X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Thu, 24 Jan 2008 17:34:57 -0500 Message-ID: X-Original-Return-Path: Received: from mtao01.charter.net ([209.225.8.186] verified) by logan.com (CommuniGate Pro SMTP 5.2c4) with ESMTP id 2691643 for lml@lancaironline.net; Thu, 24 Jan 2008 11:25:25 -0500 Received-SPF: pass receiver=logan.com; client-ip=209.225.8.186; envelope-from=troneill@charter.net Received: from aarprv04.charter.net ([10.20.200.74]) by mtao01.charter.net (InterMail vM.7.08.02.00 201-2186-121-20061213) with ESMTP id <20080124162442.BUX9082.mtao01.charter.net@aarprv04.charter.net>; Thu, 24 Jan 2008 11:24:42 -0500 Received: from axs ([75.132.198.100]) by aarprv04.charter.net with SMTP id <20080124162436.ZJQG17353.aarprv04.charter.net@axs>; Thu, 24 Jan 2008 11:24:36 -0500 X-Original-Message-ID: <00b901c85ea5$9d8987b0$6501a8c0@axs> From: "terrence o'neill" X-Original-To: "Lancair Mailing List" X-Original-Cc: "sean" , "frank o'neill" , "tim" , "Lucia" References: Subject: Re: [LML] Electric Powered Lancair - Long X-Original-Date: Thu, 24 Jan 2008 10:24:38 -0600 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_00B6_01C85E73.52B08810" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.3138 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3198 X-Chzlrs: 0 This is a multi-part message in MIME format. ------=_NextPart_000_00B6_01C85E73.52B08810 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Cool! But you forgot TAX! =20 Wait till the legislators find out about this. What hunk of current gas = prices is tax?=20 Also, fifth item in the Cons list: batteries would cut fataliitis in = half (according to my old data), considering that half the lightplane = deaths happen in survived crashes followed by fatal post-crash fires. = Recall Quincy, IL. All-in-all electrical power sounds great to me, but as a cynic I don't = see corporation-owners permitting the obsoleting of their ancient and = profitable monopolistoc battery technology without spending millions on = lobbiests to stall-delay-delay it ... unless a miracle should happen and = we elect Ron Paul ro Dennis Kucinich, and he avoids assassination.. = Oops! A politically-incorrect statement. I withdraw and retract my = last remark. : ) terrence LNC2 N211AL 99.9999% ----- Original Message -----=20 From: lancairjim@aol.com=20 To: lml@lancaironline.net=20 Sent: Thursday, January 24, 2008 07:03 AM Subject: [LML] Electric Powered Lancair - Long OK, so this is a little off-topic and its most certainly a = flight-of-fantasy but it=E2=80=99s too cold and wet to go flying or to = work on my plane so cut me some slack. I apologize in advance for its = length. The inspiration for the treatise that follows was an announcement by a = researcher at Stanford University just before Christmas. He claims to = have invented a new type of lithium-ion battery based on a silicon anode = which has 10 times the energy density compared to existing, = carbon-anode, lithium-ion batteries. A factor of 10! That's huge! = Normally, advancements in battery technology are measured a few = percentage points at a time. You can read about it here and decide for = yourself about the validity: = (http://news-service.stanford.edu/news/2008/january9/nanowire-010908.html= ) Needless to say, the blogs and newsgroups dealing with alternative = energy and electric cars have lit up like a Las Vegas night but I was = wondering how this technology might affect an airplane. In particular, = what if these batteries were used to power my still-under-construction = LNC2. A "slippery" airplane like a Lancair should be ideal as an = electric powered airplane due to its inherent efficiency in the air. Everything which follows is based on the assumption that the = announcement is accurate, that the energy density of the anode will be = reflected in the energy density of the whole battery and that the = technology will proceed to commercialization without any problems. These = are major assumptions. We all remember cold fusion. As a point of reference, Tesla Motors, Inc. (www.teslamotors.com) has = developed a 53 kWh lithium-ion battery pack to power their slick new = electric sports car, the Tesla Roadster. This battery pack uses existing = technology and only weighs 900 lbs!!! We can calculate the energy density of an existing technology battery = pack by dividing 53 kWh by 900 lbs. The result is about 0.06 kWh /lb. If = the new technology has an energy density 10 times the old, then the new = technology is 10 times 0.06 kWh/lb or 0.6 kWh/lb. The weight of batteries which can be accommodated in the LNC2 is equal = to the weight of the stuff we are removing including the IO-360 engine = and accessories and the weight of avgas less the weight we are adding = back in such as the electric motor, gearbox and associated electronics. The total avgas in a typical LNC2-320/360 is 21 gals in each wing plus = 10 in the header tank for a total of 52 gals times 6 lbs per gal = resulting in a total avgas weight of 312 lbs. Assuming the engine = installation is 350 lbs (I'm going by memory here) gives a total weight = of 662 lbs (312 plus 350) which can be eliminated from the LNC2 if you = are converting it to electric. Calculating the weight of an electric = motor and controls is a little less precise. Again turning to Tesla = Motors, they have developed a 185 kW (about 250 HP) electric motor for = their roadster which weighs only about 70 lbs. This is a bigger motor = than we actually need compared to the 160 =E2=80=93200 HP engines = usually found in LNC2s but this isn't all that accurate so lets go with = it. To that we have to add the weight of the gearbox (the motor turns at = 13,000 rpm) and the electronic controls. I don't have a handle on those = but lets assume that the whole package of motor, gearbox and controls = weighs 162 lbs. Subtracting the motor, gearbox and controls (162 lbs) = from the weight of the avgas and Lycoming (662 lbs) leaves us with 500 = lbs available for batteries (funny how these things work out). With = batteries storing 0.6 kWh/lb we have a total energy storage of 300 kWh = (500 lbs times 0.6 kWh/ lb). I suppose someone on this list will insist = that a backup set of batteries is required! They will be ignored for = now. Assuming an LNC2 with a 180 HP engine running at 65% power cruises, at = altitude, at 200 kts (230 mph) we see that there is 117 HP (180 HP times = 0.65) going to the prop. This is equal to about 88 kW (0.75 kW per HP). = Assuming that the electric motor and controls are about 85% efficient we = find that the electric motor will be drawing about 103 kW (88 kW divided = by 0.85) of