4 ms·

I recently commented about synthetic jet fuel in another thread https://news.ycombinator.com/item?id=31704829 https://news.ycombinator.com/item?id=31704829: >

I recently commented about synthetic jet fuel in another thread https://news.ycombinator.com/item?id=31704829 https://news.ycombinator.com/item?id=31704829: > A problem with biofuel is scaling it up, see: https://ieeexplore.ieee.org/document/7498153 https://ieeexplore.ieee.org/document/7498153. According to that article the U.S. would need to devote "an area bigger than Texas and California and Pennsylvania combined" to crops specifically for its own jet biofuel needs. That's just for flying, not for food or fuel for ground transportation or anything else. Also that article says that from 2009-2013 a $100 million effort was made to figure out how to get sufficient synthetic fuel from algae but they eventually gave up and went back to the drawing board.

ncmncm 4y ago
Biofuel is an obvious dead end. The future has no place for biofuel in any substantial amount.
- trashtester 4y ago
  Ethanol made from food (like corn) is a dead end. Firewood and derivatives have always had an important place in heating and cooking, and are likely to continue in that role for a while. Other types of biomass based hard fuels (from recycled garbage/waste, algae, etc) will most likely also play a role in electricity production and heating, but perhaps a small one (unless algae based biomass takes off). And for liquid fuels for transportation use, algae may also end up being a competitor to hydrogen when oil runs out. I remember there were a lot of companies working in that space 10 years ago, but then there was the oil price crash in 2015, and it seems many switched away. For instance algenol was positioning itself as a fuel company, but appear to have diversified: https://www.algenol.com/sustainable-products/?category=ndustrials https://www.algenol.com/sustainable-products/?category=ndust... If oil prices remain at current levels, though, algae may be only a few years away from scaling up to take a significant part of the market.
  - ncmncm 4y ago
    Firewood does not constitute a "substantial amount", by any industrial measure. It will continue being used, in decreasing amounts as very cheap efficient stove designs gradually penetrate the tropics. Growing algae occupies >10x the area of floating solar panels producing the same usable energy. Harvesting and processing algae costs >>1 orders of magnitude more than delivering electrical power via wire. The reasonable expectation is that transitions will be toward cheaper alternatives, with societal inertia acting to delay transition well beyond the point of obvious benefit. Thus, existing nukes will continue operating well after building solar + storage and then switching to that would be cheaper.
    - Gibbon1 4y ago
      I keep thinking the direction kitchens are headed in developing countries is a solar powered microwave, induction cooktop, and fridge. Does the lady of the house want to collect scraps of firewood and then cook in a hot already smokey kitchen or on a only heats the pan induction cooktop? Yeah.
      - ncmncm 4y ago
        The bottom billion people have no counter to put a microwave on. A solar panel, battery, microwave, induction cooktop, and fridge would cost several years' income preferentially spent (e.g) eating. Getting together $10 for a stove that needs 5x less firewood is a challenge. They need a new one every year because making one that lasts costs more.
    - trashtester 4y ago
      In Norway, biofuel (mostly firewood) accounts for a bit more energy used than coal and a little less than natural gas: https://www.nve.no/Media/7326/energibruk_energivar_2014-kopi.png https://www.nve.no/Media/7326/energibruk_energivar_2014-kopi... Here is similar data from Sweden: https://www.researchgate.net/profile/Egnell-Gustaf/publication/236656238/figure/fig6/AS:668498074275840@1536393769085/Production-of-energy-petajoule-from-biomass-peat-and-solid-waste-in-district-heating.png https://www.researchgate.net/profile/Egnell-Gustaf/publicati... Here is for the world, my understanding is that "Traditional Biomass" is mostly firewood there too: https://ourworldindata.org/exports/global-energy-substitution_v4_850x600.svg https://ourworldindata.org/exports/global-energy-substitutio...

ncmncm 4y ago

Biofuel is an obvious dead end. The future has no place for biofuel in any substantial amount.

trashtester 4y ago
Ethanol made from food (like corn) is a dead end. Firewood and derivatives have always had an important place in heating and cooking, and are likely to continue in that role for a while. Other types of biomass based hard fuels (from recycled garbage/waste, algae, etc) will most likely also play a role in electricity production and heating, but perhaps a small one (unless algae based biomass takes off). And for liquid fuels for transportation use, algae may also end up being a competitor to hydrogen when oil runs out. I remember there were a lot of companies working in that space 10 years ago, but then there was the oil price crash in 2015, and it seems many switched away. For instance algenol was positioning itself as a fuel company, but appear to have diversified: https://www.algenol.com/sustainable-products/?category=ndustrials https://www.algenol.com/sustainable-products/?category=ndust... If oil prices remain at current levels, though, algae may be only a few years away from scaling up to take a significant part of the market.
- ncmncm 4y ago
  Firewood does not constitute a "substantial amount", by any industrial measure. It will continue being used, in decreasing amounts as very cheap efficient stove designs gradually penetrate the tropics. Growing algae occupies >10x the area of floating solar panels producing the same usable energy. Harvesting and processing algae costs >>1 orders of magnitude more than delivering electrical power via wire. The reasonable expectation is that transitions will be toward cheaper alternatives, with societal inertia acting to delay transition well beyond the point of obvious benefit. Thus, existing nukes will continue operating well after building solar + storage and then switching to that would be cheaper.
  - Gibbon1 4y ago
    I keep thinking the direction kitchens are headed in developing countries is a solar powered microwave, induction cooktop, and fridge. Does the lady of the house want to collect scraps of firewood and then cook in a hot already smokey kitchen or on a only heats the pan induction cooktop? Yeah.
    - ncmncm 4y ago
      The bottom billion people have no counter to put a microwave on. A solar panel, battery, microwave, induction cooktop, and fridge would cost several years' income preferentially spent (e.g) eating. Getting together $10 for a stove that needs 5x less firewood is a challenge. They need a new one every year because making one that lasts costs more.
  - trashtester 4y ago
    In Norway, biofuel (mostly firewood) accounts for a bit more energy used than coal and a little less than natural gas: https://www.nve.no/Media/7326/energibruk_energivar_2014-kopi.png https://www.nve.no/Media/7326/energibruk_energivar_2014-kopi... Here is similar data from Sweden: https://www.researchgate.net/profile/Egnell-Gustaf/publication/236656238/figure/fig6/AS:668498074275840@1536393769085/Production-of-energy-petajoule-from-biomass-peat-and-solid-waste-in-district-heating.png https://www.researchgate.net/profile/Egnell-Gustaf/publicati... Here is for the world, my understanding is that "Traditional Biomass" is mostly firewood there too: https://ourworldindata.org/exports/global-energy-substitution_v4_850x600.svg https://ourworldindata.org/exports/global-energy-substitutio...