UK Electricity Supply Capacity

[SimonH2]

Sure, but if one reached the situation of "more-often-than-not 'work out' reasonably well" in relation to, say, renewables, that would minimise the amount of flexible generation by other means (and/or storage) that was needed to 'fill in the gaps' and turn it into a "reliable" supply.

Yes it would minimise it - but would introduce (or rather, exacerbate) other problems such as the economics of having near 100% standby that was rarely (if ever) actually used.

It's all very well saying "would not be sufficient", and I can understand the thinking behind your statement, but once (beyond our lifetimes), all fossil fuels (and, I suppose, trees etc.!) are exhausted, what alternatives will there be beyond 'renewables' and nuclear?

A very long time past our lifetimes - the reality is that there is still a lot of fossil fuel still in the ground. I can recall when I was at school hearing the doom-mongers saying that oil was running out - and if they'd been correct we'd have run out a decade or two ago, but I think we can all agree they were wrong. What they forgot to factor in is that the business case of looking for and extracting more oil depends on price, and if it looks like we're heading for an oil shortage, then that business case changes in favour of more exploration & extraction.
I've heard it said that we have in excess of a couple of centuries of coal still in the ground in the UK alone.

However, what about using nuclear-generated electricity to produce burnable gas or liquid fuels? The simplest, and 'cleanest' variant of that would presumably be to use the electricity to generate hydrogen by electrolysis of water - and that would have zero impact on global resources, since burning the hydrogen would regenerate the same amount of water as had been used to create it.

That is in fact one avenue being investigated by various groups - though IIRC there are other methods of doing the water+lecky->hydrogen conversion than electrolysis. A few years ago I went to a talk about a project that would take hydrogen plus atmospheric CO2 and make methanol. That is far more useful than hydrogen since it's actually practical to store and use it in large amounts. Even if it were only used to displace oil from mobile power (mostly transport) requirements, it would make a massive impact on CO2 emissions. The major benefit as a mobile fuel is how it can be moved, stored, and dispensed using all the same infrastructure that we currently use for oil derived products - and burned in existing engines that could still run on petrol/diesel. By comparison hydrogen comes into the "what ****ing idiot thinks that is a good idea" - which seems to be why politicians are wedded to it

I agree with the larger lake, but where in the UK could you build that? To be worthwhile, it has to have a suitable head / height.

Indeed. And I think we can all imagine the anti campaigning from a different (but probably overlapping) group of green campaigners if any new scheme were to be proposed

As an aside, over a century ago the City of Manchester Corporation set out to find an alternative water supply - the city was running short at times, and the "brown" water they were getting from some peaty areas was not suitable for the textile industry. Thirlmere was chosen because of several factors - a large surface are meant a lot of storage for a given change in water level, it had enough elevation to get the water to Manchester without pumping, and the properties affected were of relatively low financial value compared with (say) the likes of Windermere which was already seeing the value of lakeside property getting quite high

 

[JohnW2]

That is in fact one avenue being investigated by various groups - though IIRC there are other methods of doing the water+lecky->hydrogen conversion than electrolysis.

I'm sure there are - that was just an example. Mind you, I would be surprised if any other methods were 'simpler' or more efficient than electrolysis, but I might be wrong.

A few years ago I went to a talk about a project that would take hydrogen plus atmospheric CO2 and make methanol. That is far more useful than hydrogen since it's actually practical to store and use it in large amounts.

Yes, I almost mentioned that. However, in some senses hydrogen (although more difficult to store etc.) would presumably be environmentaly preferable, since burning methanol would presumably result in CO2 (and probably some CO) production - so industrial synthesis of methanol would, in some senses, be creating a man-made equivalent of fossil fuel.

If electrically-produced hydrogen were being use just as a method of short-term energy storage (to iron out/ top-up variations in demand and other sources of electricity), it presumably would not have to be stored in enormous/impractical quantities?

Kind Regards, John

 

[SimonH2]

Yes, I almost mentioned that. However, in some senses hydrogen (although more difficult to store etc.) would presumably be environmentaly preferable, since burning methanol would presumably result in CO2 (and probably some CO) production - so industrial synthesis of methanol would, in some senses, be creating a man-made equivalent of fossil fuel.

Yes, but that CO2 would be using carbon that had only recently been taken from the atmosphere - so a carbon neutral cycle. BTW, one use for methanol would be to make plastics - thus locking up carbon long-term.

If electrically-produced hydrogen were being use just as a method of short-term energy storage (to iron out/ top-up variations in demand and other sources of electricity), it presumably would not have to be stored in enormous/impractical quantities?

Dunno. See earlier comments about having to replace wind (almost entirely) for perhaps a week or two - that's a lot of hydrogen to store.

 

[JohnW2]

Yes, but that CO2 would be using carbon that had only recently been taken from the atmosphere - so a carbon neutral cycle.

True.

BTW, one use for methanol would be to make plastics - thus locking up carbon long-term.

Are we allowed to talk about plastics, even as a means of long-term carbon storage?

Dunno. See earlier comments about having to replace wind (almost entirely) for perhaps a week or two - that's a lot of hydrogen to store.

I haven't got a clue as to what that would mean about the amount of hydrogen storage required, and the practicability of doing it. Of course, even 'without' wind for a week or two, there would still be other 'renewables' around.

Kind Regards, John

 

[SimonH2]

... even 'without' wind for a week or two, there would still be other 'renewables' around.

Yes, but perhaps not in very substantial quantities. If it's a "Dec 2010" situation, then while sunlight would be plentiful, it would be for short hours and at a low angle (poor incidence angle on most panels). Hydro might be OK, but we have a fairly limited amount of that in the UK.