Electric Winch Project

On Monday, September 10, 2018 at 6:21:06 AM UTC-6, Martin Gregorie wrote:
On Mon, 10 Sep 2018 01:35:01 -0700, flybd5 wrote:

I saw make electric winches and put huge wind turbines next to them to
recharge the batteries.

Actually, the turbine would be fairly small.

A winch launch takes about 35 seconds from first movement until release
and about the maximum launch rate achievable with a two drum winch is 20
an hour[*], so the winch duty cycle is 20% at the most. If we assume the
winch burns a continuous 300kW during a launch (yes, that's probably a
large overestimate), then the average draw over an hour is 60kW - well
within the capability of a diesel trailer generator or a 22m diameter
three-blade wind turbine.

If the winch averages half power over the whole launch and the launch
rate is a more typical 10 an hour, the average power requirement drops to
15kW or a 9m diameter three-blade turbine.

The rule is simple, if you can land through the blades the launch
is free.

... but an glider bigger than about 5m span would not fit through the
blades of a suitable turbine, even if it was stationary.

[1] Several years ago a bunch of us made periodic attempts to see how
high a launch rate was possible with a two drum diesel winch (Supacat).
We could hit 20 launches an hour, but never managed to exceed it, and
apart from the winch driver and launch marshal, we needed a full-time
driver in the cable retrieval truck, and another two people to collect
gliders as they landed, put them back on the dual launch queues, and keep
the launch queues moved up to the launch point. It didn't need much to
drop the rate either - an instructor who briefed when he and his student
reached the front of the queue, rather than one or two launches earlier
would do it.


--
Martin | martin at
Gregorie | gregorie dot org

The numbers are simpler if one uses 1 - 2 kWh per launch (depends on glider weight and height of release) so 20 launches an hour would need a continuous 20 - 40 kW supply to maintain a steady-state battery charge. With a battery buffer, this supply can be very unsteady. The max power demand is not as important as long as the battery can deliver it.

40 kW is well within the range of various renewable sources. The incredible drop in solar panel prices make that a reasonable possibility. I estimate it would take about 2,500 sq. ft of them (~$25,000). One can imagine an accordion package which could be spread out on the ground near the winch.

While on the subject of dropping prices, Battery costs are dropping so fast that one can imagine a pack large enough for a whole day's winching. Recharging overnight from grid power simplifies the whole idea of an electric winch. Further imagine the winch mounted on an electric truck using the truck's enormous battery pack.

On Sunday, September 2, 2018 at 7:43:29 AM UTC-5, gotovkotzepkoi wrote:
Germans have had an electric winch for a long time. Nothing now. Don't
hold your breath for one built in the US. Won't happen. Charge with an
internal combustion engine? What's the point? Why not just use a piston
engine for the winch then?




--
gotovkotzepkoi

Dear goto, I listened to Bill Daniels' presentation on his new electric winch at Reno and was highly impressed with the innovative and technically convincing design and features. As a German trained engineer and someone who has done thousands of winch launches of gliders and who was trained on a winch my hopes are high that this project is successful. The Bill Daniels winch allows for electric, diesel or gas powered versions, btw. Educate yourself before spewing off under a not-funny pseudonym!
Herb

Didn't the German winch require being hooked up to the electrical grid?Â*
It seems the one currently under discussion would be self contained and
portable (on the back of a truck).

On 9/2/2018 7:48 AM, wrote:
On Sunday, September 2, 2018 at 7:43:29 AM UTC-5, gotovkotzepkoi wrote:
Germans have had an electric winch for a long time. Nothing now. Don't
hold your breath for one built in the US. Won't happen. Charge with an
internal combustion engine? What's the point? Why not just use a piston
engine for the winch then?




--
gotovkotzepkoi
Dear goto, I listened to Bill Daniels' presentation on his new electric winch at Reno and was highly impressed with the innovative and technically convincing design and features. As a German trained engineer and someone who has done thousands of winch launches of gliders and who was trained on a winch my hopes are high that this project is successful. The Bill Daniels winch allows for electric, diesel or gas powered versions, btw. Educate yourself before spewing off under a not-funny pseudonym!
Herb

--
Dan, 5J

The German winch can be found he http://www.startwinde.de/
I know one club in the Netherlands using it. I only heared good comments. They have a battery pack on board and feedercables in the airfield, below the grass.

