Chip with simple program for Toy

[Rob Dekker]

"terryc" <newssixspam-spam@woa.com.au> wrote in message newsan.2008.07.24.13.50.30.164653@woa.com.au...

On Tue, 22 Jul 2008 18:34:37 -0700, Rob Dekker wrote:

True. But technically speaking, a 300 kWh battery is not completely rediculous : It will cost about $100,000 wholesale, and weigh
less than 2 ton.

Well, that is an interesting battery advancement.

For current deep-discharge lead acid, it would weigh 84 tonnes.
In LiPoly,it would currently weigh 20 tonnes.

Did I make a calculation mistake ?
Mmm. Not really :

Li-poly gets us about 160 Wh/kg. That's less than 2 ton for 300 kWh.
Here is a cell of that type :
http://www.all-battery.com/index.asp?PageAction=VIEWPROD&ProdID=1631&HS=1

The only problem with this one (technically) is that it recharges up to 500x.
That makes it expensive to use. Should be more like 2000x.

Rob

 

[Rob Dekker]

"John Fields" <jfields@austininstruments.com> wrote in message news:1o4h84tdn70gfvqvjbmlr66e9r242qse35@4ax.com...

On Thu, 24 Jul 2008 23:40:20 +1000, terryc
newssixspam-spam@woa.com.au> wrote:

On Wed, 23 Jul 2008 09:23:06 -0500, John Fields wrote:


notie this paragraph after I flicked the other answer....

Now, when you consider that that electricity has to come from
_somewhere_ and that is has to be brought into the field using
conductors of finite resistance, then the problem becomes even more
severe.

So instead of 415V supply, you just tap the 11Kv lines instead.

---
How would you do that?

You throw a wire over it. Just make sure to wear rubber gloves )

 

[Rob Dekker]

"Mark Thorson" <nospam@sonic.net> wrote in message news:4889025D.EB3033EB@sonic.net...

Bret Cahill wrote:

The small cell phone or lap top batteries wired in parallel would
charge up in a couple of minutes.

10 recharges during a work-day

I was planning for 6 - 10 an hour.

Every time the tractor makes it across the field or back it recharges.

Laptop batteries are typically good for about 1000 charges
before becoming seriously degraded. �Your hypothetical
tractor would need a fresh set of batteries about every
2 weeks. �You haven't taken this major cost into account.

How would this cost be any different than the plug in hybrid or EV
like the Tesla?

Because a car is only charged once or twice a day.
If we assume an 8-hour shift, your tractor
is being recharged 48-80 times a day. If this
big, expensive tractor is used for multiple
shifts, it could be much higher than that.
You'll be producing mountains of dead, expensive
batteries. There isn't enough hazmat landfill
to handle them all.

Please RECYCLE batteries.
The metals in there are valuable (especially for lithium-based cells).

Although for tractors, you probably would not use Li-ions that are designed for small applications, although even these would
already be economical (as Tesla shows).
But for tractors, the low-cost, high energy density molten salt batteries (Zebra's, sodium/sulfur etc) are excellent :

http://en.wikipedia.org/wiki/Molten_salt_battery

Cheap, powerfull, thousands of cycles, and easy to recycle.
With their high operating temperatures, these are rather 'clumsy' for small applications.
But for tractors, busses and anything big, they should be great.

Rob

 

[Rob Dekker]

"Bret Cahill" <BretCahill@aol.com> wrote in message news:6205dd4f-cf84-4f0e-ae1f-8bdd49aedeed@i24g2000prf.googlegroups.com...

A new diesel engine can cull up to 50 kW-hrs from a gallon of diesel.

Bret, the story is much more in favor of electricity than what you present.

Diesel has a heating value average of 38.6 MJ/liter, or 146MJ/gallon. That is 40.7 kWh.
Efficiency of diesel engines, mmm, varies widely, but probably in between 30% and 40% (anyone has any better numbers?) in real life
use in a large vehicle.

That would mean that a diesel engine would release between 12 kWh and 16 kWh of work from one gallon of diesel.

At close to $5/gallon (current diesel retail price in California), this is $0.30-$0.40 per kWh.

For gasoline, the story is even worse : 34.8MJ/liter (132MJ/gallon), and lower efficiency (20%-25%) in real life vehicles, gives 7.3
kWh - 9 kWh of work.
At $3.80/gallon gasoline, this is $0.42-$0.52 per kWh.

