Kraftwerk - Page 1
Forum section: electronics / general

author: salamander
author_rank: Contributor
timestamp: January 09, 2015, 11:41:03 am
content: Hi, I came across this project on Kickstarterhttps://www.kickstarter.com/projects/265641170/kraftwerk-highly-innovative-portable-power-plant/descriptionand I would like to hear your feedback. Can it work as they claim, or is it another bullsh*t / scam?

author: firewalker
author_rank: Super Contributor
timestamp: January 09, 2015, 02:29:53 pm
content: I would guess alcohol would be more suitable for such an application.Alexander.

author: salamander
author_rank: Contributor
timestamp: January 09, 2015, 05:09:23 pm
content: OK, but the idea behind it is ok? I have no idea how fuel cell technology has advanced over the years :/But I really like the idea behind it, so maybe I will throw my money at them

author: Marco
author_rank: Super Contributor
timestamp: January 09, 2015, 05:19:59 pm
content: It can work, although the lifetime of the SOFC is an open question.On the other hand a battery pack will have about the same energy density.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: January 09, 2015, 09:49:29 pm
content: I think a bunch of German synth players might have something to say about the name....

author: TopLoser
author_rank: Unknown
timestamp: January 09, 2015, 09:54:07 pm
content: Quote from: mikeselectricstuff on January 09, 2015, 09:49:29 pmhmmm maybe not - they call it "kraftwerk" not "Kraftwerk", and kraftwerk is just German for "power station"?

author: RobertoLG
author_rank: Frequent Contributor
timestamp: January 09, 2015, 10:09:47 pm
content: here is one that is around for some timehttp://www.powertrekk.com/It's a flexible 2-way solution. A fuel cell charger that generateselectricity on the go from water and salt. Including a portable battery á 3800 mAh.

author: sleemanj
author_rank: Super Contributor
timestamp: January 09, 2015, 11:07:36 pm
content: Quote from: RobertoLG on January 09, 2015, 10:09:47 pmThat's rather misleading.The "salt" is a mixture of Sodium silicide and Sodium borohydride, not exactly common household ingredients, combined with water this produces hydrogen for the fuel cell. It's provided in a single use proprietary canister ("puck"), and each canister produces hydrogen sufficient to provide 1200mAh at 5v apparently, in their words "equivalent to 6 AA batteries".9 canister cost you 45 Euro (minimally, if you are in the EU, a lot more if you're not), so that's 5 Euro each.

author: eas
author_rank: Frequent Contributor
timestamp: January 10, 2015, 03:07:08 am
content: Quote from: mikeselectricstuff on January 09, 2015, 09:49:29 pmWhy, are they also in the portable power business? Trademark protection is generally limited in scope. It looks like the principles in the band haveactiveregistrationsfor recordings, performances, and a vast variety of merch (aka, the sweetest plum).As for the project itself, assuming they are who they say they are, it seems legit. It looks like a commercialization spin-off from a well-established major R&D operation, and is likely well funded. Given the origin, and the amount of money they are raising, this seems more like a way to validate and get some exposure than an essential source of funding.I haven't benchmarked it against other commercial fuel cell offerings, but it doesn't seem like they are making outrageous promises. As a compact way to charge USB devices without depending on access to grid power, it seems reasonably cost competitive, particularly at the Kickstarter price. If they were planning on shipping it by June, I might buy in. By next December though, I have no idea how I'd feel.They really should have hired and (and listened to) some english/american marketing people though. There are a few important points that don't really get communicated well.

author: janekm
author_rank: Unknown
timestamp: January 10, 2015, 06:41:03 am
content: Looks way more plausible than most actually... The CEO of the company behind it has a PhD from Fraunhofer and the investment arm of Fraunhofer has invested in the company (Fraunhofer is the most famous research institute in Germany).Sure having a PhD is no guarantee that they'll manage a successful product introduction but at least I wouldn't expect them to make basic order-of-magnitude mistakes like the various solar projects

author: babysitter
author_rank: Frequent Contributor
timestamp: January 10, 2015, 01:52:10 pm
content: Quote from: janekm on January 10, 2015, 06:41:03 amHave not read the original article, but Fraunhofer is a research institute which is not related to a university. They dont hand out PhDs, although you might possibly work at your doctorate thesis there. German universities hand out Dr., not Ph.D.So saying somebody has a PhD from FHG is at least misleading.

