11–20 of 32 posts
"In a renewable energy grid, batteries can handle about 80 percent of storage needs." Why couldn't you just add 25% more batteries?
It's not 25% more batteries. It's some 500% to 1000% more. But those would be used very few times.
This is remarkably hard to follow. The actual technology at play here is bicarbonate-formate redox; as the linked paper states: >It is also clear that more integration between the disciplines of electrochemistry and heterogeneous catalysis is needed to overcome the challenges for advancing the HCO3−–HCO2− system as a feasible green alternative for storing and transporting energy. The idea of storing energy by convert…
Hydrogen is needed for all kinds of industrial processes, but it is best generated at the point of use as needed, as storage and transport is too problematic. If absoultely needed, the most obvious way to ship hydrogen is as methane. Synthesis of methane from water-sourced hydrogen and atmosphere-sourced CO2 is at present a good deal more expensive than fossil natural gas, but that's a somewhat artificial situation:…
> If absoultely needed, the most obvious way to ship hydrogen is as methane. Methane has 2 problems: 1. it's a massive greenhouse gas if it leaks, 2. it requires CO2 to make, and in a decarbonized future that can only come from either biomass (limited) or DAC (expensive). You would either want ammonia or methanol. Ammonia does not have any of these problems, but it's very toxic. Methanol has the CO2 problem as well,…
Ammonia is a greenhouse gas itself, and it tends to react with air creating various nitrous oxides, that are much more potent greenhouse gases than methane, very toxic, and create acid rain (after what it becomes fertilizer).
The best shipping option is probably just to face all the issues and ship the hydrogen. But storage is a different matter.
"In a renewable energy grid, batteries can handle about 80 percent of storage needs." Why couldn't you just add 25% more batteries?
Earlier quoted context omitted.
It's not 25% more batteries. It's some 500% to 1000% more. But those would be used very few times.
So in other words batteries don't get us anywhere close to 80% of the way.
However that last 25% needs to be stored over long periods where the cost is prohibitive to store in current battery systems.
Earlier quoted context omitted.
> If absoultely needed, the most obvious way to ship hydrogen is as methane. Methane has 2 problems: 1. it's a massive greenhouse gas if it leaks, 2. it requires CO2 to make, and in a decarbonized future that can only come from either biomass (limited) or DAC (expensive). You would either want ammonia or methanol. Ammonia does not have any of these problems, but it's very toxic. Methanol has the CO2 problem as well,…
> Ammonia does not have any of these problems Ammonia is a greenhouse gas itself, and it tends to react with air creating various nitrous oxides, that are much more potent greenhouse gases than methane, very toxic, and create acid rain (after what it becomes fertilizer). The best shipping option is probably just to face all the issues and ship the hydrogen. But storage is a different matter.
Earlier quoted context omitted.
It's not 25% more batteries. It's some 500% to 1000% more. But those would be used very few times.
So in other words batteries don't get us anywhere close to 80% of the way.
Yes, in terms of amount of energy stored at full capacity, batteries would not get us to 80%. But those last 20% have reduced requirements for charge/discharge rates, effiency, cost/kWh, which makes many other solutions viable.
This is remarkably hard to follow. The actual technology at play here is bicarbonate-formate redox; as the linked paper states: >It is also clear that more integration between the disciplines of electrochemistry and heterogeneous catalysis is needed to overcome the challenges for advancing the HCO3−–HCO2− system as a feasible green alternative for storing and transporting energy. The idea of storing energy by convert…
Looks like they're using Pd/Pt for the best catalyzers... that's definitely not going to be scalable. Though there should be effective alternatives, but it's surprising how unsophisticated much of the research in this field can be.
Hydrogen is needed for all kinds of industrial processes, but it is best generated at the point of use as needed, as storage and transport is too problematic. If absoultely needed, the most obvious way to ship hydrogen is as methane. Synthesis of methane from water-sourced hydrogen and atmosphere-sourced CO2 is at present a good deal more expensive than fossil natural gas, but that's a somewhat artificial situation:…
> If absoultely needed, the most obvious way to ship hydrogen is as methane. Methane has 2 problems: 1. it's a massive greenhouse gas if it leaks, 2. it requires CO2 to make, and in a decarbonized future that can only come from either biomass (limited) or DAC (expensive). You would either want ammonia or methanol. Ammonia does not have any of these problems, but it's very toxic. Methanol has the CO2 problem as well,…
This is remarkably hard to follow. The actual technology at play here is bicarbonate-formate redox; as the linked paper states: >It is also clear that more integration between the disciplines of electrochemistry and heterogeneous catalysis is needed to overcome the challenges for advancing the HCO3−–HCO2− system as a feasible green alternative for storing and transporting energy. The idea of storing energy by convert…
"The electrochemical regeneration is not optimized...If the cell voltage could be reduced to 2 V and the faradaic efficiency raised to 80%, the total cost of hydrogen would be nearly cut in half...if the regeneration and reaction could be performed at 8 M rather than 3 M concentration along with an improved process and discounted electricity...the cost of hydrogen could drop to just over $3 per kg...[which is] below the cost of on-site electrolysis with full-priced electricity"
Why formate? Can't you get hydrogen from any acid, because that's literally the definition of an acid? "If the cell voltage could be reduced" sounds super fishy to me; isn't that just a useless wish that the elements / molecules you're working with have different properties than they actually do? "If the regeneration and reaction could be performed at 8 M rather than 3 M concentration...", why can't they? Doesn't a reaction usually proceed faster in more concentrated solutions?
It seems like several breakthroughs that are needed, some of which possibly stretch the laws of physics. But once you have that. But even with those improvements, they still compare formate+discounted electricity to electrolysis+fullprice electricity? Isn't that doing an apples-to-oranges comparison, blatantly putting your thumb on the scale in favor of formate?
For that matter, what's wrong with electrolysis for making hydrogen for bulk energy storage? Isn't water electrolysis super well-understood, cheap, simple, scalable, as safe as anything involving bulk quantities of hydrogen gas can be, and only requires water and electricity for inputs?