<future predictions snipped>

TVA now sells now electricity for 7 cents/kW-hr off peak.

You can buy a lot of cell phone or laptop batteries with the amount of
money you are now paying for diesel, gasoline or other hydrocarbon
fuel.

Polar bears and tropical frogs never even enter the equation.

Future predictions don't even enter the equation either.

Bret Cahill

 

[Tom Biasi]

<algortex@gmail.com> wrote in message
news:91d6e299-90ed-4c85-9c37-ed6775178262@w39g2000prb.googlegroups.com...

Bret Cahill wrote:

Polar bears and tropical frogs never even enter the equation.


Al says,

Try our new and improved Low Temperature BEC, now with Rubidium!

Would you guys kindly remove "sci.electronics.basics" from the group list.

It has nothing to do with electronics.
If you want to jump on Bret Cahill please do so on sci. energy, or alt.
politics. , or alt philosophy, or what ever.

OK I'm calm now.
Best Regards,
Tom

 

[Rob Dekker]

"Bret Cahill" <BretCahill@aol.com> wrote in message news:58cfec07-a606-4c22-87f2-93be5337296c@w39g2000prb.googlegroups.com...

That's the point of the trolly wire. The size of the battery can be
reduced by 1 - 2 orders of magnitude because, unlike an EV or plug in,
the tractor charges up every 6 - 10 minutes, after each pass.

Bret, if the tractor goes (what was it?) 1 mph or so, and it needs 10 minutes for one pass (5 min each way), then the field is no
wider than 440 feet.
Is that a reasonable assumption ?

If so, why not just use a high-voltage extension cable ?

Actually, a 10kV line can be miles long without too many losses (for the 300 kW that you need).

Rob

 

[Rob Dekker]

"Tom Biasi" <tombiasi***@optonline.net> wrote in message news:g-GdndPpI_zjsBTVnZ2dnUVZ_uCdnZ2d@giganews.com...

algortex@gmail.com> wrote in message news:91d6e299-90ed-4c85-9c37-ed6775178262@w39g2000prb.googlegroups.com...
Bret Cahill wrote:

Polar bears and tropical frogs never even enter the equation.


Al says,

Try our new and improved Low Temperature BEC, now with Rubidium!

Would you guys kindly remove "sci.electronics.basics" from the group list. It has nothing to do with electronics.
If you want to jump on Bret Cahill please do so on sci. energy, or alt. politics. , or alt philosophy, or what ever.

OK I'm calm now.
Best Regards,
Tom

Hi Tom,

I understand that it's never nice to find a posting in your newsgroup that is about something other than what you think the
newsgroup should be about.
But you must admit that batteries are pretty close to the subject of science of basic electronics.
I have no idea why Bret put alt.philosophy here, but sci.electronics.basics seems rather applicable to me....
Besides, you can always ignore a posting.
Either way, isn't this (a human written post) at least better than a robot posting spam on on the NGs ?

That's my 2 cts.

Rob

 

[Sid9]

"turtoni" <turtoni@fastmail.net> wrote in message
news:2b405835-12ee-4b9a-8c3f-4b3c9aa8ff7e@k36g2000pri.googlegroups.com...

Going electric would seem to be the way forward. Getting the electric
in and out of the grid is the big stumbling block.

On Jul 24, 6:45 pm, "Sid9" <s...@bellsouth.net> wrote:
There are many ways to do it.
All America needs is the leadership to provide the motivation.
Republican have demonstrated that they haven't got what's needed.

Politicians are salesmen.

For example Clinton had eight years.

I'm not interested in salesmen.

I'm interested in Scientists.

Einstein had a letter from scientists that would have gone nowhere without a
politician.
FDR had the leadership necessary the start the Manhattan project.

I believe Obama has the
leadership qualities that
will get a scientific solution
to our energy problem going.

 

[Tom Biasi]

"Rob Dekker" <rob@verific.com> wrote in message
news:UCaik.31193$co7.3541@nlpi066.nbdc.sbc.com...

"Tom Biasi" <tombiasi***@optonline.net> wrote in message
news:g-GdndPpI_zjsBTVnZ2dnUVZ_uCdnZ2d@giganews.com...

algortex@gmail.com> wrote in message
news:91d6e299-90ed-4c85-9c37-ed6775178262@w39g2000prb.googlegroups.com...
Bret Cahill wrote:

Polar bears and tropical frogs never even enter the equation.


