Electrically Powered Ultralight Aircraft

Larry Dighera wrote:
On Mon, 06 Aug 2007 05:39:01 -0700, wrote in
. com:

When they start selling cars only powered by batteries I'm going to
invest in a tow truck business.

The time has arrived:
http://www.teslamotors.com/index.php


And a good place to base the new tow truck business is about half way
between SF and LA, because that's about how far this $100,000 car will take
you.

Scroll to the bottom of the page.

http://www.teslamotors.com/performan..._batteries.php

On Mon, 06 Aug 2007 06:33:20 -0700, Airjunkie
wrote in .com:

Eric Raymond has been at it for a long time. Check it out at
www.solar-flight.com

http://www.solar-flight.com/sslink.html

Thank you for the information. His achievement is remarkable for the
time. Imagine what he could do 17 years later with today's ~40%
efficient photovoltaic cells and light weight lithium-ion polymer
batteries:



The Boeing Company http://www.boeing.com/news/releases/index.html
Boeing Spectrolab Terrestrial Solar Cell Surpasses 40 Percent
Efficiency

ST. LOUIS, Dec. 06, 2006 -- Boeing [NYSE: BA] today announced that
Spectrolab, Inc., a wholly-owned subsidiary, has achieved a new world
record in terrestrial concentrator solar cell efficiency. Using
concentrated sunlight, Spectrolab demonstrated the ability of a
photovoltaic cell to convert 40.7 percent of the sun's energy into
electricity. The U.S. Department of Energy's National Renewable Energy
Laboratory (NREL) in Golden, Colo., verified the milestone.

"This solar cell performance is the highest efficiency level any
photovoltaic device has ever achieved," said Dr. David Lillington,
president of Spectrolab. "The terrestrial cell we have developed uses
the same technology base as our space-based cells. So, once qualified,
they can be manufactured in very high volumes with minimal impact to
production flow."

High efficiency multijunction cells have a significant advantage over
conventional silicon cells in concentrator systems because fewer solar
cells are required to achieve the same power output. This technology
will continue to dramatically reduce the cost of generating
electricity from solar energy as well as the cost of materials used in
high-power space satellites and terrestrial applications.

"These results are particularly encouraging since they were achieved
using a new class of metamorphic semiconductor materials, allowing
much greater freedom in multijunction cell design for optimal
conversion of the solar spectrum," said Dr. Richard R. King, principal
investigator of the high efficiency solar cell research and
development effort. "The excellent performance of these materials
hints at still higher efficiency in future solar cells."

Spectrolab is reducing the cost of solar cell production through
research investments and is working with several domestic and
international solar concentrator manufacturers on clean, renewable
solar energy solutions. Currently, Spectrolab's terrestrial
concentrator cells are generating power in a 33-kilowatt full-scale
concentrator system in the Australian desert. The company recently
signed multi-million dollar contracts for its high efficiency
concentrator cells and is anticipating several new contracts in the
next few months.

Development of the high-efficiency concentrator cell technology was
funded by the NREL's High Performance Photovoltaics program and
Spectrolab.

A unit of The Boeing Company, Boeing Integrated Defense Systems
http://www.boeing.com/ids/index.html is one of the world's largest
space and defense businesses. Headquartered in St. Louis, Boeing
Integrated Defense Systems is a $30.8 billion business. It provides
network-centric system solutions to its global military, government,
and commercial customers. It is a leading provider of intelligence,
surveillance and reconnaissance systems; the world's largest military
aircraft manufacturer; the world's largest satellite manufacturer; a
foremost developer of advanced concepts and technologies; a leading
provider of space-based communications; the primary systems integrator
for U.S. missile defense; NASA's largest contractor; and a global
leader in sustainment solutions and launch services.
###

As the invertor can exert more retardation than brakes, the
conventional disc brakes have been discarded altogether.

Oh, boy. Knowing first-hand the reliability of
electrical stuff...

Dan

In rec.aviation.piloting Gig 601XL Builder wrDOTgiaconaATsuddenlink.net wrote:
Larry Dighera wrote:
On Mon, 06 Aug 2007 05:39:01 -0700, wrote in
. com:

When they start selling cars only powered by batteries I'm going to
invest in a tow truck business.

The time has arrived:
http://www.teslamotors.com/index.php


And a good place to base the new tow truck business is about half way
between SF and LA, because that's about how far this $100,000 car will take
you.

