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Post by Deleted on May 5, 2017 10:35:23 GMT
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will
Member of DD Central
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Post by will on May 8, 2017 16:06:20 GMT
I'm still not sure hydrogen will take off, my biggest concern with hydrogen as a fuel is the efficiency of production, or more correctly, the lack of. Then there are the compression and transport costs. Electricity can just be flung down a wire. If we get some decent batteries then EVs are the future.
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Post by Deleted on May 8, 2017 16:31:53 GMT
I'm still not sure hydrogen will take off, my biggest concern with hydrogen as a fuel is the efficiency of production, or more correctly, the lack of. Then there are the compression and transport costs. Electricity can just be flung down a wire. If we get some decent batteries then EVs are the future. Well most electricity production is incredibly inefficient from the likes of coal or oil. Transmission loses are not good (say 1% per 100 miles) and part of the debate here is localised nets rather than whole country systems (we needed whole country systems when we used coal in one part to drive factories in other parts). All these changes open up the intelligent net debate. Hydrogen is generated at the required 700bar by ITM from solar or wind power and a bucket of water. 700bar gives you enough fuel in a car's tank to do what a car has to do 350miles plus. A whole bunch of producers did use to have to produce at atmosphere and then compress but that was sorted about 12 years ago. Efficiencies, I've struggled to get good info on this but I'm seeing around 85% which makes the humble thermal power station (at 47%) look what it is, a dinosaur. If we get decent batteries, good point. The reason our favorite Tesla CEO likes batteries is that if we turn our backs on batteries he has lost the game, control of H2 will be open source. H2 in a tank is a "battery of energy", just doesn't look like one. Surely the point is that for either route first we need enough copper to drive all the electric motors, then with batteries we need shed loads of special chemicals while with H2 we need a bucket of water. I suspect the market will divide as it has into diesel and petrol, but my brain thinks H2 is far superior.
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will
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Post by will on May 8, 2017 16:40:21 GMT
The efficiency issues are not in the conversion of hydrogen into electricity, they're in the conversion of electricity into hydrogen. You lose at both ends. You're much better off sticking the power from your solar panel into a battery. I've not looked too carefully, but a quick Google found this link. |
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Post by tybalt on May 8, 2017 16:54:21 GMT
The core problem with Batteries is the time to recharge. Electric and Steam Cars were serious contenders up to the 1920s. Unless and until I can recharge to 300 miles range in less than 15 minutes I cannot make batteries work except for inner city commuting. Having lived in London while they were in service and watched Reading scrap them I seriously believe in trolley buses rather than trams.
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fp
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Post by fp on May 8, 2017 18:32:40 GMT
I've been keeping an eye on H2 as a fuel for quite some time, mainly because it has been a revenue stream for me up until late 2015 when I gave up on that line in my business, one of the biggest problems has been storage of the gas in vehicles without the need for a heavy tank, carbon fibre seems to have resolved that issue...... just a shame i've given up my free supply of H2  |
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skippyonspeed
Some people think I'm a little bit crazy, but I know my mind's not hazy
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Post by skippyonspeed on May 8, 2017 19:10:26 GMT
The core problem with Batteries is the time to recharge. Electric and Steam Cars were serious contenders up to the 1920s. Unless and until I can recharge to 300 miles range in less than 15 minutes I cannot make batteries work except for inner city commuting. Having lived in London while they were in service and watched Reading scrap them I seriously believe in trolley buses rather than trams. There are other things to consider as well as charging times. In London most people have to park in the street so a typical road could have cables trailing across pavements so insurance would cost more to cover all the pedestrian accidents. New excuses for being late for work, my kid unplugged my car so they could plug in their phone charger etc.......and the cost of replacing knackered batteries I believe is horrendous. People are used to the convenience of squirt and go cars.......so I shall ignore the "Betamax" era of cars and go for H2. I converted a car to run on LPG about 15 years ago and still wonder why it wasn't more popular especially with the Chelsea tractor owners (conversion would pay for itself in fuel savings in less than six months). It was about 45% cheaper than petrol.....there was a very slight decrease in power which was unnoticable for every day motoring. It burnt a lot cleaner, ie used engine oil was the same colour as new oil. Exhaust systems lasted a lot longer. It never went wrong, having said that....the car is still used every day.....it will probably go wrong within the next week!!! The only component I had to renew once was a lambda sensor.