Al says,

Try our new and improved Low Temperature BEC, now with Rubidium!

Would you guys kindly remove "sci.electronics.basics" from the group
list. It has nothing to do with electronics.
If you want to jump on Bret Cahill please do so on sci. energy, or alt.
politics. , or alt philosophy, or what ever.

OK I'm calm now.
Best Regards,
Tom


Hi Tom,

I understand that it's never nice to find a posting in your newsgroup that
is about something other than what you think the newsgroup should be
about.
But you must admit that batteries are pretty close to the subject of
science of basic electronics.
I have no idea why Bret put alt.philosophy here, but
sci.electronics.basics seems rather applicable to me....
Besides, you can always ignore a posting.
Either way, isn't this (a human written post) at least better than a robot
posting spam on on the NGs ?

That's my 2 cts.

Rob


OK Rob,

I block Google Groups because of the enormous spam.
I only see these post when someone replies.
From what I see its not electronics but a rant regarding energy of crop
farming.
I guess I can tolerate it.
My fingers got a little excited.
Really, its just light hearted poking based on what usually goes on here.

Tom

 

In sci.physics Green Xenon [Radium] <glucegen1x@gmail.com> wrote:

Hi:

I remember reading somewhere than ELF [Extremely Low Frequency] radio
transmission is inefficient because it requires to much power.

Then your memory isn't worth a crap or what you read was wrong.

<snip crap>

--
Jim Pennino

Remove .spam.sux to reply.

 

[Rob Dekker]

"Tom Biasi" <tombiasi***@optonline.net> wrote in message news:HYOdnarlO6PkpBTVnZ2dnUVZ_vzinZ2d@giganews.com...
...

Would you guys kindly remove "sci.electronics.basics" from the group list. It has nothing to do with electronics.
If you want to jump on Bret Cahill please do so on sci. energy, or alt. politics. , or alt philosophy, or what ever.

OK I'm calm now.
Best Regards,
Tom


Hi Tom,

I understand that it's never nice to find a posting in your newsgroup that is about something other than what you think the
newsgroup should be about.
But you must admit that batteries are pretty close to the subject of science of basic electronics.
I have no idea why Bret put alt.philosophy here, but sci.electronics.basics seems rather applicable to me....
Besides, you can always ignore a posting.
Either way, isn't this (a human written post) at least better than a robot posting spam on on the NGs ?

That's my 2 cts.

Rob


OK Rob,
I block Google Groups because of the enormous spam.
I only see these post when someone replies.
From what I see its not electronics but a rant regarding energy of crop farming.
I guess I can tolerate it.
My fingers got a little excited.
Really, its just light hearted poking based on what usually goes on here.

Tom

Thanks Tom.

I'm not sure how you read the NGs, but maybe you can configure your newsreader so that you can delete entire posting trails, from
the top down, so that all responses disappear.

Also, maybe you guys (at sci.electronics.basics) can help us out a bit here :
We often talk about energy efficiencies on sci.energy, and efficiency of power electronics is kind of getting important (we often
see 90-100% efficiency for power electronics).
Do you know much about that ? Efficiency of power inverters, voltage regulators, transformers, brushless DC or AC motors etc ?
Any power electronics components that have much less than 100% efficiency ?

Rob

 

[Spaceman]

Green Xenon [Radium] wrote:

Hi:

I remember reading somewhere than ELF [Extremely Low Frequency] radio
transmission is inefficient because it requires to much power.

True and not true.
Maybe this will help shed some ELF light on the subject.
http://en.wikipedia.org/wiki/Extremely_low_frequency

--
James M Driscoll Jr
Spaceman

 

[Rob Dekker]

"Bret Cahill" <BretCahill@aol.com> wrote in message news:98294e54-bb4d-4229-af29-ff72d7edc8e7@z11g2000prl.googlegroups.com...

A new diesel engine can cull up to 50 kW-hrs from a gallon of diesel.

Bret, the story is much more in favor of electricity than what you present.

Diesel has a heating value average of 38.6 MJ/liter, or 146MJ/gallon. That is 40.7 kWh.
Efficiency of diesel engines, mmm, varies widely, but probably in between 30% and 40% (anyone has any better numbers?) in real
life
use in a large vehicle.

That would mean that a diesel engine would release between 12 kWh and 16 kWh of work from one gallon of diesel.

