AngelLestat

if you can not admit that you are wrong.. then is your issue. Pride is an impediment to learning. I dint said nothing wrong.. Read word by word of everything I said.. What now? All scientist needs to change how they measure electrolysis efficiency? If you are not providing the heat energy because is comming from the enviroment, you dont need to include that in your efficiency calculation, because you are only providing a X amount of electrical power which is the only that matters. Chemical reactions takes energy from the enviroment in case you dont know that. Is not the same try electrolysis close to 0k than at 300K.

http://www.cres.gr/kape/publications/papers/dimosieyseis/ydrogen/A%20REVIEW%20ON%20WATER%20ELECTROLYSIS.pdf "For water electrolysis, under ideal reversible conditions, the maximum theoretical efficiency with respect to the electrical energy source would be εmax = 120%" Because you are not providing the heat! Is measure only from your electrical input. I will waiting a "sorry to doubt of you"

Rubisco.. I bet that you dint read any of my post or check any of the info that I show. The efficiencies that you are talking about is for small industries or home made. Of course if you use cheap catalyst you find those efficiencies, who cares if you waste 1 kw more in produce hydrogen for your own, or 100kw.. At those scales the most important is that you can produce without depend on others. But if you want to buy platinum catalyst or combinations with steam systems, then the investment increase a lot, but if your productions is big enoght, then you achieve low the final cost due higher efficiencies. The values are close of what I mention, you need to take with the info that you read, sometimes the compression and transport is included, other times it takes into account the whole process efficiency from solar radiation by m2 or wind speed to hydrogen. Some theory: Electrolysis can reach in theory using waste heat of other process an efficiency of 120%, this means that if you enter 1 kw, you get 1,2 kw of hydrogen without compression. Even the ambient temperature is an external source of energy which helps to increase your efficiency on electrolysis. You get 39 kw per kg of hydrogen (or 39Mw by per tonne) http://en.wikipedia.org/wiki/Electrolysis_of_water#Efficiency The best PEM systems or steam reach 95% of efficiency, then you need to add 5% on compression 250 bar and 5% in transportation. Take a look in this study about offshore wind farm with direct hydrogen production on sea water. http://download.springer.com/static/pdf/25/art%253A10.1007%252Fs40095-014-0104-6.pdf?auth66=1427420658_263eeeb4adcc54ae0fd6a23f65eb5a48&ext=.pdf For 404gw you get 8020 tons including transport and Inverter AC to DC (which add a lost on 5%) So there you have my 15% estimated with the extra 5% on the inverter. A different source on compression: http://ec.europa.eu/research/participants/portal/desktop/en/opportunities/h2020/topics/8067-fch-02.6-2014.html "The energy consumption of the system should be below 4 kWh / kg H2 when compressed from 20 to 500 bar." Also you dont need as I mention many times deal with hydrogen tanks.. You can use ammonia which it has 1.6 times more energy density than liquid hydrogen and can be cracked on demand with little efficiency lost, and you can use the same infrastructure of oil with minor changes. New discoveries which already talk about on hydrogen managment and catalyst are very close to release which will reduce by a lot the investment cost. Final question: If you said that hydrogen is not needed, how you save Co2 from vehicles bigger than 1500kg? Can a 747 fly with batteries?? Even using hydrogen the volume is not important, because you have a huge amount of energy, and volume increase with the cube and it is much light.

I delete it before see your post, but not because that detail which I notice but I could not find the exact word, it was due the extra details that I needed to point like if the shape is very aerodynamic you may have equal drag than a 747 at lower speeds.

There are taste and needs for everything, the problem is how much people is interested in pay a lot more for a ticket just to save few hours. You will find always some people which want to fly faster, but those same people are the ones which reach the airport to buy a ticket and fly in that same instant. So if there is not "concorde" ready, they will take another fly, so you are loosing the few people who may pay that ticket, but if you have a lot of "concorde" to secure instant demand, then there is not much people dealing to pay that. So that is the why..

