4 ms·

OK, I was curious so just did some math. Gasoline has energy density of 34.2 MJ/L, or 9.5 kWh/L[1]. Its retail price is about $3/gallon, or $0.8/L. So, assum

OK, I was curious so just did some math. Gasoline has energy density of 34.2 MJ/L, or 9.5 kWh/L[1]. Its retail price is about $3/gallon, or $0.8/L. So, assuming 100% efficiency, the energy source for making gasoline should be ~$0.084/kWh to break even. Energy Information Administration (EIA) estimates 2022's solar/wind generation cost at $73.7 and $55.8 per MWh [2], or $0.0737 and $0.0558 per kWh. Assuming wind power, gasoline generation has to be ~66% efficient to break even, which is (I guess) not physically impossible, but an incredible engineering challenge. ...and that's assuming retail price. I'm not an energy expert, but [3] seems to say that gasoline's current bulk price is ~$1.5/gallon, which pushes the technology firmly on the side of losing money. [1] https://en.wikipedia.org/wiki/Energy_density https://en.wikipedia.org/wiki/Energy_density [2] https://en.wikipedia.org/wiki/Cost_of_electricity_by_source#Energy_Information_Administration https://en.wikipedia.org/wiki/Cost_of_electricity_by_source#... [3] https://www.eia.gov/dnav/pet/hist/LeafHandler.ashx?n=pet&s=ema_epm0_pwg_nus_dpg&f=m https://www.eia.gov/dnav/pet/hist/LeafHandler.ashx?n=pet&s=e...

ajross 8y ago
If there were realistic competitors for fossil fuels, we wouldn't be worrying about a climate crisis in the first place. Nothing is going to compete with pumping fuel out of the ground, and it never will. Any realistic scenario starts with some kind of regulation on carbon extraction and then worries about the economics of replacements. And technologies like this one that claim to be within a factor of two seem very worth investigating. Whether it works or not, who knows.
- ip26 8y ago
  Pumping oil has some big advantages, but procuring & distributing refined gasoline, propane, etc from crude is not exactly trivial or free. There might be political advantages to having a proven process with proven cost. $40/ton carbon tax is awfully arbitrary... Until carbon can be captured for $40/ton.
- yongjik 8y ago
  But all these renewable energy sources are already competing with fossil fuels and sometimes even winning! And even with these sources you can't make synthetic gasoline economically viable. That leads to the question: if one can sell synthetic gasoline at profit, they must have a really cheap source of energy, in which case why go through the trouble of gasoline instead of selling the energy directly?
  - slfnflctd 8y ago
    Imagine a remote military outpost-- the only supply chain access is limited & expensive. Having vehicles that can go from empty to full in seconds by fuel you pulled out of the air yourself with solar panels last week could be much more valuable than using those same solar panels to charge an electric vehicle (or a battery bank and then later a vehicle). Certain types of municipal or commercial fleets also have quick-refuel requirements. There are likely a few other limitations to current electrics that ICE engines don't have, as well.
jillesvangurp 8y ago
A couple of issues with your numbers. 1) you are basing yourself on average grid prices in the US and the local cost of petrol. You should instead be looking at dedicated clean energy installations that you'd be using 100% for fuel production in places where that are optimal/ideal to do so. 2) those petrol costs exclude taxation that would apply in e.g. the EU. Current prices in e.g. Germany for a liter of petrol are around 1.20 euros. Much more in e.g. the Netherlands, which taxes much more aggressively. Bottom line is that petrol is really expensive already in a lot of places and not likely to get cheaper when people are getting worried about global warming. So, petrol is a lot more expensive in a lot of places and clean energy is a lot less expensive in a lot of places. I'd say, we have about a 3-6x margin of error here. And that's just at the current rates. Luckily, clean energy cost is dropping rapidly and projected to continue to do so for quite some time. The EIA's estimates appear to be averages for the US in the context of grid electricity. There are already places in the world where those prices are far lower (i.e. by magnitudes) and projected to drop even further. Solar grid prices in places like e.g. Dubai, would be something like 0.024$/kwh. That number might already be obsolete. So, well below what you seem to consider the break even point. Even at 30% efficiency (as opposed to your 100%) this is starting to look pretty feasible. The Prometheus founder seems to be suggesting 60% is the efficiency rate elsewhere in this thread. Boom economically viable right now in Dubai. A region well known for its dependence on crude oil exports. How cheap would this have to get for them to not bother pumping oil out of the ground anymore at all? Incidentally, they are already using solar to power those pumps (burning oil/gas to do the same is already uneconomical). They could be producing petrol with that energy directly instead. You have to wonder at what point that starts making more sense and what that would do the global oil/gas markets. I think it's more a question of volumes/scale than cost. So, this is not "an incredible engineering challenge" but a simple matter of how soon the cost lines cross and economies of scale. Depending on your point of view, this may already be cheap enough right now. The point is kind of moot because by the time production is ramped up to the point where this has meaningful impact, energy cost per kwh will have come down much further whereas crude oil and associated taxes are not anywhere near as likely to go down or even stay the same. I'm guessing ramping this up will take quite a bit of time (2-3 decades?). In the process, economies of scale, will impact the pricing some more.
- 8y ago

