This is a bit of a smokescreen--pretending like aviation will soon be sustainable is a way of hiding just how unsustainable it is right now. Of course, this is an upper-middle-class strategy, as it is the wealthy who mainly do all the flying, such as Lloyd. All those folks like to fly without accounting or paying for their excess pollution, such as with valid offsets. Indeed, the science world doesn't spend much time figuring out the added warming from high-altitude emissions, which may be very significant. Those same scientists also love to fly frequently with no penalties for their pollution. It's a big blind spot, or an intentional looking away.
Some useful statistics to include in this subject would be: the energy cost of energy for making those sustainable fuels (i.e. the "energy returned for energy invested. For ethanol, this might be negative but there are some studies that have a 1.3:1 energy return. These studies rely on a lot of assumptions). Also, simply stating the cost of this fuel would show its problems. I've read it's 3-5x the cost of jet fuel, which would raise the cost of flying a similar amount.
But Lloyd is right in showing the system implications of trying to grow and process this type of fuel.
Wouldn't surprise me if there was military money behind some of this. There may come a time when the remaining oil is so difficult to extract that this technology would actually become cheaper than trying to coax the oil out of rock and such. The elite will be flying long after the rest of us but the last things humanity launches into the sky will probably be fighter planes and satellites.
I don't agree with you on a lot of things, but I agree here, to date it a total ruse. Richard Branson is a marketer and BS and no engineer. SAF isn't necessarily impossible if using a non-depletable feedstock and a LOT of energy, but its going to be very expensive and not available at scale for a long time. It will very likely need nuclear energy for process heat, at scale. In some sense it is the only solution to the aviation emissions problem, H2 fuel and electric aviation aren't solutions.
It's like I've said, if the climate emergency is real then let's do something about it (like those of us with land paying us to grow tree, and not having to rent the land from the state (taxes)), not feel good projects like this, but something real.
Instead we get politicians like John Kerry, Al Gore, Joe Biden and the ilk stumping for reduced carbon emissions, rather than leading by example. In fact if you look at their lifestyles one would conclude that these politicians are chest-thumping for dollars.
This is a bit of a smokescreen--pretending like aviation will soon be sustainable is a way of hiding just how unsustainable it is right now. Of course, this is an upper-middle-class strategy, as it is the wealthy who mainly do all the flying, such as Lloyd. All those folks like to fly without accounting or paying for their excess pollution, such as with valid offsets. Indeed, the science world doesn't spend much time figuring out the added warming from high-altitude emissions, which may be very significant. Those same scientists also love to fly frequently with no penalties for their pollution. It's a big blind spot, or an intentional looking away.
Some useful statistics to include in this subject would be: the energy cost of energy for making those sustainable fuels (i.e. the "energy returned for energy invested. For ethanol, this might be negative but there are some studies that have a 1.3:1 energy return. These studies rely on a lot of assumptions). Also, simply stating the cost of this fuel would show its problems. I've read it's 3-5x the cost of jet fuel, which would raise the cost of flying a similar amount.
But Lloyd is right in showing the system implications of trying to grow and process this type of fuel.
Thanks for sharing, what a story of greenwashing!
Wouldn't surprise me if there was military money behind some of this. There may come a time when the remaining oil is so difficult to extract that this technology would actually become cheaper than trying to coax the oil out of rock and such. The elite will be flying long after the rest of us but the last things humanity launches into the sky will probably be fighter planes and satellites.
I don't agree with you on a lot of things, but I agree here, to date it a total ruse. Richard Branson is a marketer and BS and no engineer. SAF isn't necessarily impossible if using a non-depletable feedstock and a LOT of energy, but its going to be very expensive and not available at scale for a long time. It will very likely need nuclear energy for process heat, at scale. In some sense it is the only solution to the aviation emissions problem, H2 fuel and electric aviation aren't solutions.
It's like I've said, if the climate emergency is real then let's do something about it (like those of us with land paying us to grow tree, and not having to rent the land from the state (taxes)), not feel good projects like this, but something real.
Instead we get politicians like John Kerry, Al Gore, Joe Biden and the ilk stumping for reduced carbon emissions, rather than leading by example. In fact if you look at their lifestyles one would conclude that these politicians are chest-thumping for dollars.