"The Natural Philosopher" wrote in message
...
IMM wrote:


Because there have been minor improvements in a flawed highly
inefficient
piston engine design over the past 30 years, you appear to think this
exonerates the internal combustion engine, or it is efficient or clean
or
something. It is NOT.

The engine it at the end of its lifespan, it should have gone 50 years
ago.

snip

As I mentioned in another post, according to MIT the fuel cell is not
viable
yet for vehicles, which are the world's worst polluters.

Far more efficient Rotary and Stirling diesel and petrol units appear
the
best options to fill the gap. The Stirling is external combustion,
which is
much a clean on the burn. Even the Rev Tec Aussie engine, a piston
engine,
improves thermal efficiency from 25% to over 50%.


What you have failed to realise, is that even these are only stopgaps too.

It is obvious that I know that, as I have already said that.

At the very best, a fuel BURNING engine delivers only 60%

efficiency - maybe a little more. The rest is waste heat.

If you had goine to a snotty uni, where
the theory is taught, you would
understand that any heat engine - and
all the above are heat engines -
has its efficiency dictated by the ratio
of the temperature of burn to
the echaust temperature.

Not quite right. The overall mechanical efficiency of the unit has to be up
to it. Also in road engine, the power to weight ratio is one of the most
important factors.

The big picture is about energy conservation, especially in terms of
waste heat, and the irreversible (in the short to medium term) problem
if taking fossilised carbon out of the ground and pumping it into the air.

To solve that you need to

- use less.
- burn plants you grew last year.
- generate power by means that don't generate waste heat OR
- use waste heat to replace the use of fuel elsewhere (CHP)

...and use less fuel cleanly.

Use of the engines described does not solve any of these apart from, in
a minor way, the first.

I did say in the short to medium term the diesel and gasoline engines will
have to do, but there are far more efficient versions around than the
abomination we all currently use.

Fuel cells can solve many of the above, but in the end. electricity is
bets because it generates very little waste heat when used to generate
mechanial motion.

It is the loses at generation and transmission losses. This can be reduced
by having smaller local power stations, the UK had, using natural, using CHP
to heat the local district. Transmission losses then are low and overall
energy efficient is very high. Sweden do this.

The issues then become how to generate electricity without using fossil
fuel and/or heat engines. Feul cells are not heat engines, but usually
use fossil fuel. Nuclear power doesn't use fossil fuel, but does use a
heat engine. windmills do neither, but are ugly, of variable power, and
woefully inefficient in terms of space used.

"woefully inefficient in terms of space used"? You see cows grazing under
them. They can be in the middle of fields and only occupy a small footprint.
There are windmill farms being built off-shore all over the UK right now,
Out of sight.

Water and wave power does
neither, but is localised as to its applicability. solar cells are even
ore woefully inneficient,

Wet solar panels generally inefficient per squ foot, but have the whole of a
south facing roof being a solar panel and the by shear size you have an
efficient collector, that will virtually provide all of the houses needs if
you can store the heat in a large thermal store

Put PV cells on every south facing roof and most of the power generation
station will not be needed. The solutions are there. It needs political
will to force it through.

but there mat be better technology coming..
burning domestc rubbish and biomass is
good as it doesn't use (much)
fossil fuel - i.,e. it's more or less carbon neutral,
but it does tend to need treatement to reduce
pollution of toxic flue gasses.

There is no easy answer. But simply slightly better heat engines
burining fossil fuils are almost the worst of all possible answers.

On the domestic and commercial build front, insulation levels to
superinsulation, passive solar design of homes, as Germany as doing with
Passiv Solar regs, south facing roofs having integrated wet solar/PV cells,
boiler with integrated CPH elec/gas Stirling boilers and soon to be
introduced. The Stirling CPH boilers cut the peaks of electricity usage.
All this is right now, and can and should be implemented. Doing so will
drastically cut fuel usage and emissions and prevent fuel poverty. And more
efficiency is on the way...

What looks promising and appear likely to be introduced is the Zeolithe heat
pump, which runs on natural gas for the provision of domestic heating and
hot water. Currently these units are floor mounted and resemble a typical
boiler in appearance. Zeolithe heating appliance's use less energy and are
more environment-friendly than electric heat pumps and gas boilers. It
provides considerably higher output levels than the current conventional and
condensing boilers. Carbon-dioxide emissions are reduced by approximately
20 to 30%.

On the vehicle side, matters are more complex. Of course, local CHP power
stations drip charging electric car overnight is very sensible, but we do
not have the infrastructure for this, as yet. Also what do you do in a
city, when you car is parked on the road? How do you charge it?

There are far more efficient diesel and gasoline engines around, and are
running. These can be developed fully and integrated into a hybrid setup.
Another method suggested is waste heat from an advanced rotary engine (not
an inefficient Wankel design) which has well over 50% efficiency, driving a
small Stirling engine from its waste heat, which drives a compressor, which
charges an air tank. The compressed air assists drive via an air motor in a
hybrid setup. This is a fine stop gap, and around town the car can run on
non-polluting air, which is generated from what would have been wasted heat.
The whole setup can be small in size as rotary engines are small and a
compressor/air motors is also small. The compressor can also be the starter
motor too.



---
--

Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.558 / Virus Database: 350 - Release Date: 02/01/2004