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 - Memberrenewables ...........
but they are not the magic cure that the green lobby claim
Nope - but along with [b]serious[/b] 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 - MemberJust 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 [i]if[/i] 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?
Where do people find these PV red herrings?
I did some research on the energy cost of making solar panels before buying and came to the conclusion that a panel pays for itself in energy terms in the first year of use. In northern Europe it would be a year and a half. The anti-PV people are still quoting sources from the mid 70s when the first cells took over six years to produce the energy used to make them.
On the PV maintenance issue. Compare washing them once a year with the maintenance of a nuclear power station. 25 years is half the life of a nuclear station and it takes a few hours to replace them. I chose [url= http://www.solarworld.de/fileadmin/downloads/produkt/sunmodule/_testsieger/sonderdruck_solarworld_deutsch_2009.pdf ]Solar World[/url] as they have a take back scheme, their panels are entirely recyclable and contain nothing toxic. They are guaranteed for 82.5% of max production after 25 years.
The power loss in the less than 4m of cable running at 700V linking my panels to the onduleur is negligible and a fraction of what is lost in the grid from the nuclear station which is thankfully 150km away. There are hydro stations a few km away but given the distance from my local step-down transformer the losses will still be greater in the grid.
Almost forgot to say, Fukushima is now out of control. Who was it who said it couldn't happen?
and contain nothing toxic
I seriously doubt that - what are the cells made from?
Where do people find these PV red herrings?
Amusingly enough, the ecogumph justifying the apalling building I used to work in's green credentials. In North wales they expected 45 years to break even, whilst the building's design-life was 40 years. Even more astounding (and admittedly this isn't directly the PV panels' fault) was that they were positioned over the glass roof of the atrium. You'll never guess what had to be kept on most of the day then as no light could get in... 🙄
Almost forgot to say, Fukushima is now out of control. Who was it who said it couldn't happen?
Do you have a source for that ?
It's been the headline caption on N24 since about 5:00 this morning your time, Cranberry. The radiation levels are such that they can't enter the control room so the plant is out of control. They are finally talking about boron in large quanties rather than a feeble quantity of boric acid in the sea water coolant. Korea is sending supplies that can be dropped in from a helicopter. The containment vessel of #2 reactor is thought to be breached and at least partial meltdown probable. All from N24.
[url= http://www.n24.de/news/newsitem_6732416.html ]N24 TV's website[/url]
[i]Die Lage im Katastrophen-Atomkraftwerk Fukushima in Japan ist vollkommen außer Kontrolle[/i]
I don't think that needs translating but will all the same: "the situation in the catastophe hit Fukushima nuclear plant is completely out of control".
From the BBC ( time is GMT ):
0759: If you're just joining us, the latest on the nuclear crisis in Japan is that staff have returned to work at the Fukushima-Daiichi nuclear plant, after a rise in radiation levels forced them to temporarily abandon the facility. Earlier, a blaze struck reactor four at Fukushima Daiichi for the second time in two days, and smoke was seen billowing from reactor three.The pant has suffered several explosions, triggering radiation leaks.
From The Times:
07.24 GMT: Live TV footage is showing an army helicopter its on way to dump water on stricken nuclear plant in Fukushima in northeastern Japan. Meanwhile the plant’s operator has released a statement saying the temperature has stabilised and pressure dropped at the No. 2 reactor.07.04 GMT: Japan’s Nuclear and Industry Safety Agency says the computer that forecasts the spread of radiation at the Fukushima nuclear plant is not working because of malfunctioning monitoring posts, according to Japan’s national broadcaster. It has also been reported that the spike in radiation earlier this morning may have been caused by a radiation leak in reactor No 2
06.55 GMT: It turns out the workers who were evacuated from the plant because radiation levels were too high eariler this morning, were later allowed to return after about an hour.
"the temperature has stabilised and pressure dropped at the No. 2 reactor."
That's a huge relief. Lets hope the others stabilise soon too.
(Where do people find these PV red herrings?)
try ignoring the greenwash..... and do some real research
Pv is a useful technology and has a place in the energy mix...especially so when some one else is subsidising it. 😉
As a commentator on N24 said the pressure drop could be (is likely to be) due to a hole in the reactor containment unit which would explain the sudden increase in radioactivity along with a pressure drop.
Subsidising it or simply paying the real cost of clean, sustainable energy. I would argue that the real cost of nuclear power and greenhousing the planet with fossil fuels will ultimately be higher. I've done the PV research, quoted it and linked an article with graphs anyone can understand.
Edit: Actually, i'm not getting involved in this.
In North wales they expected 45 years to break even
In money terms or energy terms?
A PRV lifting can't explain a pressure drop. The PRV will maintain the highest pressure allowed. Any pressure lower than that is due to a lower temperature or a leak or both.
[ I've done the PV research, quoted it and linked an article with graphs anyone can understand]
go on post the link again lets have a laugh......
As a commentator on N24 said the pressure drop could be (is likely to be) due to a hole in the reactor containment unit which would explain the sudden increase in radioactivity along with a pressure drop.
That would be the radiation that's now dropped, would it?
http://www.bbc.co.uk/news/science-environment-12745186
http://www.theregister.co.uk/2011/03/15/fukushima_update_tuesday/
I know this is exactly the sort of incident the anti-nuclear lobby have been waiting for to demonstrate just how far they can't see past the end of their noses, but really - whilst it is certainly serious, the emotive issue tends to cloud sensible objective judgement somewhat...
Ah, just found a report saying that the pressure has dropped to 1atm,(was ill yesterday and missed the news). So yes, it's jiggery buggered.
In money terms or energy terms?
Energy, apparently. Dread to think how long it would take from an economic perspective. Stupid - given the location, a wind turbine would have been far more effective.
scary stuff in japan! the fact the french are imposing a moratorium on nuclear energy is quite telling of the scale of this problem.
on the subject of PV, my father is re-roofing his chapel and has haggled the price of a massive solar roof down from £30k to £9k (its a very big roof) just by being the tight fisted guy he is! expected pay off is £5-7k per year with FIT's
nice retirement plan i think!
In money terms or energy terms?
Is there a difference? Surely money represents end-to-end energy.
I've done the PV research, quoted it and linked an article with graphs anyone can understand.
The graphs (from my rudimentary German) seem to indicate that the panels do indeed produce some electricity, some better than others, and most of it in summer. Hardly surprising.
[Dons simulated anti-nuclear hat] Well, it would say that, it's produced by a company selling them [/hat off]
Nowhere does it say what your 'pollution-free' panels are actually made from (that a non-German speaker - like most of this forum - can discern). Please feel free to edukate (sic).
I accept they may in some circumstances represent a 'greener' source of energy, but the spin you're giving is almost as bad as the infamous 'too cheap to measure' line that I suspect just about anyone involved in energy policy or the nuclear industry wishes had never been uttered...
It's worth noting that there are bad PV installations and good ones though zokes.
I thought about our house - we would almost certainly be better off putting them on the end wall rather than the roof I reckon.
It's worth noting that there are bad PV installations and good ones though zokes.
I'm aware of that, and these were laughably bad (especially as in the next door, much taller building overshadowing the one I worked in, is a chemistry research group working on new PV technology!) However, they are certainly not all good either, which is the point (I accept, rather obtusely) that I was trying to make.
sorry zokes is your argument about nuclear power stations or PV arrays? it seems fitting for both 😉
