A fascinating takeaway from that video for me... If you take the US land that is dedicated to growing corn for ethanol that is put in gasoline, and replace all the corn on that land with solar panels, how much energy would it produce? Twice today's total electrical generation in the US, from all sources. And that's in the corn belt, which is far from ideal for solar. It would be billions of panels, but it's a pretty interesting perspective on the questions about the land use requirements of solar.

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nozzlegear 2 days ago | parent | next [-]

Another genuine question: I wonder how that would change the climate in those areas. I live in Iowa and "corn sweat" is a thing that never fails to make several weeks of summer completely unbearable.

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pfdietz 2 days ago | parent | prev | next [-]

It shows that bioenergy is very land inefficient.

There was a book about renewable energy in Britain about 17 years ago, "Sustainable Energy -- Without the Hot Air" that tried to make the argument that renewables could not power Britain, there wasn't enough land. But if you drilled down, this conclusion was due to use of biofuels.

	▲	_aavaa_ a day ago \| parent [-]
		The significant problem with that book is that it commits the primary energy fallacy. It sees that we need X GWh of chemical energy from fuels and says we have to replace it with X GWh of electricity. Which is of course completely wrong since it ignores the efficiencies of the processes and conflates two different things simply because they are measured in the same units.

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adrianN a day ago | parent | prev | next [-]

Germany uses less land for energy crops and is further north, but still could satisfy most of its electricity needs if it replaced the plants with solar panels.

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johng 2 days ago | parent | prev [-]

Genuine question: How much energy, minerals, transportation, manufacturing, etc, etc. goes into making the panels. How much are the panels going to make back percentage wise in it's lifetime vs. the cost to make and transport, install?

Corn kind of reproduces itself every year (If you don't get the GMO kind), so you only need natural resources to continue to grow it right? Water, sunlight and labor?

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MrDrMcCoy 2 days ago | parent | next [-]

He goes over that in the video. It's long, but very much worth watching.

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tfyoung 2 days ago | parent | prev [-]

> Corn kind of reproduces itself every year (If you don't get the GMO kind), so you only need natural resources to continue to grow it right? Water, sunlight and labor?

At industrial scale, it has a huge petro-chemical fertiliser input.

	▲	pfdietz 2 days ago \| parent [-]
		Total energy input to agriculture in the US is less than 2% of total energy consumption. So "huge" there has to be taken in context. All the energy inputs to agriculture could be replaced with non-fossil inputs. Fertilizer in particular needs hydrogen to make ammonia, but that can be produced from non-fossil sources.