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Interesting Items...

I think there is an issue of targets which is skirted by some of the comments above.
There are two: Reducing pollution, especially in built up areas, and reducing fossil fuel use. 'The public' tend to not see the distinction and blindly believe that anything that doesn't burn petrol or diesel is 'green' and fixes both problems.

Battery and hydrogen do both address the first target but not the second unless the power comes from renewables, not fossil fuels.
Incidentally although hydrogen (in quantity) can be produced by using electricity it is quite likely a lot of it will come from processing oil, which suggests it won't do a lot to reduce fossil fuel use. (However, as the carbon will be separated at the processing plant there is probably a better chance of capturing and storing it.)
 
prpr said:
50kW is 200A or so. This is way more than most people's domestic supplies can cope with. It would mean massive amounts of recabling would be required both in the property and in the street all the way back to the substation... and probably further.
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I am wondering what the effect will be on global warming of 50kW going into a battery.

Hope they have good protection against spontaneous combustion.
 
Trev said:
. (or a power station in the boot):)
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The power station in the boot is the Hydrogen Fuel Cell, that was kind of the point of the post. There is a lot of research going into light weight mobile fuel cells. You really are a bit of a dinosaur aren't you. Thank heavens there are others more enlightened. What did you say about the first transistors, they will never replace the valves in my radio. :eek:

In case you did not know, fuel cells directly convert hydrogen into electricity, they do this and only output pure water . If the source of the power is renewables it's a zero carbon solution, as is burning fast growing crops and then burning them for energy. The efficiency is around 60% (at the present time), the motor probably in the 90% range. Compare that to the thermal efficiency of your car engine and the pollutants it generates.

Who knows, in the next 50 yrs we may have a practical fusion source of power, but not if anyone as short sighted as you has anything to do with it.
 
antipodean said:
I am wondering what the effect will be on global warming of 50kW going into a battery.

Hope they have good protection against spontaneous combustion.
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Another dinosoar, ancient lead acid batteries produce combustible gases. These are exactly what we need to store. How much power do you think the battery on a large diesel is required to start it in the first place. Be sure to add on the preheaters required. The answer is if the efficiency of the charging process is 100%, then the effect is zero. Which school did you learn your physics from ? Do know how pumped storage works as used at Dinorwig ? The batteries we are talking about are capable of delivering power much higher than 50kW and hence much more current. Why would a lower charging current than they can output be an issue :geek:
 
grahamlthompson said:
Another dinosoar, ancient lead acid batteries produce combustible gases. These are exactly what we need to store. How much power do you think the battery on a large diesel is required to start it in the first place. Be sure to add on the preheaters required. The answer is if the efficiency of the charging process is 100%, then the effect is zero. Which school did you learn your physics from ? Do know how pumped storage works as used at Dinorwig ? The batteries we are talking about are capable of delivering power much higher than 50kW and hence much more current. Why would a lower charging current than they can output be an issue :geek:
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But that is exactly it, the efficiency of the charging process ISN'T 100%, so there is normally some heat generated when charging a battery. The scheme is to fast charge a 50kW battery, so I am expecting anything around 5kW of heat.
 
grahamlthompson said:
The power station in the boot is the Hydrogen Fuel Cell, that was kind of the point of the post.....In case you did not know, fuel cells directly convert hydrogen into electricity, they do this and only output pure water .
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Of course I know that, but where does all this hydrogen come from? It isn't exactly a particularly abundant free gaseous element. Shedloads in water. How do you get it out? Electrolysis? How do you generate the electricity? Fuel cell that produces more water. Hang on, we have now invented a perpetual motion machine.
If the source of the power is renewables it's a zero carbon solution, as is burning fast growing crops and then burning them for energy.
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So burning fast growing crops produces no carbon emissions eh? Well, let's do that when all the coal and oil have gone.
 
Trev said:
So burning fast growing crops produces no carbon emissions eh?
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Correct. The CO2 produced by burning them came from the atmosphere in the first place (in growing the plants).

