contrails

On Sun, 10 Jan 2010 12:47:53 -0800, Tom Gardner wrote:

2) If everyone turns their thermostats one degree closer to the outside
temperature, drives a smaller car, and switches off phone chargers when
not in use, will an energy crisis be averted?

My sister pointed out recently that British people tend to keep their
houses warmer than we did/do in NZ, so turning down the thermostat is not
a hardship - just put on a pullover over your T-shirt in winter.

Smaller cars is a problem for us in the trailer towing fraternity. My
main gripe with the current crop of electric and hybrid cars is that
nobody mentions towing, that I've seen anyway. There's one exception:
Aptera say NO TOWING up front. I guess the same goes for many of the rest
but they're too chicken to mention it.

Hungry chargers are just stupidly bad technology and should be banned.
Chargers that use no power[1] when they're plugged in but not connected
to anything have been around for at least 8 years, so there's no excuse
for selling one that burns power when its under no load.

Anyway, I just looked at four chargers I happened to have handy and
here's what it shows they burn when plugged into the mains and
disconnected from the things they charge:

18 month old Lenovo laptop PSU (65w o/p) 0 watts.
my much older Thinkpad 560Z PSU (54w o/p) 1.9 watts.
iPAQ 3630 PSU (10w o/p) 2.0 watts.
2001 Motorola T250 phone charger (2.5w o/p) 0 watts.

[1] I recently bought myself a power meter for a tenner from Maplins. It
which reads to 0.1 watts, so a reading of 0.0 should mean 50 mW
consumption or less. These power meters are simple to use: they have a 13
amp plug on the back and a 13 amp socket on the front, so you just plug
them in between the wall and the device you want to measure.


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |

On Jan 12, 1:56*am, Martin Gregorie
wrote:
On Sun, 10 Jan 2010 12:47:53 -0800, Tom Gardner wrote:
2) If everyone turns their thermostats one degree closer to the outside
temperature, drives a smaller car, and switches off phone chargers when
not in use, will an energy crisis be averted?

My sister pointed out recently that British people tend to keep their
houses warmer than we did/do in NZ, so turning down the thermostat is not
a hardship - just put on a pullover over your T-shirt in winter.

Smaller cars is a problem for us in the trailer towing fraternity. My
main gripe with the current crop of electric and hybrid cars is that
nobody mentions towing, that I've seen anyway. There's one exception:
Aptera say NO TOWING up front. I guess the same goes for many of the rest
but they're too chicken to mention it.


It's interesting how 4x4s suddenly went from being reviled 'gas-
guzzling destroyers of the planet' and 'Chelsea Tractors' to being the
best thing since sliced bread, during the UK's recent return to the
ice age!

As far as I am aware, none of the current electric or hydrid vehicles
have much in the way of towing capacity, which would be a big problem
for glider pilots, even those who own electrically powered self
launchers such as the Antares. It should be accepted that some
vehicles do need to be gasoline or diesel powered for some
applications.

Derek Copeland

On Jan 11, 6:56*pm, Martin Gregorie
wrote:
On Sun, 10 Jan 2010 12:47:53 -0800, Tom Gardner wrote:
2) If everyone turns their thermostats one degree closer to the outside
temperature, drives a smaller car, and switches off phone chargers when
not in use, will an energy crisis be averted?

My sister pointed out recently that British people tend to keep their
houses warmer than we did/do in NZ, so turning down the thermostat is not
a hardship - just put on a pullover over your T-shirt in winter.

Smaller cars is a problem for us in the trailer towing fraternity. My
main gripe with the current crop of electric and hybrid cars is that
nobody mentions towing, that I've seen anyway. There's one exception:
Aptera say NO TOWING up front. I guess the same goes for many of the rest
but they're too chicken to mention it.

Hungry chargers are just stupidly bad technology and should be banned.
Chargers that use no power[1] when they're plugged in but not connected
to anything have been around for at least 8 years, so there's no excuse
for selling one that burns power when its under no load.

Anyway, I just looked at four chargers I happened to have handy and
here's what it shows they burn when plugged into the mains and
disconnected from the things they charge:

18 month old Lenovo laptop PSU (65w o/p) * * * *0 * watts.
my much older Thinkpad 560Z PSU (54w o/p) * * * 1.9 watts.
iPAQ 3630 PSU (10w o/p) * * * * * * * * * * * * 2..0 watts.
2001 Motorola T250 phone charger (2.5w o/p) * * 0 * watts.