At close to $5/gallon (current diesel retail price in California), this is $0.30-$0.40 per kWh.

For gasoline, the story is even worse : 34.8MJ/liter (132MJ/gallon), and lower efficiency (20%-25%) in real life vehicles, gives
7.3
kWh - 9 kWh of work.
At $3.80/gallon gasoline, this is $0.42-$0.52 per kWh.



future predictions snipped

TVA now sells now electricity for 7 cents/kW-hr off peak.

You can buy a lot of cell phone or laptop batteries with the amount of
money you are now paying for diesel, gasoline or other hydrocarbon
fuel.

Polar bears and tropical frogs never even enter the equation.

Future predictions don't even enter the equation either.

The calculations are not even as sophisticated as back of envelope.

The real problem is psychological. Everyone is in a state of denial.

And this is not limited to newsgroups. You see this in industry,
government, think tanks, universities . . . even independent
inventors.

What did you expect ? Oil is a $4 trillion dollar/year industy. It's part of EVERYBODYs life ! This is the biggest supertanker in
the history of humanity !

Psychologically, I think most (informed) people actually DO know what's going on, and where we are heading, but it takes some pretty
big steps to change the course of this supertanker. And remember, most people are reluctant to make big changes (big changes means
big risks, which often decreases success). It's often better to 'wait and see'.... So that's what people are doing.

Wait and see. I think that many people hope that somehow the whole Peak Oil thing might not be so difficult to get through. Or that
the peak is still more than 10 years away. That oil prices ARE caused by a temporary shortage in supply, or a speculators frenzy,
not a structural inability to produce more and certainly not a decline in supply. Many hope that some more offshore driling will fix
the problem for a while until we find a better solution. Or some CTL, more biofuels, more efficient transport methods or something
like that. So I think there is still hope with many that we can still jog on for quite a while longer in the direction that we have
been going for the past century. Maybe some hope that some scientific breakthrough or some find of oil will come just in time and
prevent that we have to change something drastically.

Global Warming could not reduce human's appetite for fossil fuels. So now there is an even stronger reason to kick the fossil fuel
habit : Peak Oil.
Psychologically speaking, I think Peak Oil is the biggest test of human nature that we have had since the indutrial revolution.
If we still don't get it, then I fear that modern civilisation may end with the 21st century.

I think most people (businesses and individuals alike) "wait and see" for a very clear signal from their authorities as to how we
will tackle these problems. So that we can start working together towards that solution.

Here, the next president will have the chance to make the most memorable speach in the history of the US, answering how will we
generate our energy in the decades and even the century to come.

Meanwhile, you have an advantage over most people : you know that electricity is cheaper than liquid fuel, so find the businesses
that will do well in that scenario. Or even start a business yourself that makes electrical farm equipment or anything else that you
think makes sense.

As Stanford Ovshinsky said : "if you want to change the world, don't just talk about it. Do it !".

Rob

 

[Rob Dekker]

"Bret Cahill" <BretCahill@aol.com> wrote in message news:6bd255d2-77d4-4f5b-be69-3cc35203bab3@p10g2000prf.googlegroups.com...
...

If so, why not just use a high-voltage extension cable ?

Another moveable wire off of the stationary wire?

More like two winches with 1 mile wire each (connected in series). One winch unrolls along the side of the field, The other unrolls
over the field towards the tractor.
Just need a system to make sure the field wire stays high above the tractor (so it does not accidentally get cut).

Actually, a 10kV line can be miles long without too many losses (for the 300 kW that you need).

Losses aren't an issue.

As long as they stay withing reasonable limits. Which should be OK for (standard) 11kV AC distribution power line and a few miles of
cable.

Rob

 

[Androcles]

"Green Xenon [Radium]" <glucegen1x@gmail.com> wrote in message
news:5f2d91fa-5edb-49d2-bc9a-a5b0f00de178@x29g2000prd.googlegroups.com...
| Hi:
|
| I remember reading somewhere than ELF [Extremely Low Frequency] radio
| transmission is inefficient because it requires to much power.
|
| If that is the case, wouldn't MW [Medium Wave] radio transmission
| require even more power?
|
| MW and ELF are forms of electromagnetic radiation in the RF spectrum.
|
| An photon [or electromagnetic wave] of a higher-frequency has more
| energy than a photon of a lower-frequency.
|
| Let's say there are there are two radio transmitters, one emits 2 GHz
| waves while the other emits 2 kHz waves. If the two radio transmitters
| use the same modulation scheme [AM/FM, etc.] and emit the same amount
| of photons-per-second-per-square-meter, the 2 GHz transmitter will be
| using more watts than the 2 kHz transmitter -- because a 2 GHz photon
| requires more power to generate than a 2 kHZ photon. Right?
|
| So how would transmitting a lower-frequency radio wave require more
| power than transmitting a higher-frequency radio wave?
|
|
| Thanks,
|
| Radium