author: RobertoLG
author_rank: Frequent Contributor
timestamp: January 10, 2015, 06:11:18 pm
content: Quote from: sleemanj on January 09, 2015, 11:07:36 pmya you are right, this thing is kinda expensive to buy/use, just tought it was on topic

author: janekm
author_rank: Unknown
timestamp: January 12, 2015, 03:49:47 pm
content: Quote from: babysitter on January 10, 2015, 01:52:10 pmYeah, sorry about that, I paraphrased that inaccurately, their description is more accurate: "Dr. Sascha Kuehn graduated in material sciences at the Saarland University. He prepared his diploma thesis at the Fraunhofer-Gesellschaft."http://www.ezelleron.eu/en/team.html

author: codeboy2k
author_rank: Super Contributor
timestamp: January 12, 2015, 07:17:13 pm
content: Quote from: Marco on January 09, 2015, 05:19:59 pmMarco nailed it.(I use capital L for liter so it doesn't look like a number 1)hobbyking ANR26650 A1232500mAh3.3V / 2.5Ah / 8.25 Whweight 70gdimensions 66.5mm x 26mmSpecific Energy= 8.25 Wh / 70g = 0.118 Wh/g = 0.118 Wh/g * 3600 J/Wh =424 J/gEnergy DensityJoules = 8.25 Wh * 3600 J/Wh = 29700 Jvolume = ¼*pi*d2*length= (0.25) * 3.1415 * (26mm)2* 66.5 mm = 35306 mm3= 0.035306 Liters= 29700 J / 0.035306 Liters = 841217 J/L =0.84 MJ/LKraftwerk56Whweight 200gdimensions 3.95 x 2.95 x 1.18 INCHES!! (WTF? mixing metric and imperial)Specific Energy= 56 Wh / 200g = 0.28 Wh/g = 0.28 Wh/g * 3600 J/Wh =1008 J/gEnergy DensityJoules = 56Wh * 3600 J/Wh = 210600 Jvolume = 3.95 x 2.95 x 1.18 = 13.75 Cubic Inches = 13.75 in3* 0.016387064 L / in3= 0.225 Liters= 210600 J / 0.225 L = 936000 J/L =0.936 MJ/LSummaryThe Specific Energy (energy per unit mass) of the KraftWerk is more than twice that of a typical LiFePo battery, but the Energy Density (energy per unit volume) is only slightly better than the battery.So it's about the same physical size of a battery pack that can deliver the same energy, but it can do that at only half the weight of the battery pack.You would need 6-7 batteries to get the same volume of the Kraftwerk, and they are $12.80 from HobbyKing, so it's about $90. The lowest price on the Kickstarter page is $99. So price is good, and half the weight, same energy density.It would seem that the only real benefit here is the weight. It's not bad if you need or want the lower weight.I didn't calculate the recharge costs. Maybe someone else wants to tackle thatHowever, a 3 second recharge time beats the battery too.And there's also other considerations, such as lifetime as Marco already pointed out.Batteries fade too. Is it better or worse than a battery?One huge advantage of the Kraftwerk is the portable power aspect. You can carry the Kraftwerk and a butane cylinder and get several recharges out of it no matter where you are. That alone is what's going to make it worthwhile for anyone who finds themselves away from the power grid often enough.

author: eas
author_rank: Frequent Contributor
timestamp: January 13, 2015, 03:20:48 am
content: Most powerbanks use a more typical Li-Ion chemistry, not LiFePO4, and will do significantly better than LiFeP04 on both energy density and specific energy. On the other hand, LiFePO4 will beat Li-Ion when comparing power delivery, and both will likely beat this fuel-cell device. They claim a continuous power output of 2W, though they also claim to be able to charge 10W devices at full-rate for some amount of time. A single LiIon 18650 cell can deliver 5-10W, and I think a similar size LiFePO4 can go way beyond that. This is no doubt why a battery-based USB power bank of similar size would have two outputs, and at least 3A output, while this only has one output.If this thing works, amount of power you can get by carrying this with a small butane cylinder is definitely when it gets really interesting.

author: mux
author_rank: Regular Contributor
timestamp: January 20, 2015, 01:54:31 pm
content: It's one of the most affordable portable fuel cells I've ever seen around, but there is absolutely no mention of the dreaded SOFC cathode poisoning that will happen before long. Have they invented a new kind of small SOFC?Looking in the Q&A section: they give it a 2-year warranty and expect 2 years of 'standard use'. That is about on par with current-generation fuel cell technology, so nothing new there. Basically 1000 hours of use before power output really starts trailing off. Not what I'd call a lot.What I don't understand is how this competes against solar chargers. There are some really good solar chargers around nowadays that are basically nothing but a fold-out solar panel and battery. Better energy density, much longer lifetime and the prices are getting insanely low nowadays, even for brand name models. Then you don't need any (very hard to come by if you want to live off-grid) LPG cartridges!Last remark: they seem to mention that it doesn't produce anything besides CO2 and water, but that's a lie. All SOFCs produce hydrogen cyanide, sulfur dioxide, carbon monoxide and nitrous oxide in (very) small quantities. The quantities are negligible in normal use, but it should never be used for prolonged times in a sealed environment!

