Can Aircraft Be Far Behind?

Larry Dighera wrote:

"Danny Deger" wrote:

I think the 75 hp for an hour is very close. Not enough for
an airplane in my opinion.

How much horsepower does a Cessna 150 equipped with a Continental
O-200 power plant develop at 75% cruise power?

Take a look at the chart here
http://www.teslamotors.com/performance/performance.php, and notice
that at ~8,000 RPM the Tesla electric motor will develop nearly 200
Hp. Now what's your opinion?

The issue is not the maximum horsepower that the engine can produce, but
the capacity of the batteries. 75 HP-hr means that the batteries can
supply 75 HP for a period of one hour, under ideal conditions. If the
motor drew 150 HP, then the batteries could only supply power for 30
minutes.

Consider that a Cessna 150 can fly for perhaps 3 hours, at 75% power. To
get the equivalent range with batteries would require about 3,000 lb. of
batteries, which would be totally impractical for an aircraft that now
grosses at 1,600 lb.

On Tue, 09 Jan 2007 16:13:39 -0600, Chris W wrote in
:

Larry Dighera wrote:

Electrically powered vehicles are the only hope to reduce the transfer
of wealth from the western world to the middle east,

Electric cars will never eliminate our dependence on oil from the middle
east. That is a bold statement and I could be wrong

In the short term, there is no question your statement is true, IMO.
In the long term, the US will need to develop many alternate power
technologies to remain independent.

but I believe the
only way to eliminate our dependence on foreign oil, is to use every
possible alternative to power cars and trucks, including bio diesel,

Vegetable oil seems like a great renewable alternative fuel to me. The
question is, is there enough agricultural land to grow the amount
necessary.

methanol (from something other than corn),

To my thinking, methanol is never going to be a significant source of
energy due to its low energy density and high energy demands for
manufacture. Its in vogue now due to farm lobby interests, IMO.

natural gas,

There is an enormous amount of natural gas frozen under the seas.
We'll have to learn how to harvest it, but there is little doubt it
will become a prime fuel source in the future, IMO.
http://marine.usgs.gov/fact-sheets/g...tes/title.html

maybe hydrogen,

As a storage medium for photovoltaic solar energy, hydrogen and
oxygen, the natural products of the disassociation of water, can be
"burned" directly in fuel cells. But that technology is still in its
infancy from what I've read. Here's what Honda has in mind:
http://world.honda.com/FuelCell/HomeEnergyStation/
This sort of equipment is making fuel whenever the sun is shining.

and to what I believe will be a limited extent battery power. At the
same time we should stop using fuels to generate electricity that work
well in vehicles so as to save it for vehicles and use nuclear,

Nuclear has shown itself to be problematic:


http://environment.newscientist.com/...n-uplands.html
Chernobyl haunts the Norwegian uplands
12:00 28 October 2006

Tougher controls on the slaughter of sheep have been imposed in
Norway after they were found to be contaminated with unusually
high levels of radioactivity from the Chernobyl disaster in 1986.

The Norwegian Radiation Protection Authority (NRPA) says the
problem has arisen because the sheep have feasted on an unusually
large crop of mushrooms, which were more plentiful than usual
because of wet weather. Previous research has shown that fungi
take up more radioactivity from the soil than grasses or other
plants.

... the discovery of such high levels of radioactivity so long
after the Chernobyl accident came as a surprise. "No one at the
time expected contamination to be so high more than 20 years after
the event," he says.

This occurred a long distance from Chernobyl. I'd prefer that we
didn't poison ourselves in the search for fuel.

coal (which can be made clean with the byproduct useful for making concrete
stronger),

Coal is plentiful and can be made a cleaner source of energy, but it's
not happening yet:
http://environment.newscientist.com/...d=FGPEPLHHNEGB

hydro-electric, wind and solar (and I don't mean PV cells).