ajross 8y ago

If there were realistic competitors for fossil fuels, we wouldn't be worrying about a climate crisis in the first place. Nothing is going to compete with pumping fuel out of the ground, and it never will. Any realistic scenario starts with some kind of regulation on carbon extraction and then worries about the economics of replacements. And technologies like this one that claim to be within a factor of two seem very worth investigating. Whether it works or not, who knows.

ip26 8y ago
Pumping oil has some big advantages, but procuring & distributing refined gasoline, propane, etc from crude is not exactly trivial or free. There might be political advantages to having a proven process with proven cost. $40/ton carbon tax is awfully arbitrary... Until carbon can be captured for $40/ton.
yongjik 8y ago
But all these renewable energy sources are already competing with fossil fuels and sometimes even winning! And even with these sources you can't make synthetic gasoline economically viable. That leads to the question: if one can sell synthetic gasoline at profit, they must have a really cheap source of energy, in which case why go through the trouble of gasoline instead of selling the energy directly?
- slfnflctd 8y ago
  Imagine a remote military outpost-- the only supply chain access is limited & expensive. Having vehicles that can go from empty to full in seconds by fuel you pulled out of the air yourself with solar panels last week could be much more valuable than using those same solar panels to charge an electric vehicle (or a battery bank and then later a vehicle). Certain types of municipal or commercial fleets also have quick-refuel requirements. There are likely a few other limitations to current electrics that ICE engines don't have, as well.

jillesvangurp 8y ago

A couple of issues with your numbers. 1) you are basing yourself on average grid prices in the US and the local cost of petrol. You should instead be looking at dedicated clean energy installations that you'd be using 100% for fuel production in places where that are optimal/ideal to do so. 2) those petrol costs exclude taxation that would apply in e.g. the EU. Current prices in e.g. Germany for a liter of petrol are around 1.20 euros. Much more in e.g. the Netherlands, which taxes much more aggressively. Bottom line is that petrol is really expensive already in a lot of places and not likely to get cheaper when people are getting worried about global warming. So, petrol is a lot more expensive in a lot of places and clean energy is a lot less expensive in a lot of places. I'd say, we have about a 3-6x margin of error here. And that's just at the current rates. Luckily, clean energy cost is dropping rapidly and projected to continue to do so for quite some time. The EIA's estimates appear to be averages for the US in the context of grid electricity. There are already places in the world where those prices are far lower (i.e. by magnitudes) and projected to drop even further. Solar grid prices in places like e.g. Dubai, would be something like 0.024$/kwh. That number might already be obsolete. So, well below what you seem to consider the break even point. Even at 30% efficiency (as opposed to your 100%) this is starting to look pretty feasible. The Prometheus founder seems to be suggesting 60% is the efficiency rate elsewhere in this thread. Boom economically viable right now in Dubai. A region well known for its dependence on crude oil exports. How cheap would this have to get for them to not bother pumping oil out of the ground anymore at all? Incidentally, they are already using solar to power those pumps (burning oil/gas to do the same is already uneconomical). They could be producing petrol with that energy directly instead. You have to wonder at what point that starts making more sense and what that would do the global oil/gas markets. I think it's more a question of volumes/scale than cost. So, this is not "an incredible engineering challenge" but a simple matter of how soon the cost lines cross and economies of scale. Depending on your point of view, this may already be cheap enough right now. The point is kind of moot because by the time production is ramped up to the point where this has meaningful impact, energy cost per kwh will have come down much further whereas crude oil and associated taxes are not anywhere near as likely to go down or even stay the same. I'm guessing ramping this up will take quite a bit of time (2-3 decades?). In the process, economies of scale, will impact the pricing some more.

8y ago