On Sun, 02 Sep 2018 09:15:40 -0600, Dan Marotta wrote:

Didn't the German winch require being hooked up to the electrical grid?
It seems the one currently under discussion would be self contained and
portable (on the back of a truck).

All the electric winch designs I know about (and I assume the new US
design is similar) require three things: a power supply, a large electric
motor and a battery bank to act as a buffer between the first two items.

The German Electrowinde winch needs a 12-20 kw mains supply to feed a
220kw motor via its battery buffer, so the batteries aren't just for
decoration.

It seems to me that the winch motor and battery bank capacity will be
much the same whether the winch is configured as a towable trailer, on a
truck chassis or built into a permanent building: they all need the same
three part power train and it really doesn't matter whether the power
source is the mains, a COTS 12-12kw trailer generator parked alongside or
a truck with all three items installed on it.

A major issue for a mains-powered electric winch, in the UK anyway, is
the cost of cabling the airfield. We looked at it some years back: there
are four places were we put our winch - normally on one end of 04/22 and
less often on one end of 16/34 (obviously this is wind dependent), so
we'd need to wire up all four points on the field with buried cables, and
the winch points for 34 and 22 are both around 1km from the club house
and hence the nearest mains supply. Wiring our airfield would be quite
expensive. Consequently, we've gone with a Skylaunch running on LPG
(cheap and environmentally benign fuel). And we already had the tractor
used to move it between garage and the day's winchpoint.

What's the point? Why not just use a piston engine for the winch then?

Because a (much) smaller engine driving a generator to keep the battery
bank topped up is probably more economical to run than a socking great V8
being running intermittently at high power, particularly when you include
the cost of wear and tear from temperature-cycling the big engine.


--
Martin | martin at
Gregorie | gregorie dot org

I find all this stuff sexy, in Australia we all live in a bit of a fantasy of energy, we export our LPG, Coal and Oil like it’s going out of fashion and the “green” movements of our parties ensure that subsidies and grants are available to clubs and organisations for being green. My home club of Kingaroy would be a perfect site to go for a huge grant for four elec whinches 2xmain and 2x retrieve. The runway area is 2000m x100m of grass right next to a bitumen runway, there is power available within 200m of both winch sites. The only problem is the fact that it’s a certified runway with probably 1-2 private movements per hour, so the local Shire council are unlikely to approve winching. It’s a pity as there is a coal mine 20km away and there is a planned coal mine next to the airstrip and we have elections soon. If there was ever a time to pitch an alternative to burning smelly dinosaur bones and reducing the noise foot print for our solar powered sport now is it

I guess the panacea is to have an electric winch next to a battery bank powered by solar panels. In Australia this is feesable given the space and sunshine, BUT here is the crux - it’s battery technology.

The future will have elec self launch gliders, elec tow planes, elec winches and all of this will be powered by a battery system that is dual use. The batteries will be in runway edges, house bricks and other structural items not just a battery.

You will wake up in your house that is a storage facility hooked to the grid, most of the time you will be a next exporter of energy.

Jump in your electric car and drive up to the field.

Unplug your elec self launch Libelle and plug your car in, your hangar will have a storage battery bank in the wall bricks.

Tow your glider out to the runway with your elec golf cart and launch into the wild blue yonder with your retractable self launch system with prop goverening.

Once airborne you will go find a big fat thermal and redeploy your self launch prop mast and reverse the prop to recharge your batteries thereby extending your range.

The next type of comps will be range comps that will allow much greater distances and speeds, perhaps one day we will see solar panels on wings that can feed power to the battery system built into the composite fibres.

Fly until sunset and head to the clubhouse for a beer.

I just don’t understand why so many on here are negative to people trying to improve things, because let’s face it if we don’t improve things our sport is dead.

Justin

Originally Posted by Martin Gregorie[_6_]

On Sun, 02 Sep 2018 09:15:40 -0600, Dan Marotta wrote:

Didn't the German winch require being hooked up to the electrical grid?
It seems the one currently under discussion would be self contained and
portable (on the back of a truck).

All the electric winch designs I know about (and I assume the new US
design is similar) require three things: a power supply, a large electric
motor and a battery bank to act as a buffer between the first two items.

The German Electrowinde winch needs a 12-20 kw mains supply to feed a
220kw motor via its battery buffer, so the batteries aren't just for
decoration.

