wind turbines will rise and fall and can do so at any time.

Eirgrid maintains a history of estimate wind turbine power yeilds nationwide, as well as a record of our national power demands.
http://www.eirgrid.com/operations/systemperformancedata/windgeneration/

As for nuclear power taking "hours/days to lower its output" that only applies to traditional large nuclear facilities, the upcoming Pebble Bed and Toshiba 4S small nuclear designs are much more flexible and could easily compliment a large group of wind farms.

probe

While Wikipedia is often a useful source of basic information, I don’t think I would use it as a basis for strategic planning for a country’s energy resources. Unprovable “facts” like reserves of stuff in the ground, political, personality, and many other topics are often exaggerated on the high or low side by people who have ideological or vested interests. Wikipedia is a curate’s egg on “facts”.

The European Commission “energy green paper” (2001) (misnomer: nuclear is not green) estimated annual consumption of uranium to be some 67,000 tonnes and reserves to be 2.8 million tonnes. Which = 42 years. You might add another few years to that for military uranium no longer required, being recycled and made available for energy use, at least while Obama occupies 1600 Pennsylvania Ave, [putting aside for a moment the awful spectre of war mongering Bush’s partner in global terror, bomber Blair, with his eyes on the presidency of the EU].

Most countries that don’t have Ireland’s wind, wave and other renewable resources, and therefore are lining up to buy nuclear reactors as a short/medium term expediency. Areva has an order backlog worth some EUR 50 billion for nuclear power plants. Countries with big populations such as China, India, Iran, and similar are energy hungry with growing appetites, and shaking every tree in the jungle of energy for fruit. A doubling of nuclear power plant capacity might cut your 2001 reserve estimate to 20+ years ignoring military recycling. Being generous and realistic, you are really talking about a 30 year odd time horizon for nuclear’s shelf-life. Even allowing for everyone updating their plant to the latest technology almost overnight (which is impossible in reality), there is less than 50 years – probably 40 years at a push, left.

As for uranium in the sea, there is lots of gold in the sea too …… 0.006 mg/tonne of sea water in the Mediterranean. About 50,000 tonnes of gold in total in the Med alone. However it takes a lot of energy to pump a tonne of sea water to extract 0.006 mg of gold (aside from refining costs/energy consumption etc). Even with gold’s price of EUR 25,000 per kg at present, it will never happen. The market price of uranium is typically just over EUR 100 per kg.

There is about 3.3 mg of uranium in 1 x m3 of water – ie 1kg of uranium in 303,000,000 litres of water. World production of uranium at present is about 43,853 tonnes. If you were to get that from the sea, you would have to pump 13,288,774,590,000,000 litres of water into your extraction systems and out again.

That would require a lot of energy just to do the pumping. 1 kWh of electricity can pump about 2,400 litres of water for 100 m vertically (eg sucking water into your U boat (see below for details of “U” boat) processing farm from 100 m depth). A similar amount of electricity might pump it 200 m in from a sea collection point to a land based processing facility. Not very far. Assuming you are paying 9c per kWh (French electricity prices – half that of the ESB), your water pumping bill would be about EUR 500 billion. – which is about EUR 11,000 per kg of uranium produced for single stage electricity for pumping alone! That assumes your processing plant requires no internal pumping, and the processed water flows back into the sea by gravity. The current market price of uranium is under $200 per kg. If your uranium is that expensive, the electricity used to pump your water will cost far more than 9c per kWh. This puts you in a vicious circle of electricity costs to create the uranium to pump the water, to create new uranium.

Let’s assume for a moment that you put an uranium extraction plant in Ringsend (a likely scenario in a country where people are intolerant of garbage to energy incineration – a technology that is accepted and used in most European countries). The water in Dublin Bay and beyond would become depleted of uranium. Unless the uranium extraction plant is located somewhere on a global sea current highway where the water is constantly changing and circulating. Your uranium from sea extraction kit might really need to be on board a floating vessel (fishing for uranium), in search of “fresh fish”. (You might call them “U boats” from the chemical symbol for uranium!) Building that extraction kit into a mega fleet of ships, and providing the on board energy they would require to operate, and move the unrefined uranium to land, refine same, etc etc would cost mega zillions. Totally uneconomic, forever and a day, I suspect. Aside from the other realities of why they haven’t bothered to extract the 50,000 tonnes of gold from the Med – where the water only changes every 50,000 years or so. Sitting duck gold!

Moving back to Toshiba’s proposed 200 kW fully automatic micro nuclear reactor for “the bottom of your garden” – roll this kit out all over the place, and even with a small probability of accidents, faults, etc (ie technical issue which turns into a “nuclear fallout” type story in 300 pt type in the tabloid newspapers) there would be no shortage of news generated by even minor issues. Anyway you are still faced with two key issues.
1) Your Tosh radiation machines still need the nuclear raw material – lots of it, and economically recoverable reserves are limited.

