Talk:EEStor

Charging time and sources

"If the technology works as claimed, a five-minute charge costing $9..."

$9 worth of electricity flowing through the lines in five minutes? Where are people going to charge this thing? In their backyard hydroelectric plant?

It's been a while since that electrical engineering course back in the day so these calculations could be all wrong... but they look OK to me:

Assume $0.10/KWH and that you're recharging from your 220V outlet (yeah, you'd need much higher voltages to charge this capacitor but I guess you'd need some sort of transformer at your house between the 220V outlet and the capacitor). $9.00 = 90 KWH. 90 KWH in 5 minutes is 90 * 60/5 = 1080 kilowatts of power. I = P/V so I = 1,080,000 Watts/220 Volts ~= 4910 Amperes.

That's what, about 50 times the current you normally get through the main line into your house?

12.13.70.254 17:48, 10 September 2007 (UTC)

Charging time would, presumably, vary depending on what it's plugged into. Your home's wall current won't charge it very quickly -- and unless they want to be causing brownouts all over the country when this thing hits market, there will almost certainly be some kind of regulator to detect how quickly to pull in the current. --GoodDamon 22:47, 10 September 2007 (UTC)

Assuming the Eestor unit works in the first place, there is no reason apart from cost why you should not have two Eestor units. The house Eestor unit would be charged overnight on cheap off-peak electricity, and would be available on demand to charge the EEstor unit in the car at a few thousand volts in 5-10 minutes. Apparently the US military have a spec for such a charging interface. The house Eestor unit could pay for itself by allowing domestic electricity use exclusively at cheap, off-peak rates. Technopete (talk) 23:24, 21 December 2007 (UTC)

Banks of charging capacitors

If you look at the EEstor patent, you will see that, even for service station charging, they are anticipating charging banks of capacitors in the station at a steady rate during the utility off-peak hours and then rapidly transferring the charge to vehicles on demand. Bottom line: fastest charging requires more expensive equipment. Even the cables, connectors and safety interlocks could turn out to be fairly expensive. C J Cowie 20:59, 10 September 2007 (UTC)

I would note that actually the potential to charge overnight at home, for up to 300 mile range, will complicate the economics of charging stations. The fact that no one can realistically "gas up at home" is why we have so many gas stations. 300 miles per day will cover 99% of driving, so the demand for charging stations will be limited at best. But, on the plus side, presumably such stations will only be needed for longer road trips, so even just a few along the interstates might suffice. Tricky stuff. cap69.62.205.115 21:52, 21 September 2007 (UTC)

Electric filling stations would not use banks of EESU capacitors, that would cost millions, instead they would use a 1 MW natural gas generator that costs about $200K and could fill 6 cars at once, and in the 6 minute time. The station would chose between grid power or generating its own to sell, whichever is the least expensive at the time. During the summer, most of the power would be self generated due to peak demand upon all generating resources on the grid. December 9, 2007

Objections to new language in mainspace

Here is the patent with images: http://www.freepatentsonline.com/7033406.html.

I object to this paragraph, "Let's do the math however. A small electric car driving at 50mph would require approximately 17kW to maintain that speed. Over 500 miles, this would have to be sustained for 10 hours. Therefore, the capacitors would have to have a capacity of 170 kW-hrs. Let's say that you get all the power out of the device that you put in so this is the amount of power required to charge the device. 170kW-hrs converts to 2040 kW-'5min's or 408,000 W-min. 1 Volt x 1 Amp = 1 Watt so at a charging voltage of say, 1000 Volts, that would require 408 Amps to get the job done. Not something I'd want to handle at home or at the local electron filling station. Electricity at this voltage has a tendency to 'leak' and it's consequences are quite toxic in their own way."

The 17kW to maintain a small car at 50mph is not referenced and does not agree with the Eestor patent. The Eestor patent indicates, "It is estimated that is takes 14 hp, 746 watts per hp, to power an electric vehicle running at 60 mph with the lights, radio, and air conditioning on. The energy-storage unit must supply 52,220 W·h or 10,444 W for 5 hours to sustain this speed and energy usage and during this period the EV will have traveled 300 miles." Thus, according to the patent, the car will use roughly 10kW per hour at 60 mph with stated amenities running.

"a charging voltage of say, 1000 Volts..." is an inaccurate estimate because in the patent they state, "the proper voltage breakdown selected from this range could allow the voltage of the energy-storage unit to be 3500 V or higher."

I object to the statement, "Electricity at this voltage has a tendency to 'leak' and it's consequences are quite toxic in their own way." We already have power stations safely generating many times this energy. The statement is not referenced, subjective, and questionable -- not really suitable for an encyclopedia.

I would like for the above paragraph to be a little more referenced and perhaps more in accord with the information as stated by Eestor.