It seems to me that the winch motor and battery bank capacity will be
much the same whether the winch is configured as a towable trailer, on a
truck chassis or built into a permanent building: they all need the same
three part power train and it really doesn't matter whether the power
source is the mains, a COTS 12-12kw trailer generator parked alongside or
a truck with all three items installed on it.

A major issue for a mains-powered electric winch, in the UK anyway, is
the cost of cabling the airfield. We looked at it some years back: there
are four places were we put our winch - normally on one end of 04/22 and
less often on one end of 16/34 (obviously this is wind dependent), so
we'd need to wire up all four points on the field with buried cables, and
the winch points for 34 and 22 are both around 1km from the club house
and hence the nearest mains supply. Wiring our airfield would be quite
expensive. Consequently, we've gone with a Skylaunch running on LPG
(cheap and environmentally benign fuel). And we already had the tractor
used to move it between garage and the day's winchpoint.

What's the point? Why not just use a piston engine for the winch then?

Because a (much) smaller engine driving a generator to keep the battery
bank topped up is probably more economical to run than a socking great V8
being running intermittently at high power, particularly when you include
the cost of wear and tear from temperature-cycling the big engine.


--
Martin | martin at
Gregorie | gregorie dot org

On Sunday, September 2, 2018 at 8:43:10 PM UTC-4, Skypilot wrote:
I find all this stuff sexy, in Australia we all live in a bit of a
fantasy of energy, we export our LPG, Coal and Oil like it’s going
out of fashion and the “green” movements of our parties
ensure that subsidies and grants are available to clubs and
organisations for being green. My home club of Kingaroy would be a
perfect site to go for a huge grant for four elec whinches 2xmain and 2x
retrieve. The runway area is 2000m x100m of grass right next to a
bitumen runway, there is power available within 200m of both winch
sites. The only problem is the fact that it’s a certified runway
with probably 1-2 private movements per hour, so the local Shire council
are unlikely to approve winching. It’s a pity as there is a coal
mine 20km away and there is a planned coal mine next to the airstrip and
we have elections soon. If there was ever a time to pitch an alternative
to burning smelly dinosaur bones and reducing the noise foot print for
our solar powered sport now is it

I guess the panacea is to have an electric winch next to a battery bank
powered by solar panels. In Australia this is feesable given the space
and sunshine, BUT here is the crux - it’s battery technology.

The future will have elec self launch gliders, elec tow planes, elec
winches and all of this will be powered by a battery system that is dual
use. The batteries will be in runway edges, house bricks and other
structural items not just a battery.

You will wake up in your house that is a storage facility hooked to the
grid, most of the time you will be a next exporter of energy.

Jump in your electric car and drive up to the field.

Unplug your elec self launch Libelle and plug your car in, your hangar
will have a storage battery bank in the wall bricks.

Tow your glider out to the runway with your elec golf cart and launch
into the wild blue yonder with your retractable self launch system with
prop goverening.

Once airborne you will go find a big fat thermal and redeploy your self
launch prop mast and reverse the prop to recharge your batteries thereby
extending your range.

The next type of comps will be range comps that will allow much greater
distances and speeds, perhaps one day we will see solar panels on wings
that can feed power to the battery system built into the composite
fibres.

Fly until sunset and head to the clubhouse for a beer.

I just don’t understand why so many on here are negative to people
trying to improve things, because let’s face it if we don’t
improve things our sport is dead.

Justin
--
Skypilot

Amen to that, Justin! You hit the nail squarely on the head!

Uli
'AS'

That was a pretty interesting bit of science fiction.Â* And the
proceeding was not meant as criticism, only that most of the mentioned
technology is so far into the future that most, if not all of us will
never see it.

My one criticism is not acknowledging that it takes power to make power
(currently) and using a propeller to drive a motor/generator in flight
will create a LOT of drag which translates directly into sink rate.Â*
There's no free lunch yet, except in California.

