4 ms·

> Even former critics must admit that adding e-fuels through PtX makes 100% RE possible at costs similar to fossil fuels E-fuels and "ptx" are ambiguous terms

> Even former critics must admit that adding e-fuels through PtX makes 100% RE possible at costs similar to fossil fuels E-fuels and "ptx" are ambiguous terms for energy storage. That plan is making the same allusions to storage systems that do not yet exist. What is "X"? Can it actually be built as cheaply as people promise? Until that's answered, this is just wishful thinking.

pfdietz 4y ago
If you are assuring us storage won't do it, the ambiguity doesn't matter, as it is on your plate to refute every last possibility. So step up and do you job and refute all possible interpretations of those terms. It's your responsibility to do so. You also have to refute all possible combinations of all the elements in the message you are responding to. But I assume you've done that, otherwise your assurance that 100% renewables can't work would be a lie.
- Manuel_D 4y ago
  No, the burden of proof is one the one saying that X is a viable approach. You're asking people to prove a negative. Here's a thought: we don't need fission nor renewables nor storage. Fusion will give us unlimited cheap energy! Now you have to refute every possible implementation of fusion energy - even methods we haven't built or tested - otherwise you're lying. Step up and do your job refuting all possible implementations of fusion! This is the kind of logic you're making with energy storage, and it's faulty logic. If someone wants to claim the viability of fusion, they actually have to deliver a working fusion reactor and at a viable cost. It's not the burden of other people to disprove every possible implementation of fusion.
ZeroGravitas 4y ago
> Modern 100% RE scenarios often make wide use of power-to-X (PtX) technologies, in particular, power-to-heat [22] and power-to-hydrogen [23]–[24][25][26]. Where direct hydrogen cannot yet be used, such as in the chemical industry or for long-distance marine and aviation transportation, hydrogen can be further converted to synthetic electricity-based fuels (e-fuels) as chemically bound RE and such as e-methane [27], [28], Fischer-Tropsch fuels [29], [30], e-ammonia [31], [32], and e-methanol [33], [34].
- Manuel_D 4y ago
  This is hydrogen electrolysis and the Sabatier process. There have been attempts to do this, but difficulties continue to prevent it from being deployed at scale. Hydrogen electrolysis is less efficient and maintaining the electeolysis systems expensive. The Sabatier process (aka power to gas) requires hydrogen as an input so it shares all of the above. It also requires a source of carbon dioxide to fix into hydrocarbons. Usually this is only done opportunistically when industrial processes produce carbon dioxide as a byproduct. The carbon dioxide in the atmosphere is at too low a concentration to be useful. This could be delivered through biofuels but there's not much energy density in them. If they can actually deliver these systems at viable costs, great. But no one has accomplished this so far.
  - pfdietz 4y ago
    The main thing that prevents it from being applied at scale is the availability of cheap natural gas unburdened by CO2 charges. But right now, renewable electrolytic hydrogen would be far cheaper than natural gas in Europe, where NG prices have reached 8x those in the US.
    - Manuel_D 4y ago
      If this were true, then Europe would be building lots of hydrogen electrolysis plants. Get back to me when they're actually built.

pfdietz 4y ago

If you are assuring us storage won't do it, the ambiguity doesn't matter, as it is on your plate to refute every last possibility. So step up and do you job and refute all possible interpretations of those terms. It's your responsibility to do so. You also have to refute all possible combinations of all the elements in the message you are responding to. But I assume you've done that, otherwise your assurance that 100% renewables can't work would be a lie.

Manuel_D 4y ago
No, the burden of proof is one the one saying that X is a viable approach. You're asking people to prove a negative. Here's a thought: we don't need fission nor renewables nor storage. Fusion will give us unlimited cheap energy! Now you have to refute every possible implementation of fusion energy - even methods we haven't built or tested - otherwise you're lying. Step up and do your job refuting all possible implementations of fusion! This is the kind of logic you're making with energy storage, and it's faulty logic. If someone wants to claim the viability of fusion, they actually have to deliver a working fusion reactor and at a viable cost. It's not the burden of other people to disprove every possible implementation of fusion.

ZeroGravitas 4y ago

> Modern 100% RE scenarios often make wide use of power-to-X (PtX) technologies, in particular, power-to-heat [22] and power-to-hydrogen [23]–[24][25][26]. Where direct hydrogen cannot yet be used, such as in the chemical industry or for long-distance marine and aviation transportation, hydrogen can be further converted to synthetic electricity-based fuels (e-fuels) as chemically bound RE and such as e-methane [27], [28], Fischer-Tropsch fuels [29], [30], e-ammonia [31], [32], and e-methanol [33], [34].

Manuel_D 4y ago
This is hydrogen electrolysis and the Sabatier process. There have been attempts to do this, but difficulties continue to prevent it from being deployed at scale. Hydrogen electrolysis is less efficient and maintaining the electeolysis systems expensive. The Sabatier process (aka power to gas) requires hydrogen as an input so it shares all of the above. It also requires a source of carbon dioxide to fix into hydrocarbons. Usually this is only done opportunistically when industrial processes produce carbon dioxide as a byproduct. The carbon dioxide in the atmosphere is at too low a concentration to be useful. This could be delivered through biofuels but there's not much energy density in them. If they can actually deliver these systems at viable costs, great. But no one has accomplished this so far.
- pfdietz 4y ago
  The main thing that prevents it from being applied at scale is the availability of cheap natural gas unburdened by CO2 charges. But right now, renewable electrolytic hydrogen would be far cheaper than natural gas in Europe, where NG prices have reached 8x those in the US.
  - Manuel_D 4y ago
    If this were true, then Europe would be building lots of hydrogen electrolysis plants. Get back to me when they're actually built.