Beginners guide to nuclear power stations ?

Edukator – I’ve just put two and two together – you’re not in the UK are you?

true about the Govt subsidies molgrips, but they subsidize the building of power stations anyway. without them nuclear power stations wouldnt be economically viable. id rather see these subsidies going to uk residents then offshore power companies.

You provided the pump storage capacity yourself, aracer. France, Germany and Spain are already on target (or ahead of target in the case of Spain and Germany) for achieving 20% renewables at current consumption levels by 2020 and 25% by 2030 is not unrealistic. I’ve stated a 75% reduction in domestic consumption is achieveable and more than proved it to myself. I’m equally certain that the companies I’ve worked for could achieve savings greater than that.

I worked in a factory where the main energy cost was “cold”. The food industry has to keep things cool and heat things up. Between insulating the buildings, using heat exchangers to simultaneously heat some things whilst cooling others and powering the lot with solar panels on the huge roof area the plant could have become pretty much self sufficient.

My proposals were turned down on cost grounds of course because with nuclear electricity being sold at a fraction of it’s long term cost in France energy saving is not a company’s priority. charging the real cost of nuclear electricity is not going to happen in France where cheap energy for French industry is a political choice to help competetivity. The group I worked for also had factories in Germany and Italy which cost more to run simply due to energy costs.

They can hardly just cut subsidies just like that, can they? Esp if business models depend on it and decommissioning costs as much as running.

EDIT: Re refrigeration – I always thought it would be useful to have a fridge vented to the outside by means of a valve. Then, when it’s cold you could simply draw air in from outside. Anyone know if industrial plants use this?

The factory I worked in had the heat exchangers outside. I pointed out that in winter it would be better to use the heat to heat the offices rather than the outside air but the engineer in charge just gave me a dirty look.

France, Germany and Spain are already on target (or ahead of target in the case of Spain and Germany) for achieving 20% renewables at current consumption levels by 2020

I’m assuming that’s based on the usual “peak capacity” BS numbers the renewables lobby used, the actual contribution being much smaller.

I’m far from being against making an effort – your ideas for the factory sound great, and it is a shame that energy is sold for less than its real cost, so making these sort of schemes unviable.

Still to be convinced the real figures add up – you realise that we have very little inherent hydro capacity in the UK (ie not many places we could build any more), and already use all our pumped storage capacity to cover changes in demand, so there’s not really any spare to cover changes in generation capacity if we go for lots more renewables. Even 25% renewable is only feasible if there is 75% from other sources, not if it suddenly becomes 100% due to decreases in demand (which simply aren’t going to happen on that scale).

Edukator – Member

The factory I worked in had the heat exchangers outside. I pointed out that in winter it would be better to use the heat to heat the offices rather than the outside air but the engineer in charge just gave me a dirty look.

LOL

Nope, not peak, aracer. Simply the proportion of energy produced from renewable soureces.

As mentioned in previous posts pumped storage is only one strategy to iron out demand peaks. In Italy they have intelligent meters and consumers soon learn to run the washing machine, dishwasher, immersion heater, electric heating and anything else that can be deferred when it costs less off-peak.

In France you can sign up to a scheme wher you get very cheap electricity except when demand is high – you then pay a small fortune. The people that sign up just organise their lives so that they don’t consume when it’s expensive. The roast gets replaced with a microwaved lasagne that week..

Still to be convinced the real figures add up – you realise that we have very little inherent hydro capacity in the UK (ie not many places we could build any more),

That’s totally wrong, there are new hydro schemes being built all the time, in fact there is a recent rush for them as was on the news recently. Expect to see more run of river rather than stonking huge dams though.

As I understand it the current pretty stable UK 60GW will need largely need replacing in the next few decades as plants reach the end of their lives, and with the increase of use of renewables this will have to increase to something like 100GW to cover the times when the wind ain’t blowing etc.

In the absence of things like renewable energy storage technology this does leave room for nuclear or fossil , CHP etc. The true costs of nuclear are really not known though – look at the cost of decommisioning Dounreay alone, rising by billions every few years and going to take long enough to keep people in a job for life.

We need a good crisis like falling out with Qatar or something bigger to make people realise how much energy they use to make people use less – pestering people to unplug their phone chargers ain’t enough.

there are new hydro schemes being built all the time

Yeah, but only little ones.

Edukator – you going to answer the question about where you live to generate 3300kWh a year from solar? From your other answers I think we can safely assume not the UK.

the proportion of energy produced from renewable soureces.