On 9/2/2018 3:08 PM, Skypilot wrote:
I find all this stuff sexy, in Australia we all live in a bit of a
fantasy of energy, we export our LPG, Coal and Oil like it’s going
out of fashion and the “green” movements of our parties
ensure that subsidies and grants are available to clubs and
organisations for being green. My home club of Kingaroy would be a
perfect site to go for a huge grant for four elec whinches 2xmain and 2x
retrieve. The runway area is 2000m x100m of grass right next to a
bitumen runway, there is power available within 200m of both winch
sites. The only problem is the fact that it’s a certified runway
with probably 1-2 private movements per hour, so the local Shire council
are unlikely to approve winching. It’s a pity as there is a coal
mine 20km away and there is a planned coal mine next to the airstrip and
we have elections soon. If there was ever a time to pitch an alternative
to burning smelly dinosaur bones and reducing the noise foot print for
our solar powered sport now is it

I guess the panacea is to have an electric winch next to a battery bank
powered by solar panels. In Australia this is feesable given the space
and sunshine, BUT here is the crux - it’s battery technology.

The future will have elec self launch gliders, elec tow planes, elec
winches and all of this will be powered by a battery system that is dual
use. The batteries will be in runway edges, house bricks and other
structural items not just a battery.

You will wake up in your house that is a storage facility hooked to the
grid, most of the time you will be a next exporter of energy.

Jump in your electric car and drive up to the field.

Unplug your elec self launch Libelle and plug your car in, your hangar
will have a storage battery bank in the wall bricks.

Tow your glider out to the runway with your elec golf cart and launch
into the wild blue yonder with your retractable self launch system with
prop goverening.

Once airborne you will go find a big fat thermal and redeploy your self
launch prop mast and reverse the prop to recharge your batteries thereby
extending your range.

The next type of comps will be range comps that will allow much greater
distances and speeds, perhaps one day we will see solar panels on wings
that can feed power to the battery system built into the composite
fibres.

Fly until sunset and head to the clubhouse for a beer.

I just don’t understand why so many on here are negative to people
trying to improve things, because let’s face it if we don’t
improve things our sport is dead.

Justin




'Martin Gregorie[_6_ Wrote:
;975440']On Sun, 02 Sep 2018 09:15:40 -0600, Dan Marotta wrote:
-
Didn't the German winch require being hooked up to the electrical grid?
It seems the one currently under discussion would be self contained and
portable (on the back of a truck).
-
All the electric winch designs I know about (and I assume the new US
design is similar) require three things: a power supply, a large
electric
motor and a battery bank to act as a buffer between the first two items.


The German Electrowinde winch needs a 12-20 kw mains supply to feed a
220kw motor via its battery buffer, so the batteries aren't just for
decoration.

It seems to me that the winch motor and battery bank capacity will be
much the same whether the winch is configured as a towable trailer, on a

truck chassis or built into a permanent building: they all need the same

three part power train and it really doesn't matter whether the power
source is the mains, a COTS 12-12kw trailer generator parked alongside
or
a truck with all three items installed on it.

A major issue for a mains-powered electric winch, in the UK anyway, is
the cost of cabling the airfield. We looked at it some years back: there

are four places were we put our winch - normally on one end of 04/22 and

less often on one end of 16/34 (obviously this is wind dependent), so
we'd need to wire up all four points on the field with buried cables,
and
the winch points for 34 and 22 are both around 1km from the club house
and hence the nearest mains supply. Wiring our airfield would be quite
expensive. Consequently, we've gone with a Skylaunch running on LPG
(cheap and environmentally benign fuel). And we already had the tractor
used to move it between garage and the day's winchpoint.
-
What's the point? Why not just use a piston engine for the winch then?
-
Because a (much) smaller engine driving a generator to keep the battery
bank topped up is probably more economical to run than a socking great
V8
being running intermittently at high power, particularly when you
include
the cost of wear and tear from temperature-cycling the big engine.


--
Martin | martin at
Gregorie | gregorie dot org




--
Dan, 5J

At 17:57 02 September 2018, Martin Gregorie wrote:
On Sun, 02 Sep 2018 09:15:40 -0600, Dan Marotta wrote:

Didn't the German winch require being hooked up to the electrical grid?
It seems the one currently under discussion would be self contained and
portable (on the back of a truck).

All the electric winch designs I know about (and I assume the new US
design is similar) require three things: a power supply, a large electric

motor and a battery bank to act as a buffer between the first two items.

The German Electrowinde winch needs a 12-20 kw mains supply to feed a
220kw motor via its battery buffer, so the batteries aren't just for
decoration.

