Why Electric Motors Are 3X - 4X More Efficient Than Internal

[Eeyore]

DB wrote:

You were the one that came along and changed the subject. What was the
point of that?

Got to hell you whingeing old windbag. I did no such thing. And take your peak oil
with you.

Graham

 

[Eeyore]

DB wrote:

I have not seen NG used in any plant other than a peaker or a CC plant
in the U.S.

Is the USA the only place in the world ?

Graham

 

[DB]

Eeyore wrote:

DB wrote:

You were the one that came along and changed the subject. What was the
point of that?

Got to hell you whingeing old windbag....

Bawhawhawh. Have another pint....

 

[Sevenhundred Elves]

On Thu, 21 Aug 2008 20:48:12 +0100, Eeyore
<rabbitsfriendsandrelations@hotmail.com> wrote:

"rlbell.nsuid@gmail.com" wrote:

z <gzuck...@snail-mail.net> wrote:
Eeyore > wrote:

Overall thermal efficiency from typical power plant to power socket is in
the 30-40% region.

A very large marine diesel can and does EXCEED 50% thermal efficiency. Only
now are combined cycle gas turbine generators coming on line that can beat
that but you still have transmission losses.

Little known fact; efficiency of electrical generation is currently
half of what it was in Edison's day. Well, it's a trick question,
though; Edison was businessman enough to sell off the heat as a
byproduct (isn't that what they call cogeneration?) but today
utilities, as monopolies, are too lazy too chase that efficiency/cash.
too bad for all of us.

Edison's DC power scheme had to make a virtue out of a necessity. For
his DC generators to supply loads, they had to be close to them.
Westinghouse's AC system supplied the entire Chicago World's Fair from
a single, central station. Edison would have needed to space 27
generator across the grounds to provide the same coverage(why he lost
the bid). With a DC electrical power system, you were within walking
distance of the power station that supplied your home. Without fancy
power electronics to create buck/boost convertors, the voltage at your
socket was the generator terminal voltage, less ohmic drops in the
transmission line.

Edison could sell you the waste heat from his steam turbines (you hope
they were turbines, reciprocating pistons could be felt for hundreds
of yards through the soles of your feet), but NIMBYism meant no power
connection. Westinghouse could supply your house from halfway across
the continent. I am sure that there are utilities in large cities
that supply heat and light, in the core areas, but the return is too
small to lay the pipes in areas of low density housing.

Scandinavian countries can do it.

Graham

We not only can, we actually do it. Many households here in Sweden are
heated with waste heat from power plants. Thus the heat is not really
wasted.

S.

 

[tg]

On Aug 19, 3:10 pm, Eeyore <rabbitsfriendsandrelati...@hotmail.com>
wrote:

z wrote:
Eeyore wrote:
"Daniel T." wrote:
John Larkin wrote:

Sure, but where does the electricity come from?

Power plants that run at much higher efficiency

Not that great actually.

(and much cleaner per kilowatt of energy produced) than any automobile
engine

How do you reckon they're cleaner ?

could ever hope to do.

Overall thermal efficiency from typical power plant to power socket is in
the 30-40% region.

A very large marine diesel can and does EXCEED 50% thermal efficiency.. Only
now are combined cycle gas turbine generators coming on line that can beat
that but you still have transmission losses.

Graham

Little known fact; efficiency of electrical generation is currently
half of what it was in Edison's day. Well, it's a trick question,
though; Edison was businessman enough to sell off the heat as a
byproduct (isn't that what they call cogeneration?) but today
utilities, as monopolies, are too lazy too chase that efficiency/cash.
too bad for all of us.

Good point.

Certain Scandinavian countries in particular make use of this 'waste heat' for
district heating.

I can see a potential move to local district co-gen (as opposed to GW central
plants) being very attractive.

Graham

There's always a tendency to think about heating and forget about
cooling. The US population has shifted towards the South, and there is
that pesky warming trend we hear about...

The point is, without AC it would be difficult to live in lots of
places, so waste heat would have to be converted to cooling to get the
same effect. Can be done, but requires big changes. For places like
Texas, solar panels that generate the most when the sun is beating
down on your roof seem like a better bet---plus they would shade the
roof.

-tg

 

[Eeyore]

DB wrote:

Eeyore wrote:
DB wrote:

You were the one that came along and changed the subject. What was the
point of that?

Got to hell you whingeing old windbag....

Bawhawhawh. Have another pint....

