Comment on New York Startup Builds Fridge-Sized Machine That Can Turn Air Into Gasoline
Womble@piefed.world 22 hours ago
I wonder is a scaled up version of this could work for grid-scale medium length storage. Smoothing out weeks of dunkleflaute is the main blocker to going to a primarily renewable grid. Gasoline is a lot easier to store than hydrogen and large scale gasoline generators should get close to the efficiency of natural gas peaker plants.
Grid scale storage doesn’t strike me as an area of application where high energy density is important, so wouldn’t batteries with less conversion loss do an overall better job? I think grid scale Lithium-ion battery stores have become somewhat common.
I’d see gasoline from CO2 capture of interest more for airplanes, drones, ships, maybe even certain modes of long haul terrestrial transport where weight and volume is important.
I could see this being useful in places where day/night cycle is skewed to prolonged periods of each. Or perhaps holding excess power from summer into winter since days are so much shorter.
But yeah, this doesn’t really seem like the best way to store grid power.
jj4211@lemmy.world 20 hours ago
Problem is that the efficiency is on the ground here.
The same energy that might get an EV 200 miles instead produces a single gallon of gasoline, to get a sense for the relative value of the efficiency.
Womble@piefed.world 19 hours ago
Sure, but you cant store that electricity as electricity. IMO this is most interesting as a energy storage technology, so the comparison isnt what that gasoline would do in an ICE car compared to an EV, its to what it would cost compared to battery storage (or compressed air or whatever other technology) to store a few weeks of output on the order of months.
Rivalarrival@lemmy.today 16 hours ago
Liquid fuels have a couple advantages in certain scenarios. Aircraft, for example. The energy density of liquid fuels is considerably higher than batteries. Aircraft only take on as much fuel as they need to safely reach their destination. They takeoff with more weight than they can safely land, burning off fuel weight throughout their flight until they are light enough to land. Dumping fuel overboard to get down to landing weight in an emergency.
Switch these aircraft over to batteries, and their landing weight is the same as their takeoff weight. They carry the same “fuel” weight for a regional flight as they do for a maxinum-range flight.
jj4211@lemmy.world 13 hours ago
Well, I don’t know if the reason given is that significant, they’d just plan around the fixed weight. The issue being the energy per unit volume/weight being so far behind hydrocarbons that some applications do demand it.
So while stationary/grid applications may lean battery since size/weight hardly matters, and EVs are debatable good enough for many scenarios, I will grant that for aircraft, boats, and some heavy equipment it’s hard to beat hydrocarbons.
Unfortunately, on that front it has to compete with extracted hydrocarbons and doesn’t seem like it can compete as yet. It however may give hope for a more resource constrained future that the battery-hostile scenarios may still be fulfilled in a sustainable way, just at higher relative expense than today. Or they iterate on their processes to have cheaper equipment and/or increased efficiency to come closer to competitive with extracted hydrocarbons. Or a viable thing to reference for some governments mandating sustainably sourced hydrocarbons when they are really needed.
Rivalarrival@lemmy.today 8 hours ago
There is another major advantage…
There is a major problem with solar and wind. Daily and seasonal variation in solar flux and wind speed forces us to size our renewable generators based on their minimum expected output. We have to install enough solar panels that we can supply our needs with only low-angle sunlight on short, winter days. But we won’t do that, because that many solar panels are about four times what we need to supply our needs on long summer days. With that much oversupply on the grid, generators won’t be able to command sufficient revenue to justify that number of panels. But we need that number of panels to supply our winter demands.
We can match a large percentage of daily variation with sufficient grid-scale storage. We fill up reservoirs with our excess mid-day production, and run that water through hydropower plants overnight. But it is simply not possible to expand storage sufficiently to match seasonal variation.
If we build out sufficient solar generation capacity to meet winter demand, we don’t need seasonal storage. The problem we have becomes one of seasonal oversupply. The solution to that problem is an increase in demand. We need energy-intensive products that can be brought online in daylight hours from spring to autumn, then shut down for winter.
Producing net carbon-zero fuels could very well create part of the demand needed to justify massive expansion of our renewable power grid.
ozymandias117@lemmy.world 17 hours ago
Honestly, I would have expected worse than that
jj4211@lemmy.world 12 hours ago
At least taking their figures at face value, about 75kwh to generate a gallon of gas, and let’s say 67 kwh to get a an EV 200 miles (assuming some losses between the generation and the actual battery capacity, and 3 miles/kwh which is on the low-ish end of EVs, but realistically close). The most aggressive hybrids getting 50 mpg so we end up with it being about 4x worse than charging an EV with that energy source.
At least at residential rates where I live, that’s about $10, so it would only really make sense when gas gets to $10/gallon, otherwise, go to the pump for the fossil fuel. That’s ignoring the cost of the station itself.
So maybe nearer than one might imagine, but still highly impractical. Maybe if they doubled the efficiency and gas eeks up without residential electricity rates going up…
But all this is assuming it will work exactly as well as they say it is, and I’ve learned to have a healthy dose of skepticism… Here though I can be as optimistic as they like and it’s still a tough sell…