>Sorry, but your figures are wrong.  Total transmission and 

>distribution losses from a nuclear plant or any other plant are 

>about 7% in the US, and conservation contributes to a 100% reduction 

>in emissions immediately from the marginal units generating 

>electricity.

>

>-- Rich Rosen



Rich is correct: the figures from Caffrey are wrong.  But what the 

true figures may be is not easy to find out.  As an inventor of solar 

water heaters I have asked Amory Lovins' 'Rocky Mt Inst' for figures 

but the task seems beyond them.



Some stages of loss in electric  grids:



1  Power station alternator thru switchyard onto grid



2  Long-distance EHV transmission 200kV, 400kV or more



3  Substation stepdown (in NZ typically to 11kV) at 'city gates'



4  Local stepdown to 230V in NZ, 110V in USA



5  Local reticulation at this 'retail' voltage



6  Losses between the retail meter on the front of my house and the 

3kW element in my HW cyl (which is on only 15 - 30 min to top up 

after even quite a cloudy winter's day with my SWH gives me ca. 80 

litre tepid water).





	(1) and some other little-mentioned losses (esp in nuclear 

stations) are of interest, but not for the present purpose of 

comparing SWH against grid elec'y for HW.

	What we want is 2, and {3 + 4 + 5 + 6}.

	We gather (2) loses around 10 - 11% of annual energy in NZ; 

Poms claim as low as 3%.  Is the USA avg for losses in just the EHV 

transmission as low as 7%?

	My suspicion is that {3 + 4 + 5} may be considerably larger.

	Transmission losses from nukes are marginally larger in that 

they haven't been allowed within a few dozen mi of any big city i.e 

centre of consumption.  Some big fuel-fired generators are closer 

than that to main load centres.  On the other hand, some are very 

remote e.g Four Corners coal-monster  ...



R





>

>________________________________

>

>From: Science for the People Discussion List on behalf of Mitchel Cohen

>Sent: Fri 2/9/2007 5:59 PM

>To: [log in to unmask]

>Subject: Pelosi calls for nuclear power to offset global warming

>

>

>

>From: Andy Caffrey <[log in to unmask]>

>

>My fellow Earthlings,

>

>You lose 80% of the energy generated by nukes in the transmission to

>the end use.

>

>You can get a 50% reduction in emissions almost immediately with conservation.