But there is something of interest here. Ms Merkel studied physics, as did many other anti-nuclearites (e.g. Amory Lovins). But for those people physics is trivial. What they do not know is nuclear economics - they don't know it and are too dumb or lazy to learn it, which is why they buy into crackpot schemes like getting rid of nuclear.

Germany will seek to use domestic and imported wind, hydroelectric, solar and other forms of renewable power.

It would be untoward if the central government ended up getting more natural gas royalty revenue, and perhaps excise tax revenue if it's imported from Russia, as a result of extreme lethargy in this seeking.

How did it work out for Italy, after that country swore off nuclear energy in about 1989? I suspect renewable energies and conservation were touted to take over for it there too.

Banning the use of a dollar's worth of uranium in a system of water-cooled reactors and -- where necessary -- enrichment plants can mean that $14 in natural gas is burned instead, and government gets more than $2 of that. But that is, I'm sure, something no-one in Germany wants to see, and in the ridiculously unlikely event that it does somehow happen, those whose cheques are fattened with the $2 will be almost too surprised to cash them.

However, all thermal electric power plants (Coal, natural gas, nuclear,etc.), for thermodynamic purposes, need an ultimate heat sink, usually water. There is no water to spare in a desert and the economics of using very hot desert air as the ultimate heat sink do not look attractive. Further, solar insolation in southern California is about half in the winter as compared to peak summer months and North Africa's winter/summer variation might be almost as severe.So not only are there diurnal variations in the output of electricity, there are seasonal ones as well. Add to this questions of how solar panels are supposed to survive sand storms, particularly if they use rotating equipment to focus the parabollic mirrors.

A collection of impractical systems does not make an overall practical system.

Herschel Specter mhspecter@verizon.net

I have been thinking for years about how to run an efficient condensing turbine without a water heat sink. I have made no progress. It is a daunting engineering problem, perhaps without a solution. (Tell me again, isn’t it lack of water that makes deserts deserts?)

Professor Banks, I was amused by your pointing out that Merkel and others had “studied physics.” Which in turn reminded me of what 70 years ago went to the very definition of engineering, i.e. the ECONOMIC application of science. At the time I felt a bit insulted, as if I was merely Gunga Din carrying water for the important people as if engineers were merely the handmaidens of economists. It was even more bitter as engineering flunk-outs often became economists. To make it worse physics and chemistry students had far easier courses and could play bridge in the Union.

I find it regrettable that the German government is so venal as to so readily pander on this important issue to ill-informed people.

As far as Germany is concerned, they seem to have a track record for collectively making poor decisions.

From a crass American's standpoint, by all means let Germany get rid of nuclear and go all renewable. By doing so, Germany becomes a has-been competitor and we in America can sell more of our goods and services! America has plenty of fuel resources and I confidently predict the renewable "bubble" is about to pop here in the US.

But my point is that the best thermal solar energy locations are very often locations without cooling water. What do we do with the heat? No matter what the fuel, whether coal or uranium. It is ordinarily used to make steam to turn condensing turbines. With water doing the condensing. Lots of it, even if in a cooling tower closed system. We need to evaporate about a pound of water in the cooling tower (hence the great plumes) for every pound of steam sent to the turbine.

While a gas turbine combined-cycle unit does employ a steam turbine, the station's overall water needs are much smaller than an equivalent thermal plant. This is due, in part to the air being the gas turbine's heat sink, with the gas turbine providing about 50% of the plant's output. Also, an air cooled condenser, while somewhat impacting overall efficiency and cost, can be and is being used with combined-cycle plants.

In hot desert locations, evaporative cooling of the gas turbine's inlet air requires water, but those needs are relatively modest. Use of some form of chiller system is also possible, but some cooling water is also generally needed. Combined-cycle plants in the US Southwest employ such methods while rountinely using recycled sewage water. Incidentally, the Palo Verde nuclear plant (with it's huge water needs) employs such a method, with the treated sewage water obtained from Phoenix, some 60 or so miles from the plant.

In the larger context, I think some water can always be obtained (e.g. from desalination of sea water as rountinely done in the MiddleEast), as long as one is willing to pay the extra cost.

Ultimately, however, the Brayton cycle requires much less water than conventional steam plants while using significantly less fuel. As such, the gas turbine technology is replacing conventional thermal plants. Also, for a whole host of reasons, I predict the nuclear Brayton cycle will ultimately replace conventional nuclear power.

As for desalination of sea water I suspect that the costs for the quantities we are talking about would be astronomical besides being energy hogs.

There is an enormous but essentially finite supply of fresh water on this planet. But no finite amount can satisfy an exponational demand, and a population of 7 billion and still growing at about 0.1 billion per year.

To make aluminum one needs lots of cheap electricity and bauxite ore (alumina, A2O3) from a nearby mine or port.

I didn’t think we were considering energy generation boutiques here. I thought we were considering the replacement of generating capacity needed to replace nuclear sources.