I find all kind of asteroid missions (more if they are not manned) boring.

flour is also explosive under certain mixtures.. so?? we need to stop use it? Everybody use ammonia to wash things, how many die from flames or toxic aspiration?? the vapor mixture to be flamable is from 24% to 32% much lower than any other fuel. Is used all days as fertilizer, is enviromental hazard? Corrosive? what level of corrosion seriusly.. is not acid, in fact you can use chepear tanks than the used in gasoline Any chemical has their own cares that we need to follow, but this is not enoght to be so negative about their applications. Use the same phylosofy against everything else and you will not use nothing. But with hydrogen+fuel cell instead combustion, you get the same noice than any other electric car I dint answer this like 3 times already? -A battery has 80% in the charge discharge round trip, so you lost a 20% of efficiency. -USA has an average of 6.6% on transmission and distribution losses. -Renewable energy sources (which are the ones that can solve the ecologic problems) will have a 17% of loses in storage (with the best methods) -If you use oils and natural gas to produce electricity, you are polluting the enviroment, but if you extract the hydrogen from Hydrocarbons instead, you capture the co2 with ease, then the hydrogen is used to produce electricity with a fuel cell (which has higher efficiencies than any thermal power plant, so if you lost any energy in the hydrogen conversion, you gain back that lost efficiency with the fuel cell. -Nuclear reactors when they dont need generate base load, they can be used to generate hydrogen.. So you dont lose energy. Now the hydrogen case. -Electrolysis you lost 5% -compression you lost 5% -distribution you lost 5%. If a renewable source directly transform the energy to hydrogen saving the energy lost in back process, you are saving a 13% and a lot of money in storage devices and transmission. So hydrogen will reach the fuel station at lower price (for the same energy) than the cost of charge your car from your house. You lost like 15 % of efficiency in the fuel cell VS battery, but the final cost will be similar. So any vehicle that needs higher autonomy, or beyond 1500kg, or which needs fast charges. It will use hydrogen. The only that hydrogen needs is wait not more than 5 to 7 years to some technologies reach the market. That is including war times! I encourage to search because I already did an extensive reasearch before, I am quite airship enthusiastic, so I read a lot about them. Fire... when it crash due bad weather and we can not be sure if oil was the cause. Also not deads due fire aside the hinderberg which I remember. Now check this list: Accidents involving commercial aircrafts (not in war times as the list you post it) http://en.wikipedia.org/wiki/List_of_accidents_and_incidents_involving_commercial_aircraft Is almost 200 times larger, this counting all the technologic advances that we have. Of course there are a lot more airplanes, but is a number to have in mind. Yeah, true. So if you ask me for today.. I will said batteries for vehicles of 2500 kg or lower.. If you ask me in 7 years, I will said hydrogen for vehicles of +1500kg, this also counting all new technologies that are comming for batteries. The same as petroleum, which it comes from all the energy than animals or plants storage millons of years before. Hydrogen is a fuel that in this case we use it as energy carrier. Staggering??? 5% on loses? The platinum catalyst is expensive (for now, new remplacement are comming) but not dangerous. Is not.. http://forum.kerbalspaceprogram.com/threads/113563-Electric-or-hydrogen-cars?p=1799538&viewfull=1#post1799538 And hydrogen cards dont?? I wonder.. the last time I check they use an electric engine and a small battery too. toyota, audi, honda, Hyundai and many more brands are working on them. https://www.parc.com/content/attachments/fuelcells_arpa-e_parc.pdf http://hypertextbook.com/facts/2005/MichelleFung.shtml Previous image source which include the weight of all the equipment: http://www.rebresearch.com/blog/hydrogen-versus-battery-power/ Co2 emmisions by source: http://www.nuvera.com/blog/index.php/tag/the-economist/ mass/range comparison: Also on the weight and compression issue, you can use ammonia instead, which it has 1.6 times more energy density than liquid hydrogen. Not need for pressure tank.. just a plastic tank with a 2 liter size device to split the ammonia into hydrogen.