2) It would be a brave politician who would sign-off legally on rolling this “super safe, small and simple” technology out all over a country. Try getting the planning application for a house or apartment building with its own nuclear power plant through a local authority, and past ABP.

I’ll stop at this point – one could go on, and on.......

dahak

probe wrote: »

While Wikipedia is often a useful source of basic information, I don’t think I would use it as a basis for strategic planning for a country’s energy resources. Unprovable “facts” like reserves of stuff in the ground, political, personality, and many other topics are often exaggerated on the high or low side by people who have ideological or vested interests. Wikipedia is a curate’s egg on “facts”.

While Wikipedia is should never be used as a sole source of information on a subject, trying to tar all the information contained within as unreliable is unfair.
There was no suggestion that Wikipedia should be used for the 'strategic planning for a country’s energy resources'. I agree with you that it's a good source for basic information, this is because it gives links to the the references that the articles are based on. There can be a large degree of variability in the quality of the Wikipedia articles, however you can't write off all information presented there with a wave of the hand.

probe wrote: »

The European Commission “energy green paper” (2001) (misnomer: nuclear is not green) estimated annual consumption of uranium to be some 67,000 tonnes and reserves to be 2.8 million tonnes. Which = 42 years. You might add another few years to that for military uranium no longer required, being recycled and made available for energy use...

I'm not sure if you meant the 'misnomer: nuclear is not green' comment in jest (referring to the green paper), but a EC green paper is a discussion document. The full list of EC green papers can be found here. Looking at this list I could not find a title which matched your reference, the closest I could find was:

Towards a European strategy for the security of energy supply
Brussels, 29.11.2000, COM(2000) 769 final
http://ec.europa.eu/energy/green-paper-energy-supply/doc/green_paper_energy_supply_en.pdf

This document is a 111 page green paper on energy security in the EU. The section that discusses uranium supply is four paragraphs. It should also be noted that when they talk about reserves that are economically recoverable at a price of US$ 80/kg.

http://ec.europa.eu/energy/green-paper-energy-supply/doc/green_paper_energy_supply_en.pdf
Towards a European strategy for the security of energy supply (page 20)

The world has two and half million tonnes of known uranium reserves (uranium being the only part of the nuclear fuel cycle in which the Union is not self-sufficient) at a market price lower than US$ 80 a kilo, representing 40 years' demand at present rates of consumpt ion (the current market price is around US$ 20 a kilo). Further known resources come to about 850 000 tonnes (corresponding to 15 years' demand) at the same price and are mainly located in Australia, Kazakhstan, Uzbekistan and Canada.

The European Union, for its part, is home to barely 2% of the world's natural uranium reserves (i.e. 52 000 tonnes) at a price lower than US$ 80 a kilo but production will shut down around 2005 in France and Portugal. Europe's uranium mines have closed principally because the deposits have been exhausted and it is expensive to extract relat ive to the world price, and because world physical stocks of nuclear fuel are very high.
Origin of uranium imports used in the Union.

More uranium could be made available, but only at a higher price. There are in fact non convent ional reserves which would be sufficient in the long term. But this would have little impact on the cost of electricity per kilowatt/hour, since it would concern only a very small part of total production.

The recyclable nature of the used fuel accounts for the promising outlook for reserves. Nuclear fuel differs from other primary energy sources in that fission products can be recycled, proportionately reducing import requirements. Once separated from their waste products (amounting to around 4%), both recovered uranium and plutonium can be used again to generate more electricity (96%). Material obtained from the decommissioning of nuclear weapons can also be recycled as nuclear fuel.

It should also be noted that these figures are from nearly 10 years ago. The Uranium resources and reserves section that I linked to on Wikipedia article uses a World Nuclear News article as one of it's sources. This was a news report on the publication of 'Uranium 2007: Resources, Production and Demand' by OECD Nuclear Energy Agency (NEA) and the International Atomic Energy Agency (IAEA). While the 2007 version of this document is unavailable without paying for it, the 2003 version is available online.

I suspect that the EC green paper uses an older version of of the Uranium : Resources, Production and Demand publication, this is unclear as it gives no references for this, unlike the wikipedia article.

probe wrote: »

A doubling of nuclear power plant capacity might cut your 2001 reserve estimate to 20+ years ignoring military recycling. Being generous and realistic, you are really talking about a 30 year odd time horizon for nuclear’s shelf-life. Even allowing for everyone updating their plant to the latest technology almost overnight (which is impossible in reality), there is less than 50 years – probably 40 years at a push, left.

