Germany facing blackouts...

[An Inspector Calls]

No doubt experts from CAT will be advising them on how to manage with only nice green electrons without the benefit of any nasty radioactive ones in their generating mix.

I'd like to see that CAT report - can't find anything on their website. But I suspect that it'll be the usual rubbish such as 'build 20 GW of pumped storage'.

Germany's problems will have a knock-on effect here. I think we'll see yet another extension to the life of our knackered coal plants and our oldest magnox nukes . . . well, they're cheap to run!

[Potemkin Villager]

I'd like to see that CAT report - can't find anything on their website. But I suspect that it'll be the usual rubbish such as 'build 20 GW of pumped storage'.

Whilst I am not nearly such a nuke-enthusiast as AIC, I do not believe his arguments can casually be dismissed with reference to hard to find reports by amateur enthusiasts who do not have to stand behind their wishful thinking. This sort of thing really does lower the level of debate here to a very low level of greenwash sloganeering.

I would very much like to be proven wrong but suspect I will not be.

I repeat once again that I would really like to hear some workable ideas as to how to run an electricity grid system mainly with intermittent renewables and no base load generating plant, and/or recourse to imported nuclear power as the UK and Denmark do and Germany is (in reality) proposing......

Otherwise the lights are going to go out.

[ujoni08]

Roger, it's a valid question, and surely one of the most important ones facing us. I don't know what the answers are.

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.

Another thought is community combined heat and power, or even micro CHP at the house level. That way the heat is captured and used locally, rather than being lost to the atmosphere from cooling towers. The grid also has transmission losses, which I believe are around 7%, and that's a massive amount, when we consider the daily total consumed.

I don't know what the answers are, but if we only look at current cost, we may be ignoring the medium to long-term implications.

Just my thoughts, and I welcome those of others.

[Yves75]

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...

No it's not, can't refind the numbers right now but was surprised, in France private transport plus private housing (including heating), around 40% or even 50% of total energy I think, for electricity only not sure.
Maybe can be found in D MacKay book.

[JavaScriptDonkey]

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...

No it's not, can't refind the numbers right now but was surprised, in France private transport plus private housing (including heating), around 40% or even 50% of total energy I think, for electricity only not sure.
Maybe can be found in D MacKay book.

I have yet to read it thoroughly but he doesn't seem to consider industrial usage much. He comes up with a figure of around 37kWhr/d per person for heating and hot water. Another 4 kWhr/d/p for light and 5 kWhr/d/p for gadgets.

Private transport stacks up with 40kWhr/d/p for cars and 30kWhr/d/p for jets.

That lot tots up to 146kWhr/d/p out of 195kWhr/d/p for everything.

Seems like private heating and transport are the big burners after all with around 60% of energy usage even without air transport.

[Catweazle]

I repeat once again that I would really like to hear some workable ideas as to how to run an electricity grid system mainly with intermittent renewables and no base load generating plant,

Tides are reliable, perhaps a few large tidal projects could fill in the gaps.

[kenneal - lagger]

With some local redundancy you could get a more or less constant lecky supply from tidal as the timing of high and low tides is staggered around the country. There is only a short time at the top and bottom of the tidal range when there is no water movement so with the slightly staggered tidal timing a constant supply should be available. I don't think the total resource can match the fossil fuel supply, but I await correction on this.

[An Inspector Calls]

I repeat once again that I would really like to hear some workable ideas as to how to run an electricity grid system mainly with intermittent renewables and no base load generating plant,

Tides are reliable, perhaps a few large tidal projects could fill in the gaps.

Tidal barrage can be operated to provide firm base load. The Severn Barrage has been modelled to deliver 1.6 GW of firm capacity, even during neap tides. (You could, of course, operate it in other ways and thus make it provide ancilliary services such as response and reserve, and mix and match these with baseload).

A London Barrage could be operated in a similar manner, but the output would be less.

Both would also provide tangible secondary benefits such as communication links and flood mitigation (especially important in the case of London).

From what I can see of the economics, both of these would provide cheaper electricity than windmills. And they'd last centuries (civil works only, but the mechanical plant can be upgraded on a rolling basis).

And of course, offer many good quality jobs for a decade during which economic diificulties perhaps force unemployment elsewhere.

But then, tidal barrage is not liked by the greenies . . .

And this is not going to solve the immediate supply problem created by the LCPD, plant ageing, and Germany's silly abandonment of nuclear because a barrage would take too long to build.

Given that 15 GW of generation is - supposed - to vanish by 2015, there's no chance that any scheme of renewables will fill the gap - 20,000 windmills anyone?

My guess is that the issue will have to be dodged. The LCPD can go hang (mitigated by the force majeur of Germany) and we'll build lots of gas stations JIT (we're building 7 GW now). It's that, or the lights go out; can you imagine the refrigeration crisis that would cause in supermarkets, hospitals, etc?