electric power from the batteries to maintain the same = speed. Endurance is the energy stored (300 kWh) divided by the rate of usage = (103 kW) or 2.9 hours. Range is endurance (2.9 hours) times the speed = (230 mph) or about 670 statue miles without reserves. This performance = isn't as good as the existing avgas powered version but this is still a = very usable, practical, airplane. The range can be extended by going to = higher altitudes or by flying at a lower speed. Alternatively, = redesigning the airplane for say, another 200 lbs of wing mounted = batteries would put it in the same league as the avgas version of the = LNC2 in terms of range and endurance at the same speed. Recharging batteries this large is a major issue. A 240 volt , 200 = amp, single phase service would require about 6 hours and 15 minutes = (neglecting charger loses) to fully charge a 300 kWh battery pack = (300,000 Wh divided by 240 V divided by 200 A). This is probably = acceptable for overnight charging in a hangar assuming it has that kind = of a power feeder available ;-) Fast recharging, say something like a 5C = charge rate ( i.e., 12 minutes) at a public use charging station at a = remote airport would be a real technical challenge. That would require a = 1.5 MW feed. If we assume that the charging is done at 500 volts, a 5C = charge rate is equivalent to 3,000 amps! Oooops! Based on my = understanding of the inventor's data, he hasn't tested the new batteries = at anything greater than a 1C charge rate (i.e., 1 hour) and that = resulted in reduced energy density. However, the battery is in the = earliest stages of testing and development. One last calculation. My local utility has a special off-peak rate of = 5 cents per kWh for charging electric cars. Assuming this is also = applicable to electric airplanes, we have $0.05 per kWh times 300 kWh = used during the above described flight or $15 total fuel cost. That's = roughly one-tenth the cost of avgas (at $5/gal) for the same flight. I = doubt you can buy a 600 mile bus ticket for $15. Of course this ignores = battery replacement cost which is unknown for this new technology but, = at worst, is probably comparable to an engine rebuild. So why would anyone want an electric airplane assuming one could be = built with comparable performance and price? The following "Pros" have = occurred to me: 1.. Virtually eliminates noise and vibration.=20 2.. Lower operating cost.=20 3.. No consumption of petroleum products, foreign or domestic (very = little electricity is generated in the US from burning oil).=20 4.. No exhaust emissions from the airplane including either = greenhouse gases (e.g., CO2) or traditional pollutants (e.g., NOx, SOx, = particulates, etc.). Emissions from the electric generating plants that = supply the electricity is a whole 'nuther subject.=20 5.. No danger from avgas fires or explosions.=20 6.. Ultimate altitude engine. An electric motor will continue to = produce rated power from sea level to outer space if you figure out a = way to cool it.=20 7.. No more worries about future supplies of tetraethyl lead or from = EPA mandates for cleaner burning engines or fuel.=20 8.. No more concerns about fuel contamination by water, ethanol, = etc.=20 9.. No more worries about fuel supply in general. Just the = occasional black- or brown-out.=20 10.. No more worries about LOP/ROP, cylinder head cracking, broken = crankshafts, galled cams, arcing mags, etc., etc.=20 11.. Potential for much higher component reliability. The electric = powered plane would probably only have two moving parts, the motor shaft = and the prop shaft, as opposed to the myriad of parts going suck, = squish, bang, blow hundreds of times a second.=20 12.. By combining two half-size electric motors on one shaft in one = housing and supplying each set of windings with its own electronics and = dedicated battery pack, you have almost the same system level = reliability as you do with a twin engine airplane with very little = increase in cost or weight and no asymmetric thrust problems.=20 13.. Reduced maintenance (e.g., no oil and filter changes, etc.)=20 14.. No carbon monoxide to worry about.=20 15.. No vapor lock to worry about. There are, of course, a few reasons why one would not want an electric = airplane. Here is a list of the "Cons" that I thought of: 1.. Virtually eliminates noise. Yes, I know its also in the "Pro" = list but have you ever stood near a P-51 or a Corsair doing a high = speed, low altitude pass. If you haven't and you like airplanes then = that should be items 1 and 2 on your "Bucket List".=20 2.. Lack of infrastructure for "slow" recharging in your hangar. No = real technical issues so this is a solvable problem. All it takes is = time and money.=20 3.. Lengthy recharge times at public use facilities. Many technical = challenges to "fast" recharging in terms of the infrastructure on the = supply side, the interconnection and battery considerations. May have to = await the development of suitable ultracapacitors instead of batteries.=20 4.. Battery life and replacement cost unknown. May turn out to be a = non-issue.=20 5.. Potential for electrical shocks, fires and explosions. Hard to = quantify relative to the danger of fires and explosions from avgas.=20 6.. Increased potential for engine failure due to static discharge = or lightning strikes. With increased use of electronics for = reciprocating engine control, this may be a moot point determined mostly = by the quality of component level design and installation rather than = any inherent system level considerations.=20 7.. Landing weight equals takeoff weight. A potential problem for = the LNC2 although should not be a problem for a clean-sheet-of-paper = design.=20 8.. Risk of the batteries self-immolating like certain laptop = batteries have done. Unknown if this new technology precludes that type = of event. So where does all this leave us? No where for now as the inventor says = it will take 5 years to commercialize the new battery design. We will = have lots of time to see if it lives up to its hype. Hope you all = enjoyed this little exercise and will find it thought provoking. It = makes you wonder what general aviation will look like in 50 years. Yes, I know I should stop daydreaming and get back to work on my = plane. Jim McKibbin LNC2 =E2=80=93 30% and holding -------------------------------------------------------------------------= ----- More new features than ever. 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Cool!
But you forgot = TAX! =20
Wait till the = legislators find=20 out about this. What hunk of current gas prices is tax? =
 