I have a number of problems with this paragraph so I'll go through them in order:

• As I stated above the figures that you used are 10 years old and do not fit with figures presented from the 2007 NEA/IAEA report.
• The 2.5 million tonne figure used in the EC green paper is an economic reserve based on a uranium price of less than US$ 80/kg. As the price of uranium goes up so do the economic reserves.
• You, whether purposely or not, totally ignore reprocessing (apart from a token military amount). The EC green paper has the following regarding reprocessing

  Once separated from their waste products (amounting to around 4%), both recovered uranium and plutonium can be used again to generate more electricity (96%). Material obtained from the decommissioning of nuclear weapons can also be recycled as nuclear fuel.

• You also totally ignore the Thorium fuel cycle of where there are considerable reserves.

The cost of mined uranium is also a relatively small percentage of the cost of the generated electricity. The cost per kWh of of uranium including the enrichment process is relatively low, at around US$ 0.005/kWh, (see break down of figure below), with the mined uranium being about half of that. So a doubling or tripling of mined uranium price, while increasing electricity price does at a low ratio.

http://www.world-nuclear.org/info/inf02.html

Areva figures early in 2008 showed 17% of the total kWh generation cost for its EPR being fuel costs, and these broke down: 51% natural uranium, 3% conversion, 32% enrichment, and 14% fuel fabrication.

In January 2007, the approx. US $ cost to get 1 kg of uranium as UO2 reactor fuel at likely contract prices (about one third of current spot price):

Uranium:		8.9 kg U3O8 x $53	US$ 472
Conversion:		7.5 kg U x $12		US$ 90
Enrichment:		7.3 SWU x $135		US$ 985
Fuel fabrication:	per kg			US$ 240
Total, approx:					US$ 1787

At 45,000 MWd/t burn-up this gives 360,000 kWh electrical per kg, hence fuel cost: 0.50 c/kWh.

If assuming a higher uranium price, say two thirds of current spot price: 8.9 kg x 108 = 961, giving a total of $2286, or 0.635 c/kWh.

probe wrote: »

As for uranium in the sea...

Your figures for extracting of uranium from sea water by pumping seem to be accurate (I didn't go through them line by line). You are correct that an uranium extraction system that uses pumps to pass water over an extraction surface would have astronomical costs.

However this is not the suggested way of extracting uranium from sea water. Japanese scientists have developed 'Fabric-Adsorbent' that is placed in cages submerged in sea water.

Research was published last year with cost estimations of this method. They ranged from US$ 900/kg to US$ 280/kg with a possibility of US$ 167/kg of uranium. As already stated above the cost of mined uranium is a relatively small part of the cost of electricity generation.

probe

The nuclear lobby have taken this thread completely off topic. Nuclear has nothing to do with green or combined power plants. They should start off a nuclear power topic for this propaganda!

Anyway, the idea of ocean based uranium being refined on a scalable basis does not compute in my books, even if you remove the need to pump large quantities of water from the equation. To look at a few aspects:

You hang a “lobster pot” (a yellowcake collecting cage), weighing about 118kg in the ocean for 8 months. The cage contains 52,000 sheets of uranium specific non woven fabric (no doubt these cages are available in Wal Mart for under $5 each), and you end up with about 1 kg of yellow cake (not processed uranium), which has to removed, carefully extracted from the 52,000 sheets of collectors in the cage, refined into usable fissionable material, bla bla bla.

Even if you had 52,000 sheets of ordinary paper (ie 104 packs of 500 sheets) and had to remove an animal’s hair, or something similar, from between each sheet of dry paper, (using machines or by hand), it would be a non-trivial, expensive task. One suspects that removing the yellowcake collected from the fabric is even more tedious/complicated and prone to yield reductions. Perhaps you would like to put on a pair of rubber gloves and try the job out with a few dozen cages that have been in the sea for 8 months :-)

With a current annual demand of 67,000 tonnes of processed uranium, that would imply you need 67 million cages submerged in the ocean for 8 months to replace land based resources when they run out economically (assuming zero processing loss, which would not be the case in reality). To meet the future energy demands of China, India and most of the rest of Asia (not to mention Africa), you will need a lot more than 67 million cages to get this show on the road on a “sustainable basis.”

You are going to have to hang these lobster pots in the sea. This suggests that you will have to suspend them off massively large structures when you scale it up. The Öresund bridge (E20) between Copehagen and Malmö, the longest road/rail bridge in Europe, is just under 8 km long cost about EUR 4 billion in 2000. Let’s assume that you hang your U “lobster pots” every 33 cm underneath the bridge (ignoring pylons and other things reducing the cage density), you would get 3,000 collectors per km of bridge. That is about 20,000 cages hanging off your EUR 4 billion bridge, adding about 2,400 tonnes to the weight of the bridge - excluding the mooring chains and related hardware. That would imply about 22,000 km of bridge type structure to hold 67,000,000 cages. A trans-Atlantic bridge would be about 6,000 km long and would be an incredible engineering challenge, to put it mildly. Denmark to Sweden is relatively easy to bridge between. In 2015 let’s say the bridge cost is a billion per km (which is cheap in terms of Irish construction costs). One wouldn’t get much change from EUR 25 trillion for the hardware to suspend these uranium collecting cages. A lot more for trans-Atlantic type structures.

