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I've been thinking about this. Gasoline is a much better form of energy storage than lithium-ion. Perhaps if we mandated that gasoline (or a similar fuel) be sy

I've been thinking about this. Gasoline is a much better form of energy storage than lithium-ion. Perhaps if we mandated that gasoline (or a similar fuel) be synthesized from carbon extracted from the air instead of dug out of the ground, we'd be able to get, say, carbon-neutral flight with current technology.

kabouseng 7y ago
You should read up on thermodynamic laws...
- rcxdude 7y ago
  Thermodynamics is OK with this. It's not a way of producing the energy, just a means of storing transporting it which has some advantages over batteries (that said, energy in vs energy out efficiency is not one of them right now)
  - greatpatton 7y ago
    Which is really bad as ICE have a very poor yield... The efficiency of the global solution (transforming carbon to gas -> gas to mechanical energy) will be under 20%...
    - jerf 7y ago
      On the other hand, you tend to get energy -> liquid carbon fuel -> consumer, where once the fuel is liquid it's cheap to move around without much further loss, whereas with electricity you tend to get generator -> AC to DC -> transmission -> AC to DC -> lithium ion battery. Each step is individually more efficient, but the whole is not necessarily obviously worse than liquid fuels. Electricity does have a lot more optimization opportunity, though, whereas those liquid fuel processes are pretty much at their optimum already. A local solar panel DC'ing straight into your car's batteries is going to be pretty good compared to the "generic" pipeline I gave you above. (On the other hand, it can go the other way, too; if your electricity notionally passed through something like a gravity storage step, you lost more there too.) Although from what I've gathered from looking at solar setups, most local solar setups won't actually do that, so it's an optimization yet to be done rather than something all roof-mounted solar panels already do.
dmurray 7y ago
A YC company doing just this was the top story on HN just a few days ago https://news.ycombinator.com/item?id=19842240 https://news.ycombinator.com/item?id=19842240
notabee 7y ago
Carbon neutral is not enough at this point to prevent a great deal of climate change. It just extends the timeline enough for us to figure out something better. Negative emissions technology is going to be necessary because the sheer quantity of excess carbon in the air is already far greater than what any of the natural sinks (which are also quite saturated already) will draw down in any reasonable timeframe. We also need at least a fighting chance if and when the natural feedbacks kick in. I encourage you to look up the number of metric tonnes of carbon debt we have above pre-industrial baseline and play around with the EPA equivalencies calculator. https://www.epa.gov/energy/greenhouse-gas-equivalencies-calculator https://www.epa.gov/energy/greenhouse-gas-equivalencies-calc...

kabouseng 7y ago

You should read up on thermodynamic laws...

rcxdude 7y ago
Thermodynamics is OK with this. It's not a way of producing the energy, just a means of storing transporting it which has some advantages over batteries (that said, energy in vs energy out efficiency is not one of them right now)
- greatpatton 7y ago
  Which is really bad as ICE have a very poor yield... The efficiency of the global solution (transforming carbon to gas -> gas to mechanical energy) will be under 20%...
  - jerf 7y ago
    On the other hand, you tend to get energy -> liquid carbon fuel -> consumer, where once the fuel is liquid it's cheap to move around without much further loss, whereas with electricity you tend to get generator -> AC to DC -> transmission -> AC to DC -> lithium ion battery. Each step is individually more efficient, but the whole is not necessarily obviously worse than liquid fuels. Electricity does have a lot more optimization opportunity, though, whereas those liquid fuel processes are pretty much at their optimum already. A local solar panel DC'ing straight into your car's batteries is going to be pretty good compared to the "generic" pipeline I gave you above. (On the other hand, it can go the other way, too; if your electricity notionally passed through something like a gravity storage step, you lost more there too.) Although from what I've gathered from looking at solar setups, most local solar setups won't actually do that, so it's an optimization yet to be done rather than something all roof-mounted solar panels already do.

dmurray 7y ago

A YC company doing just this was the top story on HN just a few days ago https://news.ycombinator.com/item?id=19842240 https://news.ycombinator.com/item?id=19842240

notabee 7y ago

Carbon neutral is not enough at this point to prevent a great deal of climate change. It just extends the timeline enough for us to figure out something better. Negative emissions technology is going to be necessary because the sheer quantity of excess carbon in the air is already far greater than what any of the natural sinks (which are also quite saturated already) will draw down in any reasonable timeframe. We also need at least a fighting chance if and when the natural feedbacks kick in. I encourage you to look up the number of metric tonnes of carbon debt we have above pre-industrial baseline and play around with the EPA equivalencies calculator. https://www.epa.gov/energy/greenhouse-gas-equivalencies-calculator https://www.epa.gov/energy/greenhouse-gas-equivalencies-calc...