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Don't throw biofuels out, there are plenty of fuels you can make from the parts of plants that we do not eat. Corn stover, walnut shells, bigasse, olive pits,

Don't throw biofuels out, there are plenty of fuels you can make from the parts of plants that we do not eat. Corn stover, walnut shells, bigasse, olive pits, etc. are all unused components that can be converted into fuel sources through gasification, anaerobic digestion, fermentation, etc. into usable fuel. Many times it's better than letting these leftovers rot in the fields and release methane into the atmosphere. Honestly, I'd like to see some of the excess solar energy put into up converting such waste streams into storable fuels that can be used as denser alternatives to batteries when needed (winter heating, air travel, etc.).

gamblor956 2y ago
Also, biofuels have >10x the energy per unit of mass compared compared to even the best batteries in the lab (and some sources put that at closer to 100x). There are a lot of use cases for biofuels (as a replacement to petroleum) that batteries can't come close to handling. Converting the waste stream from agrivoltaics into biofuels appears to be the best option: reduced land for "energy" crops, increased output for food crops, and biofuel to replace petroleum.
- corysama 2y ago
  Converting waste to fuel is great. Meanwhile, I’m pretty excited about this project to make it cheap and easy to convert solar power to liquid fuel. Starting with carbon-neutral natural gas. https://youtu.be/cRg1ZVwttNU?si=JWK5ZUdlNWooNYtt https://youtu.be/cRg1ZVwttNU?si=JWK5ZUdlNWooNYtt
- 542354234235 2y ago
  I feel like hydrogen is the answer to fossil fuels, not biofuels. Battery electric vehicles (BEV) are great for personal vehicles. But for heavy transport, batteries just don’t work. They are too heavy and can’t be “refueled” quickly for continuous operations. We are already having issues with having too much solar power and not enough demand. We could be load shedding that by using it to create hydrogen. We have gas stations everywhere because individuals need that kind of convenience to operate comfortably. BEVs have the same infrastructure in that every outlet is a charging station. While the barrier to entry for hydrogen is too high for personal vehicles, the logistic hub nature of heavy transport would be much easier to convert, using hydrogen storage/filling stations at strategic location to support hydrogen powered semi-trucks, local delivery trucks, busses, etc.
  - nanomonkey 2y ago
    The most effective way to store hydrogen as a fuel is in hydrocarbons. Hydrogen gas, as itself, seems at first blush, to be great because it combusts into water, but it doesn't store as efficiently or safely as hydrocarbons. The wax candles on your table don't spontaneously combust when you touch them with a static charged finger. The fact that plants already will produce hydrocarbons for us without much over sight only makes things easier. Now that being said, our current natural gas infrastructure can accommodate something like 10% hydrogen gas, so it would be great if we could store extra solar electricity within our own pipelines by generating hydrogen gas, back feeding it into the lines, and then deplete it later, with a molecular sieve to pull out hydrogen gas alone, or burn it with the methane.
    - 542354234235 2y ago
      I understand what you are saying but I disagree. Yes, hydrogen is not as energy dense and has different safety issues, but I think it is overall still the better long term option. Biofuel is not scalable in the same way as green hydrogen. The more biofuel we produce, the more agricultural land it competes for that could be used for food, timber or even carbon capture vegetation. The more solar and wind we add to the gird, the more load shedding issues we will have and the more opportunity we have to convert that to hydrogen. ICE engines running on biofuel are about as efficient as they are going to get, whereas hydrogen power is a fairly immature technology and has a lot of potential efficiency gains as the technology matures. I think biofuel from waste products will still be useful for certain applications, for instance in medium and long haul aviation, where the energy density of hydrogen would pose a significant challenge. But biofuels are just not scalable to the levels required for global demand vs land requirements. Using biofuels just for aviation would require cultivating land the size of Texas, California, and Florida. [0][1][2] It is just not feasible to scale as a primary fuel in a fossil fueless future. Hydrogen can scale with electrical capacity, which can come from nuclear, solar, wind, geothermal, hydro, etc. [0] back of the napkin math/conversions based on 2 and 3 [1] https://its.ucdavis.edu/blog-post/making-policy-in-the-absence-of-certainty-biofuels-and-land-use-change/ https://its.ucdavis.edu/blog-post/making-policy-in-the-absen... [2] https://www.theglobaleconomy.com/USA/jet_fuel_consumption/ https://www.theglobaleconomy.com/USA/jet_fuel_consumption/