Trev said:
where does all this hydrogen come from?
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Anywhere there is waste or surplus energy you can use to split water, however intermittent the source might be. There are algae under research which can even do it direct from sunlight.

Once you have a system for bulk distribution and supply of hydrogen, you have a choice of using it in a fuel cell to run your Tesla, or running an existing petrol engine vehicle converted to hydrogen. The existing population of vehicles do not all need to be replaced before significant inroads can be made into non-carbon transportation.
 
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There's a short series starting on BBC 4 tonight (Tues 17) called Power to the People which is about power generation. Might be of interest regarding the above discussion.
 
Trev said:
So burning fast growing crops produces no carbon emissions eh? Well, let's do that when all the coal and oil have gone.
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The problem is as follows: buried coal and oil are where the CO2 from the primordial atmosphere went. There was very little oxygen in the early Earth's atmosphere - indeed, the primordial organisms would have found oxygen (in more than trace amounts) toxic. Once plants got established, they used sunlight to metabolise the atmospheric CO2 and produced O2 as waste, but then the increased levels of O2 permitted the evolution of the more complex organisms we have today (including us), using more efficient metabolic systems based on oxidising sugars (but without having to create the oxygen in the first place).

The plants locked up the atmospheric carbon in their tissues, but the carbon is then released back to the atmosphere when the plant dies and decays - unless you bury it in mud and lock it away deep in the geological strata as fossilised carbon (coal and oil).

By digging up all that fossilised carbon and burning it, mankind is returning the atmosphere to the primordial state*. That's not going to bother the Earth as such, life (in some form) will continue, but it will become pretty difficult for a lot of species that we depend on for our existing way of life or have some emotional attachment to (what use is a Giant Panda except as a symbol?).

In the shorter term, the increased temperatures due to the insulating effect of a higher concentration of CO2 in the atmosphere shifts the existing delicate balance in the existence of water between its vapour, liquid, and solid states to the point where very little will exist in the solid state and there is a greater volume cycled between vapour and liquid. The sea levels rise and there is more rain. The threat of that is the reduction in land area available - and the reduction comes mostly from the "useful" land area for food production and habitation.

That's why it matters (to our children or grandchildren, if not to us). Any delay in taking preventative action makes prevention more difficult. All the above has been said before, but I hope I have summarised it with some extra clarity.

* I have glossed over the fact that a hugely greater amount of CO2 is locked up in the limestone and chalk that were deposited as the shells and skeletons of sea life. Some is on the surface of the land, and will return to the atmosphere by reacting with acid rain, while that in the sea (corals) will do similar when the acidity of sea water increases. Meanwhile, huge volumes of methane (a far more efficient greenhouse gas than CO2) stand ready to be released when the permafrost melts or the seas warm.
 
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This is an unusual paragraph, and I'm curious to know just how quickly you can work out what is so unusual about it. It looks so ordinary and plain that you would think nothing was wrong with it, and in fact nothing is wrong - it is highly unusual though. Study it and think about it. You still might not find anything odd, but if you work at it a bit, you may catch on.
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For what it's worth, I didn't. I have edited (improved) the example shown to me, which wasn't very good.
 
I also didn't work it out, but, I did find a solution. I would switch two words starting at word four, as it's difficult to surf that way

OOPS

Original did not conform
 
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According to a brief article in the December 2015 issue of Scientific American, neutrinos originating within one second of the Big Bang have been detected by their effect on the Cosmic Microwave Background radiation (which itself originates from as late as B+100,000 years, when the universe had cooled sufficiently to become transparent).

I can't get my head around how something can be shining from 18 billion years ago, therefore be 18 billion light-years away, and yet at the time the universe could only have been a few hundred thousand light years across... :boggle:
 
Raspberry Pi Zero

Just came across this article featuring a Mini RPi (in cost anyway), It's supposed to be only £4, but I'm sure the U.K. retailers will find to push that up a bit

rasp2.jpg


The link to the article is here :-
http://www.wired.co.uk/news/archive/2015-11/26/raspberry-pi-zero-launch
 
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