[mdf]

Yes, and the corn-based ethanol here is used for "feeding cars" that have combustion engines, i.e. it's already used exactly for energy production. The most recent Technology Connections video[1] quoted some numbers on this. All this land dedicated to disposable energy production could be dedicated to renewable energy production instead.

[1] https://www.youtube.com/watch?v=KtQ9nt2ZeGM

[marc_g]

Such an unfathomable waste when you put it in the context of “feeding cars”. I really appreciated the way this channel broke down this viewpoint. Made me want to finally get some panels for my balcony.

[aaomidi]

I feel like a chunk of the video was kinda pushing against the idea of just putting some solar on your roof.

[nosuchthing]

upwards of 60% of the ethanol used in combustion engines is completely wasted.

[riffraff]

What does "wasted" mean in this context?

[piva00]

It means that it doesn't generate any mechanical work, it's wasted as heat not captured for any other productive purpose (since waste heat can be useful in some contexts).

It's a measure of efficiency.

[weaksauce]

i assume heat since most energy in an ICE engine is wasted to heat (~60% wasted iirc)

[ytpete]

Your main point still stands, but aren't both of them renewable? Corn is a renewable resource, thus ethanol derived from it is too. It's just seemingly a much less efficient renewable fuel for powering a car compared to solar.

[mdf]

You're right. Perhaps clean would better capture the distinction in favor of solar in this context? Both corn and solar convert insolation to usable power with a short time between capture and use. Solar, on the other hand, is net negative when it comes to emissions, while the corn harvest is just burnt with the CO2 escaping back to the atmosphere. (And potentially, the solar panels can just be recycled back to new solar panels when they reach the end of their lifetimes. They're mostly aluminum and glass after all.)

[hedora]

Corn ethanol isn't a renewable resource. The land use of corn is a problem, but it's rounding error compared to the petroleum consumption of that industry, or the topsoil degradation.

To get one Joule out of corn ethanol, the US is burning more than one Joule of oil. This is probably the main reason corn subsidies are so popular politically. They serve the oil barons, mega farms, and big agriculture firms like Monsanto.

On top of that, modern farming practices degrade topsoil over time. It's gotten a bit better than the Dust Bowl days, but we're still burning through topsoil at crazy rates, and it is beyond current technology to manufacture new topsoil.

So, ethanol corn is like heating your house by dumping gas on a field and burning it to boil water. Then you carry the water inside. There only difference is the number of levels of indirection.

The last I checked, it took less energy to make a solar panel than the expected lifetime output of the panel. So, at least you can power solar factories (in theory) with solar. There's still the problem of the environmental impact of rare earth refining, but at least it's a second order issue, and not like the first order issues corn ethanol has.

(Note that not all ethanol farming is as dumb as what the US does: For example, Brazil has had a net positive energy industry from sugar ethanol for a while. They "just" have to clear cut the rain forest to replace the farmland that house of cards is destroying.)

[pfdietz]

> The last I checked, it took less energy to make a solar panel than the expected lifetime output of the panel.

An order of magnitude less.

[afiori]

Even ignoring all non renewable consumption in growing the corn to be turned into ethanol it is still going towards an incredibly polluting infrastructure.

While each solar panel is a small step towards more and better electrification