Also, fifth item in = the Cons=20 list:  batteries would cut fataliitis in half (according to my = old=20 data), considering that half the lightplane deaths happen in survived = crashes=20 followed by fatal post-crash fires. Recall Quincy, IL.
 
All-in-all = electrical power=20 sounds great to me, but as a cynic I don't see corporation-owners = permitting the=20 obsoleting of their ancient and profitable monopolistoc battery = technology=20 without spending millions on lobbiests to stall-delay-delay it ... = unless a=20 miracle should happen and we elect Ron Paul ro Dennis Kucinich, and he = avoids=20 assassination.. Oops!  A politically-incorrect statement.  I = withdraw=20 and retract my last remark. : )
 
terrence
LNC2 N211AL=20 99.9999%
 
----- Original Message -----
From:=20 lancairjim@aol.com
Sent: Thursday, January 24, = 2008 07:03=20 AM
Subject: [LML] Electric Powered = Lancair -=20 Long

OK, so this is a little off-topic and its most certainly a=20 flight-of-fantasy but it=E2=80=99s too cold and wet to go flying or to = work on my=20 plane so cut me some slack. I apologize in advance for its = length.

The inspiration for the treatise that follows was an = announcement by=20 a researcher at Stanford University just before Christmas. He claims = to have=20 invented a new type of lithium-ion battery based on a silicon anode = which has=20 10 times the energy density compared to existing, carbon-anode, = lithium-ion=20 batteries. A factor of 10! That's huge! Normally, advancements in = battery=20 technology are measured a few percentage points at a time. You can = read about=20 it here and decide for yourself about the validity:

(http://news-service.stanford.edu/news/2008/january9/nanowire-010= 908.html)

Needless to say, the blogs and newsgroups dealing with = alternative=20 energy and electric cars have lit up like a Las Vegas night but I was=20 wondering how this technology might affect an airplane. In particular, = what if=20 these batteries were used to power my still-under-construction LNC2. A = "slippery" airplane like a Lancair should be ideal as an electric = powered=20 airplane due to its inherent efficiency in the air.