[JavaScriptDonkey]

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.

[adam2]

To provide reliable baseload electric power without large scale coal or nuclear generation is challenging, but can be done.

Solar is variable, and contributes nothing at peak load times of early evenings in the winter. Solar is of course valuable in that it replaces other fuels.
Wind is variable, but greater in the Winter, which is desireable.

Tidal power can provide firm power but sufferes from the NIMBY factor.

Other renewables show more more promise, especialy hydro.
Most hydroelectric schemes use water stored behind a dam, and released via turbines.
The generators and turbines are often sized so as to run 24/7 and utilise all the available water.
In many cases it will be worth replacing the machinery with alternatives of perhaps 4 or more times the capacity.
The total anual output in MWH will be unchanged as this is limited by the amount of water available.
The peak output would be exceeding valuable for peak demand/low wind conditions.
1,000MW for 870 hours a year is lot more use than 100MW for 8,700 hours a year.

Interconnectors to other countries help a lot, and not JUST for importing French nuclear power.
Peak load times differ in different countries, and it is likely to be windy in one part of Europe when calm elsewhere.
Norway in particular has a lot of hydroelectric capacity, they could export this to neighbours when wind is short, and then import wind generated power to conserve water, during windy weather.

And finally remember that diesel fuel and natural gas are not going to vanish for decades, but will become a lot more costly.
Very limited burning of expensive gas or oil could well be justified for a few hundred hours a year, but not for baseload generation.

[JavaScriptDonkey]

You consider offshore tidal may have a NIMBY factor but not dam building in the valleys?

I'd also worry that hydro would be rainfall dependant....remember the low reservoirs of only a couple of years ago?

I'd have thought that solar and low head hydro would great for the local and low intensity production of hydrogen destined to be burnt in local buses/council lorries. The hydro running from rivers will sit there churning away all the time, topped up in Summer by the PV with any excess siphoned off to the local grid. Makes more sense to be that trying to supply the world with new batteries every 5 years even though it is less efficient.

[adam2]

It depends how far offshore, but the most recently proposed tide power scheme was in the Severn Estuary, and that certainly attracted some determined NIMBYs.

I was not proposing that any more large hydroelectric dams be built, apart from the NIMBY factor, most of the good sites in the UK are already in use.
I was suggesting that the generating capacity at existing hydro sites be increased by the fitting of larger or additional turbines and alternators, this would assist in meeting peaks in demand or troughs in other production.

In times of drought the output of hydro electric plants does sometimes have to be curtailed, in order to make the water behind the dam last until the next wet season.
Wind or solar is valuable in such cases. Every MWH generated thus is more water saved for generating when wind and solar are lacking.

[An Inspector Calls]

I'd have thought that solar and low head hydro would great for the local and low intensity production of hydrogen destined to be burnt in local buses/council lorries. The hydro running from rivers will sit there churning away all the time, topped up in Summer by the PV with any excess siphoned off to the local grid. Makes more sense to be that trying to supply the world with new batteries every 5 years even though it is less efficient.

Forget production of hydrogen from renewables. The capacity factor of all renewables is dire, and then you propose to run it's output through a production process that is about 30 % efficient. So the outturn capacity factor for wind would then be 30 % of 25 % (solar: 30 % of 10%)!

Adam2 I'd love to agree withn you on hydro but it won't take us very far, even less than tidal barrages. Yes, we should do it because most hydro schemes give a good capital return (apart from idiocies like Settle Hydro). However, you should realise that any trend towards replacement with larger machines means that the owners may lose their ROCs payments. SSE actually changed the runner on one of their hydro schemes such that the output dropped from 24 MW to 19 MW and brought the machine into ROCs payment (and they got a grant for the redesign!).

KPMG have just produced their overview of the Government's 'Green Transition'. It doesn't punch very hard at first glance, but then there's throw-away lines to the point that dropping renewables and going gas would save as much CO2 and be tens of billions £ cheaper (I'd say more than £100b cheaper).
http://www.kpmg.com/UK/en/IssuesAndInsi ... rdable.pdf

(Discuss the KPMG report elsewhere . . .)

[JavaScriptDonkey]

Forget production of hydrogen from renewables. The capacity factor of all renewables is dire, and then you propose to run it's output through a production process that is about 30 % efficient. So the outturn capacity factor for wind would then be 30 % of 25 % (solar: 30 % of 10%)!

So what's your estimate for using that solar energy for first mining the ore and then making the battery to store it in?

I didn't suggest using renewable-power-produced hydrogen was efficient in energy terms, I suggested that it was efficient in time terms.

Once we have a base load satisfied by renewable sources then hydrogen cracked by excess renewable energy is essentially free and very convenient for vehicles.

[An Inspector Calls]

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.

Once we have a base load satisfied by renewable sources

How? 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).