You are making the classic mistake of confusing quality with quantity,
energy with power.
Which has more pressure, a 55,000 psi water jet or Niagara Falls?
http://www.laserfab.co.uk/cnc_water_jet_cutting.htm


A cigar tip is red hot and will painfully burn your skin. Can you heat a
cup of coffee with it?

How big is this ELF photon?
http://www.crystalinks.com/solarnews.html
Now that's extreme.

 

[Paul E. Schoen]

"Rob Dekker" <rob@verific.com> wrote in message
news:R88ik.31155$co7.18077@nlpi066.nbdc.sbc.com...

"terryc" <newssixspam-spam@woa.com.au> wrote in message
newsan.2008.07.24.13.50.30.164653@woa.com.au...
On Tue, 22 Jul 2008 18:34:37 -0700, Rob Dekker wrote:

True. But technically speaking, a 300 kWh battery is not completely
rediculous : It will cost about $100,000 wholesale, and weigh
less than 2 ton.

Well, that is an interesting battery advancement.

For current deep-discharge lead acid, it would weigh 84 tonnes.
In LiPoly,it would currently weigh 20 tonnes.



Did I make a calculation mistake ?
Mmm. Not really :

Li-poly gets us about 160 Wh/kg. That's less than 2 ton for 300 kWh.
Here is a cell of that type :
http://www.all-battery.com/index.asp?PageAction=VIEWPROD&ProdID=1631&HS=1

The only problem with this one (technically) is that it recharges up to
500x.
That makes it expensive to use. Should be more like 2000x.

Rob

Right. I figure these batteries themselves cost $1100/kWH so for 500
charges that is about $2/kWH. Even at 2000 charges it's $0.50/kWH. Now, if
it is true that, at $5/gallon, diesel costs $0.30-$0.40/kWH, it would not
have to go up a whole lot more for a crossover point to be reached, and the
battery cost would certainly be a lot less than the advertised sale price
of $44 each for singles or even $38 each for 500. You would need 7500
batteries for 300 kWH and that would cost about $300,000. You could run for
an hour, but then (per spec) it would take 2 hours to recharge. You would
need to replace the batteries after 500 hours running time, or 1500 total
hours, or every 9 weeks.

There will certainly be some new technology (and economies of scale) that
will lower the cost and extend the charge cycles. It would not be
unreasonable to have two extra plug-in packs that could be charging while
the third is working, and then be changed every hour to permit continuous
use. A tractor could have a loader attachment that could be used to handle
a two ton plug-in pack. 200 batteries in series would be 740 VDC, which is
about the normal link voltage of a 480 VAC VF motor controller, and each
would supply up to 11 amps, or 8 kW, or almost 11 HP.

As long as the battery packs are designed to be recyclable, there would be
low environmental impact, and an active recycling program might lower the
real cost of the batteries even more.

I still think it may be better to use a tethered power system and connect
continuously to the grid. A pivot arm could hold a three-wire 480 VAC cable
rated at 200 amps for the 300 HP tractor, which is probably oversized
anyway, and this would be not much bigger than the standard 200 amp service
cable for most homes. #2 AWG might be large enough, and for a 400 ft pivot
arm (for about a 12 acre field) the voltage drop would be about 12 volts,
or about 97% efficient. You could have underground HV cables or overhead
poles spaced at 800 ft with distribution transformers, and that will
increase capital cost, but probably this would be only about $10,000 per
field, and maintenance costs would be low.

There are also many other ways to save energy, but they may be unpopular.
Railroads now move 1 ton of freight 438 miles per gallon of fuel:
http://www.aar.org/PubCommon/Documents/AboutTheIndustry/Overview.pdf This
is comparable to a 30 ton truck getting 15 MPG. I think it's more like 5 or
less. A half-ton Durango only gets 12 MPG on a good day. In fact, you could
strap the Durango, fully loaded, on a flatcar and it would go 150 miles on
a gallon of fuel! And its occupants, and driver, could relax and chat on
cell phones and not endanger others on the road. But the Teamsters would
have a fit if there were no more "long-haul" trucking. A train with a crew
of 3 or 4 people could replace 100 or more trucks and their drivers. But
getting all those big rigs off the public highways will greatly reduce
congestion and improve safety, and highway repairs will be minimized.

