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thijson an hour ago

Brazil has had a pretty active program of converting cane sugar to ethanol for a while now.

https://en.wikipedia.org/wiki/Ethanol_fuel_in_Brazil

Sugar cane doesn't require replanting every year either, like corn does.

Plants are actually not a good converter of solar energy to chemical energy though. They capture a few percent of it.

Solar cells are able to capture about 10 times that, a much smaller footprint.

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jl6 an hour ago | parent [-]

Ethanol is quite a useful thing to have though, as a multi-season stable store of energy. We will need to synthesise it (or other synfuels and feedstocks), to fully transition away from fossil sources, and that 10x efficiency factor will be essential, as synthesis is highly energy-lossy.

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busterarm 39 minutes ago | parent [-]

> Ethanol is quite a useful thing to have though, as a multi-season stable store of energy.

Am I missing something? Ethanol is hydrophilic and hygroscopic. In concentrations used as a fuel (e.g., E85), it acts like a desiccant and spoils quickly. In a closed system this ends up with phase separation and the freed water causes engine corrosion.

I'm not sure we want people running a still or molecular sieve in their homes to deal with fixing long-term-stored ethanol.

	▲	bluGill 3 minutes ago \| parent [-]
		> In concentrations used as a fuel (e.g., E85), it acts like a desiccant and spoils quickly Citation needed. (hint you won't find one because it isn't true). Be careful here - this myth has been repeated enough that a search will find plenty of claims that don't check out. High concentration alcohol doesn't spoil. Even lower concentrations don't spoil, but they mix with poor quality gas that does spoil. Well when you get very low it will, but alcohol is poison to living things and so it won't spoil. (I'm not sure how ethanol stands up to UV - but we generally keep it in a tank so that isn't an issue) Ethanol will absorb water, but it doesn't take it out of the air anymore than anything else.