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[EVDL] Zenn Says See You Later, Batteries!

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>From the ET list. Lawrence Rhodes.....
Posted by: "Remy Chevalier" [email protected] cleannewworld
Date: Sun Sep 2, 2007 9:50 am ((PDT))

Startup Says See You Later, Batteries!
Breakthrough Power Technology Claims to Deliver 500 Miles on 5-Minute Charge
By GRANT SLATER
AUSTIN, Texas -- Aug. 31, 2007-

http://abcnews.go.com/Technology/Story?id=3D3547157&page=3D1


Millions of inventions pass quietly through the U.S. patent office each
year. Patent No. 7,033,406 did, too, until energy insiders spotted six words
in the filing that sounded like a death knell for the internal combustion
engine.

An Austin-based startup called EEStor promised "technologies for replacement
of electrochemical batteries," meaning a motorist could plug in a car for
five minutes and drive 500 miles roundtrip between Dallas and Houston
without gasoline.

By contrast, some plug-in hybrids on the horizon would require motorists to
charge their cars in a wall outlet overnight and promise only 50 miles of
gasoline-free commute. And the popular hybrids on the road today still
depend heavily on fossil fuels.

"It's a paradigm shift," said Ian Clifford, chief executive of Toronto-based
ZENN Motor Co., which has licensed EEStor's invention. "The Achilles' heel
to the electric car industry has been energy storage. By all rights, this
would make internal combustion engines unnecessary."

Clifford's company bought rights to EEStor's technology in August 2005 and
expects EEStor to start shipping the battery replacement later this year for
use in ZENN Motor's short-range, low-speed vehicles.

The technology also could help invigorate the renewable-energy sector by
providing efficient, lightning-fast storage for solar power, or, on a small
scale, a flash-charge for cell phones and laptops.

Skeptics, though, fear the claims stretch the bounds of existing technology
to the point of alchemy.

"We've been trying to make this type of thing for 20 years and no one has
been able to do it," said Robert Hebner, director of the University of Texas
Center for Electromechanics. "Depending on who you believe, they're at or
beyond the limit of what is possible."

EEStor's secret ingredient is a material sandwiched between thousands of
wafer-thin metal sheets, like a series of foil-and-paper gum wrappers
stacked on top of each other. Charged particles stick to the metal sheets
and move quickly across EEStor's proprietary material.


The result is an ultracapacitor, a battery-like device that stores and
releases energy quickly.

Batteries rely on chemical reactions to store energy but can take hours to
charge and release energy. The simplest capacitors found in computers and
radios hold less energy but can charge or discharge instantly.
Ultracapacitors take the best of both, stacking capacitors to increase
capacity while maintaining the speed of simple capacitors.

Hebner said vehicles require bursts of energy to accelerate, a task better
suited for capacitors than batteries.

"The idea of getting rid of the batteries and putting in capacitors is to
get more power back and get it back faster," Hebner said.

But he said nothing close to EEStor's claim exists today.

For years, EEStor has tried to fly beneath the radar in the competitive
industry for alternative energy, content with a yellow-page listing for an
indiscriminate office building and a handful of cryptic press releases.

Yet the speculation and skepticism have continued, fueled by the company's
original assertion of making batteries obsolete - a claim that still
resonates loudly for a company that rarely speaks, including declining an
interview with The Associated Press.

The deal with ZENN Motor and a $3 million investment by the venture capital
group Kleiner Perkins Caufield & Byers, which made big-payoff early bets on
companies like Google Inc. and Amazon.com Inc., hint that EEStor may be on
the edge of a breakthrough technology, a "game changer" as Clifford put it.

ZENN Motor's public reports show that it so far has invested $3.8 million in
and has promised another $1.2 million if the ultracapacitor company meets a
third-party testing standard and then delivers a product.

Clifford said his company consulted experts and did a "tremendous amount of
due diligence" on EEStor's innovation. EEStor's founders have a track
record. Richard D. Weir and Carl Nelson worked on disk-storage technology at
IBM Corp. in the 1990s before forming EEStor in 2001. The two have acquired
dozens of patents over two decades.

Neil Dikeman of Jane Capital Partners, an investor in clean technologies,
said the nearly $7 million investment in EEStor pales compared with other
energy storage endeavors, where investment has averaged $50 million to $100
million.

Yet curiosity is unusually high, Dikeman said, thanks to the investment by a
prominent venture capital group and EEStor's secretive nature.