author: tszaboo
author_rank: Super Contributor
timestamp: January 20, 2015, 02:26:52 pm
content: Quote from: codeboy2k on January 12, 2015, 07:17:13 pmEnergy density is only half of the part. If you are mobile, and you want to charge something, speed is essential. I would place powerbank in my backpack, with the thingie charged, but I'm not sure if I would do this with a fuel cell. I dont know how much stuff it generates, but I would never use it in an enclosed space, in my bedroom, in a backpack etc...And notice, how they dont talk about the power output. They only say, peak 10W, continious 2W. Well, 2W is 400mA@5V. A 2A powerbank would charge your device five times faster, a lot safer. I think what is missing from the concept is a intermediate step. Say, we put a 18650 in it, and the fuel cell is charging that, continiusly with 2W, when we want to charge anything, we discharge the said battery with 10W. The fuel cell even could be smaller, as it could run continously reducing the size of the whole unit.Price wise it is also not a breakthrough. For this 99 dollars one can buy 5 xiaomi 10Ah powerbank, and charge a phone on the go for weeks. Or one can use their brain, and bring a nokia 3310 if you go to an area without mains electricity.

author: helius
author_rank: Super Contributor
timestamp: January 28, 2015, 04:18:46 am
content: This is a very interesting technology and I foresee a lot of interest based on its cool factor.But I think it is sort of being oversold, like the "off-grid" stuff is just ridiculous.Be cool, be off-grid in your local coffee shopIt would be more practical than battery only for the uses where you can't predict the capacity you will need, or must operate from battery continually but for sporadic periods. The camping example is a little more sensible, but is using so many devices while camping really a good idea? The best use I could come up with is UV water sterilization.

author: zl2wrw
author_rank: Regular Contributor
timestamp: July 10, 2016, 10:40:50 am
content: Well, according to the Kraftwerk Kickstarter page, it looks like they haven't shipped yet (and I can't read their recent updates as it seems that they are for backers only and I am not a backer).Anyway, with reference to the cutaway diagram on their Kickstarter page:https://ksr-ugc.imgix.net/assets/003/298/765/21169f6c00d022da67a96df61ef87c23_original.jpg?w=680&fit=max&v=1424193639&auto=format&q=92&s=7d44b16ad3b62136b67c56765e3fd36dI'd really like to know how they manage tostartthe fuel cell?I admit that I am not a fuel cell expert, but I am under the impression that SOFCs will not work unless they areHOT(something like 500 to 1000 C).So, presumably to start the Kraftwerk, either there needs to be an internal battery (not visible in the cutaway on Kickstarter), or, without electricity (no internal battery) or external manual starting controls, you've got to somehow open the gas control valve and start a small flame burning to heat the SOFC up to operating temperature?Don't get me wrong, I think that it would be awesome to be able to stash a micro-fuel cell and a can of butane into my pack when I head off into the bush, but unless someone can explain how they intend to actually start this thing, I do not think it is going to work...

author: Kilrah
author_rank: Unknown
timestamp: July 10, 2016, 11:49:23 am
content: Quote from: zl2wrw on July 10, 2016, 10:40:50 amA simple common battery power bank of the same capacity would be simpler, cheaper and probably even smaller though - and it's available, and we know it works

author: edy
author_rank: Super Contributor
timestamp: July 10, 2016, 04:39:12 pm
content: Quote from: mikeselectricstuff on January 09, 2015, 09:49:29 pmI object to them using the name Kraftwerk, one of my favourite classic electronic music pioneers!Otherwise, I guess the word is a common German word it's just I need to remember now that it is not exclusively tied to the group.

author: zl2wrw
author_rank: Regular Contributor
timestamp: July 10, 2016, 08:15:42 pm
content: Quote from: Kilrah on July 10, 2016, 11:49:23 amButane has an energy content of about 46 MJ/kg. So, lets assume that the Kraftwerk (ifit works?) is only about 33% efficient (I understand SOFCs commonly run something like 50 to 60 % efficiency but lets assume that small ones aren't as efficient as big ones), and that if I packed a 200g Kraftwerk, and 200g of Butane in a 200g can, I'd get ~ 3 MJ of electrical energy for 600g of mass. If I tried to carry the same electrical energy in a rechargeable battery, I'd need to carry about 3.3 kg of Lithium secondary cell.Yes a battery is probably cheaper and simpler, however, it is more than 5 times as heavy.