Everything which follows is based on the assumption that the=20 announcement is accurate, that the energy density of the anode will be = reflected in the energy density of the whole battery and that the = technology=20 will proceed to commercialization without any problems. These are = major=20 assumptions. We all remember cold fusion.

As a point of reference, Tesla Motors, Inc. (www.teslamotors.com) has = developed a 53=20 kWh lithium-ion battery pack to power their slick new electric sports = car, the=20 Tesla Roadster. This battery pack uses existing technology and only = weighs 900=20 lbs!!!
We can calculate the energy density of an existing technology = battery=20 pack by dividing 53 kWh by 900 lbs. The result is about 0.06 kWh /lb. = If the=20 new technology has an energy density 10 times the old, then the new = technology=20 is 10 times 0.06 kWh/lb or 0.6 kWh/lb.

The weight of batteries which can be accommodated in the LNC2 = is=20 equal to the weight of the stuff we are removing including the IO-360 = engine=20 and accessories and the weight of avgas less the weight we are adding = back in=20 such as the electric motor, gearbox and associated electronics.

The total avgas in a typical LNC2-320/360 is 21 gals in each = wing=20 plus 10 in the header tank for a total of 52 gals times 6 lbs per gal=20 resulting in a total avgas weight of 312 lbs. Assuming the engine = installation=20 is 350 lbs (I'm going by memory here) gives a total weight of 662 lbs = (312=20 plus 350) which can be eliminated from the LNC2 if you are converting = it to=20 electric. Calculating the weight of an electric motor and controls is = a little=20 less precise. Again turning to Tesla Motors, they have developed a 185 = kW=20 (about 250 HP) electric motor for their roadster which weighs only = about 70=20 lbs. This is a bigger motor than we actually need compared to the 160 = =E2=80=93200 HP=20 engines usually found in LNC2s but this isn't all that accurate so = lets go=20 with it. To that we have to add the weight of the gearbox (the motor = turns at=20 13,000 rpm) and the electronic controls. I don't have a handle on = those but=20 lets assume that the whole package of motor, gearbox and controls = weighs 162=20 lbs. Subtracting the motor, gearbox and controls (162 lbs) from the = weight of=20 the avgas and Lycoming (662 lbs) leaves us with 500 lbs available for=20 batteries (funny how these things work out). With batteries storing = 0.6 kWh/lb=20 we have a total energy storage of 300 kWh (500 lbs times 0.6 kWh/ lb). = I=20 suppose someone on this list will insist that a backup set of = batteries is=20 required! They will be ignored for now.

Assuming an LNC2 with a 180 HP engine running at 65% power = cruises,=20 at altitude, at 200 kts (230 mph) we see that there is 117 HP (180 HP = times=20 0.65) going to the prop. This is equal to about 88 kW (0.75 kW per = HP).=20 Assuming that the electric motor and controls are about 85% efficient = we find=20 that the electric motor will be drawing about 103 kW (88 kW divided by = 0.85)=20 of electric power from the batteries to maintain the same speed.

Endurance is the energy stored (300 kWh) divided by the rate = of usage=20 (103 kW) or 2.9 hours. Range is endurance (2.9 hours) times the speed = (230=20 mph) or about 670 statue miles without reserves. This performance = isn't as=20 good as the existing avgas powered version but this is still a very = usable,=20 practical, airplane. The range can be extended by going to higher = altitudes or=20 by flying at a lower speed. Alternatively, redesigning the airplane = for say,=20 another 200 lbs of wing mounted batteries would put it in the same = league as=20 the avgas version of the LNC2 in terms of range and endurance at the = same=20 speed.

Recharging batteries this large is a major issue. A 240 volt = , 200=20 amp, single phase service would require about 6 hours and 15 minutes=20 (neglecting charger loses) to fully charge a 300 kWh battery pack = (300,000 Wh=20 divided by 240 V divided by 200 A). This is probably acceptable for = overnight=20 charging in a hangar assuming it has that kind of a power feeder = available ;-)=20 Fast recharging, say something like a 5C charge rate ( i.e., 12 = minutes) at a=20 public use charging station at a remote airport would be a real = technical=20 challenge. That would require a 1.5 MW feed. If we assume that the = charging is=20 done at 500 volts, a 5C charge rate is equivalent to 3,000 amps! = Oooops! Based=20 on my understanding of the inventor's data, he hasn't tested the new = batteries=20 at anything greater than a 1C charge rate (i.e., 1 hour) and that = resulted in=20 reduced energy density. However, the battery is in the earliest stages = of=20 testing and development.

