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frankv
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  #2716121 31-May-2021 12:00
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SomeoneSomewhere:

 

Building our grid and generation out to 4x its present size would be horrifically expensive and there would be a lot of carbon involved in the construction.

 

 

Where do you get the figure of 4 x current size? Our electricity grid (except for Otahuhu?) is currently designed to meet peak demand. But I'd guess that if there was battery storage at the periphery (i.e. substations and households) and significant amounts of solar at households, the existing grid would be sufficient even if electricity usage quadrupled, because hardly any households, and probably most small businesses, wouldn't demand any electricity at all from the grid.

 

 


frankv
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  #2716123 31-May-2021 12:11
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raytaylor:

 

Hydrogen is probably a good idea even at 30% efficiency when its used for vehicles. 

 

No, it's a really dumb idea. Throwing away 2/3 of your energy for what? And where does that energy go? Into heat, warming the atmosphere.

 

And especially if you use it to run an ICE, because that in itself is only about 40% efficient, so you're down to using 12%, and wasting 88%.

 

Not to mention the problems with storing that hydrogen that have already been covered.

 

 


Fred99
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  #2716125 31-May-2021 12:13
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frankv:

 

raytaylor:

 

Hydrogen is probably a good idea even at 30% efficiency when its used for vehicles. 

 

No, it's a really dumb idea. Throwing away 2/3 of your energy for what? And where does that energy go? Into heat, warming the atmosphere.

 

And especially if you use it to run an ICE, because that in itself is only about 40% efficient, so you're down to using 12%, and wasting 88%.

 

Not to mention the problems with storing that hydrogen that have already been covered.

 

 

 

 

H2 would be used for electric fuel cells in cars - not burned in an ICE.


frankv
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  #2716126 31-May-2021 12:20
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Scott3:

 

Basically all on grid home storage batteries are Li Ion, so yes they degrade exactly like a Li ion battery...

 

 

In development... https://en.wikipedia.org/wiki/Vanadium_redox_battery

 

 


mrdrifter
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  #2716127 31-May-2021 12:21
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It's interesting to see people suggesting Hydrogen is just around the corner, this was the same thing people were saying ~15-20 years ago and I'm yet to see any research that puts us any closer to it being a reality. The numbers just don't add up.

 

 

 

On the topic of Gas for households, residential usage is somewhere around ~3%, this would point to it being much more impactful and potentially better economically, to work with industrial consumers to reduce usage. This would reduce both the impact on residential consumers and overall usage. It's also much more meaningful to move our on-shore industries to things such as Biomass boilers, as opposed to letting them buy carbon credits (feel good certificates) that fund a discount Biomass boiler overseas, while not actually reducing their overall impacts.


frankv
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  #2716130 31-May-2021 12:27
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Scott3:

 

Either way, with or without Onslow, we are going to need a lot more renewable generation. Large hydro seems fairly unlikely at this stage (although if we got desperate we could bring a couple of proposals back from the dead). I think the heavy lifting will come from New Geothermal, and wind schemes, with a bit of smaller "run of the river" (no big dam) hydro, and a bit of solar on rooftops.

 

 

I see home solar + home batteries doing the heavy lifting (millions of them lifting a little bit each). It's easily scalable, without impacting the grid at all. And pretty close to economic now, depending on how you do the arithmetic. Increasingly, the grid and "big generation" will be to supply industry.

 

 


Behodar
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  #2716136 31-May-2021 12:46
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It's rather amusing when I see this thread and the article "Natural Gas Is (Mostly) Good for Global Warming" on the same day.


Rikkitic
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  #2716137 31-May-2021 12:47
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Fred99:

 

H2 would be used for electric fuel cells in cars - not burned in an ICE.

 

 

After fossil fuels are banned, the 1955 Chevrolet club will want to burn H2 in their vehicles. 

 

 





Plesse igmore amd axxept applogies in adbance fir anu typos

 


 


Rikkitic
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  #2716140 31-May-2021 12:58
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mrdrifter:

 

It's interesting to see people suggesting Hydrogen is just around the corner, this was the same thing people were saying ~15-20 years ago and I'm yet to see any research that puts us any closer to it being a reality. The numbers just don't add up.

 

 

Not disputing your facts but I vividly recall 'experts' proclaiming in the 1950s that space travel was impossible because the weight of the fuel would always exceed the thrust it could produce. I think it was the British Astronomer Royal who famously said space travel was 'utter bilge'. The numbers won't add up until they do.

 

 





Plesse igmore amd axxept applogies in adbance fir anu typos

 


 


1101
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  #2716575 1-Jun-2021 09:51
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Rikkitic:

 

Not disputing your facts but I vividly recall 'experts' proclaiming in the 1950s that space travel was impossible because the weight of the fuel would always exceed the thrust it could produce. I think it was the British Astronomer Royal who famously said space travel was 'utter bilge'. The numbers won't add up until they do.