GreemWolf: Thanks to your clarification on thermite and the cause of fire in the hinderburg, I never said that thermite cause the flame, I just said that it was the main cause of the disaster/fatalities. I am 100% agree with your review of the accident. But... 1- If you have a not flamable envelope, even if you have a leak (which always will be from inside to the outside) and this ignite, you get a flame depending the size of the hole and the pressure difference (in airships the pressure difference is very low), but the hole will not grow in size, in fact the flame will help to avoid any danger oxygen-hydrogen mixture to develope in any closed ambient. We have cheap hydrogen sensors which detect even as 0.1% in mixture. Today materials not flamable and heat insulators are those which are most lightest than all. You have thermal cameras that will detect any flame. So if the hinderberg envelope would be not flamable, this disaster never would happen. 2- So you are quoting dirigibles which were used in war as an example of not safety???? hahahaha Of course I was just refering to the comercial age, so with your logic a Tank vehicle is not safety because thousands was destroyed in war?? lol And dirigibles was the most feared weapon in that time, because airplanes could not fly so high, they carry tons of bombs, bullets reach the dirigibles but they get only holes, at equal pressure they almost not lost any hydrogen, so the dirigible keep bombing and returned safe to base. That was after some time and many bombs they started to use incendary bullets. But even with that it would not be a problem if you have a not flamable envelope. 3- You said that fire is the most common way that dirigibles are lost?? Ok, name a case where hydrogen flame was the cause of a dirigible fall or when people die... I will save you the search, all dirigible disaster (which was not many) was do it weather. If some get fire after crash, was due the crash (they carry fuel too), and they was very very few and there is not fatalities (even with flamable envelope). Hydrogen is not more danger than gasoline or batteries. And you can use ammonia instead hydrogen which eliminate all issues with pressure and fire.

Everybody who has to said something bad about hydrogen, they all quote the Hindenburg.. Now I ask them.. ok.. give me another example in the history where people die due a hydrogen vehicle... ... ..... ....... space shuttle? -well there a lot of rocket explosions without hydrogen in it.. but well, one more example?? none? Ok, so hinderburg then, it was the only airship which burn in flames.. From the 97 passagers and crewmembers plus people on the ground, only 35 died. But it was not all due hydrogen, the major cause of this disaster was that hinderburg was the only dirigible painted with thermite, iron oxide+aluminum as others know as rocket fuel. Airships fly over decades using hydrogen and technology from 1930 carring 350000 people without any problem. Ignorance is the thing that most kill, in that time the hinderburg explosion was one of the first disaster transmitted by TV and radio to all the world, that is why is in the memory of everyone.

In that graph, the mass value is already integrated and related in the autonomy value. Yeah these are PEM electrolysis (platinum catalyst) which can reach 95% or even overseed 100% if you use waste heat of any other process. In theory, electrolysis may reach 100% efficiency without add any external heat. But different catalyst with 70% or 80% of efficiency make hydrogen at lower cost than PEM in some cases due how much cheap is the catalyst. http://en.wikipedia.org/wiki/Electrolysis About batteries, we need to take into account the lifetime in the cost.

What flaws? And the only flaw of oil is Co2 + depleted reserves in 50 years which hydrogen does not share. Hydrogen is not an energy source. Is a way to storage energy like a battery. A real comparison is battery vs "hydrogen+tank+fuel cell". Lets compare energy density: Hydrogen: 142mj/kg and 5.6 mj/liter Best Ion lithio in the market: 0.67mj/kg and 1.8mj/liter Look how little you rise the volume, and how much autonomy you get.. This is a clear case that any kind of vehicle beyond 1500kg and over 500km on autonomy hydrogen is a clear winner. Also hydrogen tanks are much cheaper than buy batteries. The only drawback for the moment is the fuel cell and electrolysis catalyst (platinum). But it will take no more than 5 or 7 years to be remplaced in the market by a graphene base catalyst. When this happen, the cost would drop, the efficiency will rise and the production will be faster (so extra power) in both cases. About energy production comparison in make hydrogen vs direct power I already detailed in this post: http://forum.kerbalspaceprogram.com/threads/113563-Electric-or-hydrogen-cars?p=1796829&viewfull=1#post1796829

not you cant, there are good breakthrough coming on electric storage as new batteries (flow, air, chemical...) , super capacitors, air compression, kinetics, etc. But none of these had a the weight energy ratio of hydrogen, neither the cost. Also these advances in hydrogen are not very related to wherever you want to mean with "electric/artificial petrol". Or maybe I didnt understand your point. Imagine an airplane or ship, at certain scale you can have batteries to storage X amount of energy at the same cost than hydrogen tanks + fuel cell, but if you increase the scale, hydrogen becomes much more cheaper.