Scroll to the bottom of the page.

http://www.teslamotors.com/performan..._batteries.php

Or half way between LA and Vegas.

The page leads to some "interesting" information.

If you cruise around you find claims that the energy usage is 110 Wh/km,
and recharge time of about 3.5 hours.

110 Wh/km is about 11.7 kWh for a 100 mile trip.

If the charging process is 100% efficient (not in this universe), to
recharge in 3.5 hours requires 11.7/3.5, or about 3.3 kW.

At 120 V, that's 27.5 A, which is a bit beyond the standard 15 A outlet.

At 220 V, that's about 15 A, so you better have a 220 outlet nearby.

Elsewhere they talk about recharging in 2 hours with some 70 A system.

Anyone out there got a 70 A plus safety factor outlet in their house?

They talk about "With your electrical company's incentive pricing
factored in, it will cost you roughly 1 cent per mile to drive the
Tesla Roadster".

Keep in mind they are targeting California.

In California, the "incentive pricing" is the more you use, the more
you pay per kWh.

There is the quote "Single-occupancy access to all carpool lanes".

Yeah, true for a while, but all the permits that are ever going to
be issued were issued long ago.

Just too much hype and inconsistancy for me.


--
Jim Pennino

Remove .spam.sux to reply.

On Aug 5, 1:12 pm, Larry Dighera wrote:
On Sun, 05 Aug 2007 10:53:30 -0700, Phil wrote
in om:

Very interesting. It doesn't mention how long it takes to charge the
batteries.

There's a pod-cast here in which Sonex's owner John Monnett and
engineer Pete Buck discuss that topic:http://www.aviationweek.com/media/audio/sonex.mp3

I wonder if anyone has done any experiments with a hybrid drive system
for an aircraft. I am thinking of something like a 3-cylinder diesel
engine providing enough power for cruise, supplemented with a battery
pack and motor for takeoff and climb.

On Aug 6, 11:14 am, wrote:
In rec.aviation.piloting Gig 601XL Builder wrDOTgiaconaATsuddenlink.net wrote:

Larry Dighera wrote:
On Mon, 06 Aug 2007 05:39:01 -0700, wrote in
. com:

When they start selling cars only powered by batteries I'm going to
invest in a tow truck business.

The time has arrived:
http://www.teslamotors.com/index.php
And a good place to base the new tow truck business is about half way
between SF and LA, because that's about how far this $100,000 car will take
you.
Scroll to the bottom of the page.
http://www.teslamotors.com/performan..._batteries.php

Or half way between LA and Vegas.

The page leads to some "interesting" information.

If you cruise around you find claims that the energy usage is 110 Wh/km,
and recharge time of about 3.5 hours.

110 Wh/km is about 11.7 kWh for a 100 mile trip.

If the charging process is 100% efficient (not in this universe), to
recharge in 3.5 hours requires 11.7/3.5, or about 3.3 kW.

At 120 V, that's 27.5 A, which is a bit beyond the standard 15 A outlet.

At 220 V, that's about 15 A, so you better have a 220 outlet nearby.

Elsewhere they talk about recharging in 2 hours with some 70 A system.

Anyone out there got a 70 A plus safety factor outlet in their house?

They talk about "With your electrical company's incentive pricing
factored in, it will cost you roughly 1 cent per mile to drive the
Tesla Roadster".

Keep in mind they are targeting California.

In California, the "incentive pricing" is the more you use, the more
you pay per kWh.

There is the quote "Single-occupancy access to all carpool lanes".

Yeah, true for a while, but all the permits that are ever going to
be issued were issued long ago.

Just too much hype and inconsistancy for me.

--
Jim Pennino

Remove .spam.sux to reply.

I was aware of this project based upon the Lotus Elise which is a
pretty amaxing performance car with only a small gas engine. Its
pretty much hand built with composites and looks even better in person
than in pictures. With enough battery power the power potentail is
impressive. I think I'll hold off on the tow truck business until they
sell enough $100,000 (assuming they will give away the charging
station) cars to justify my investment.

On Mon, 06 Aug 2007 09:42:46 -0700, wrote
in .com:

As the invertor can exert more retardation than brakes, the
conventional disc brakes have been discarded altogether.

Oh, boy. Knowing first-hand the reliability of
electrical stuff...