"The EEStor claims are around a process that would be quite revolutionary if
they can make it work," Dikeman said. Previous attempts to improve
ultracapacitors have focused on improving the metal sheets by increasing the
surface area where charges can attach.

EEStor is instead creating better nonconductive material for use between the
metal sheets, using a chemical compound called barium titanate. The question
is whether the company can mass-produce it.

ZENN Motor pays EEStor for passing milestones in the production process, and
chemical researchers say the strength and functionality of this material is
the only thing standing between EEStor and the holy grail of energy-storage
technology.

Joseph Perry and the other researchers he oversees at Georgia Tech have used
the same material to double the amount of energy a capacitor can hold. Perry
says EEstor seems to be claiming an improvement of more than 400-fold, yet
increasing a capacitor's retention ability often results in decreased
strength of the materials.

"They're not saying a lot about how they're making these things," Perry
said. "With these materials (described in the patent), that is a challenging
process to carry out in a defect-free fashion."

Perry is not alone in his doubts. An ultracapacitor industry leader, Maxwell
Technologies Inc., has kept a wary eye on EEStor's claims and offers a
laundry list of things that could go wrong.

Among other things, the ultracapacitors described in EEStor's patent operate
at extremely high voltage, 10 times greater than those Maxwell manufactures,
and won't work with regular wall outlets, said Maxwell spokesman Mike Sund.
He said capacitors could crack while bouncing down the road, or slowly
discharge after a dayslong stint in the airport parking lot, leaving the
driver stranded.

Until EEStor produces a final product, Perry said he joins energy
professionals and enthusiasts alike in waiting to see if the company can own
up to its six-word promise and banish the battery to recycling bins around
the world.

"I am skeptical but I'd be very happy to be proved wrong," Perry said.



Copyright =A9 2007 ABC News Internet Ventures

Messages in this topic (1)

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Discussion Starter · #21 ·
I think the key to using this type of technology will be to hide it from
the user behind a dc-dc converter having it's own inductance and
capacitance.
A very high efficiency bidirectional dc-dc converter (QR-ZVS?) would
provide something like a 300V, -100 to 400 amp interface .
This can then feed an AC 3phase hbridge or a dc motor. Maybe the dc
link voltage would be controllable and be part of the control or maybe
it is just dumb, acts like a battery and lets us use whatever controller
we want. At 300:3500 we are already at 12:1 voltage ratio in the dc-dc.
That is pushing the limit on practical high power dc-dc converters,
especially if we are asking to have a dynamic range of 12:1 to 2:1

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Discussion Starter · #22 ·
Jeff Shanab wrote:
> A very high efficiency bidirectional dc-dc converter (QR-ZVS?) would
> provide something like a 300V, -100 to 400 amp interface. This can
> then feed an AC 3-phase h-bridge or a DC motor. Maybe the DC link
> voltage would be controllable and be part of the control or maybe it
> is just dumb, acts like a battery and lets us use whatever controller
> we want.

Yes; that makes sense.

> At 300v:3500v we are already at 12:1 voltage ratio in the DC-DC.
> That is pushing the limit on practical high power dc-dc converters,
> especially if we are asking to have a dynamic range of 12:1 to 2:1

Not really. Any PFC boost converter has a fixed output (about 400vdc)
and an input that varies from 0v to the peak of the AC line (370v for a
240vac line). These are mass produced by the millions and have
efficiencies of 95% or so.

Wide-range DC/DC step-down converters are also common. Universal input
switching power supplies will deliver 12vdc with a 90-265vac input
range, and there are many DC/DCs with a 4:1 input range. A 6:1 input
range is a little more difficult, but straightforward.

--
Ring the bells that still can ring
Forget the perfect offering
There is a crack in everything
That's how the light gets in -- Leonard Cohen
--
Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart_at_earthlink.net

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Discussion Starter · #23 ·
> > At 300v:3500v we are already at 12:1 voltage ratio in the DC-DC.
> > That is pushing the limit on practical high power dc-dc converters,
> > especially if we are asking to have a dynamic range of 12:1 to 2:1
>
> Not really. Any PFC boost converter has a fixed output (about 400vdc)
> and an input that varies from 0v to the peak of the AC line (370v for a
> 240vac line). These are mass produced by the millions and have
> efficiencies of 95% or so.

Except that in a PFC boost converter, the power drawn is proportional
to the square of the input voltage, so there is low current at low
voltage. For an EV, you want constant power, so current is inversely
proportional to voltage. I suspect that this will have a big effect on
efficiency.

Also, we're talking much higher power here. How many 20kW wall
adapters do you see?

