Germany facing blackouts...

[clv101]

...and there's not enough to provide base load (30 GW UK).

30GW? Maybe today, but what about 10, 20 or 30 years time?

[UndercoverElephant]

As least they're trying to do the right thing.

And what exactly is this "right thing" they are trying to do?

I think he's assuming that nuclear is necessarily A Bad Thing.

What's good about it?

This is a judgement about what is least bad. None of the options are good.

[Potemkin Villager]

I have to think that for the UK tidal power is the future however the scale of what we require is far beyond a couple of tidal barrages.

MacKay examines the scale required at length.

We'd have to embed tidal turbines on the seabed in the Channel off Cornwall and in the North Atlantic off Scotland. MacKay's illustration below.



We'd also have to construct tidal pools all around our coast with turbines running on the fill and flush phases.

Lots of construction work but once in place we'd 'just' have mechanical upkeep costs and the tides are a lot more reliable than the wind.

Yes indeed JSD the scale is well beyond a couple of tidal barrages and in a very challenging off shore environment.

The near off shore environment around say the wave energy test site in Orkney is impressively demanding enough but out to sea it is unimaginably more challenging.

Worthwhile for a high energy density installation like an oil rig but a different kettle of fish for a low energy density installation like tidal power turbines - although anything using water of course is 1,000 times energy denser than a wind turbine.

In theory this might do the job but it would involve cutting a very expensive and unproven furrow with massive snag and environmental issue potential and would require great political vision and courage (!) .......... and of course these options are not open to the Germans.

Maybe we should be thinking of a much less complex and more energy modest proposal altogether for the future? ( I presume this is what Chris is alluding to).

[UndercoverElephant]

massive...environmental issue potential...

It would be an understatement to say that is an understatement. A barrage like that would be an marine ecological catastrophe of indescribable propotions, for numerous reasons. Absolute non-starter.

[Potemkin Villager]

It would be an understatement to say that is an understatement.

[SleeperService]

As I said before, I'm prepared to power down massively, and have already. Our total household usage is 3.5 KWh per day. I believe the UK average for a two-person home is 11 KWh. If we all power down, the base load needed will be much lower, but I imagine domestic consumption is a smallish part of the total, compared to industrial consumption. I'm not sure how industry can be persuaded to power down... perhaps with financial incentives.

This seems to be a very good point. If it's possible to cut consumption by 2/3rds in a domestic enviroment then how much generating capacity do we need?

As with oil generally reducing waste would enable supplies to go much further. The problem seems to be that big new nukes or barrages are much more appealing than waste reduction.

In fact wouldn't a saving energy board be a good idea?

[vtsnowedin]

I do not think it is a choice between conservation and building alternative energy supplies be they renewable, nuclear or fossil fueled. We will have to do as much as is possible on both fronts and will still most likely have to do a lot of doing without energy we really need. If you can conserve it, do so . If you can replace it with a green or even a nuclear source do that as well. But add up all the possibilities then subtract the decline of available oil derived energy and you will still come up short. Spending time arguing about which way to proceed just puts off the start of a race in which we are already a lap behind.

[JavaScriptDonkey]

I don't understand your first sentence - what ore are you talking about?

I see your point in your second sentence, but it would far more productive just to use the low grade power of renewables to heat hot water.

Perhaps we're confused.

I was suggesting using low head hydro to produce hydrogen which is convenient as a fuel for vehicles. I thought your objection to that was that the inefficiencies involved supported the idea of using electric vehicles (ie no losses in conversion). I then asked what the overall efficiency would be after you had calculated actually manufacturing the battery packs in which to store the electricity.

I envisage using tanks to store compressed hydrogen which is then convenient to use in vehicles. You envision using batteries to store electricity. I contend that my solution is a better engineering compromise as it doesn't require the endless production of batteries.

We still haven't seen the CAT report that's supposed to demonstrate renewables can provide base load. Then only types that can are tidal barrage and biomass and there's not enough to provide base load (30 GW UK).

I agree that there are not enough tidal generators to even think about providing a power base. I suggest that it might be prudent to start building them now but I also accept that the scale we require is massive.

[JavaScriptDonkey]

massive...environmental issue potential...