Decentralizing electrical power is a great idea. Small wind turbines
seem like a good idea: http://www.quietrevolution.co.uk/

Another untapped power source, ocean waves, seems ripe to help fill
the need: http://en.wikipedia.org/wiki/Wave_power

What I can't understand is why solar heat for your house isn't being
pushed more. Unlike solar electric cells, solar heat can easily and
quickly pay for it's self. In many parts of the country it can provide
over 90% of your heating needs. The only disadvantage I can see, is for
it to be most cost effective, you need to have it built into the house
from the start. It's hard to add it to existing homes and have it be
efficient unless certain things just happen to be right. That may be
part of why it isn't talked about more.

Of course, solar swimming pool heating is being used extensively in
locations where it is feasible.

We seem to have strayed a bit from the topic of aviation, but I
believe you are correct in intimating that it will be an aggregate of
technologies that will eventually supplant middle east petroleum in
the US if we are to remain independent in the future.

On Tue, 9 Jan 2007 18:17:26 -0500, "Morgans"
wrote in :


"Larry Dighera" wrote

Electrically powered vehicles are the only hope to reduce the transfer
of wealth from the western world to the middle east, and reduce global
warming. If the US doesn't find some breakthrough technology soon,
we'll all be speaking Farsi before long. :-(

How do you figure that?

Well, not the ONLY hope, but part of the solution to petroleum
independence.

What do you suppose generates the majority of the electricity to recharge
that car? Fossil fuels.

That is true today, but petroleum based energy sources should be
diverted over time to the manufacture of alternate energy producing
technology, rather than burned as motive fuels if the US is to slip
out of the middle east grip toward which it is headed.

Until we start building nuke plants,

Not my first choice, nuclear has shown itself to be problematic in a
number of ways, financially, environmentally, politically ....

or find a breakthrough in solar power generation, we will be stuck
with the oil and gas noose around our necks.

I agree.

Currently, we are poised on the brink of a global revolution in
photovoltaic cell production. Manufacturing plants for new, cheaper
cell technologies that require less environmental impact to produce,
and higher efficiencies are slated to begin coming on now as supply is
unable to meet demand. Much of the venture capital that fueled the
dot com boom is being diverted toward solar technology startups. I
look for photovoltaic costs to decline and efficiencies to increase in
the near future. And with the power companies paying customers for
running their meters in reverse, the stage is set for decentralized
energy production in the US.

Larry Dighera wrote:
Nuclear has shown itself to be problematic:


http://environment.newscientist.com/...393-chernobyl-
haunts-the-norwegian-uplands.html Chernobyl haunts the Norwegian
uplands 12:00 28 October 2006

This occurred a long distance from Chernobyl. I'd prefer that we
didn't poison ourselves in the search for fuel.


That's what happens when you let a morally and finacially bankrupt country
play with fire. Overall Nuclear energy has a damn good safety record. There
is, of course, the issue of what to do with the waste but technology and
reuse of the material should be able to take care of that.

But the Chernobyl issue is also a symptom of the Big Nuke Plant that we and
virtually all other counties have used. The outcome of this is astonomical
costs for each plant because first they are so damn big and virtually each
one is designed on a clean sheet of paper.

On the other hand we have nuclear powered ships with smaller reactors that
are fairly uniform and have been proven to be very safe. And those reactors
are designed to be shot at.

Here's a cool idea that our own government came up with for developing
nations. I see no reason it couldn't be used on a local basis right here at
home. http://www.llnl.gov/str/JulAug04/Smith.html

On 9 Jan 2007 15:41:53 -0800, wrote in
. com:

Larry Dighera wrote:
http://www.teslamotors.com/

The real issue is probably the lack of a big enough market for such
innovations in the GA sector.

That is an excellent point, as it always is when considering the
aviation market. Thank you for raising it.

Aviation in general is a very hard business to make money in and
even giants like Boeing and Airbus seem to be never too far from
slippery ground.