I didn't btw. In fact I'd had very little to drink. So there.

Graham

 

[Eeyore]

Sevenhundred Elves wrote:

Eeyore wrote:
"rlbell.nsuid@gmail.com" wrote:

Edison could sell you the waste heat from his steam turbines (you hope
they were turbines, reciprocating pistons could be felt for hundreds
of yards through the soles of your feet), but NIMBYism meant no power
connection. Westinghouse could supply your house from halfway across
the continent. I am sure that there are utilities in large cities
that supply heat and light, in the core areas, but the return is too
small to lay the pipes in areas of low density housing.

Scandinavian countries can do it.

Graham

We not only can, we actually do it. Many households here in Sweden are
heated with waste heat from power plants. Thus the heat is not really
wasted.

It's brilliantly simple. And more should be done along these lines. Yet why do the
'greens' just want more taxes, wind turbines and hopelessly inefficiencent and
expensive solar farms ? Because they just want to change our lifestyle, not make it
more efficient.

Graham

 

[Eeyore]

Sevenhundred Elves wrote:

Eeyore wrote:
DB wrote:

You were the one that came along and changed the subject. What was the
point of that?

Got to hell you whingeing old windbag. I did no such thing. And take your peak oil
with you.

You think the oil will last forever?

No, but it's all HE ever wants to talk about.

Graham

 

[Eeyore]

tg wrote:

Eeyore wrote:

Certain Scandinavian countries in particular make use of this 'waste heat' for
district heating.

I can see a potential move to local district co-gen (as opposed to GW central
plants) being very attractive.


There's always a tendency to think about heating and forget about
cooling. The US population has shifted towards the South, and there is
that pesky warming trend we hear about...

You mean cooling at the moment actually.

The point is, without AC it would be difficult to live in lots of
places, so waste heat would have to be converted to cooling to get the
same effect. Can be done, but requires big changes. For places like
Texas, solar panels that generate the most when the sun is beating
down on your roof seem like a better bet---plus they would shade the
roof.

Only 15% of the incident sunlight is converted to electricity. It won't cool you
much. What you need is better insulated and built housing, offices etc.

A/C is NOT the outstanding problem for most of the world.

Graham

 

[DB]

Eeyore wrote:

Sevenhundred Elves wrote:

Eeyore wrote:
DB wrote:

You were the one that came along and changed the subject. What was the
point of that?
Got to hell you whingeing old windbag. I did no such thing. And take your peak oil
with you.
You think the oil will last forever?

No, but it's all HE ever wants to talk about.

Wow, now Graham is a drunk lier. Read back in this thread and it is
Graham that mentions peak oil first.

 

[Eeyore]

DB wrote:

Eeyore wrote:
Sevenhundred Elves wrote:
Eeyore wrote:
DB wrote:

You were the one that came along and changed the subject. What was the
point of that?
Got to hell you whingeing old windbag. I did no such thing. And take your peak
oil with you.
You think the oil will last forever?

No, but it's all HE ever wants to talk about.

Wow, now Graham is a drunk lier.

Sure it's YOU that's not drunk with spelling errors like that ?

Read back in this thread and it is
Graham that mentions peak oil first.

So ? Am I supposed never to mention it ?

Graham

 

[RLDeboni]

Eeyore wrote:

BretCahill@peoplepc.com wrote:

CO2 is not a pollutant.
That's not what the supreme court says :
http://www.dieselnet.com/news/2007/04epa.php
Then they're BARKING MAD.
That hardly changes the fact that man made CO2 is a pollutant.

NO CO2 is a pollutant.

Almost all plants grow faster and better in higher levels of CO2. Hence
more food.

And beverages taste better
A "pollutant" with many uses, also in the food chain ...

R.L.Deboni

 

[RLDeboni]

John Larkin wrote:

On Sat, 16 Aug 2008 12:05:38 +0200, RLDeboni
robertodeboni@deboni.name> wrote:

John Larkin wrote:

5PM, I'm in a hotel in Santa Barbara. We had a late breakfast in San
Francisco.
It's a long trip for an electric car ...
I am thinking about commuting, about 50 km range.


A smallish plug-in hybrid is a sensible vehicle. One could use it as
an electric for short trips, and run a small, efficient, fixed-speed
gasoline engine when you do need to drive all day, or when the local
electric grid is collapsing from a few million of your neighbors
trying to charge their cars overnight, too.