If it were not for the huge profits to be made by maintaning the status
quo, and if overall efficiency were the main motivating factor, there would
not be an energy crisis, and the Saudis would still be mostly poor nomads,
and terrorists would be broke. But the US economy, and our lifestyles, are
based on greed, competition, aggression, and conspicuous consumption, so it
will take a major kick in the pants to see any major change. But it is
inevitable.

Paul

 

[Rob Dekker]

Bret,

You know that I appreciate your input in this newsgroup, but there is
something that I think you should take to heart :

You postulate an idea here on sci.energy, with the (probable) reason to get
comments and feedback from fellow newsgroup visitors.

When these people give you feedback or stipulate possible inefficiencies and
problems with your idea, there is no need to attempt to prove them wrong or
offend them if they simply slightly disagree with your exact thought
process.

In fact, it starts to look like you simply are looking for conflict, which
eventually destroys some of the good parts in your ideas.

If you cannot handle any criticism at all, maybe it is better if you just
start a company that implements your idea, rather than bother sci.energy
visitors with it. Then you can prove everyone wrong.

Rob

 

[Paul E. Schoen]

"Rob Dekker" <rob@verific.com> wrote in message
news:R9bik.31195$co7.1630@nlpi066.nbdc.sbc.com...

"Tom Biasi" <tombiasi***@optonline.net> wrote in message
news:HYOdnarlO6PkpBTVnZ2dnUVZ_vzinZ2d@giganews.com...
..

Would you guys kindly remove "sci.electronics.basics" from the group
list. It has nothing to do with electronics.
If you want to jump on Bret Cahill please do so on sci. energy, or
alt. politics. , or alt philosophy, or what ever.

OK I'm calm now.
Best Regards,
Tom


Hi Tom,

I understand that it's never nice to find a posting in your newsgroup
that is about something other than what you think the newsgroup should
be about.
But you must admit that batteries are pretty close to the subject of
science of basic electronics.
I have no idea why Bret put alt.philosophy here, but
sci.electronics.basics seems rather applicable to me....
Besides, you can always ignore a posting.
Either way, isn't this (a human written post) at least better than a
robot posting spam on on the NGs ?

That's my 2 cts.

Rob


OK Rob,
I block Google Groups because of the enormous spam.
I only see these post when someone replies.
From what I see its not electronics but a rant regarding energy of crop
farming.
I guess I can tolerate it.
My fingers got a little excited.
Really, its just light hearted poking based on what usually goes on
here.

Tom



Thanks Tom.

I'm not sure how you read the NGs, but maybe you can configure your
newsreader so that you can delete entire posting trails, from the top
down, so that all responses disappear.

Also, maybe you guys (at sci.electronics.basics) can help us out a bit
here :
We often talk about energy efficiencies on sci.energy, and efficiency of
power electronics is kind of getting important (we often see 90-100%
efficiency for power electronics).
Do you know much about that ? Efficiency of power inverters, voltage
regulators, transformers, brushless DC or AC motors etc ?
Any power electronics components that have much less than 100% efficiency
?

Rob

Electrical machines can be made very efficient at converting mechanical and

electrical energy back and forth, as with motors and generators. Nothing
can be 100% efficient, except maybe a heat source, so if you want a motor
and a heater, you are in luck!

Converting electricity to light (and vice versa) is currently not very
efficient, and 20-30% is usually considered pretty good. CFLs have provided
about a five-fold increase in efficiency for producing light, and LEDs are
even better, with much longer life. Photovoltaics are also in the 20-30%
efficiency range (or less).

When examining overall efficiency, you really need to look at the total
costs involved in designing, manufacturing, maintaining, and eventually
disposing of a device. I believe Don Lancaster maintains that solar cells
have not produced any net savings over other sources of energy, if you take
into account the overall costs of manufacturing and useful life. But in
many cases they are worth the extra cost as a matter of convenience. A
calculator could probably run for several years on 10 cents worth of
electricity from the grid, but a $1 solar cell is much more convenient and
fully appropriate. A solar powered all-electric house in an area with
little sunlight would not be economical.

