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In the lab is a very very very very very different thing than at scale. Hydrogen is not feasible anytime soon. Maybe when we get Fusion but then it's most like

In the lab is a very very very very very different thing than at scale. Hydrogen is not feasible anytime soon. Maybe when we get Fusion but then it's most likely going to be used for materials not energy.

ben_w 4y ago
4% of current industrial hydrogen production is from electrolysis. This is 8 GW electrical for a production of about 3.5e6 tons/year, i.e. 72 MJ/kg, compared to the energy density of hydrogen of 120 MJ/kg is an efficiency of 60% in the actually deployed systems. While we know how to do better even at industrial scale, PV (in the right place) is so cheap that even 60% makes sense economically. Technologically, hydrogen electrolysis predates batteries by nearly 50 years, and practically speaking it is so trivial today that I first did it when I was single-digit-years-old. Not sure what you're thinking of when you suggest fusion might be used for materials instead of energy. Transmutation?
- ThomPete 4y ago
  Fusion is the sun. In the future we will be able to do what the sub does which is to create the raw materials we all do. Keep in mind fusion is not just another way to power our lightbulbs, it's a different type of energy among others with the ability to get us to 10% of the speed of light. Electrolyses uses mostly fossil fuel and will continue to do so. It's a simple question of physics.
  - ben_w 4y ago
    The sun only fuses up to carbon; bigger stars go up to iron; supernova and colliding neutron stars produce the heavier stuff we currently use. Trying to use this process artificially for various elements in current annual demand by our economy involves more than enough energy to boil the ocean in fairly short periods — I'd have to redo the calculations to see if that period was hours or years, but it's a simple question of physics. We might skip fusion rockets for antimatter (making that is painfully expensive, but it would get us up to 0.4c) or laser propulsion (needs massive infrastructure, but can arbitrarily approach c). > Electrolyses uses mostly fossil fuel and will continue to do so. It's a simple question of physics. Physics doesn't require that electrolysis uses fossil fuels, it requires only electricity. Electrolysis will use whatever electricity is cheapest. Right now, for new installations, that's PV. Ten years ago it was not. It's a simple question of economics.
    - ThomPete 4y ago
      You are agreeing with me.
      - ben_w 4y ago
        How? Are you counting PV as fusion? In which case I think you used the wrong tense earlier. I still claim you're wrong about fossil fuels being necessary for hydrogen, BTW.
        ThomPete 4y ago
        You can claim that all you want. Let me know when we are creating hydrogen without fossil fuels and at scale.

ben_w 4y ago

4% of current industrial hydrogen production is from electrolysis. This is 8 GW electrical for a production of about 3.5e6 tons/year, i.e. 72 MJ/kg, compared to the energy density of hydrogen of 120 MJ/kg is an efficiency of 60% in the actually deployed systems. While we know how to do better even at industrial scale, PV (in the right place) is so cheap that even 60% makes sense economically. Technologically, hydrogen electrolysis predates batteries by nearly 50 years, and practically speaking it is so trivial today that I first did it when I was single-digit-years-old. Not sure what you're thinking of when you suggest fusion might be used for materials instead of energy. Transmutation?

ThomPete 4y ago
Fusion is the sun. In the future we will be able to do what the sub does which is to create the raw materials we all do. Keep in mind fusion is not just another way to power our lightbulbs, it's a different type of energy among others with the ability to get us to 10% of the speed of light. Electrolyses uses mostly fossil fuel and will continue to do so. It's a simple question of physics.
- ben_w 4y ago
  The sun only fuses up to carbon; bigger stars go up to iron; supernova and colliding neutron stars produce the heavier stuff we currently use. Trying to use this process artificially for various elements in current annual demand by our economy involves more than enough energy to boil the ocean in fairly short periods — I'd have to redo the calculations to see if that period was hours or years, but it's a simple question of physics. We might skip fusion rockets for antimatter (making that is painfully expensive, but it would get us up to 0.4c) or laser propulsion (needs massive infrastructure, but can arbitrarily approach c). > Electrolyses uses mostly fossil fuel and will continue to do so. It's a simple question of physics. Physics doesn't require that electrolysis uses fossil fuels, it requires only electricity. Electrolysis will use whatever electricity is cheapest. Right now, for new installations, that's PV. Ten years ago it was not. It's a simple question of economics.
  - ThomPete 4y ago
    You are agreeing with me.
    - ben_w 4y ago
      How? Are you counting PV as fusion? In which case I think you used the wrong tense earlier. I still claim you're wrong about fossil fuels being necessary for hydrogen, BTW.
      - ThomPete 4y ago
        You can claim that all you want. Let me know when we are creating hydrogen without fossil fuels and at scale.