[1] I recently bought myself a power meter for a tenner from Maplins. It *
which reads to 0.1 watts, so a reading of 0.0 should mean 50 mW
consumption or less. These power meters are simple to use: they have a 13
amp plug on the back and a 13 amp socket on the front, so you just plug
them in between the wall and the device you want to measure.

--
martin@ * | Martin Gregorie
gregorie. | Essex, UK
org * * * |

I suspect the concept of "powered trailers" will pop up more
frequently. This is not an unproven concept since the mining industry
has used it for years.

If you use a load cell to measure the push-pull loads at the trailer
hitch, the data can be used to control electric motors in the trailer
wheels. If a glider trailer housed a large battery, possibly charged
with a large solar panel on top and wheel motors, it could minimize
the loads imposed on the towing vehicle by essentially powering
itself. The wheel motors would also provide regenerative braking.

The whole car-trailer combo then becomes a parallel hybrid which
permits the use of a much smaller and less powerful car. The fuel
savings while towing would be small compared to the fuel savings
achieved by driving a small, fuel efficient yet tow capable car when
not towing.

The energy capacity of the trailer battery pack coupled to an inverter
could also power things like power tools and polishers when parked at
the airport.

On Jan 12, 11:12*am, bildan wrote:
On Jan 11, 6:56*pm, Martin Gregorie
wrote:



On Sun, 10 Jan 2010 12:47:53 -0800, Tom Gardner wrote:
2) If everyone turns their thermostats one degree closer to the outside
temperature, drives a smaller car, and switches off phone chargers when
not in use, will an energy crisis be averted?

My sister pointed out recently that British people tend to keep their
houses warmer than we did/do in NZ, so turning down the thermostat is not
a hardship - just put on a pullover over your T-shirt in winter.

Smaller cars is a problem for us in the trailer towing fraternity. My
main gripe with the current crop of electric and hybrid cars is that
nobody mentions towing, that I've seen anyway. There's one exception:
Aptera say NO TOWING up front. I guess the same goes for many of the rest
but they're too chicken to mention it.

Hungry chargers are just stupidly bad technology and should be banned.
Chargers that use no power[1] when they're plugged in but not connected
to anything have been around for at least 8 years, so there's no excuse
for selling one that burns power when its under no load.

Anyway, I just looked at four chargers I happened to have handy and
here's what it shows they burn when plugged into the mains and
disconnected from the things they charge:

18 month old Lenovo laptop PSU (65w o/p) * * * *0 * watts.
my much older Thinkpad 560Z PSU (54w o/p) * * * 1.9 watts.
iPAQ 3630 PSU (10w o/p) * * * * * * * * * * * * 2.0 watts.
2001 Motorola T250 phone charger (2.5w o/p) * * 0 * watts.

[1] I recently bought myself a power meter for a tenner from Maplins. It *
which reads to 0.1 watts, so a reading of 0.0 should mean 50 mW
consumption or less. These power meters are simple to use: they have a 13
amp plug on the back and a 13 amp socket on the front, so you just plug
them in between the wall and the device you want to measure.

--
martin@ * | Martin Gregorie
gregorie. | Essex, UK
org * * * |

I suspect the concept of "powered trailers" will pop up more
frequently. *This is not an unproven concept since the mining industry
has used it for years.

If you use a load cell to measure the push-pull loads at the trailer
hitch, the data can be used to control electric motors in the trailer
wheels. *If a glider *trailer housed a large battery, possibly charged
with a large solar panel on top and wheel motors, it could minimize
the loads imposed on the towing vehicle by essentially powering
itself. *The wheel motors would also provide regenerative braking.

The whole car-trailer combo then becomes a parallel hybrid which
permits the use of a much smaller and less powerful car. *The fuel
savings while towing would be small compared to the fuel savings
achieved by driving a small, fuel efficient yet tow capable car when
not towing.

The energy capacity of the trailer battery pack coupled to an inverter
could also power things like power tools and polishers when parked at
the airport.

The problem with EVs isn't power, it's on-board energy storage.

I have a friend who is a hybrid/EV enthusiast. He reckons the holy
grail is 40 mile range. Okay, adequate for most people buying
groceries or going to work, but completely useless for XC travel. We
need 1 - 2 magnitudes of improvement in energy density and 3 or 4 in
re-fueling time before you can reasonably talk about competing with
existing gas/diesel for hauling pilot/plane/crew to a site several
hundred miles distant.

That, or we turn I80 into a giant sized nuclear powered HO slot car
track :-).

Back to trailers: From fuel consumption numbers, I can back out that
my Komet trailer/glider has an effective fuel consumption of 120 miles
to the gallon at 60 - 65 mph on level road, no wind. Figure about 6
hp. Two or three times that under acceleration or ascending steep
grade. The point is: it's a small load. A decently capable EV could
tow it without difficulty.