However, new technologies do seem to appear in the aviation
marketplace regularly, the use of composites and titanium for aircraft
structures for instance. And an electrically powered aircraft was
recently certified, so there is evidence, that despite the small
aviation market, aviation still manages to lead the way in technologic
innovation to some extent.

On 2007-01-09, Larry Dighera wrote:
Charge time for the Altair batteries is only a few minutes as I
recall.

I'm extremely skeptical - if these batteries are not snake oil, consider
this. Let's call "a few minutes" 10 minutes, and let's say the battery
pack stores 70kWh (enough to run a motor producing 94 hp for 1 hour).

To put 70kWh's worth into a battery pack in 10 minutes would require a
charger capable of putting out 420kW.

At 120 volts, 420kW would require a current of 3500 amps. Look at the
massive thick wire coming into your house (which maybe is rated at 80
amps).

Now let's say these batteries give three hours worth at 70kWh, and
charge in 10 minutes - now you're up to 10,500 amps at 120 volts. YOU
CANNOT AVOID high voltage, high amperage controls in a vehicle like the
Tesla, regardless of the battery technology. You are moving around
tremendous amounts of current. If this mythical charger was 99%
efficient, the 1% emitted as heat could heat an entire office building
in the dead of winter in central Canada. To consider this new battery
technology a silver bullet is to ignore the well established laws of
physics. Now imagine if *everyone* is charging their mythical car. No
practicable electricity distribution network that's feasable in the near
term could cope.

It would be totally and utterly impractical to charge these batteries at
this rate. I'll let you do the calculations for the equivalent in
electricity that filling a Cessna 150 with avgas in 4 minutes (the
typical time to do it at a self serve pump) would be.

--
Yes, the Reply-To email address is valid.
Oolite-Linux: an Elite tribute: http://oolite-linux.berlios.de

Consider that a Cessna 150 can fly for perhaps 3 hours, at 75% power. To
get the equivalent range with batteries would require about 3,000 lb. of
batteries, which would be totally impractical for an aircraft that now
grosses at 1,600 lb.

How about fuel cells?

Jose
--
He who laughs, lasts.
for Email, make the obvious change in the address.

On 2007-01-10, Larry Dighera wrote:
Vegetable oil seems like a great renewable alternative fuel to me. The
question is, is there enough agricultural land to grow the amount
necessary.

The trouble is the US is often looking at the wrong things for biofuels
because of the farming lobby wanting subsidies. There are much better
ways of making biofuel than using corn for ethanol.

Algae processes can deliver 10,000 us gallons/acre of biofuel (compared
with about 150 gal/acre for ethanol). It can be done as an industrial
process, using rust belt industrial land - no agricultural land needed.

Research on cellulosic ethanol continues. This means any old plant
matter will do. You can grow weeds in very poor soil, and make fuel from
that - you don't even need fertiliser, just find a vigorous invasive
plant and grow it on land marginal for agricultural use.

"In June 2006, a U.S. Senate hearing was told that the current cost of
producing cellulosic ethanol is US $2.25 per US gallon (US $0.59/litre).
This is primarily due to the current poor conversion efficiency. At
that price it is not competitive when distribution costs are added.
However, the Department of Energy is optimistic and has requested a
doubling of research funding. The same Senate hearing was told that the
research target was to reduce the cost of production to US $1.07 per US
gallon (US $0.28/litre) by 2012."

So there's far more than one source available, so long as politicians
aren't bought and paid for. Aviation will ALWAYS require a very high
energy density fuel, and no battery in the forseeable future will cut it
for practical aviation. But biofuels will.

--
Yes, the Reply-To email address is valid.
Oolite-Linux: an Elite tribute: http://oolite-linux.berlios.de

On Wed, 10 Jan 2007 03:16:27 GMT, wrote in
:

Larry Dighera wrote:
If an aircraft were covered in Spectrolab* triple-junction solar
cells, fuel would be free during the daylight, quiet, and pollution
free.