Fairy nuff – quite impressive if so, but it still doubtless suffers from the unreliability problems of current renewables, which means that almost the same amount of conventional generation capacity has to be kept online as backup.

As mentioned in previous posts pumped storage is only one strategy to iron out demand peaks. In Italy they have intelligent meters and consumers soon learn to run the washing machine, dishwasher, immersion heater, electric heating and anything else that can be deferred when it costs less off-peak.

Which is all very well for smoothing out normal demand peaks, not so good for getting rid of consumption when the wind doesn’t blow – I don’t suppose people will be too impressed at being told they have to wear dirty clothes, eat of dirty plates and sit in a cold house because there’s a big high pressure area sitting over the UK.

Which is all very well for smoothing out normal demand peaks, not so good for getting rid of consumption when the wind doesn’t blow – I don’t suppose people will be too impressed at being told they have to wear dirty clothes, eat of dirty plates and sit in a cold house because there’s a big high pressure area sitting over the UK.

I realise there’s a touch of devil’s advocate going on here, but even so this is grasping at straws.

Are these really insurmountable problems? More difficult to deal with than the problems of nuclear waste?

I seem to remember (on several occasions) you berating others for raising their strawman arguments, but you’re doing the same.

No one (other than you) has suggested that there will be times with no power whatsoever available, but even so, I for one am prepared to step up to the parapet and offer to hand-wash my dishes if that means we can avoid the next wave of nuclear power stations in this country – OK?

Aracer – use hydrogen as a way of storing the energy? – use excess electricity to make hydrogen by electrolysis when the wind blows, sun shines and the tides run high and use that to make electricity when the wind don’t blow and the sun don’t shine?

You also need tidal stuff to help provide a steady base load – one each side of the country to ensure continuous generation

I realise there’s a touch of devil’s advocate going on here

Not at all – it’s a perfectly serious point.

Are these really insurmountable problems?

The wind not blowing and the sun not shining for a few days are pretty awkward if you’re basing your whole energy supply on (current) renewables. There simply isn’t anywhere near enough storage to cope – remember it’s already almost fully utilised anyway.

There might not be no power available at all, but it will be little enough that if there’s domestic supply at all there will have to be some sort of pricing mechanism making it very expensive to use at such times – so the poor will have cold homes if using electric heating, the middle classes won’t be washing clothes (the alternative being blackouts as everybody tries to switch stuff on and the grid can’t cope). It’s not a strawman at all because it’s basic cause and effect rather than an extreme situation which won’t happen. Unfortunately your laudable offer to make the deep sacrifice of handwashing dishes won’t be quite enough to solve the problem.

More difficult to deal with than the problems of nuclear waste?

Possibly, yes, given I’ve not seen a sensible solution put forward – the usual answer being lots of handwaving and assuming we’ll come up with something later (actually a remarkably similar problem!)

use hydrogen as a way of storing the energy?

Nice idea – using renewables to generate hydrogen is definitely one of the better things to do, though better used to replace oil for road transportation rather than power generation IMHO. Give me some figures to suggest it might be anywhere near feasible – given it doesn’t seem to be used at all at the moment suggests to me it’s impractical until proved otherwise.

You also need tidal stuff to help provide a steady base load – one each side of the country to ensure continuous generation

Where are you putting these tidal generation stations? If you’re going to suggest the Severn, then we’re going to have a big disagreement – definitely destroying habitat and a natural wonder has to be far worse than any theoretical risks due to nuclear. In fact I’d happily have a nuclear station in my back garden rather than put tidal barrages on the Severn. In any case you’ll still need to provide me with some figures to prove that’s enough (and that there’s anywhere useful to put tidal generation on the East coast).

I feel the need to point out as always that I’m far from against renewables, and very much in favour of decreasing our energy consumption. I’m also convinced that at some point renewables will be developed which are both practical and economic to replace the whole of our current generation system. We’re just not there yet – a new generation of nuclear might just tide us over until we are.

Aracer – hydrogen?

there is a small scale plant running on Unst IIRC wind power with hydrogen storage for smoothing

OK – I hadn’t realised it was being used at all. You suggest small scale though – any idea how scaling it up is likely to work?

Tidal – ~corryvraken and dornoch sorts scotland 🙂 Maybe a bit of minch to export to england.

You can generate from tidal without barrages – large scale trials going on in the north of Scotland at the moment.

figures? I don’t know. I fear with hydrogen you would need some seriously big tanks – or some form of local distributed storage.

Tidal definitely can be a part of the solution.

Oops, sorry I didn’t answer the question aracer. I’m a frog living at 43°N with 1850h of sunshine a year.