Here: http://arxiv.org/ftp/arxiv/papers/1405/1405.2360.pdf The first time I read this was an improvement in 100 times longer durations on hydrogen tanks leaks treated with rGO, it seems that now with a 100nm cover is enoght to remove any leak. But you still have the problem of the weight of the tank due pressure, for big volumes this is not a problem, but for small ones is considerable, from here my posture that small vehicles should use batteries instead, plus you can charge them in home, besides it helps to balance the economy, because not all the energy should be produced in electrical way the same that not all energy should be distribute as h2/ammonia. Although using ammonia as hydrogen carrier has a lot more sense now that they found a cheap and simple way to cracked. And you can use the existing fuel infrastructure (with few changes) and fertilizer infrastructure to transport and sell it. http://phys.org/news/2014-06-hydrogen-breakthrough-game-changer-future-car.html#jCp here a complete study of a ammonia economy without take into consideration the new discover of how to craked with cheap materials. http://lib.dr.iastate.edu/cgi/viewcontent.cgi?article=2119&context=etd

An hydrogen base economy is coming, of course this does not mean that all will work with hydrogen, the same that now not all works with oil. All or almost all hydrogen problems were already solve it in labs, of course they need more research to find the best affordable way to reach the market, quality test, life-time, know the best way to achieve something from all the different approaches, etc.. This may take from 5 years in some application to 10 or 15 years in others. But there is not rush, because the infrastructure and products that use hydrogen will start to appear slowly. Hydrogen Leak: Reduced Graphene Oxide "rGO", which it is cheap to make, it can be used as a paint to make any hydrogen tank impermeable, it makes them 100 times more effective to stop hydrogen leaks. Of course pure graphene is better, it will take 1 millon years to leak, but we are not close to make them at big scale. Hydrogen sensors: The same graphene oxide helps in this matter too, you can make hydrogen leak sensors to control the amount of hydrogen in the air. Hydrogen spliting (electrolisys) and hydrogen to electricity (fuel cells): Graphene has also the answer in this too, right now this devices use platinum which is very expensive and it has some efficiency problems, they achieve to drop cost from 200 to 50 in the last 10 years, but is not enoght. Now they discover a lot of different ways to remplace the platinum catalyst, the most easy way but hard to implement at bigger scale is with a single graphene layer heat up to 200c, they discover that at that temperature graphene only allow protons to pass making it the perfect solar cell due how fast is this process against platinum. Another way is with imperfections in the graphene layer without heat, make a imperfect graphene layer is simple than a perfect, this allow protons to pass. With these devices you can also split the hydrogen from the air humidity, so in the future will be possible to harvester hydrogen meanwhile you drive. Chain collision of hydrogen cars: It depends, the same that will happen if fuel cars collide, the benefic of hydrogen is that in the face of any tank rupture (depending how you storage the hydrogen, there are ways that it will not present any risk) the hydrogen leaks so fast that it does not gives time to any posterior ignition, this does not happen with fuel which remains with you in the car. Also hydrogen rise fast, so the flames will rise, so if you are below you will not be touch it. http://www.avsusergroups.org/tfug_pdfs/2014_9_Urban.pdf http://spectrum.ieee.org/nanoclast/green-tech/fuel-cells/nanoscale-material-enables-cheap-emissionfree-hydrogen-production http://www.nature.com/ncomms/2014/140911/ncomms5843/abs/ncomms5843.html http://www.greencarcongress.com/hydrogen_storage/ http://spectrum.ieee.org/nanoclast/green-tech/fuel-cells/graphenebased-fuel-cell-membrane-could-extract-hydrogen-directly-from-air http://spectrum.ieee.org/nanoclast/green-tech/fuel-cells/platinum-catalysts-are-outshined-by-graphene-quantum-dots http://www.natureworldnews.com/articles/13507/20150318/imperfect-graphene-leads-to-better-fuel-cells.htm Another possibility is use ammonia as hydrogen carrier, to a given volume ammonia carry 1.7 times more hydrogen than liquid hydrogen, it does not need to be pressurized and is safe, not bad for the enviroment. They found very easy ways and cheap to crack ammonia on demand as a car would need in a device not bigger than 2 liters. Easy, electric cars has lower carbon footprint in their life time even with its low production and yet not perfect systems. But even if the footprint right now is equal, you need to start developing electric cars in some moment. When you reach higher production and they are manufacture in several countries that footprint is reduced way more. You save energy in the process, transportation, and many other factors. For cars works fine, the problem is when you need higher energy densities, for a large vehicle as bus, trucks, airplanes, ships, etc.. You can not use batteries. It will be always better hydrogen.

http://forum.kerbalspaceprogram.com/threads/104177-Nasa-is-considering-a-Manned-Mission-to-Venus-before-Mars!