You get something like 1 kW/m^2 of energy from the sun under good
conditions, like being on the equator on a clear day in the summer. I
think current PV cells are somewhere around 10% to 15% efficient,

That's why I specified the Spectrolab triple-junction photovoltaic
cells and provided a link to them. They are able to provide 30%
efficiency as they are tuned for red, blue and IR wavelengths.

so that's 100-150 watts per square meter. Google says a Cessna 182 has
about 16.2 m^2 of wing area, so you might get around 1.6-2.4 kW from
solar cells covering the wings. You'd get a little more from the rest
of the skin, but IMHO probably not more than 50% additional, or 2.4
to 3.6 kW. That's 3.2 to 4.8 hp that the cells are contributing.

Assuming your figures are correct, and given the specified cells, that
figure could be 200% to 300% of your figures. It could take a day to
fully recharge a exhausted battery in locations where city power was
unavailable.

Also, does the solar cell factory run on solar cells?

Ummm.. There is that issue, but Honda is addressing it. Search on
their web site for solar cells, and you will learn that they beginning
production of a new type of cell not based on silicon. It's
manufacture is supposed to reduce the environmental impact resulting
from their creation.

What is the weight of the Continental O-200 complete with its
manifolding, muffler, oil, and fuel?

http://en.wikipedia.org/wiki/Continental_O-200 says about 170 lbs (77
kg) dry for just the engine.

The Tesla Motors engine weighs less than 70 lbs per their specs.

For an electric drive, in addition to the weight of the motor and
batteries, you'll also need to figure in the weight of the inverter
that changes DC into three-phase AC. Some of these inverters are
air-cooled and some are liquid-cooled.

True. I read that the Tesla Motors system is liquid cooled.

http://www.wired.com/news/wiredmag/0...l?tw=rss.index
Tesla has managed to produce an impractical and exorbitantly
expensive vehicle just as a revolutionary new battery has appeared
on the scene.

I've only been involved in hybrid cars for about six years,

How are you involved in hybrid cars? As a manufacturer, designer,
prototype builder, driver, or what?

but I've already seen a few "revolutionary new batteries" come and go.

True. GM's EV1 originally employed lead-acid batteries. The
follow-on integration used NiMH technology, but it wasn't a success
either. Clearly, GM lacks the creative insight to produce a viable
electric car. It's like teaching an elephant to dance.
http://en.wikipedia.org/wiki/Ev1

Many of these batteries turn out to be quite good at ensuring a steady flow of
press releases out and money in, but never quite manage to push any
actual electrons.

Agreed. But lithium technology is used in millions of laptop
computers worldwide. It's mainstream, and proven (despite Sony's
manufacturing anomalies).

On Tue, 9 Jan 2007 21:24:33 -0500, "Capt. Geoffrey Thorpe" The Sea
Hawk at wow way d0t com wrote in
:

"Larry Dighera" wrote in message
.. .
On Tue, 09 Jan 2007 18:20:07 GMT, "Neil Gould"
...
Perhaps the Tesla roadster doesn't need to develop 75 Hp during it's
entire run time, and there's the issue of regenerative braking, but
these things are not germane to electrically powered aircraft which
typically must produce 75% rated Hp continuously in cruise flight.

Unlike automobiles, aircraft not only require motive power to propel
them forward, but they are not afforded the luxury of a roadway to
support their weight, and I would presume aircraft drag is
considerably more than an automobile.


That's probably not a good assumption.

From http://www.t18.net/resources/T-18%20orig%20hdbk.doc page 34

(Perhaps you'd be good enough to cut and paste the reverent section
into a follow up. I'm uneasy opening MS Word documents from anonymous
sources.)

An O-290 Powered T-18 can get 20+ miles per gallon at 170+ mph true air
speed

Not many gasoline powered cars can match this.

That's for sure, whether you're referring to automobile speed or MPG
of SUVs. :-)