Taking Europe as a whole then the lack of sun or wind in any one area for a few days is not an issue. We need to view energy on a continental basis. There’s not much point having solar panels in northern Scotland or windmills in Aquitaine. However, windmills in northern Scotland and solar panel in southern France or Spain are perfect. A solar water heater is viable in the UK.

I for one am prepared to step up to the parapet and offer to hand-wash my dishes

Lol, if only this was about the luxury of dishwashers!

Hospitals, factories etc aren’t important then?

Plus not sure we could generate and store enough H for two weeks of still weather in winter…

large scale trials going on in the north of Scotland at the moment

That’s wave energy, is it not?

Link to unst project

The PURE project consists of two 15kW wind turbines. It has a 3.55Nm3 per hour high-pressure hydrogen electrolyser, high-pressure hydrogen storage, and a hydrogen dispensing facility to fill hydride cylinders. The cylinders are used in a fuel cell/battery hybrid vehicle and other hydrogen applications as an alternative to fossil fuels.

A back-up power supply was also installed. This takes the form of a 5kW fuel cell and an inverter. The hydrogen used by the fuel cell is produced from the electrolyser. The inverter was installed to convert the output power of the fuel cell from Direct Current (DC) into mains equivalent Alternating Current (AC).

A battery based electric vehicle was converted to run with a hydrogen fuel cell. This electric/fuel cell hybrid car is now fuelled exclusively by the PURE system, using hydrogen produced from the renewable source. This makes the electric car one of the only 100% carbon free vehicles on the British roads.

renewables…. yawn……

arguments are weak at best…. feebly technologies with v short lifespans for wind turbines, photovoltaics (sure the cells last but there performance falls off dramaticaly past yr 20 and then all the control infrastructure, inverters, fieldwiring etc falls to bit + becomes technologically obsolete….) to produce comparable outputs to large generating plant ever thermal or nuculear you have to have a difuse system with v high maintenance and lifecycle costs

they have a place in the mix (especially when they benefit from incentive schemes like RHI & FITs…..)

but they are not the magic cure that the green lobby claim

T1000 – Member

renewables ………..
but they are not the magic cure that the green lobby claim

Nope – but along with serious work on energy conservation it could get us a long long way

TJ Pure project is V laudable but despite it’s claim it’s going to have to travel a long way before / if ever it will ever be carbon free…it’s likely to wear out 1st…. it and it’s supporting infrastructure have a created a substaintial carbon burden during manufacture…

real answer is reduction….

You can generate from tidal without barrages

Of course you can. I knew that 😳 I’ve seen a bit about what they’re doing with that and it looks promising – certainly far more worthy of plowing money into than windmills. Still not sure there’s quite enough to provide the required base load, but happy to be proved wrong. The bigger problem right now is it’s not mature, hence we still need the nukes to fill the gap.

I fear with hydrogen you would need some seriously big tanks

Exactly my thoughts. Thanks for the link to PURE – looks like just the right sort of way of using renewable power as I suggested, though far from being a model to power the whole country.

That’s wave energy, is it not?

Nope – undersea tidal as TJ suggests (and I had forgotten about). Stick a turbine in a tide race (where you have large tidal currents). Wonderfully reliable energy, little impact on the environment if done right, just a little problematic because it stops twice a day.

but they are not the magic cure that the green lobby claim

They don’t claim that.

The anti-greens claim that the greens do though, to save having to have a real argument.

How many greens are pro nuclear for this very reason?

Reduction is indeed the answer.

Just a thought – if you install PV on your house, how much energy is wasted stepping it up to 240VAC to send it down your walls simply for it to be turned back to low voltage DC in your telly/computer etc?

I think they hydrogen generation for smoothing load and capacity is a well worth working further with. this is a new tech,

Fuel cells are a big issue tho – expensive and complex to make with rare earths and stuff in ’em. By no means carbon free. Might be better to use it to run gas turbines on a large scale You can switch them on an off fairly easily?

Every step you do incurs significant losses. I suspect the amount of hydrogen you can store might be a limiting factor as well.

molgrips – Member

Just a thought – if you install PV on your house, how much energy is wasted stepping it up to 240VAC to send it down your walls simply for it to be turned back to low voltage DC in your telly/computer etc?

Lots

How many greens are pro nuclear for this very reason?

A surprising number.

I think fuel cells are much more efficient than gas turbines for H power generation.

Problem with H is very low energy density and problems with storage, but you knew that of course.