It would be an understatement to say that is an understatement. A barrage like that would be an marine ecological catastrophe of indescribable proportions, for numerous reasons. Absolute non-starter.

Well, perhaps but I don't think a floating barrage in the Atlantic is the idea at all. You only need to use barrages where you need to catch the wave surge as it runs up land. With the offshore idea the entire deep North Atlantic is trying to slosh in to the much shallower North Sea. We in effect use the North Sea as a tidal pool, catching the constant flow in and out via the Scotland or Cornwall. The turbines are sub surface, fixed to the sea bed away from the ravages of most storms.

No barrage.

No environmental impact.

Does it start now?

[An Inspector Calls]

massive...environmental issue potential...

It would be an understatement to say that is an understatement. A barrage like that would be an marine ecological catastrophe of indescribable propotions, for numerous reasons. Absolute non-starter.

Why? The tidal area of the Severn (taking that as an example) would still be tidal - if it wasn't you'd have no generation. The only significant flow management you'd do would be in times of potential flood - very high tides/Severn in flood.

There'd be some environmental impact, but I don't see a catastrophe. Even Porridge was in favour!

[Potemkin Villager]

It would be an understatement to say that is an understatement. A barrage like that would be an marine ecological catastrophe of indescribable propotions, for numerous reasons. Absolute non-starter.

UE would you care to give some examples of the "numerous reasons" referred to making this an absolute non starter?

[the_lyniezian]

I'd have thought of mentioning pumped storage and although it would be difficult to find more sites like Dinorwig, I've heard of ideas which involve the use of some sort of glorified water towers. Otherwise, some sort of mass storage at least to provide energy for hospitals or industry might be needed, or some sort of small-scale back-up generator such as I think hospitals already have (but how will you power it? Biomass?)

All in all though, that would mean added energy lost in the process (2nd law of thermodynamics) which would eat into an already much reduced energy supply.

[adam2]

I'd have thought of mentioning pumped storage and although it would be difficult to find more sites like Dinorwig, I've heard of ideas which involve the use of some sort of glorified water towers. Otherwise, some sort of mass storage at least to provide energy for hospitals or industry might be needed, or some sort of small-scale back-up generator such as I think hospitals already have (but how will you power it? Biomass?)

All in all though, that would mean added energy lost in the process (2nd law of thermodynamics) which would eat into an already much reduced energy supply.

Pumped storage using water towers or similar constructions is most unlikely be viable.
Neither the small volume of water stored, nor the modest height of such structures would permit of storing econmic amounts of energy.
Some energy could no doubt be stored, but batteries would almost certainly be cheaper and simpler for such small scale uses.

Hospitals do indeed have back up generators, almost always diesel fueled. There is no reason why diesel can not be used in the future, it is not going to vanish, just become too expensive to use as we do now.
Bio diesel is not ideal for standby generators unless they are run regularly since it has a shorter shelf life than FF diesel.

[PS_RalphW]

My family domestic electricity consumption is 4.5KWh/day. Certainly a modern lifestyle is possible on half or less current domestic electricity demand. Bringing industrial and service demand down by as much may be technically harder.

The problem is that I am intelligent, educated and motivated to put the time and (modest) investment in to bring my consumption down, and to forego the the (questionable) pleasures and conveniences that are only possible with higher consumption. I designed my life around low consumption - my choice of where to live, what house to buy, what job to take, were all influenced over the years by environmental factors. I then settled down and married and imported a family with that starting point.

Not many other people have the time, money, motivation or life choices necessary. Ignorance and selfishness are our worst enemies, but real economic limitations are also there.

It will take a top down change of culture, and at least a generation , for most people to treat energy with the same respect that I give it. Massive education programmes as well as infratsructure investment would be needed. Any government that did it would be booted out at the next election for being such a sourpuss.

[JavaScriptDonkey]

Pumped storage using water towers or similar constructions is most unlikely be viable.
Neither the small volume of water stored, nor the modest height of such structures would permit of storing economic amounts of energy.
Some energy could no doubt be stored, but batteries would almost certainly be cheaper and simpler for such small scale uses.

That'll be the London Hydraulic Power Company amongst others then.

Very handy for converting a steady trickle of low power into occasional and predicable bursts of high power.

The advantage over batteries is that the towers last much, much longer.