Even after setting up all this hardware to mine yellow cake from the seas, you have to either create a mechanised system to empty the cages, refurbish them, and replace them every 8 months. You can’t throw yellow cake into a nuclear power plant, like throwing coal on a fire. It has to be refined, and only about 0.7% of the weight of the gross amount of yellow cake going into the refinery ends up as fissionable material.

The low marginal cost of uranium to electricity is well established. However it is missing the point. Once you have extracted the easy to refine yellowcake (be it on land or in the sea – if there is such a thing) you end up with material residues that consume more energy to collect, process and refine, compared with what they yield in electricity. No different to connecting an electric motor to power a generator, to generate electricity. The electric motor would consume more electricity than the generator would produce. A pointless contraption!

From the human health perspective, even France is getting worried about nuclear. A TF1 main evening news (20h00) item about a month ago (from memory) suggested that some 5,000 people working with nuclear materials in French generating stations will face premature death, and this was apparently known to gouv.fr for some considerable time. Factor in the litigation risk costs on top of everything else, putting it coldly.

The FI-Olkiluoto nuclear plant has been under construction since Jan 05 and it looks as if it won't now be ready until 2015 or thereabouts. A long lead time for a tiny 1.6 GW plant (in terms of global demand for energy). It is one of the few nuclear power plants under construction in the world, and the only third gen plant. The Finns have the resources of Areva and Siemens behind this project.

Nuclear is a massive scalability challenge everywhere one looks. In contrast Germany and Spain each added about 3.5 GW of PV solar capacity in the three years to 2008.

SeanW

probe wrote: »

The nuclear lobby have taken this thread completely off topic. Nuclear has nothing to do with green or combined power plants. They should start off a nuclear power topic for this propaganda!

But don't you see? Nuclear/Coal has EVERYTHING do with your "Green" or "combined" power plants.

The central claim of the Kassel experimentors was that the problem of instability inherent in weather-based renewables could be dealt with by

1. Assuming that when one site starts to deliver too much or too little, another site might be doing the opposite.
2. Excess power could be stored in flooded valleys via pumped hydro.
3. Biomass farms could be used to begin generating power quickly.

It is my contention that 1. is total nonsense, and 2. and 3. both have problems of scale (i.e. could these be multiplied 10,000 times in Germany alone) and opportunity costs. That is, if by some miracle, the land and mountain valleys required, to commit them to service in your "Green" power plant, you lose the opportunity to use them for some other - potentially more deserving - purpose. For example, the mountain valleys if not yet populated, are currently in service as wildlife and nature reserves. Flooding them would destroy the reserve and potentially kill a large amount of wildlife and permanently displace much more. The farmland for use with biomass if it exists, could itself also be commited to nature, or used to grow transport biofuels, or any number of other worthwhile uses.

For the Kassel experiment to pass the "Opportunity Cost" test, three things would have to happen.

1. The test would need to be takeable, i.e. the land and valleys needed to serve a national distributed power plant would have to exist. (Doubtful)
2. There would need to be no superior use for the land and valleys. (Not a chance)
3. The resulting renewable power generation would need to be the best way to produce electricity, superior by a wide enough margin to justify any losses incurred in Test No.2. (I don't think so)

You have never seriously contested 1. never contested 2. at all, and it is my contention that with nuclear option, 3. also fails.

Ironically, Germany almost agrees with me (link to Der Spiegel). You've ignored that BTW, as do most anti-nukes here, for some inexplicable reason.

Anyway, the idea of ocean based uranium being refined on a scalable basis does not compute in my books, even if you remove the need to pump large quantities of water from the equation. To look at a few aspects:

I don't know enough about Uranium from the sea to discuss this but you are ignoring some key points:
1) You've totally ignored the Thorium fuel cycle.
2) You've totally ignored the issue of nuclear fuel reprocessing - most Uranium is used on a once-through basis despite being reusable at least once. Very wasteful in my opinion.

Nuclear is a massive scalability challenge everywhere one looks.

Not where small scale and nuclear-battery technologies are used.

In contrast Germany ...

is going on a coal-fired power plant building spree the likes of which cannot otherwise be seen outside of China. This is ALL being done at the behest of anti-nuclear "environmentalists."