yes. All these thing are secondary energy sources. In fact there is only really one primary energy source in the universe. The big bang.
Taking it locally, the prime energy sources in the Earth, are the big fusion reactor in the sky, and the heat and energy still left in the earth. We have dug up or pumped most of the low hanging chemical fruit
- carbon fuels - already. All that is left is nuclear fuel, but there's a lot of that still left..although the low hanging fruit of Uranium 235 may not be in such abundance.
With a secondary energy source, what counts is cycle efficiency. How much you get out later for how much you put in earlier. Batteries are really very good. Plus energy density: How much your storage devices weighs per unit energy stored. Batteries are not so good there.
We tend to use electricity as a transmission energy form, because its very very cheap and easy to *transport*.
Its a bitch to store though.
We use heat in heat engines, to turn heat to mechanical or electrical power because heat engines are simple and well understood.
WE tend to want to store energy in chemical ways because its a pragmatic way to run transport and its easy to stockpile.
What we don't have are efficient ways to go from one sort of form to another.
Ideally a back box that you shovel uranium,. CO2 and water in at one end, and get diesel and oxygen out at the other, would be everyone's dream come true.
Or a black box you sit in the middle of a desert by the sea, that takes water, CO2 and sunlight and makes diesel..
PS I note that as of ten minutes ago, the total power output of all the UKs metered wind was just 20MW . Its up to a whoping 24 now.
And what's with this facination with electricity. You could use compressed air or liquid air. There is a "technology demonstrator" for a small city type compressed air driven car somewhere and small commercial scale liquid air power plants are being devleoped/built.
TBH I'm not quite sure how liquid air works as a fuel, it's down to the phase change and expansion but I struggle with where the energy comes from to liquify the air in the first place. I have niggly doubt it's a bit like hydrogen as a fuel, you need to shove just as much energy in to split water as you get back out later (less losses).
You may not see large scale gas storage as being feasible but that doesn't mean it can't and won't happen: there's a lot of work on it in connection with hydrogen fuelled-vehicles, or on a larger scale we could even liquefy it. Or use other electrical-to-chemical-energy transformations -- the point being that we can only use so much electrical energy directly and if we want to get away from fossils (either to avert/alleviate AGW or as oil becomes more expensive) then we'll have plenty of uses for leccy which will more happily accommodate the sort of variable supplies one gets from renewables.
Isn't there much the same problem with nuclear? AIUI you can't turn nukes up and down at will so you need either a lot of storage or fossil-fuelled fill-in. Or an energy economy based on large amounts of electricity production with the excess over direct consumption used for conversion into chemical and other forms of energy.
The last lot I bought (4th March) was 56.52p/l ex VAT. Red will be about 10p/l more than that due to the duty. And of course will attract VAT at 20% not 5% as for domestic heating oil.
The heating oil price tracking sites have had 28sec oil at 60p/l for a week or so now. So I reckon red will be 80p+/l which fits with about 50p/l less than pump diesel.
No, thats bollocks the major part of carbon fuel stocks remain in the ground. Even if we had reached "peak oil" - and there's no evidence that we have - the shape of the curve is skewed to the right so there would still be more oil below than above. For coal, we haven't even scratched the stocks remaining despite two centuries of use.
Bollocks.
There's about a century of nuclear fuel in the UK. The only barrier to using it is the weakness of the knees of politicians.
No, we have coal burning power stations, and enough coal for at least
600 years. They can be used when the water in the hydro dams is low. Also we have huge tide power potential. Iassume that hydro power is still needed at change of tide.
New technology solar panels are getting cheaper all the time.
The important point I am making is that a great deal of money has to be borrowed to build nuclear and other large generators. Interest has to be paid for maybe 10 years or more during construction, while there is no income at all during that time. Contrast that with small generators that come virtually of fthe shelf, are made on an efficient production line, and can be installed in months and generate income immediately.
Yes unfortunately the major parties, National Labour and Greens, are obsessed with trying to reduce CO2 when as we now know man-made global warming is the greatest scientific fraud of the last century.
there are some products of fission which decay with alpha IIRC some of the lighter Isotopes of antimony e.g. 109 (not the high n/p isotopes e.g. 134) and tellurium 107 and 105 an alternative to alpha decay for those isotopes with lower (lighter) n/p ratios would be proton emmision.
Actually you CAN to an extent turn nukes up and down. Classic MOX fuel tends to get IIRC Xenon poisoning if you do it too much, but the French do in fact do it. Boron is used to control the poisoning.
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an interesting technical study.
Also, since fuel is relatively cheap, you can also to an extent throw the power away.