Converting electricity from one voltage to another can be accomplished at
very high efficiency, but again there are considerations of size and cost.
Small DC-DC converters are about 85% to 90% efficient, while larger ones
are often 95% or better. Yet there are also some very small low power
converters that are about 98%.

I think the discussion of excessive energy use in agriculture,
transportation, or anywhere else is appropriate for the groups listed. It
may be a stretch for philosophy, but then again it will take a revised
attitude about living to achieve a sustainable economy and a healthy
society. And it will take real cooperation among many diverse fields of
study to meet the needs of the future.

Paul

 

[Rob Dekker]

"Paul E. Schoen" <pstech@smart.net> wrote in message
news:48897b33$0$19662$ecde5a14@news.coretel.net...

"Rob Dekker" <rob@verific.com> wrote in message
news:R88ik.31155$co7.18077@nlpi066.nbdc.sbc.com...

"terryc" <newssixspam-spam@woa.com.au> wrote in message
newsan.2008.07.24.13.50.30.164653@woa.com.au...
On Tue, 22 Jul 2008 18:34:37 -0700, Rob Dekker wrote:

True. But technically speaking, a 300 kWh battery is not completely
rediculous : It will cost about $100,000 wholesale, and weigh
less than 2 ton.

Well, that is an interesting battery advancement.

For current deep-discharge lead acid, it would weigh 84 tonnes.
In LiPoly,it would currently weigh 20 tonnes.



Did I make a calculation mistake ?
Mmm. Not really :

Li-poly gets us about 160 Wh/kg. That's less than 2 ton for 300 kWh.
Here is a cell of that type :

http://www.all-battery.com/index.asp?PageAction=VIEWPROD&ProdID=1631&HS=1

The only problem with this one (technically) is that it recharges up to
500x.
That makes it expensive to use. Should be more like 2000x.

Rob

Right. I figure these batteries themselves cost $1100/kWH so for 500
charges that is about $2/kWH. Even at 2000 charges it's $0.50/kWH. Now, if
it is true that, at $5/gallon, diesel costs $0.30-$0.40/kWH, it would not
have to go up a whole lot more for a crossover point to be reached, and
the
battery cost would certainly be a lot less than the advertised sale price
of $44 each for singles or even $38 each for 500.

Correct. This is a retail store, and if you visited them, you might ever
have gotten a pop-up shat with a female on-line sales person ("Shirley" or
so) offering a 10% immediate discount.
The wholesale li-poly market is different, and there are strong indications
(Wiki-page) that Li-poly goes for about $0.20-$0.30/Wh for large volume
10kWh packs from a Chinese manufacturer.
That would bring the price down to about $0.40/kWh for the 500x charge, or
$0.10 for a 2000x charge.

You would need 7500
batteries for 300 kWH and that would cost about $300,000. You could run
for
an hour, but then (per spec) it would take 2 hours to recharge. You would
need to replace the batteries after 500 hours running time, or 1500 total
hours, or every 9 weeks. There will certainly be some new technology (and
economies of scale) that
will lower the cost and extend the charge cycles.

It would not be unreasonable to have two extra plug-in packs that could be
charging while
the third is working, and then be changed every hour to permit continuous
use. A tractor could have a loader attachment that could be used to handle
a two ton plug-in pack. 200 batteries in series would be 740 VDC, which is
about the normal link voltage of a 480 VAC VF motor controller, and each
would supply up to 11 amps, or 8 kW, or almost 11 HP.

As long as the battery packs are designed to be recyclable, there would be
low environmental impact, and an active recycling program might lower the
real cost of the batteries even more.

As I noted in other posts, current Li-poly is probably not a smart choice
for heavy-duty rechargable batteries. Zebra's (or other molten salt)
batteries are much cheaper, get close to the same energy density, thousands
of cycles, and easy to recycle. They also don't use Lithium, which I now am
convinced is not ecologically harvestable in large enough quantities for a
world-wide conversion of oil to battery/electricity.
Leave the Lithium for mciro-electronics (lap-tops etc)...