Additional information I believe people should know is 1) a typical house does not have the capacity to recharge the car in 5 minutes. 2) If a car is going to be recharged in 5 minutes, it will have to be (and could be) done at a 'charging station' type place. 3) At a typical house the car could be charged overnight with present wiring. 63.3.15.1 11:41, 12 September 2007 (UTC)

The paragraph is gone. It was neither encyclopedic in nature nor properly sourced, and belongs on this discussion page, where you have placed it. --GoodDamon 22:23, 12 September 2007 (UTC)

The above editor brings up good points on the 'Let's do the Math' paragraph and quite rightly points out that data-based input only is appropriate for an encyclopedia. Therefore, the main article which discusses a $9, 5-min charge should actually read that this feat is only 'possible' or that the 'patent quotes that this is possible' instead of making it sound like a reality. I believe there's a bit of hype in the main article which is definitely not appropriate for an encyclopedic reference.

Also, patents are not always factual reference documents. They are legal 'claims' not actual, physical facts. Data/examples given in patents are typically provided to demonstrate (promote) an idea and may not necessarily reflect all practical aspects of an application. If EEStor's idea is as practical as they suggest, it should be able to stand up to examples not entirely in accord with their views. The 1000V was provided as a round number for easier math and to demonstrate the high amperage involved. 1000V would be 'safer' to handle than 3500V anyway - not that a shock from either voltage would be pleasant.

In a similar fashion, EEStor should manage their public information to avoid stretching what they put in their patent - are they targeting a 500mile range or a 300 mile range? That's a considerable difference. —Preceding unsigned comment added by 192.158.61.141 (talk) 13:19, 12 September 2007 (UTC)

EEStor used the 300 mile range example in their patent. I looked over the internet and the only source I found for the 500 miles is the Associated Press writer of the original article. EEStor may have told him the figure but I never saw that confirmed; maybe I missed it. EEStor did say their supercapacitor is capable of being charged in 4 - 6 minutes, but I can't find where they said a car would go 500 miles on this charge. I didn't go through all the math. 63.3.15.1 06:23, 13 September 2007 (UTC)

Note that the voltage to which the capacitor is charged is very important to the energy density. As stated in their patent, "high voltage breakdown assists in allowing the ceramic EESU to store a large amount of energy...the energy of the EESU increases with the square of the voltage." In other words, the voltage energy stored when the unit is charged to 1000 volts is only 8% of the energy stored when the unit is charged to 3500 volts. C J Cowie 19:38, 12 September 2007 (UTC) Corrected my previous comment. C J Cowie 14:27, 13 September 2007 (UTC)

Cost to operate 300 miles or 500 miles

According to the Department of Energy, the average retail price of electricity for June 2007 was 9.47 cents per kilowatthour (kWh). The average retail price of residential electricity for June 2007 was 11.07 cents per kWh. So, if the car is charged using residential electricity rates it will cost $1.156 per hour to operate the vehicle at 10.444 kWh. For 5 hours at 60 miles per hours gives 300 miles at a cost of $5.78, or $9.63 for 500 miles. http://www.eia.doe.gov/cneaf/electricity/epm/epm_sum.html 63.3.15.130 12:47, 16 September 2007 (UTC)

Don't forget about Time of use metering and Smart meters. Potential for load leveling is one often overlooked benefit of EVs. Distributed utility battery, basically. Off-peak should be at least a bit cheaper than "average residential". Anyway, with gas around $3/gallon, even a 60MPG hybrid would cost $15 for fuel to go 300 miles, so fuel costs look pretty nice for EV. 69.62.205.115 21:47, 21 September 2007 (UTC)

Aditionally, if this kind of car becomes popular, it would be possible for the electricity companies to use them as a distributed battery system, balancing load between off-peak and peak hours and responding very quickly to increased load. This has all sorts of advantages - maybe even enough to justify the cost of such a system. Anaholic 14:55, 16 November 2007 (UTC)

Weight of Capacitor

From the patent, "The total weight of the EESU (est.) = 336 pounds. The total volume of the EESU (est.) = 13.5 inches × 13.5 inches × 11 inches = 2005 inches cubed - - - Includes the weight of the container and connecting material. The total stored energy of the EESU = 52,220 W·h." 63.3.15.130 17:15, 16 September 2007 (UTC)

Supercapacitor / Regular capacitor

Contrary to a number of misstatements in the press, the EESU is not a supercapacitor; it's a high capacitance conventional ceramic capacitor. Supercapacitors get their capacitance from an electric double layer in a metal/electrolyte interface. -- 129.255.93.189 22:06, 15 November 2007 (UTC)

The EEstor capacitor is not so much a high capacitance device as a device with moderate capacitance and a moderately high voltage rating resulting in a high energy density. The objective of the development of multilayer electrochemical capacitors is ultimately to achieve high energy density. I suspect that if the EEstor capacitor is successful, the press and/or the scientific community will successfully redefine the term "supercapacitor" in terms of energy density. I believe the current definition has been written by those marketing multilayer electrochemical capacitors, not by the scientific community. Unless and until the EEstor capacitor proves to be successful, this article could be deleted at any time for lack "encyclopediac merit" or what ever it is called. The EEstor material has been deleted from the supercapacitor article in the past on the same grounds. C J Cowie 23:42, 15 November 2007 (UTC)

I think it's noteworthy. Does that count?  :-) One of Wikipedia's strengths is that it can be at the forefront of technical evolution. Even if EEStor isn't ultimately successful I think people would like to know of it's existance -- if for no other reason than to learn from the attempt. 63.3.15.130 (talk) 04:09, 19 November 2007 (UTC)

Controversy

Recently someone incorporated material from the following link in the article and someone else removed the material and added the link to the “In the news” section of the article.

a blog post with a discussion disputing the validity of EEstor’s claims and targets

If you look at various related news articles and blog postings, you will find quite a bit of controversy about EEStor and their invention.