It is not intrinsic to a reactor that it cant be turned down either..it wont happen fast (the paper I cite says 0.3% a minute with lowest level being 30%, so it can go from 30% to 100% in say a bit under 4 hours..) but it can happen and newer designs might well be more readily dispatchable. The reason we don't dispatch nuclear (much) is that the plant was never designed to do it. And it is probably the cheapest on the grid anyway, so it makes sense to use it as pure base load.
But yes, you probably want to keep all the pumped storage and hydro to cope with short term demand peaks. And a bit of CCGT, but coping with demand variations - typically 20 GW from evening peak to midnight low - is a fairly predictable thing..unlike say trying to put 30% wind on the grid, which gives a totally unpredictable up to 50GW swing on the grid.
Perhaps an ideal mix is as much hydro as is cost effective, about 30GW of undispatchable nuclear, and 20GW of CCGT And no wind. Because the moment demand drops to the base capacity of the nuclear, you don't want or need any CCGT or wind on the grid at all.
Replacing coal with nuclear, and stopping all wind development and keeping the approximately 20GW of CCGT as it is or upgrading it, plus the interconnects and as much hydro is is viable, would seem to be the most cost effective mix. Or with dispatchable nuclear, up to 40GW, maybe
50GW of nuclear, and a reserve of maybe 20GW of CCGT. Mostly not used. The nukes can broadly follow load then, with the hydro kicking in to cover the extra 1-2GW needed in short term emergencies, and the CCGT becomes pure reserve..there to cover a major unscheduled power station outage for example.
Looking at the demand graphs, the slew rate from nightime low to daytime highs, is easily coped with if you have dispatchable nuclear. The little evening peak around 7pm, is where you need the hydro or the CCGT.
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Nuclear and wind don't sit well together, because the wind can vary a lot faster than load can, with any large amount on the grid. You HAVE to have fast start CCGT to cover that, or hydro.
I suspect that is broadly the way the French run their system. 80% moderately dispatchable nuclear, nuclear, the rest CCGT. I think they have a few old coal plants running as well.
I am very mixed about coal, especially Drax, It does represent a huge investment in plant that shouldn't be switched off willy nilly. It also burns a lot of bio waste. But I would hope to see gradual replacement of older coal with newer nuclear.
I am very sceptical about carbon capture. I'd like to see a moratorium on new coal until a bit more is known about carbon capture, and until the climate scientists have stopped arguing about whether or not CO2 is really doing anything at all to the climate. With polar bears on the increase, glaciers and ice sheets growing back, and talk of a new little ice age, maybe we shouldn't be sacred to death about all this.
If the answer turns out to be that the whole thing is overblown, and the Chinese anyway are unstoppable coal burners, there seems little point in getting excited about it. We do have plenty left, albeit not very easy or cheap to mine, and it is easy to stockpile.
Given the times scales, and the politics, I suspect that what will actually happen is that short term wind wont happen a great deal more. Its too expensive, and its perverse. We will throw CCGT sets together in a hurry, to cover the shortfall as the older nukes come out of service. We may or may not build a new coal plant. But the main drive in the next decade will be to reform, modernise and properly get a full scale nuclear program in place. That is as much a political as a technical problem though.
What about 'low hanging fruit' did you fail to understand?
I never claimed there was none left, just that its getting increasingly expensive and complicated to get it out
No, not in terms of actual final cost of the power generated. Nuclear is THE cheap fuel today,. It would still be cheap a 100 times its current price. That's a long way into exploration and finding new reserves, or even reprocessing old coal heaps to get the uranium out..
Solar PV is still hitting the mid teens in efficiency and has been for quite a while now. At those levels on it's hardly near a theoretical max, a practical max with current techniques maybe.
The Aussies supposedly are going to try the following: lots of solar stations each of which will have a number of individual heat collectors generating 217Mwatts. Now of course one's first reaction is what about at night. This is where it got a bit more interesting.
Seems the plan is to use molten salts (potassium and sodium nitrates) as the working fluid, and this then boils water to drive the turbines. But, there is also storage of molten salt. As well as driving the turbines, there is heating of much more molten salt in storage tanks at up to
600C. Then during the night this stored salt can be used to continue to drive the turbines, the salt cooling down to 290C where it's still molten.
Of course that might work for them where they get abundant reliable sunshine, no shortage of useless land due to *overpopulation*, and general population level is lower.
Until I saw Brian Cox "Wonders of the solar system" I wasn't aware that the expansion/contraction of a planet as it orbits a body could produce so much energy. ISTR one of the moons of Jupiter or Saturn having a molten core, simply due to the effect of gravity.
Presumably the same mechanics apply to the Earth. So not only is there residual energy in the core from the creation of the Earth, it's also being topped up by the daily and annual motion of the Earth through space.
In fact, I wonder if energy input due to this process exceeds output ? In which case the Earth will heat up anyway ....
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