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Post by brianac on May 8, 2017 21:31:24 GMT
I'm still not sure hydrogen will take off, my biggest concern with hydrogen as a fuel is the efficiency of production, or more correctly, the lack of. Then there are the compression and transport costs. Electricity can just be flung down a wire. If we get some decent batteries then EVs are the future. Well most electricity production is incredibly inefficient from the likes of coal or oil. Transmission loses are not good (say 1% per 100 miles) and part of the debate here is localised nets rather than whole country systems (we needed whole country systems when we used coal in one part to drive factories in other parts). All these changes open up the intelligent net debate. Hydrogen is generated at the required 700bar by ITM from solar or wind power and a bucket of water. 700bar gives you enough fuel in a car's tank to do what a car has to do 350miles plus. A whole bunch of producers did use to have to produce at atmosphere and then compress but that was sorted about 12 years ago. Efficiencies, I've struggled to get good info on this but I'm seeing around 85% which makes the humble thermal power station (at 47%) look what it is, a dinosaur. If we get decent batteries, good point. The reason our favorite Tesla CEO likes batteries is that if we turn our backs on batteries he has lost the game, control of H2 will be open source. H2 in a tank is a "battery of energy", just doesn't look like one. Surely the point is that for either route first we need enough copper to drive all the electric motors, then with batteries we need shed loads of special chemicals while with H2 we need a bucket of water. I suspect the market will divide as it has into diesel and petrol, but my brain thinks H2 is far superior. Declaring an interest, I drive an electric car (and I love it!) How can hydrogen be considered more efficient than Electric? there are two main ways of producing hydrogen, electrolysis - so making the hydrogen has to be less efficient than producing electricity, (and it is very much less efficient) and gasification using steam and Carbon monoxide + dioxide, not, as you can imagine the most efficient means of producing it either. Efficiency of Hydrogen as a fuel? - don't know for sure, but likely similar to petrocarbon fuels/internal combustion engine (about 28%??) you'd certainly be better off if you could use a hydrocarbon fuel (such as methane propane etc) - some research has gone into multi-fuel fuel cells. Better surely to use said solar/wind power to charge cars (almost) directly and avoid the complications of vehicles driving around with a 700Bar "bomb" on board (never mind the practicalities of getting the fuel into the presssure vessel safely! on a regular basis) as well as several "conversion" stages contributing to the inefficiency. Battery technology has a long way to go for sure, but not as far as Hydrogen cars have (IMO) www.riversimple.com/Competition for the G-Whizz? (but not the Tesla) Incidently, not been able to find the figures so far, but HMG has, I gather, poured shedloads of money into Riversimple already, but not a lot of progress to show for it up to now at least. put another way - I'm out. Brian
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macro
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Post by macro on May 9, 2017 5:02:52 GMT
I'm still not sure hydrogen will take off, my biggest concern with hydrogen as a fuel is the efficiency of production, or more correctly, the lack of. Then there are the compression and transport costs. Electricity can just be flung down a wire. If we get some decent batteries then EVs are the future. .. sounds like a lot of hot air to me 
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Post by Deleted on May 9, 2017 8:37:45 GMT
Good point about needing electricity to make hydrogen, there you are right.
In terms of efficiency in the 12% figures, this is way off any actual facts I've worked with, as a Professional Engineer I've worked close to this industry and my inability to provide an efficiency figure is more to do with precision than lack of a basic figure. 85% is about right.
So, chemical batteries and hydrogen (batteries) comparison
1) speed of charging, H2 wins hands down
2) simplicity of chemicals and raw materials used, H2 wins hand down
3) attractiveness to silicon valley (basically the core innovative centre of the planet), chemical batteries win hands down 'cause they can own it.
4) efficiency of conversion electricity to motivation, well a bit more complex and probably just on the side of the battery, the weight of batteries knocks some umph out of the conversion figures so far more car specific and of course converting AC electricity to DC and then charging a battery takes effort. By chance I was looking at a Tesla this am and going this route the overall efficiency of the conversion is around 87%, so if you go this route pretty close to that of hydrogen production,
5) money, time, engineering time thrown at it, batteries win hands down but...
when I was a lad, I was told solar cells would never become main stream, it was impossible, meanwhile petrol engines were struggling to get efficiencies above SWA. Fast forward 30 years, solar cells despite lack of investment is now everwhere and very affective, petrol (with a fortune thrown at it) has now advanced to SFA plus a little bit. Why, because petrol engines thermal cycles really do limit how efficient they can be, much as thermal power stations.
The point I'd make is the H2 efficiencies will come up because they really are not limited by basic physics, just they need time and money to move them.
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will
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Post by will on May 9, 2017 13:55:04 GMT
Looking at Wikipedia, the most efficient hydrogen production method is using natural gas, at 80%, but then you're still obviously relying on fossil fuels.
On solar conversion they say:
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pikestaff
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Post by pikestaff on May 9, 2017 15:28:04 GMT
Looking at Wikipedia, the most efficient hydrogen production method is using natural gas, at 80%, but then you're still obviously relying on fossil fuels. On solar conversion they say: I think that 14 % figure is the overall efficiency of conversion of the incoming light to hydrogen, which is driven almost entirely by the efficiency of the solar panel in converting light to electricity. Solar panels do have a lot of room for improvement, but even at current efficiency levels they are competitive with fossil fuels in many places. And they will only get better. It's meaningless to compare the 14% figure with the overall conversion efficiency for fossil fuels. When you use fossil fuels they are gone, but the sun will shine for a few billion years yet. What matters is (1) the cost of the electricity and (2) the efficiency of conversion of the electricity to hydrogen and then to motive power. Hydrogen (in some form) has every chance of being the future. Batteries are a dead end because of their weight and the scarcity and toxicity of the materials used in their manufacture. They are the very opposite of green.
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Post by tybalt on May 9, 2017 16:01:25 GMT
BoBo - My quick review of Solar Panels :
UK currently not viable without substantial subsidies from conventionally produced electricity.
Germany ditto but present in large numbers because they are compulsory for new builds
France few headline projects such as Techno Pole in the Haute Vienne but as UK for domestic use.
Spain so vastly over subsidised that the Spanish government had to introduce a special tax on their income to avoid.
Malta very rare
I am not sure about Morocco.
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Post by brianac on May 9, 2017 20:56:23 GMT
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will
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Post by will on May 10, 2017 9:07:36 GMT
Wow, that was interesting. An average supermarket filling station will need 500,000 solar panels and 250 hectares (more or less a square mile) of land, as well as 100,000 litres of water per day and storage. Looking at these numbers, Hydrogen will only be feasible from carbon neutral sources after we've got fusion power. Edit: To put this into comparison, the average garage roof can fit enough solar panels to charge a car battery all year round for the average driver.
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