It seems to me that the winch motor and battery bank capacity will be
much the same whether the winch is configured as a towable trailer, on a
truck chassis or built into a permanent building: they all need the same
three part power train and it really doesn't matter whether the power
source is the mains, a COTS 12-12kw trailer generator parked alongside or

a truck with all three items installed on it.

A major issue for a mains-powered electric winch, in the UK anyway, is
the cost of cabling the airfield. We looked at it some years back: there
are four places were we put our winch - normally on one end of 04/22 and
less often on one end of 16/34 (obviously this is wind dependent), so
we'd need to wire up all four points on the field with buried cables, and

the winch points for 34 and 22 are both around 1km from the club house
and hence the nearest mains supply. Wiring our airfield would be quite
expensive. Consequently, we've gone with a Skylaunch running on LPG
(cheap and environmentally benign fuel). And we already had the tractor
used to move it between garage and the day's winchpoint.

What's the point? Why not just use a piston engine for the winch then?

Because a (much) smaller engine driving a generator to keep the battery
bank topped up is probably more economical to run than a socking great V8

being running intermittently at high power, particularly when you include

the cost of wear and tear from temperature-cycling the big engine.


--
Martin | martin at
Gregorie | gregorie dot org

I hear there's an electric winch at the gliding club at Unterwossen in
Germany. AIUI it is very fixed - in a concrete bunker. The site is in a
valley on the edge of the Alps so launching is always in the same
direction.

I've wondered if the best way to launch is by gravity, a weight falling
into a mine shaft and attached to the glider by a cable. If you have a
supply of water then the weight is by filling a tank. At the end of the
launch you dump the water, pull the much lighter tank back up, then refill
it. Given enough room you could have a circular airfield round the mine
shaft. The only energy that you need to supply is to retrieve the tank and
cable.

A few things to sort out but it's a start.

Chris

....and haul/pump the water.

On 9/2/2018 2:37 PM, Chris Rowland wrote:
At 17:57 02 September 2018, Martin Gregorie wrote:
On Sun, 02 Sep 2018 09:15:40 -0600, Dan Marotta wrote:

Didn't the German winch require being hooked up to the electrical grid?
It seems the one currently under discussion would be self contained and
portable (on the back of a truck).

All the electric winch designs I know about (and I assume the new US
design is similar) require three things: a power supply, a large electric
motor and a battery bank to act as a buffer between the first two items.

The German Electrowinde winch needs a 12-20 kw mains supply to feed a
220kw motor via its battery buffer, so the batteries aren't just for
decoration.

It seems to me that the winch motor and battery bank capacity will be
much the same whether the winch is configured as a towable trailer, on a
truck chassis or built into a permanent building: they all need the same
three part power train and it really doesn't matter whether the power
source is the mains, a COTS 12-12kw trailer generator parked alongside or
a truck with all three items installed on it.

A major issue for a mains-powered electric winch, in the UK anyway, is
the cost of cabling the airfield. We looked at it some years back: there
are four places were we put our winch - normally on one end of 04/22 and
less often on one end of 16/34 (obviously this is wind dependent), so
we'd need to wire up all four points on the field with buried cables, and
the winch points for 34 and 22 are both around 1km from the club house
and hence the nearest mains supply. Wiring our airfield would be quite
expensive. Consequently, we've gone with a Skylaunch running on LPG
(cheap and environmentally benign fuel). And we already had the tractor
used to move it between garage and the day's winchpoint.

What's the point? Why not just use a piston engine for the winch then?

Because a (much) smaller engine driving a generator to keep the battery
bank topped up is probably more economical to run than a socking great V8
being running intermittently at high power, particularly when you include
the cost of wear and tear from temperature-cycling the big engine.


--
Martin | martin at
Gregorie | gregorie dot org
I hear there's an electric winch at the gliding club at Unterwossen in
Germany. AIUI it is very fixed - in a concrete bunker. The site is in a
valley on the edge of the Alps so launching is always in the same
direction.

I've wondered if the best way to launch is by gravity, a weight falling
into a mine shaft and attached to the glider by a cable. If you have a
supply of water then the weight is by filling a tank. At the end of the
launch you dump the water, pull the much lighter tank back up, then refill
it. Given enough room you could have a circular airfield round the mine
shaft. The only energy that you need to supply is to retrieve the tank and
cable.

A few things to sort out but it's a start.

Chris



--
Dan, 5J