author: Kilrah
author_rank: Unknown
timestamp: July 10, 2016, 08:37:12 pm
content: Their specs suggest 40g of butane yields "11 iphone charges", which at 5.5Wh average would be 60Wh, so 200g of butane (+ weight of container, 100gr?) would be 300Wh, i.e. approx. 1.5kg of Li-Po batteries incl casing/electronics.So OK, 3x more... IF, and big if their specs are correct/realistic, and if it ever comes out... which I very highly doubt, becasue there's no way you could need 5 years between a proof of concept and not deliverying anything if there was any remote chance for it to meet expectations

author: edavid
author_rank: Super Contributor
timestamp: July 10, 2016, 08:48:32 pm
content: Quote from: zl2wrw on July 10, 2016, 10:40:50 amYou can read the comments though:Quote

author: Kilrah
author_rank: Unknown
timestamp: July 10, 2016, 09:12:21 pm
content: Quote from: edy on July 10, 2016, 04:39:12 pmLooks like the group's founder actually filed a suit against them!http://hellokraftwerk.com/press#news_18

author: helius
author_rank: Super Contributor
timestamp: July 10, 2016, 09:23:55 pm
content: Quote from: Kilrah on July 10, 2016, 09:12:21 pmAs well he should. Contrary to spurious claims like "trademark protection is generally limited in scope", the laws protect marks from being confused or diluted across all spheres. If a mark is has very wide recognition, it is protected in ways that obscure marks wouldn't be: any parallel use of the mark is trading on its popularity, and creating the belief that it is authorized. You can't sell "pepsi toilet paper" or "xerox tattoo art" even though those marks apply to fields separate from yours. The band Kraftwerk, I would guess, has very wide recognition and is protected in this way.

author: Kilrah
author_rank: Unknown
timestamp: July 10, 2016, 09:33:20 pm
content: With the big difference that neither Xerox nor Pepsi are common words in any language beyond the well known brands. Kraftwerk is, when the band chose their name they deliberately chose a name that was a word describing a common object in their very own language, that should by definition exclude them from being able to make any claim around it.I can't imagine if I created a music band called "knife" I'd get the right to sue anyone selling knives a few years later becasue my band became famous when knives existed for decades before...

author: helius
author_rank: Super Contributor
timestamp: July 10, 2016, 09:36:02 pm
content: Except the whole world doesn't speak German, and the product this thread is about is also being sold outside Germany. There's no requirement for a mark not to have come from any spoken language. Should Atari or Akamai be denied trademark protection?Now, if the product was a literal fixed power generator named the "Kraftwerk 20T" or something, that would be noninfringing because the use of the word was merely descriptive. But being merely descriptive would, by the same sword, invalidate a trademark for "Kraftwerk" for generating power. Either way, it seems to me that the inventors of the fuel-cell device received bad legal advice much like Batterizer.

author: Kilrah
author_rank: Unknown
timestamp: July 10, 2016, 09:46:21 pm
content: Quote from: helius on July 10, 2016, 09:36:02 pmIt's a German guy, living in Germany, suing the US distributor of... the product of a German company.Of course he's got every right to sue, but I'd expect (hope...) anyone looking at the case would laugh very loud and dismiss it straight away once they see the background. I'm obviously not a lawyer but it seems like the textbook example of "I'm just trying to get free money for absolutely no good reason". If such a thing could go through it would remove a couple more layers of my belief in the sanity of humanity (at least of the US legal system)...

author: mux
author_rank: Regular Contributor
timestamp: July 12, 2016, 10:32:10 am
content: Quote from: Kilrah on July 10, 2016, 08:37:12 pmThey're using 'iPhone charges' in a very limited sense - at 'optimum' charging speed (1.5Wish), they can deliver the equivalent of 20Ah (=65Wh) (random publication:http://www.extremetech.com/electronics/198695-kraftwerk-fuel-cell-will-let-you-charge-your-phone-with-gas). So that's about as much as one of those larger USB battery banks, but at a much lower speed and not rechargeable in any kind of convenient way. The operational efficiency is highly affected by charging speed; at minimum power a lot of extra energy is lost in keeping the cathode hot and quite a bit of uncombusted fuel is exhausted. At maximum power, they're losing a lot due to slow ion diffusion (high effective ionic resistance). So in actual use - i.e. your phone not actually charging at a constant rate but starting fast, then tapering down - capacity is probably a couple tens of percents lower.But all of this is kind of moot. They're now bankrupt, they will never deliver. This is probably the very last time we'll see these graphite-based tiny SOFCs on the market. They were interesting when the first publications came out in the early 2000s, but lithium ion has progressed so much, phones have become so much faster to charge and most importantly there are many orders of magnitude more and easier ways to charge something from an outlet or a solar panel than with compressed dead dinosaurs. *maybe* we'll see more portable PEM fuel cells (using e.g. sodium silicide hydrogen cartridges) at some point, but other than that it's batteries all the way.