-Evan Ludeman / T8

On Jan 12, 10:40*am, T8 wrote:
On Jan 12, 11:12*am, bildan wrote:



On Jan 11, 6:56*pm, Martin Gregorie
wrote:

On Sun, 10 Jan 2010 12:47:53 -0800, Tom Gardner wrote:
2) If everyone turns their thermostats one degree closer to the outside
temperature, drives a smaller car, and switches off phone chargers when
not in use, will an energy crisis be averted?

My sister pointed out recently that British people tend to keep their
houses warmer than we did/do in NZ, so turning down the thermostat is not
a hardship - just put on a pullover over your T-shirt in winter.

Smaller cars is a problem for us in the trailer towing fraternity. My
main gripe with the current crop of electric and hybrid cars is that
nobody mentions towing, that I've seen anyway. There's one exception:
Aptera say NO TOWING up front. I guess the same goes for many of the rest
but they're too chicken to mention it.

Hungry chargers are just stupidly bad technology and should be banned..
Chargers that use no power[1] when they're plugged in but not connected
to anything have been around for at least 8 years, so there's no excuse
for selling one that burns power when its under no load.

Anyway, I just looked at four chargers I happened to have handy and
here's what it shows they burn when plugged into the mains and
disconnected from the things they charge:

18 month old Lenovo laptop PSU (65w o/p) * * * *0 * watts.
my much older Thinkpad 560Z PSU (54w o/p) * * * 1.9 watts.
iPAQ 3630 PSU (10w o/p) * * * * * * * * * * * * 2.0 watts.
2001 Motorola T250 phone charger (2.5w o/p) * * 0 * watts.

[1] I recently bought myself a power meter for a tenner from Maplins. It *
which reads to 0.1 watts, so a reading of 0.0 should mean 50 mW
consumption or less. These power meters are simple to use: they have a 13
amp plug on the back and a 13 amp socket on the front, so you just plug
them in between the wall and the device you want to measure.

--
martin@ * | Martin Gregorie
gregorie. | Essex, UK
org * * * |

I suspect the concept of "powered trailers" will pop up more
frequently. *This is not an unproven concept since the mining industry
has used it for years.

If you use a load cell to measure the push-pull loads at the trailer
hitch, the data can be used to control electric motors in the trailer
wheels. *If a glider *trailer housed a large battery, possibly charged
with a large solar panel on top and wheel motors, it could minimize
the loads imposed on the towing vehicle by essentially powering
itself. *The wheel motors would also provide regenerative braking.

The whole car-trailer combo then becomes a parallel hybrid which
permits the use of a much smaller and less powerful car. *The fuel
savings while towing would be small compared to the fuel savings
achieved by driving a small, fuel efficient yet tow capable car when
not towing.

The energy capacity of the trailer battery pack coupled to an inverter
could also power things like power tools and polishers when parked at
the airport.

The problem with EVs isn't power, it's on-board energy storage.

I have a friend who is a hybrid/EV enthusiast. *He reckons the holy
grail is 40 mile range. *Okay, adequate for most people buying
groceries or going to work, but completely useless for XC travel. *We
need 1 - 2 magnitudes of improvement in energy density and 3 or 4 in
re-fueling time before you can reasonably talk about competing with
existing gas/diesel for hauling pilot/plane/crew to a site several
hundred miles distant.

That, or we turn I80 into a giant sized nuclear powered HO slot car
track :-).

Back to trailers: *From fuel consumption numbers, I can back out that
my Komet trailer/glider has an effective fuel consumption of 120 miles
to the gallon at 60 - 65 mph on level road, no wind. *Figure about 6
hp. *Two or three times that under acceleration or ascending steep
grade. * The point is: it's a small load. *A decently capable EV could
tow it without difficulty.

-Evan Ludeman / T8

Yes, pretty much any econobox can pull a glider trailer on a level
road. Where the 'powered trailer' idea would come in is on hills.
~90% of the time, the trailer would be unpowered and the trailers
wheel motors would only kick in when the towing econobox couldn't
handle the load alone. On downhill grades, the wheel motors would
switch to regenerative braking to recharge the trailer battery and
save the towing vehicle's brakes.

Set up correctly, the charge in the trailer battery should last as
long as the fuel in the towing vehicle's tank. If recharging stations
proliferate, the trailer battery could be recharged while the tow
car's tank is being refilled.

On Jan 12, 7:05*pm, bildan wrote:
*On downhill grades, the wheel motors would
switch to regenerative braking to recharge the trailer battery and
save the towing vehicle's brakes.