So energy intensive?? it has 95% of efficiency, and fossil fuels into hydrogen 80% efficiency, but then you recover part of the energy lost using fuel cells, that are more efficient that any thermal machine. So you lost only 10% from your electric source with compression and 20% from fossil fuels. But you get 100% clean energy and a good way to storage it to all those machines or vehicles that will need hydrogen, as bus, truck, ships, airplanes, etc. What is that energy intensive that you are talking about?? without cure... even after post as source the nature magazine which show how wrong is that statement, you keep trying to spread it? Is a shame. It said in the same publication that even with all "IF" and the worst possible case (that is impossible) for hydrogen, all benefics that you get overcome any possible drawback. What is the worst worst drawback? haha, someone is trying to widespread ignorance.. but is not germany. They save like 2 times european union from collapse already.. And they are still a super economic power, someone there must know what are they doing... depending in what you want to use that energy.. As I already explain 3 times. For some machines or vehicles is a lot more efficient to use hydrogen. The infrastructure needed is a problem, that is why is impossible to change fossil fuels to hydrogen from one day to the next. It takes time.. But the time it will be given by the amount of hydrogen machines or vehicles that start to come out in the market, the amount of new renewable energy sources that use hydrogen as a way to storage and distribution. Houses will start to produce hydrogen also as a way to storage energy. From little steps, you start to change the oil age into an hydrogen age. But of course it will not be 100% hydrogen, we will use direct power to all those applications which had more sense. hydrogen is very good for a lot of things, for small cars.. yeah, full electric is better.

we buy some good books and we start to play more sport games, because that it will be all our fun that we can have over the next 2 decades.

none of these has pressure or enoght gravity to reproduction. Venus is still the best case outside earth.

Why you dont read the full story before present a good guy as a bad guy... http://www.nature.com/news/1998/030609/full/news030609-14.html This is taken into account that we change fossil fuel economy by a complete hydrogen economy right now with the current ozone problems (gases from the 60th which still are in the atmosphere but its effect is ending) and without solving the leak problem, (which the technology already did) So there is too many "IF" there... It said that if this happen slowly (50 years) even with leaks and a full hydrogen economy, it will not present any problem.

Yeah it will.

Ok, now I read again your post: I am not sure I understand what you mean by "the obvious"? If you mean that electricity and hydrogen aren't clean energy sources unless their production is clean, then that was mentioned early on in this tread by lajoswinkler. If you mean that we should burn methane as an alternative to electricity, hydrogen, kerosene, gasoline, etc. then I fail to understand how that solves to problem of greenhouse gas emissions? I notice that I misunderstand your posture. Sorry PakeldHostage. But as I explain in my previous post, even with the same energy sources that we have today, electric cars are 30% more efficient than the best fuel cars plus the co2 emmited by that energy production is almost 70% lower than the cars does. Clean energy sources as wind and solar are dropping prices at a huge speed, they are already in average at the same cost than nuclear even if you include storage. But there is where is linked to this discussion, if you have a kitegen generator, instead storage and then transmit the power, why not use the same seawater + electrolisys 95% efficiency to produce hydrogen which is transported by a boat and goes directly to the cars. Then cars use it with a 50% or 60% of efficiency fuel cells, that is a similar conversion that if you produce electricity and storage electricity in other ways. But it solve the autonomy issue, of course it has more sense for bus, airplanes, trucks and any kind of big vehicle. If you stop using fossil fuels and instead you convert them in hydrogen, then is not so expensive. Even with electrolisys you get a 95% of efficiency, so you are losing whatt? 5%?? plus 5% to compress it.. Is not expensive.. is cheap. Today electric cars are expensive because batteries and mostly commercial stupidity. Why people need a luxury electric car if the thing they most want is to not waste so much money in fuel. Why all electric cars needs to be extra luxuries than any other normal car? In fact, all the car industry is very wrong with city cars, cars that does not need go beyond 90km/h, cars that brake all the time (losing big part of the energy of acceleration). Why you need 1500kg car to move 100kg (payload average)? It does not have any sense from the energy point, if you focus in move those 100 kg instead 1500 you are wasting 10 times less energy. And I am not talk about bikes, you can make very safety electric car for 2 people with only 200 or 300 kg. We need to reduce the emmisions, zero net co2 does not help now, we need negative values if we want to dodge the worst consequences of the next 50 years. Also methane fuel cells had much lower efficiencies than hydrogen fuel cell. And if you use simple combustion you end with 25% efficiency. Also graphene oxyde is the answer to any leak on hydrogen, that technology will kick in just 5 years due how easy is to make graphene oxyde. I read all the time enviroment science, that is kinda my thing, hydrogen has a real value. But I am agree that for small cars or city cars, battery cars are better than fuel cell. is not less energy efficient, I already explain this in the link that I show you. energy storage (any kind) is one of the technologies branch with higher growth on the moment.

