On 14 Aug, 03:55, James Robinson wrote:
Nelson wrote:

James Robinson wrote:

The average thermal power plant is about 35 percent efficient, and
how do you rank the efficiency of hydroelectric or nuclear?

Yes, 35 percent efficient then loose x % of this in power
transmission, another x % lost on motor efficiency, more lost on
running trains only 10% full etc. The figure of 10% is that actually
used in doing useful work. Nuclear produces heat which is what we are
trying to avoid. Hydroelectricity not often available. At least
aircraft are more fuel efficient than cars or busses.

No, 10 percent is far too low, even with those efficiencies taken into
account. Further, load factors are more like 70 percent on high speed
train services that are competitive with airlines.

The other factor that you haven't taken into account is that it is far
harder to push an airliner through the air at 800+ Km/h than a train at
300. (Air resistance rises as the square of speed.) When you boil all that
down, airliners use about twice the BTUs as a train per passenger-mile.

Nuclear power is considered to be about 70% efficient, which is higher than
the other thermal plants, plus there are no air pollutants, just nuclear
waste.

Aircraft generally fly at 32000ft which is 6 miles high and where the
air pressure is almost down to one tenth of that on the surface so I
am not convinced. There is still the question of the infrastructure of
the railway system and the amount of fuel required to keep that
going? Our nuclear powers stations are situated by the coast to make
use of sea water cooling systems! Sea is the one thing we should try
not to warm up. I notice the protestors at Heathrow have arrived in
their 4x4s, not a very convincing lot!