gamblor956 2y ago

Also, biofuels have >10x the energy per unit of mass compared compared to even the best batteries in the lab (and some sources put that at closer to 100x). There are a lot of use cases for biofuels (as a replacement to petroleum) that batteries can't come close to handling. Converting the waste stream from agrivoltaics into biofuels appears to be the best option: reduced land for "energy" crops, increased output for food crops, and biofuel to replace petroleum.

corysama 2y ago
Converting waste to fuel is great. Meanwhile, I’m pretty excited about this project to make it cheap and easy to convert solar power to liquid fuel. Starting with carbon-neutral natural gas. https://youtu.be/cRg1ZVwttNU?si=JWK5ZUdlNWooNYtt https://youtu.be/cRg1ZVwttNU?si=JWK5ZUdlNWooNYtt
542354234235 2y ago
I feel like hydrogen is the answer to fossil fuels, not biofuels. Battery electric vehicles (BEV) are great for personal vehicles. But for heavy transport, batteries just don’t work. They are too heavy and can’t be “refueled” quickly for continuous operations. We are already having issues with having too much solar power and not enough demand. We could be load shedding that by using it to create hydrogen. We have gas stations everywhere because individuals need that kind of convenience to operate comfortably. BEVs have the same infrastructure in that every outlet is a charging station. While the barrier to entry for hydrogen is too high for personal vehicles, the logistic hub nature of heavy transport would be much easier to convert, using hydrogen storage/filling stations at strategic location to support hydrogen powered semi-trucks, local delivery trucks, busses, etc.
- nanomonkey 2y ago
  The most effective way to store hydrogen as a fuel is in hydrocarbons. Hydrogen gas, as itself, seems at first blush, to be great because it combusts into water, but it doesn't store as efficiently or safely as hydrocarbons. The wax candles on your table don't spontaneously combust when you touch them with a static charged finger. The fact that plants already will produce hydrocarbons for us without much over sight only makes things easier. Now that being said, our current natural gas infrastructure can accommodate something like 10% hydrogen gas, so it would be great if we could store extra solar electricity within our own pipelines by generating hydrogen gas, back feeding it into the lines, and then deplete it later, with a molecular sieve to pull out hydrogen gas alone, or burn it with the methane.
  - 542354234235 2y ago
    I understand what you are saying but I disagree. Yes, hydrogen is not as energy dense and has different safety issues, but I think it is overall still the better long term option. Biofuel is not scalable in the same way as green hydrogen. The more biofuel we produce, the more agricultural land it competes for that could be used for food, timber or even carbon capture vegetation. The more solar and wind we add to the gird, the more load shedding issues we will have and the more opportunity we have to convert that to hydrogen. ICE engines running on biofuel are about as efficient as they are going to get, whereas hydrogen power is a fairly immature technology and has a lot of potential efficiency gains as the technology matures. I think biofuel from waste products will still be useful for certain applications, for instance in medium and long haul aviation, where the energy density of hydrogen would pose a significant challenge. But biofuels are just not scalable to the levels required for global demand vs land requirements. Using biofuels just for aviation would require cultivating land the size of Texas, California, and Florida. [0][1][2] It is just not feasible to scale as a primary fuel in a fossil fueless future. Hydrogen can scale with electrical capacity, which can come from nuclear, solar, wind, geothermal, hydro, etc. [0] back of the napkin math/conversions based on 2 and 3 [1] https://its.ucdavis.edu/blog-post/making-policy-in-the-absence-of-certainty-biofuels-and-land-use-change/ https://its.ucdavis.edu/blog-post/making-policy-in-the-absen... [2] https://www.theglobaleconomy.com/USA/jet_fuel_consumption/ https://www.theglobaleconomy.com/USA/jet_fuel_consumption/