It's a prototype. The choice not to equip the automobile with brakes
demonstrates how effective the regenerative braking is, but apparently
you have to carry chocks when you park it. :-)

In rec.aviation.piloting Phil wrote:
On Aug 5, 1:12 pm, Larry Dighera wrote:
On Sun, 05 Aug 2007 10:53:30 -0700, Phil wrote
in om:

Very interesting. It doesn't mention how long it takes to charge the
batteries.

There's a pod-cast here in which Sonex's owner John Monnett and
engineer Pete Buck discuss that topic:http://www.aviationweek.com/media/audio/sonex.mp3

I wonder if anyone has done any experiments with a hybrid drive system
for an aircraft. I am thinking of something like a 3-cylinder diesel
engine providing enough power for cruise, supplemented with a battery
pack and motor for takeoff and climb.

The advantage for hybrids comes from stop and go driving where the
battery is charged by regenerative braking.

There isn't much stop and go flying.

--
Jim Pennino

Remove .spam.sux to reply.

In article ,
Orval Fairbairn wrote:

In article . com,
James Sleeman wrote:

On Aug 6, 4:52 am, Larry Dighera wrote:
Electrically Powered Ultralight Aircraft

It's a nice idea, but realisitically there are too many problems, not
the least of which is battery size, weight, cost and safety. I don't
really see batteries as a viable in the near future (I struggle to see
them as viable in the distant future either).

Look at the problem this way: In an all-electric machine, you carry ALL
of your energy supply with you: fuel and oxidizer -- to make electricity.

With any IC engine, you carry the fuel only -- the air is free (20%
oxygen), so, at 15:1 air/fuel ratio, you would need 90 lb of air for
each gallon of fuel.

Therefore, for a nominal 50 gallon fuel capacity (300 lb), you would
have to carry an additional 7500 lb of air.

That is a lot of weight for a 3000 lb aircraft!

DUH! I meant 4500 lb of air! That is still a lot of weight penalty.

"Bill Daniels" bildan@comcast-dot-net wrote in message
. ..

wrote in message
ups.com...

For a battery-powered car todays practical approach is to have a
second engine for backup or as you suggest to generate electricity.
When they start selling cars only powered by batteries I'm going to
invest in a tow truck business. For aircraft the best use for
batteries today is to start the engine. Lange has demonstrated what is
possible with today's batteries/motors and while it provides an
attractive self-launch the cost and range tradeoffs bring it back into
perspective.



I think this is a little pessimistic. Critics of the pure electric seem
to focus on the "one-car does everything" strategy where it's easier to
find faults. The "electrics don't equal engine powered cars" isn't the
whole story.

Americans, at least, seem to have developed a another strategy for dealing
with fuel prices that spike every summer. They own an old, cheap econobox
they dust off when gas prices exceed $3. They drive their SUV's only when
they need the capacity.

This 2-car strategy works for pure electrics (EV's) too. Survey after
survey notes that a huge majority of drivers do less than 40 miles a day
which is easilly met with EV's. The current best range of 100 miles
provides better than a 2:1 safety margin.

Economically, the 2- car strategy can be implemented without owning two
cars. Just RENT the SUV when you need it. Considering total ownership
costs, this is a good deal. Looking at all the rental discounts available
to me, I don't plan to replace my SUV.

Interestingly, range alone isn't, in itself, a killer. If the battery
pack can be recharged in less than 10 minutes, the limited range is less
of a factor. The newest Lithium Phospate cells can reach 80% charge in
one minute and full charge in 5 minutes. So, if you invest in a tow
truck, get one with a diesel generator set.

Most likely, popular parking areas will be equipped with charging outlets.
I can imagine shopping centers with signs saying, "Shop here while you
recharge, FREE!" I can also imagine employers getting tax incentives to
provide their workers with access to a recharging station.

My bets are on the pure electric vehicle.


In the early 1980's, Mother Earth News made a hybrid car that got 75 miles
per gallon. It was a Opel GT (heavy) powered by a jet engine starter motor
(inefficient) and a relatively inefficient small gas motor. The gas motor
powered the alternator which charged the batteries which ran the electric
motor. At the time, they noted that this wasn't new technology, but was the
way diesel train engines worked. In 2010, GM will introduce the Chevy Volt,
which is pretty much the same concept, which I'm convinced is the way to go.
I think this does have promise for airplanes as well. The IC engine and
batteries can be place for optimum weight distribution, and the IC engine
can be heavilly vibration isolated.