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Hydrogen cars usually are electric cars. The main advantage to the owner is being able to fill the tank in minutes, and to society as a whole is being able to m

• cbolton 5y ago
  If we're going to store energy by generating H2, is it more efficient to consume it in small cars rather than in big plants that convert it back to electrical power on demand?
  • Cthulhu_ 5y ago
    I don't think the previous commenter meant converting it back; just that if there is an excess of power, e.g. on a sunny and windy day, that can be captured into H2 which is much easier to store than electricity. It wouldn't be converted back to electricity for the grid.
    • deleted 5y ago
      [deleted]
    • cbolton 5y ago
      That's also what I understood, but I'm asking if that's really an argument in favor of H2 vehicles: with electrical vehicles we can also store excess power as H2. Of course we then need to burn it in power plants to convert back to electricity. But which is more efficient? Electricity -> H2 -> electricity -> electrical motor with 80% efficiency vs Electricity -> H2 -> hydrogen motor with 30% efficiency My guess is that "H2 -> electricity" is a bit more efficient than "H2 -> hydrogen motor". So using H2 as excess power storage for hydrogen engines is only marginally better than doing the same for electrical engines. And that's for excess power storage. For "normal" production/consumption the electrical engine is way more efficient.
• _ph_ 5y ago
  Hydrogen production is not well suited to be run depending on the power supply in the grid due to the high prices of the production facilities. If you keep electric cars plugged in, they are far better suited to absorb high supply situations at a much higher efficiency.