ccc Posted March 3, 2011 Report Share Posted March 3, 2011 It all makes sense now, I see the error of my ways. Mouldy banana skins and dregs of coke will provide us with infinite energy, and cater for our every whim. Which neatly brings us back to the point about crack; John DeLorean was once caught trying to deal in a suitcase full of cocaine. Aye does sound a bit mental. However what supplies us with our efficient energy of today ? Mouldy old decayed trees dug up from the ground and refined. Not a huge difference actually... Quote Link to post Share on other sites
Slumpmonkey Returns Posted March 3, 2011 Report Share Posted March 3, 2011 What ever happened to hydrogen fuelled cars? I seem to remember watching an episode of Top Gear a couple of years ago when one of the team went to California and drove a hydrogen car. You simply fill it up at a petrol station which has a hydrogen fuel pump and it is much cheaper than petrol. Quote Link to post Share on other sites
SomethingHasToGive Posted March 3, 2011 Report Share Posted March 3, 2011 What ever happened to hydrogen fuelled cars? I seem to remember watching an episode of Top Gear a couple of years ago when one of the team went to California and drove a hydrogen car. You simply fill it up at a petrol station which has a hydrogen fuel pump and it is much cheaper than petrol. Hydrogen is only cheaper because it isn't taxed as heavily and no one uses it in their cars. From an engineering point of view, Hydrogen is worse than petrol. It is harder to store than petrol as it is a gas versus a liquid, so it has to be stored under pressure. That means a larger fuel tank, made of stronger materials. It also has a lower energy density, so it provides less energy per kilogram. So you have a larger heavier fuel for the same range. This also has implications for transporting it from production facilities to fuel stations for our cars. From a production point of view, it requires energy to make. There is no Hydrogen ready for us to burn anywhere, whereas there is oil in the ground. So we have to get it from water. Unfortunately that means that any energy used in a car needs to be used to make it. This energy will have to come from power stations. So the total amount of energy we use will go up. This means more power stations and more emissions unless we move to non carbon power generation on a massive scale. From an environmental point of view, it is much cleaner as when it burns it makes steam rather than the steam and Carbon Dioxide from petrol. However you need to solve the problem of how the energy is being generated. The advantage it has is that I believe a hydrogen fueled car would be easier to dispose of than an electric car ( because of the batteries ). But you'd need a massive investment in green energy for it to work as a replacement to petrol. Basically it has many of the same problems as electric cars. Currently we are burning yesterdays trees for energy ( from millons of years ago ). In order to achieve the environmental goals of zero net carbon we'd have to be sustainable and get most of our energy from the sun ( via light, wind, biofuel or tidal power ) or nuclear sources. Quote Link to post Share on other sites
Executive Sadman Posted March 3, 2011 Report Share Posted March 3, 2011 Did Henry Ford try this on in the 1910s when petrol cars were 'just for the rich'? Or is this yet more Banker Bailout Bandwagon jumping? Disgraceful thing is theyll probably get subsidies too, thanks to those spineless traitors we call politicians. Quote Link to post Share on other sites
happy_renting Posted March 3, 2011 Report Share Posted March 3, 2011 All that comes out of a hydrogen-powered car's exhaust is water. Which is a BIG PROBLEM when the ambient temperature falls below zero. The exhaust soon freezes up. Unless you burn more energy just keeping the exhaust system hot. Quote Link to post Share on other sites
Hyperduck Quack Quack Posted March 3, 2011 Report Share Posted March 3, 2011 (edited) What ever happened to hydrogen fuelled cars? I seem to remember watching an episode of Top Gear a couple of years ago when one of the team went to California and drove a hydrogen car. You simply fill it up at a petrol station which has a hydrogen fuel pump and it is much cheaper than petrol. Hydrogen fuelled test vehicles have been around for ages, since they can be adapted from petrol engines. But hydrogen takes more energy to produce than you get back when it's burned. A fuel cell might make more efficient use of hydrogen but I believe it's still the case that the gas still gives less energy than was used in its manufacture.So hydrogen as a fuel is a non-starter unless you have a supply of surplus unwanted hydrogen from somewhere - in which case it would make most sense to burn it all in a gas-fired power station anyway. Edited March 3, 2011 by Hyperduck Quack Quack Quote Link to post Share on other sites
happy_renting Posted March 3, 2011 Report Share Posted March 3, 2011 Hydrogen fuelled test vehicles have been around for ages, since they can be adapted from petrol engines. But hydrogen takes more energy to produce than you get back when it's burned. A fuel cell might make more efficient use of hydrogen but I believe it's still the case that the gas still gives less energy than was used in its manufacture. So hydrogen as a fuel is a non-starter unless you have a supply of surplus unwanted hydrogen from somewhere - in which case it would make most sense to burn it all in a gas-fired power station anyway. Depends where hydrogen is sourced from. Hydrogen can be produced from natural gas, or by electrolysis, etc. If it is by splitting H2O using electricity, then that would require exactly the same energy as is obtained by burning the H2 to turn it back to H2O. However, the process will not be 100% efficient, as the H2 would also have to be transported, the electrical supplies used will be lossy, etc. In this context, fuels (H2, electricity in batteries, petrol) in vehicles are energy storage mechanisms. The manufacture of these results in energy consumption, innefficiency and pollution elsewhere (such as refineries or power stations). To get a full picture, the energy innefiecency and pollution from power stations, fuel transportation, the ineffiicency of carrying heavy fuel/batteries in a car, the manufacturing enrgy cost and pollution from making fuel or batteries and their longevity, etc, all need to be taken into consideration. These equations are complex, even putting aside the issues of cost. How much nuclear waste is 'equal to' 1 ton of CO2 when weighing up nuclear power versus fossil fuel? The question has to be asked, yet it is almost meaningless, rendering quantitative comparisons about pollution more or less impossible. Many of the efficiencies of electric cars are achieved by reducing wight and drag, which could also be applied to petrol vehicles, but the market resists them as such vehicles are flimsier. I believe a lot of electric car designs do not have to meet the same crash safety criteria as petrol cars (can anyone confirm or correct me on this?) Quote Link to post Share on other sites
Hyperduck Quack Quack Posted March 3, 2011 Report Share Posted March 3, 2011 (edited) I believe a lot of electric car designs do not have to meet the same crash safety criteria as petrol cars (can anyone confirm or correct me on this?) I'm guessing that's the case with small electric runabouts that are classed as 'motorised quadricycles' but something like the Nissan Leaf probably has to comply with the same safety standards as a VW Golf. Edited March 3, 2011 by Hyperduck Quack Quack Quote Link to post Share on other sites
LJAR Posted March 3, 2011 Report Share Posted March 3, 2011 classic case of the motor industry lobbying for more money from the taxpayer. All technology is only for the rich when it starts. Anyone remember when mobile phones were only for yuppies? when computers cost £10k? Electric cars or hydrogen cars will be exactly the same. Quote Link to post Share on other sites
newbonic Posted March 3, 2011 Report Share Posted March 3, 2011 Depends where hydrogen is sourced from. Hydrogen can be produced from natural gas, or by electrolysis, etc. ..... ..... As I pointed out in post #38 in this thread - H is also being produced in syngas from the UCG trial in the Firth of Forth right now. The CO2 output is proposed to be pumped into oil wells to re-pressurise them and recover more oil. Coal gas/town gas was a source of hydrogen (and other gasses) from Victorian times through to the 1960s, when North Sea gas took over. Quote Link to post Share on other sites
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