Is that actually the case? I was under the impression
that the electrolyte will boil if you try to put energy into
batteries as fast as it can be taken out.

I'm more than happy to be corrected, if necessary.

On Jan 12, 1:47*pm, Tom Gardner wrote:
On Jan 12, 7:05*pm, bildan wrote:

*On downhill grades, the wheel motors would
switch to regenerative braking to recharge the trailer battery and
save the towing vehicle's brakes.

Is that actually the case? I was under the impression
that the electrolyte will boil if you try to put energy into
batteries as fast as it can be taken out.

I'm more than happy to be corrected, if necessary.

With the old lead-acid liquid electrolyte batteries, that would be
true.

The new "fast-charge" lithium based solid electrolyte electric vehicle
batteries can take a full charge in less than 10 minutes. They also
have a far larger energy density and power density.

However, even this may not be good enough for heavy regenerative
braking - enter the Ultra-capacitor. Ultra-capacitors can charge
almost instantly then trickle the charge into a battery pack at a
charge rate that keeps it happy.

On Jan 13, 6:40*am, T8 wrote:
Back to trailers: *From fuel consumption numbers, I can back out that
my Komet trailer/glider has an effective fuel consumption of 120 miles
to the gallon at 60 - 65 mph on level road, no wind.

That's pretty impressive.

When I was towing a Grob two seater in (admittedly a pretty crappy
trailer) it reduced the range of my 2.5l Subaru on a 56l fill up from
about 620 km to about 350 km. Say, from 32 mpg to about 18 mpg.

http://hoult.org/bruce/Subaru_with_TA.jpg

To put it into the normal units used here, the car alone normally uses
about 9 l/100 km on a long trip, and the combo used about 16 l/100km.
That implies that the trailer used about 7 l/100 km, or 40 mpg.

I'm sure a Komet with a single seat glider would be much better, but
I'm surprised it's three times better.

I note in passing that my Subaru&trailer combo used only very slightly
more fuel than my Dad's 4.1 l Falcon station wagon does by itself.


One more point: for most of us outside the USA, I believe that the
practical lower limit on vehicle size for towing is governed not by
power (you can always change down and go slower when necessary) but by
the stability and controllability of the combo under braking and on
steep downhills. Too-small cars are ones that get shoved badly when
braking on downhill switchbacks, and ones that arrive at the bottom of
a couple of thousand foot descent with the brakes smoking.

Here in Wellington NZ, the benchmark is a run over the Rimutaka Hill
to the Wairarapa for a day's gliding at Jury Hill or Masterton. The
summit is only 1800 ft but it's enough to sort the good tow cars from
the bad ones (or stupid drivers who don't use engine braking).

On Wed, 13 Jan 2010 01:33:59 -0800, Bruce Hoult wrote:

I'm sure a Komet with a single seat glider would be much better, but I'm
surprised it's three times better.

That probably depends on what you're driving: a single seat trailer is
usually no higher than the tow car. If the latter is an estate (station
wagon) then hanging a trailer on it may only add rolling drag from the
extra axle plus skin friction drag. If the trailer cross section fits
behind the tow vehicle you've effectively lost its front surface drag and
transferred the tow vehicle's rear end drag to the rear of the trailer.


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |

On Jan 13, 4:33*am, Bruce Hoult wrote:
On Jan 13, 6:40*am, T8 wrote:

Back to trailers: *From fuel consumption numbers, I can back out that
my Komet trailer/glider has an effective fuel consumption of 120 miles
to the gallon at 60 - 65 mph on level road, no wind.

That's pretty impressive.

When I was towing a Grob two seater in (admittedly a pretty crappy
trailer) it reduced the range of my 2.5l Subaru on a 56l fill up from
about 620 km to about 350 km. *Say, from 32 mpg to about 18 mpg.

http://hoult.org/bruce/Subaru_with_TA.jpg

To put it into the normal units used here, the car alone normally uses
about 9 l/100 km on a long trip, and the combo used about 16 l/100km.
That implies that the trailer used about 7 l/100 km, or 40 mpg.

I'm sure a Komet with a single seat glider would be much better, but
I'm surprised it's three times better.

The Komet wins on aerodynamics. My old Schreder trailer, despite
being lighter, had twice the incremental fuel consumption at 65 mph,
so 60 mpg. It is similar in shape to your Grob trailer. Relative to
the Komet, it was like towing a parachute! I tow 'em all European
style behind small hatchbacks. Martin's correct, towed behind a large
RV or similar, there would be less difference.

-Evan Ludeman / T8