 

 

And yet in the 40's the germans were building rockets & had planned for multi-stage rockets capable of reaching space
Sputnik : 1957. Russians didnt deem it impossible in the 50's 
so , define 'experts'
Obviously not experts in rocket design . :-)

 

Back to H2 : we use fossil fuel to extract hydrogen
And we would need alot of it to replace fossil fuels . Not some marginal experimental production run

 

From wifi
"As of 2020 most of hydrogen is produced from fossil fuels, resulting in carbon emissions"


Rikkitic
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  #2716681 1-Jun-2021 12:40
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1101:

 

Obviously not experts in rocket design . :-)

 

 

Here is one source. There are many others but you will have to do your own research if you want to know more.

 

Of course there were individual experimenters who believed space travel was possible in the early days, and of course there were the Germans, but the consensus of informed opinion at the time was against it until Sputnik proved otherwise.

 

 

 

 





Plesse igmore amd axxept applogies in adbance fir anu typos

 


 


frankv
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  #2716698 1-Jun-2021 13:32
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Rikkitic:

 

I think it was the British Astronomer Royal who famously said space travel was 'utter bilge'. The numbers won't add up until they do.

 

 

We're getting OT, but...

 

What he actually said was "All this talk about space travel is utter bilge, really.", which has a different nuance. And I suspect that it was in the context of *human* space travel, because he suggested we would learn more by spending the money on really good telescopes.

 

 


Rikkitic
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  #2716704 1-Jun-2021 13:52
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The point I was making is that even people with expert knowledge sometimes miss the big picture. I actually remember articles and even discussions on the radio in which it was 'proven' that no rocket could develop enough thrust to overcome the weight of the fuel. The mathematics were all perfectly correct but the experts cited didn't consider the possibility of multiple stages. Sometimes a little knowledge can be dangerous. A lot can be downright deceptive.

 

  





Plesse igmore amd axxept applogies in adbance fir anu typos

 


 


SomeoneSomewhere
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  #2716722 1-Jun-2021 14:35
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frankv:

 

 SomeoneSomewhere:

 

Building our grid and generation out to 4x its present size would be horrifically expensive and there would be a lot of carbon involved in the construction.

 

Where do you get the figure of 4 x current size? Our electricity grid (except for Otahuhu?) is currently designed to meet peak demand. But I'd guess that if there was battery storage at the periphery (i.e. substations and households) and significant amounts of solar at households, the existing grid would be sufficient even if electricity usage quadrupled, because hardly any households, and probably most small businesses, wouldn't demand any electricity at all from the grid.

 

 

That's in reference to this post:

 

Fred99:

 

H2 can be used to produce methane or "synthetic natural gas" from CO2. So long as the H2 is produced using zero carbon emission electricity generation, and you're not burning fossil fuel to generate the CO2, the system is carbon neutral.  

 

It's already being done.  

 

You could assume that "it's never going to be commercially useful because of cost and efficiency", but you could have once said that about making by-products from oil, but ample supply of raw material and demand created a market, massive expensive and complex petrochemical plants / oil refineries have been built all over the planet to meet that demand.

 

Where there's a will, I'm confident a way will be found. 

 

 

I admit that the math is very fuzzy, but if you want to simply electrolysis up some H2 and drop it into the gas system instead of methane (or convert it to methane), you're going to need a vast, vast amount of electricity to do that.

 

It looks like we're using roughly 150PJ/year each of both gas and electricity, though obviously some of that gas is being used for electricity, but presumably a lot of oil demand (cars, heating) moves to gas or electric. Assuming we're 33% efficient at producing 150PJ/year of H2 (450PJ/year electricity needed for the H2), the grid and generation needs to go from 150PJ/year to 600 PJ/year.


SomeoneSomewhere
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  #2716726 1-Jun-2021 14:37
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Fred99:

 

frankv:

 

raytaylor:

 

Hydrogen is probably a good idea even at 30% efficiency when its used for vehicles.

 

No, it's a really dumb idea. Throwing away 2/3 of your energy for what? And where does that energy go? Into heat, warming the atmosphere.

 

And especially if you use it to run an ICE, because that in itself is only about 40% efficient, so you're down to using 12%, and wasting 88%.

 

Not to mention the problems with storing that hydrogen that have already been covered.

 

 

 

 

H2 would be used for electric fuel cells in cars - not burned in an ICE.

 

 

They're still a decade away from being viable, though. AKA never. The heavy metals needed for the fuel cells push the cost past a battery, and it's still less efficient.


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