That may happen ... if too many misunderstand energy saving with
electricity saving and stop building power plants.
I am convinced that energy saving starts from converting transportation
from oil to electriticy and the result would be "less total energy
consumption", but "more electricity demand"

There are tons of Smart Cars here lately. They make a lot of sense as
a city car, with range for occasional trips. They don't suffer from
the weight and size penalty of batteries and electric motors. A small
car with a small gas engine is fine.

A Smart car save fuel. Surely. But you can save more fuel with and
electric car.

We stopped for gas once, for about 5 minutes, and ran 75-80
MPH most of the way. And we climbed some serious hills towards the
end.
NiMh or Li-ion batteries and new electronics for energy recovering, will
take all "serious" hills with a breeze.

But not for long. In addition to depleting the batteries, a lot of
electric motors can sustain peak output for a very short time before
they overheat. That's great as an acceleration booster, not so good
for cresting the Sierras.

Not "a lot of", but "any undersized" motor. And only if the power
controller is bad designed.
If you want a 100hp motor in needs to be a 73kW at 100% duty cycle, not
a 50kW at nominal power with 75kW burst power (your acceleration booster ;-)

We have a friend who has a new Toyota hybrid. Her gas mileage is
horrible in San Francisco, from hauling a thousand pounds or so of
batteries up and down hills.

An ICE engine, has no battery to pull up the hills, but down hills it
losses all the potential energy accumulated. An electric car, which has
a bigger electric motor than the Prius and bigger batteries and power
controlling capacity, could recover easily three fourths of that energy,
while cruising down hill. An hybrid car has the electric part undersized
to do a good job recovering energy.

The USA, especially the west, isn't like Europe or the east coast.
It's big and full of mountains and stuff.

I would say that USA has longer commuting distances as Europe, but don't
talk about mountains and hills ... Austria, Switzerland, North Italy,
South Germany. Imagine the Rocky Mountains from Main to Virginia ... ;-)

R.L.Deboni

 

[RLDeboni]

Eeyore wrote:

RLDeboni wrote:

That may happen ... if too many misunderstand energy saving with
electricity saving and stop building power plants.
I am convinced that energy saving starts from converting transportation
from oil to electriticy and the result would be "less total energy
consumption", but "more electricity demand"

Have you you had your brain examined recently ?

That's not nice
What's the reason of your comment ?

 

The general idea is that it is easier to control emissions from a few large
power plants running at optimal efficiency than it is to control it from
thousands of vehicle ICEs.

These plants have amazing filter systems. Better than what would be
affordable for automobiles.
Besides that, they run at optimal RPMs, reducing pollutions to a minimum.
That cannot said about automobile ICEs in city traffic.

Rob

A modern gasoline-powered car creates very little pollutants...
essentially zero particulates and low ppm levels of hydrocarbons and
nitrous stuff, probably cleaner watt-for-watt than the average coal
plant.

That's not what the studies say.
Daniel posted a few results in a side thread.

All IC engines are inherently dirty and the smaller they are the
dirtier they get on a per horse power basis.

Adiabatic wants a big volume/surface area which means a big engine.


Bret Cahill

 

[RLDeboni]

Rod Speed wrote:

RLDeboni <robertodeboni@deboni.name> wrote
Rod Speed wrote
RLDeboni <robertodeboni@deboni.name> wrote
Rod Speed wrote
RLDeboni <robertodeboni@deboni.name> wrote

In the example, the Power Station is powered with a MAN 5S50ME-C7 low speed engine (95 RPM, 3'800 kW power, 159
gr/kWh specific fuel oil consumption):

Thats irrelevant, hardly anyone is stupid enough to do a power station that way anymore.

It burns also natural gas (with some modifications) ...

If you're gunna power it with natural gas, you dont use that sort of engine either.

Why not ?

Because other approaches work a lot better.

50% efficiency is very good.

Not with natural gas powered power stations of any size.

Maybe 48%.
The engine modification is used on LNG Carriers Ships.

Why do you thing that a MAN 6S70ME-C engine (at 10 MW layout point)
could not keep such efficiency, fueled with natural gas ?

R.L.Deboni

 

[Sevenhundred Elves]

On Fri, 22 Aug 2008 02:13:36 +0100, Eeyore
<rabbitsfriendsandrelations@hotmail.com> wrote:

DB wrote:

You were the one that came along and changed the subject. What was the
point of that?

Got to hell you whingeing old windbag. I did no such thing. And take your peak oil
with you.

Graham

You think the oil will last forever?

S.