4 ms·

"Would" :) Sure, let's bet our future on that. Source for the "much better than 30%" efficient ? I want something that is deployed and in production. Not some

"Would" :) Sure, let's bet our future on that. Source for the "much better than 30%" efficient ? I want something that is deployed and in production. Not some kind of startup-that-will-change-everything tech.

pfdietz 5y ago
It's a safe bet that hydrogen can be made without fossil fuels. Since hydrogen is essential to maintaining current world population (via manufacture of nitrogen fertilizer), if that were false we'd be doomed.
- edhelas 5y ago
  So you didn't answered my question regarding your sources. Here's mine: - The technology to convert power to hydrogen and back to power has a round-trip efficiency of 18%-46%, according to data that Flora presented from the Massachusetts Institute of Technology and scientific journal Nature Energy. In comparison, two mature long-duration technologies, pumped-storage hydropower and compressed air energy storage, boast round-trip efficiencies of 70%-85% and 42%-67%, respectively. Flow batteries, a rechargeable fuel cell technology that is less mature, have a round-trip efficiency of 60%-80%. https://www.spglobal.com/marketintelligence/en/news-insights/podcasts/451-research-episode-49 https://www.spglobal.com/marketintelligence/en/news-insights... - https://www.volkswagenag.com/en/news/stories/2019/08/hydrogen-or-battery--that-is-the-question.html https://www.volkswagenag.com/en/news/stories/2019/08/hydroge...
  - pfdietz 5y ago
    You will notice that 46% > 30%, so you have confirmed my statement and contradicted your own. Thanks! I hope you were assuming a combined cycle power plant was being used to turn the hydrogen back to power, not a simple cycle turbine only 2/3rds as efficient. There are other storage technologies with higher efficiencies, but they also have much higher cost per kWh of storage capacity. On that metric batteries are like two orders of magnitude more expensive than hydrogen (flow batteries somewhat better but still much worse than hydrogen.) In storage use cases where it is appropriate (seasonal, rare event backup), hydrogen is hard to beat.
- ya_throw 5y ago
  Fascinating argument, but unfortunately, we are doomed. That is, unless we go nuclear. Apart from that, there is nowhere near enough energy or resources to maintain our current lifestyle (and that's ignoring the fact that the vast majority of the world's population don't enjoy this lifestyle and very much wish to) in a "renewable" fashion.
  - analog31 5y ago
    Here "lifestyle" means population. We're doomed.
  - adrianN 5y ago
    There is absolutely no reason to assume that nuclear energy will be cheaper than wind and solar. For hydrogen production the "base load!!" argument doesn't apply either. You can just produce hydrogen when power is plentiful.
    - ya_throw 5y ago
      There absolutely is - it's called energy returned on energy invested.
      - pfdietz 5y ago
        EROEI of renewables is just fine and is not an argument for nuclear over renewables. I get the feeling you're reading from a list of debunked pro-nuclear talking points.
        ya_throw 5y ago
        Just fine, if you're happy with approximately 1/4th the energy output for a given (manufacturing) energy input. And that's for the best case, for certain wind power installations. Solar is the worst, at about 1/15th the energy output for the same energy input (compared to nuclear). [1] I fail to see how this argument is "debunked". I'd also like to see what other arguments are on my supposed list. [1] https://en.wikipedia.org/wiki/Energy_return_on_investment https://en.wikipedia.org/wiki/Energy_return_on_investment

pfdietz 5y ago

It's a safe bet that hydrogen can be made without fossil fuels. Since hydrogen is essential to maintaining current world population (via manufacture of nitrogen fertilizer), if that were false we'd be doomed.

edhelas 5y ago
So you didn't answered my question regarding your sources. Here's mine: - The technology to convert power to hydrogen and back to power has a round-trip efficiency of 18%-46%, according to data that Flora presented from the Massachusetts Institute of Technology and scientific journal Nature Energy. In comparison, two mature long-duration technologies, pumped-storage hydropower and compressed air energy storage, boast round-trip efficiencies of 70%-85% and 42%-67%, respectively. Flow batteries, a rechargeable fuel cell technology that is less mature, have a round-trip efficiency of 60%-80%. https://www.spglobal.com/marketintelligence/en/news-insights/podcasts/451-research-episode-49 https://www.spglobal.com/marketintelligence/en/news-insights... - https://www.volkswagenag.com/en/news/stories/2019/08/hydrogen-or-battery--that-is-the-question.html https://www.volkswagenag.com/en/news/stories/2019/08/hydroge...
- pfdietz 5y ago
  You will notice that 46% > 30%, so you have confirmed my statement and contradicted your own. Thanks! I hope you were assuming a combined cycle power plant was being used to turn the hydrogen back to power, not a simple cycle turbine only 2/3rds as efficient. There are other storage technologies with higher efficiencies, but they also have much higher cost per kWh of storage capacity. On that metric batteries are like two orders of magnitude more expensive than hydrogen (flow batteries somewhat better but still much worse than hydrogen.) In storage use cases where it is appropriate (seasonal, rare event backup), hydrogen is hard to beat.
ya_throw 5y ago
Fascinating argument, but unfortunately, we are doomed. That is, unless we go nuclear. Apart from that, there is nowhere near enough energy or resources to maintain our current lifestyle (and that's ignoring the fact that the vast majority of the world's population don't enjoy this lifestyle and very much wish to) in a "renewable" fashion.
- analog31 5y ago
  Here "lifestyle" means population. We're doomed.
- adrianN 5y ago
  There is absolutely no reason to assume that nuclear energy will be cheaper than wind and solar. For hydrogen production the "base load!!" argument doesn't apply either. You can just produce hydrogen when power is plentiful.
  - ya_throw 5y ago
    There absolutely is - it's called energy returned on energy invested.
    - pfdietz 5y ago
      EROEI of renewables is just fine and is not an argument for nuclear over renewables. I get the feeling you're reading from a list of debunked pro-nuclear talking points.
      - ya_throw 5y ago
        Just fine, if you're happy with approximately 1/4th the energy output for a given (manufacturing) energy input. And that's for the best case, for certain wind power installations. Solar is the worst, at about 1/15th the energy output for the same energy input (compared to nuclear). [1] I fail to see how this argument is "debunked". I'd also like to see what other arguments are on my supposed list. [1] https://en.wikipedia.org/wiki/Energy_return_on_investment https://en.wikipedia.org/wiki/Energy_return_on_investment