One last calculation. My local utility has a special off-peak = rate of=20 5 cents per kWh for charging electric cars. Assuming this is also = applicable=20 to electric airplanes, we have $0.05 per kWh times 300 kWh used during = the=20 above described flight or $15 total fuel cost. That's roughly = one-tenth the=20 cost of avgas (at $5/gal) for the same flight. I doubt you can buy a = 600 mile=20 bus ticket for $15. Of course this ignores battery replacement cost = which is=20 unknown for this new technology but, at worst, is probably comparable = to an=20 engine rebuild.

So why would anyone want an electric airplane assuming one = could be=20 built with comparable performance and price? The following "Pros" have = occurred to me:
  1. Virtually eliminates noise and vibration.=20
  2. Lower operating cost.=20
  3. No consumption of petroleum products, foreign or domestic (very = little=20 electricity is generated in the US from burning oil).=20
  4. No exhaust emissions from the airplane including either = greenhouse gases=20 (e.g., CO2) or traditional pollutants (e.g., NOx, SOx, particulates, = etc.).=20 Emissions from the electric generating plants that supply the = electricity is=20 a whole 'nuther subject.=20
  5. No danger from avgas fires or explosions.=20
  6. Ultimate altitude engine. An electric motor will continue to = produce=20 rated power from sea level to outer space if you figure out a way to = cool=20 it.=20
  7. No more worries about future supplies of tetraethyl lead or from = EPA=20 mandates for cleaner burning engines or fuel.=20
  8. No more concerns about fuel contamination by water, ethanol, = etc.=20
  9. No more worries about fuel supply in general. Just the = occasional black-=20 or brown-out.=20
  10. No more worries about LOP/ROP, cylinder head cracking, broken=20 crankshafts, galled cams, arcing mags, etc., etc.=20
  11. Potential for much higher component reliability. The electric = powered=20 plane would probably only have two moving parts, the motor shaft and = the=20 prop shaft, as opposed to the myriad of parts going suck, squish, = bang, blow=20 hundreds of times a second.=20
  12. By combining two half-size electric motors on one shaft in one = housing=20 and supplying each set of windings with its own electronics and = dedicated=20 battery pack, you have almost the same system level reliability as = you do=20 with a twin engine airplane with very little increase in cost or = weight and=20 no asymmetric thrust problems.=20
  13. Reduced maintenance (e.g., no oil and filter changes, etc.)=20
  14. No carbon monoxide to worry about.=20
  15. No vapor lock to worry about.
There are, of course, a few reasons why one would not want an = electric=20 airplane. Here is a list of the "Cons" that I thought of:
  1. Virtually eliminates noise. Yes, I know its also in the "Pro" = list but=20 have you ever stood near a P-51 or a Corsair doing a high speed, low = altitude pass. If you haven't and you like airplanes then that = should be=20 items 1 and 2 on your "Bucket List".=20
  2. Lack of infrastructure for "slow" recharging in your hangar. No = real=20 technical issues so this is a solvable problem. All it takes is time = and=20 money.=20
  3. Lengthy recharge times at public use facilities. Many technical=20 challenges to "fast" recharging in terms of the infrastructure on = the supply=20 side, the interconnection and battery considerations. May have to = await the=20 development of suitable ultracapacitors instead of batteries.=20
  4. Battery life and replacement cost unknown. May turn out to be a=20 non-issue.=20
  5. Potential for electrical shocks, fires and explosions. Hard to = quantify=20 relative to the danger of fires and explosions from avgas.=20
  6. Increased potential for engine failure due to static discharge = or=20 lightning strikes. With increased use of electronics for = reciprocating=20 engine control, this may be a moot point determined mostly by the = quality of=20 component level design and installation rather than any inherent = system=20 level considerations.=20
  7. Landing weight equals takeoff weight. A potential problem for = the LNC2=20 although should not be a problem for a clean-sheet-of-paper design.=20
  8. Risk of the batteries self-immolating like certain laptop = batteries have=20 done. Unknown if this new technology precludes that type of = event.
So where does all this leave us? No where for now as the inventor = says it=20 will take 5 years to commercialize the new battery design. We will = have lots=20 of time to see if it lives up to its hype. Hope you all enjoyed this = little=20 exercise and will find it thought provoking. It makes you wonder what = general=20 aviation will look like in 50 years.

Yes, I know I should stop daydreaming and get back to work on = my=20 plane.

Jim McKibbin
LNC2 =E2=80=93 30% and holding
 
 
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