I offer the following comments related to this controversy:

If you look at EEStor’s patent, you will see that they have not claimed to have invented any part of the electrical energy storage unit (EESU) described in the patent. What they claim as their invention is a method of manufacturing the EESU that is described. The materials used and the application of the materials to the manufacture of capacitors are either part of the established art of capacitor manufacture or are covered by patents assigned to others. It appears that the description of the properties of the device is based on the claims made by others in prior patent disclosures. It appears that the EEStor patent only claims that they have developed a method of combining the various component parts into a single device.

The key components seem to be:

The ceramic basis material is barium-titanate doped with small amounts of additives as described in U.S. patent 6078494 assigned to the U.S. Phillips Corporation. The inventors of this particular ceramic formulation claim that a high value of K is provided along with a long service life, low loss factor, high insulation resistance and a capacitance with low voltage dependence. The temperature dependence of the dielectric constant corresponds to EIA standard Y5V.

The ceramic basis material is modified by coating the particles of powdered basis material with an aluminum oxide coating. A second coating of calcium magnesium aluminosilicate glass is then applied to the particles. A similar coating process is described in U.S. patent 6,268,054 assigned to Cabot Corp., Boston, MA. The inventor of this coating process claims an increase the breakdown voltage of the dielectric material from 3X10^6 V/cm to 5x10^6 V/cm or higher and a significant reduction in the leakage and aging of the dielectric.

Benefits specifically attributed to the glass coating are that it:

• lowers temperature required for sintering and hot isostatic pressing to 800C – a temperature that allows nickel to be used for electrodes rather tan more expensive platinum, palladium or palladium-silver
• assists in removing voids from the dielectric during the hot isostatic pressing helping to ensure that the high voltage breakdown will be achieved
• ensure that the dielectric layer will be uniform and homogeneous

EEStor’s success or failure seems to depend on their ability to, in a volume manufacturing environment, successfully produce all of the components and combine the components as described in the patent. Furthermore, the properties of the components must fulfill the claims made for them by their various inventors. In addition to that, the properties of the completed EEStor EESU must have properties equivalent to the sum of the properties claimed for the individual components. -- C J Cowie (talk) 20:14, 8 December 2007 (UTC)

Capacitance?

The article claimed that the capacitance of the 336lb unit was 31 farad. Now, I'm not an electrical engineer, but I know that that is clearly ridiculous. A farad is a large amount of energy as far as capacitors go, but very very very small compared to batteries. One farad of capacitance gives you enough energy to delivery 1A at 1V for 1 second. A typical 1.5V AA battery might be 2600mAh, which means it can theoretically deliver 2.6A at 1.5V for 1 hour. In actual practice it will drop below 1.5V as it loses charge, so let's call it 1V. That gives it an energy storage equivalent to 2.6 (amps) * 1 (volts) * 3600 (seconds) = 9360 farads.

So that means that, to duplicate the energy density of a single AA battery, you need 9360 farads worth of capacitance, which is already far larger than any capacitor I have ever heard of -- and that's just to match a single small battery. To reach the 52KWh claimed by the article, since a W is 1V*1A I believe you would need 52000*3600 = 187,200,000 farads of capacitance. If my math and understanding are correct (which they may well not be) I am extremely skeptical of this claim. To avoid spreading any more misinformation (in case I am incorrect) I have merely removed the 31 farad figure from the article, since there is absolutely no way in hell that that is correct. 69.134.118.239 (talk) 20:39, 13 December 2007 (UTC)

Your understanding is not correct, but that does not mean that you are wrong to be skeptical of this claim. The energy stored in a capacitor is not determined only by the capacitance. Energy stored (joules or watt-seconds) is equal to one half the capacitance (farads) multiplied by the voltage squared. What is described in the EEStor patent is a 31 farad capacitor that can be charged to 3500 volts. The energy is calculated as 0.5 X 31 X 3500^2 = 189,875,000 watt-seconds or 52,743 watt-hours. Capacitors can easily be manufactured to withstand charging to 3500 volts, but this one has a dielectric that is only 12.7 thousandths of a millimeter thick. Is that possible? This capacitor uses a barium titanate as its dielectric. That material is usually much less effective at increased voltage levels. It is claimed that adding a small amount of a “doping” material will counteract that effect. Will that work? -- C J Cowie (talk) 22:55, 13 December 2007 (UTC)