I reckon the future is:

Massive cuts in energy usage
Electric renewably powered trains everywhere
Electric taxis for end points
Everyone works from home who can on computers powered by PV
Foreign holidays by sailing ship – doesn’t matter if it takes 2 weeks, you can work on your way there
Local power generation from whatever’s available including biomass
Algal biodiesel or cellulosic ethanol for transport that can’t be electrified
Nuclear solely for the factories and hospitals etc.

Lots

Exactly. Wouldn’t take much for electronics goods manufacturers to whack an extra socket on the back of their machines would it, for a DC feed?

If the wind / hydrogen only works small scale how about on a per building basis? Scale it up that way.

More difficult to deal with than the problems of nuclear waste?

This isn’t particularly difficult. Keeping it buried within easy reach if it needs to be got at is one idea which seems to work well for just about everyone to date. Digging a very deep hole in a geologically safe area is another. It’s hardly rocket science.

The idea of renewables is laudable, and home generation definitely has a way forward. However, have a look at ’embedded energy’ in terms of PV cells in particular – they often take more to make than they’ll ever produce, especially in cloudy places like the UK.

As for energy saving – well, it’s great, but you won’t convince many people of the need without being voted out of power; with the opposition being voted in with a mandate to reduce restrictions. Most people simply don’t understand the many reasons for reducing consumption, and will simply blame any regulation on the government and ‘another tax’.

Also, We’ll need to make significantly more than 25% of our electricity, even with 75% reduction in consumption. As said, industry is a much begger user, as is transport. The push to ‘clean’ electric cars is an obvious example that we can expect electricity usage to increase, even if energy use overall decreases.

And no, nuclear fission isn’t the final answer, but it’s all we have for now that’s capable of generating low-CO2 energy. Ironic that had there not been massive cuts in its funding after TMI and Chernobyl, we’d probably have some much more developed designs by now, even maybe nearer fusion.

Food for thought: I wonder how many people were killed by the oil refinery explosion in Japan vs the nuclear disaster….

Not all our buildings are on Shetland mind. That’s one of the windiest places in the world isn’t it?

Wind gets very tricky in cities.

But I do agree local power generation is vital, if only to avoid grid losses. Even stuff like CHP is a big improvement logically.

To be honest, I am pro nuclear. The damage done by emissions of all power stations to date pales in comparison with that done by fossil fuels.

The occasional accident isn’t going to bugger up the world’s ecosystems or starve millions of people, I don’t think.

Just a thought – if you install PV on your house, how much energy is wasted stepping it up to 240VAC to send it down your walls simply for it to be turned back to low voltage DC in your telly/computer etc?

inverters are about 93% efficient these days. However the length of cable run [can be offset by cable thickness of wire] contribute to voltage drop. The longer the run the more this drops. Thicker wire offsets this but not sufficiently.
Imagine the cable looses 0.12 volts per metre so at 20 metres we have either 12.7 volts reduced to 10.3 volts or 240 volts reduce to 237.6 volts.
so we loose about 18 % first example and about 1% in the later. The amps also affect this as this is a simplified version but you get the gist

For the same reason the national grid and pylons send the voltage at huge volts to reduce this loss.
http://www.tlc-direct.co.uk/Book/4.3.11.htm
for proper calculation

You may loose more by not doing this. I suspect the runs in a standard house are sufficiently long for voltage drop to be a significant problem. I lived from 12 volts for a few years and had to do this with a wind generator and convert to 240 and send to 240 – 12 volt charger due to voltage drop.
HTH
PS Computers need a stable 12 volt supply you cant run them from a 12 v battery as the chip is sensitive to voltage fluctuation and breaks :oops:.

Computers need a range of voltages iirc. And you woulnd’t be running it from a 12v battery, you’d use a 24v or more battery and a voltage regulator.

But yes I am aware of transmission losses etc, which is why I put it as a question – wasn’t sure which was worse not having numbers. Cheers 🙂

I’m tempted to ask the mods to split this sub-thread off. Has turned into the most reasoned and civilised debate I can recall ever having about renewables and energy consumption on here, with general agreement from people normally on opposing sides. Not very much about nuclear any more. Well done chaps.

the trouble is that even if we started building nuclear power plants today (ignoring the many many pro and con arguments) they are not going to come online fast enough (20yrs from plan to production) to meet the looming energy crisis.

i think this makes the nuclear argument more or less moot

i think this makes the nuclear argument more or less moot

Only if you assume we somehow won’t need them in 20 years time (only actually 15 years for the last one we built – half of which before construction started in political wranglings).

If you spend as much as the proposed nukes on a mix of renewables, storage schemes and efficiency measures?

How far does that get you in 20 years?