> Wide-range DC/DC step-down converters are also common. Universal input
> switching power supplies will deliver 12vdc with a 90-265vac input
> range, and there are many DC/DCs with a 4:1 input range. A 6:1 input
> range is a little more difficult, but straightforward.

Most of these are low current; an EV would need 100 times more
current, which means 10000 times more resistive losses. You don't
really want to use 10000 times more copper to make up for that.

-Morgan

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Discussion Starter · #24 ·
Lee Hart Wrote:
>Not really. Any PFC boost converter has a fixed output (about 400vdc)
and an input that varies from 0v to the peak of the AC line (370v for a
240vac line). These are >mass produced by the millions and have
efficiencies of 95% or so.

>Wide-range DC/DC step-down converters are also common. Universal input
switching power supplies will deliver 12vdc with a 90-265vac input
range, and there are >many DC/DCs with a 4:1 input range. A 6:1 input
range is a little more difficult, but straightforward.


I was thinking in terms of High Power and Bi-directional converters.
Since each side needs to be sized for the max current and max voltage it
can produce, Isn't their a inheriant loss of efficiency when some of the
active components are significantly oversized for the main mode of use?

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Discussion Starter · #25 ·
Lee Hart Wrote:
>> Any PFC boost converter has a fixed output (about 400vdc) and an
>> input that varies from 0v to the peak of the AC line (370v for a
>> 240vac line). These are mass produced by the millions and have
>> efficiencies of 95% or so.
>>
>> Wide-range DC/DC step-down converters are also common... there
>> are many DC/DC's with a 4:1 input range. A 6:1 input range
>> range is a little more difficult, but straightforward.

Jeff Shanab wrote:
> I was thinking in terms of High Power and Bi-directional converters.
> Since each side needs to be sized for the max current and max voltage
> it can produce, isn't their a inheriant loss of efficiency when some
> of the active components are significantly oversized for the main
> mode of use?

Not so much a loss of efficiency. It's the price that goes up when you
demand a wider range of voltage and current. For instance, if you want a
1000w converter to work at 100vdc, its transistors need to handle 100v x
10a = 1kw. But if it needs to work from 10v to 100v, then the transistor
need to handle 100a at 10v, and 10a at 100v. Such a transistor is just
as efficient; but it costs a lot more.

--
Ring the bells that still can ring
Forget the perfect offering
There is a crack in everything
That's how the light gets in -- Leonard Cohen
--
Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart_at_earthlink.net

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Discussion Starter · #26 ·
Morgan LaMoore wrote:
> Except that in a PFC boost converter, the power drawn is proportional
> to the square of the input voltage, so there is low current at low
> voltage.

That is a consequence of the power factor control algorithm, which
forces input current to follow input voltage. But all the PFC converters
I've tested will run on a straight DC input. In this case, the input
current they draw is *inversely* proportional to the input voltage. I.e.
a 100 watt 90-264vac PFC power supply draws:

- 100v at 1a
- 200v at 0.5a
- 300v at 0.33a etc.

> For an EV, you want constant power, so current is inversely
> proportional to voltage. I suspect that this will have a big effect on
> efficiency.

It just means that the voltage and current ratings of the semiconductors
and boost inductor need to take this into account.

> Also, we're talking much higher power here. How many 20kW wall
> adapters do you see?

As a rule, cost per KW goes down as the power goes up. I.e. one 20kw
supply costs less than ten 1kw supplies.

>> Wide-range DC/DC step-down converters are also common.

> Most of these are low current

Of course; that's where the demand is. The market uses a million times
more little DC/DC's than big ones.

> an EV would need 100 times more current, which means 10000 times
> more resistive losses. You don't really want to use 10000 times
> more copper to make up for that.

No; it doesn't work like this. On a crude basis, you could get 100 times
the current by just using 100 little DC/DC converters; thus 100 times
the semiconductors, copper, etc.

But in practice, you'd use a much smaller number of semiconductors and
other parts. When you double the power of a part its size, cost, and
weight will *less* than double. A 0.3w transistor is $0.10; a 3w
transistor around $0.30; a 30w transistor $1; a 300w transistor is $3 etc.

At some point this breaks down, because nobody makes 30,000 watt
transistors. So you have to use many smaller parts in parallel. But even
then, the size/cost/weight go up linearly, not as a squared function.
--
Ring the bells that still can ring
Forget the perfect offering
There is a crack in everything
That's how the light gets in -- Leonard Cohen
--
Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart_at_earthlink.net

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