tater: this is not the place.. but you should check previus discussion on wind vs nuclear.

You wanna keep this discussing ignoring the facts? Technical Ben, EzinX, PakledHostage, Frozen_Heart: In case you skip it: http://forum.kerbalspaceprogram.com/threads/113563-Electric-or-hydrogen-cars?p=1796829&viewfull=1#post1796829 Bill Phil: (electric cars and hydrogen cars are all electrics, the only difference is how they storage the energy, one is using batteries, the other use hydrogen convert it with fuel cells.) Drunken Hobo: biofuels are far to be a solution. You keep sending co2 to the atmosphere, they burn forest or remplace food fields to sell biofuels. Even if you use the waste products of other crops, that is energy you are stealing from the soil that works to improve the next crops. So you need to use fertilizers, which are all made of "guess what" fossil fuels. vger: We're already going to be facing a serious water shortage within a decade or two. last time that I check there is still big oceans full of it. Salt water is better for electrolysis.

Let me point some common misconceptions about opinions on these technologies. 1-Elon musk said that we lost 50% of the energy making and transporting hydrogen instead use direct power. False, you can extract hydrogen from fossil fuels, in fact the 95% of the hydrogen produced come from these sources, it has a 80% of efficiency, higher than 60% of the best thermal plants. Then you lose like a 5% in the compression and another 5% in the transportation. Guess what? you had similar energy loses transporting the energy with transmission lines. Also a lot of new renewable energy sources has a lot of sense if they produce directly hydrogen instead try to storage the energy in other way and then send it by wires. 2-Electric or hydrogen fuel cell, they have sense only if your dominating energy source is environmentally friendly. Not at all, even if all our energy comes from fossil fuels (which doesn´t), a normal thermal plant efficiency is about 45%, the best reach 61% with a extra of 300mw of thermal energy, which it rise its efficiency at 85% All the other sources had a conversion of 90 to 95%, which it give us an average of 70%, less 10% on transmission loss plus car storage nad conversion we have 50% We need to compare this 50% against the 25% to 30% of efficiency than fuel cars had with its otto engine, plus electric cars can recover the brake energy, which is a 30% of the whole energy consumed, so we can reach the conclusion that electric cars are 30% more efficient than fuel cars, also the co2 emmited by thermal power plants using the same fuel that cars does is much lower. 3-other type of energy sources as propane or ethane can had similar benefics than hydrogen. Is true that if you have an hybrid car, it will be more efficient that a normal car. But lets not forget that hydrogen+oxigen combustion waste is water. ---------------------------------------------------------- So.. which is better? Electric battery cars or hydrogen electric cars? For cars, I would said Electric. Anything a bit heavy than cars (+1500 kg) as truck or bus, etc. Hydrogen is better. There are huge advances coming in the storage of electric energy and hydrogen managment and conversion. Batteries and capacitors will have a huge improvement, also with fuel cells. They found a good remplacement of the expensive platinum catalyst using graphene composite. This same material can be used to capture hydrogen from the air (wet) and then storage in the car tank. Graphene oxide can be used as a paint to avoid any hydrogen leak from tanks.´ So I guess both technologies will have huge potential in our future. PD: a fun toy

But from what I know, there is not such thing in reality as a not rotating black hole. What are the odds? Stars rotate, and the BH creation accelerate the rotation by a lot, when they consume matter they also accelerate their rotation. Mostly all massive black holes rotation speed are close to relativity limits.