I still think it may be better to use a tethered power system and connect
continuously to the grid. A pivot arm could hold a three-wire 480 VAC
cable
rated at 200 amps for the 300 HP tractor, which is probably oversized
anyway, and this would be not much bigger than the standard 200 amp
service
cable for most homes. #2 AWG might be large enough, and for a 400 ft pivot
arm (for about a 12 acre field) the voltage drop would be about 12 volts,
or about 97% efficient. You could have underground HV cables or overhead
poles spaced at 800 ft with distribution transformers, and that will
increase capital cost, but probably this would be only about $10,000 per
field, and maintenance costs would be low.

I agree. Batteries should not be needed for a field of a few square miles.
I proposed to same thing to Bret, but with a standard 11kV AC distribution
power cable.
11 kV is the standard medium grid distribution voltage, so we would not even
need a transformer from the grid.

Safe 11 kV cables are also relatively thin, and show hardly any losses over
several miles (assuming 200-300kW power usage). You just want to keep them
away from moving farm equipment (apart from the connector to the tarctor).
We need a system (of arms or so) to guarantee that accidents won't happen
(or if they do that nobody will die) regardless of if we use 480 V or 11kV
AC.

There are also many other ways to save energy, but they may be unpopular.
Railroads now move 1 ton of freight 438 miles per gallon of fuel:
http://www.aar.org/PubCommon/Documents/AboutTheIndustry/Overview.pdf This
is comparable to a 30 ton truck getting 15 MPG. I think it's more like 5
or
less. A half-ton Durango only gets 12 MPG on a good day. In fact, you
could
strap the Durango, fully loaded, on a flatcar and it would go 150 miles on
a gallon of fuel! And its occupants, and driver, could relax and chat on
cell phones and not endanger others on the road. But the Teamsters would
have a fit if there were no more "long-haul" trucking. A train with a crew
of 3 or 4 people could replace 100 or more trucks and their drivers. But
getting all those big rigs off the public highways will greatly reduce
congestion and improve safety, and highway repairs will be minimized.

I could not agree more. Rail transport is most certainly undervalued right
now. Interstate trucking is doomed (if customers can accept a day or two
more in travel/trasfer times).

If it were not for the huge profits to be made by maintaning the status
quo, and if overall efficiency were the main motivating factor, there
would
not be an energy crisis,

High liquid fuel prices should really push that focus back to efficiency.

and the Saudis would still be mostly poor nomads, and terrorists would be
broke.

They will be eventually. If they did not buy up the US in the meantime....

But the US economy, and our lifestyles, are
based on greed, competition, aggression, and conspicuous consumption, so
it
will take a major kick in the pants to see any major change. But it is
inevitable.

As Al Gore would say : "We borrow billions from china to buy oil from the
middle east to pollute our planet. Every bit of which has to change."

$700 billion per year goes out of our country like that. That's how much I
agree with Pickens.

Let's move electric instead of on oil. There is work to be done....

Rob

Paul

 

[Rob Dekker]

"terryc" <newssixspam-spam@woa.com.au> wrote in message
newsan.2008.07.25.07.09.56.904260@woa.com.au...

On Thu, 24 Jul 2008 16:20:32 -0700, Rob Dekker wrote:


"terryc" <newssixspam-spam@woa.com.au> wrote in message
newsan.2008.07.24.13.50.30.164653@woa.com.au...
On Tue, 22 Jul 2008 18:34:37 -0700, Rob Dekker wrote:

True. But technically speaking, a 300 kWh battery is not completely
rediculous : It will cost about $100,000 wholesale, and weigh
less than 2 ton.

Well, that is an interesting battery advancement.

For current deep-discharge lead acid, it would weigh 84 tonnes.
In LiPoly,it would currently weigh 20 tonnes.



Did I make a calculation mistake ?
Mmm. Not really :

Li-poly gets us about 160 Wh/kg. That's less than 2 ton for 300 kWh.

You desperately need new batteries in your calculator.

300Kwh = 300,000 wh.

Right. And 1 ton is 1,000 kg.
So what's wrong ?

The only problem with this one (technically) is that it recharges up to
500x.

This is the whole point about why diesel has to rise another order of
magnitude before this idea even gets considerable.

As I noted in other posts, current Li-poly is probably not a smart choice
for heavy-duty rechargable batteries. Zebra's (or other molten salt)
batteries are much cheaper, get close to the same energy density, thousands
of cycles, and easy to recycle. They also don't use Lithium, which I now am
convinced is not ecologically harvestable in large enough quantities for a
world-wide conversion of oil to battery/electricity.
Leave the Lithium for mciro-electronics (lap-tops etc)...

Rob