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Gibbon1 | on: Semi-transparent, colored cadmium telluride photovoltaic panels in agrivoltaics
Very conservatively solar produces 30-50 times are much energy per acre as corn ethanol. I think if you consider just the ethanol to mix with gas vs charging an electric car with solar it's a 100 times more.

Something around 2500W of solar can provide enough energy to drive an EV 12,000 miles a year.

When it comes to zoning. The state should require offices to install chargers for employees cars when the solar share of electricity generation is highest.

AnonymousPlanet | parent | next
I agree, but I always wonder: where do you store the energy from solar? Ethanol just goes into a boring tank. Electricity is expensive to store, especially at the scale we're talking. Carrying via cable all the way from the farms to the industrial centers is expensive aswell.
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sdenton4 | root | parent | next
"[lithium ion battery prices] declined by more than 99%. In 1991, lithium-ion batteries cost around $9,200 per kilowatt-hour — 33 years later, they cost just $78."

https://ourworldindata.org/battery-price-decline

The price of battery storage is dropping exponentially, just as the price of solar power has. Eventually, the price becomes pretty trivial.

AnonymousPlanet | root | parent
The scale we're talking here is not just a shack with a couple of batteries. Even with low prices of today, we're talking several millions of investment for 10 MWh.

> The price of battery storage is dropping exponentially

We're at the flat end of things. Even if this trend continues, there won't be another 99% reduction coming.

> Eventually, the price becomes pretty trivial.

Only if you can scale manufacturing and materials the same way. Hopefully not with Lithium, because that's just not abundant enough.

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shagie | root | parent | next
> Electricity is expensive to store, especially at the scale we're talking.

An old XKCD what if: https://what-if.xkcd.com/128/

> What in my pocket actually contains more energy, my Zippo or my smartphone? What would be the best way of getting the energy from one to the other? And since I am already feeling like Bilbo in this one, is there anything else in my pocket that would have unexpected amounts of stored energy?

Which in part had:

> A container of butane the size of a phone battery could, in principle, power the phone about 13 times longer than the battery itself could. The obvious question, then, is "why doesn't my phone run on propane?"

...

Also http://www.jefflewis.net/blog/2012/01/how_much_gas_to_charge...

And while that's based on a study from Exon (no longer accessible)... but the math part is math no matter who does the math.

> So, the claim that there's enough energy in a gallon of gas to charge an iPhone every day for 20 years seems pretty reasonable (in reality, when you look at the efficiencies, you won't be able to put all that energy into charging the phone).

> An iPhone may not be huge, but 20 years is a pretty long time. It really just goes to show how much energy gasoline contains, and why it's so useful for powering vehicles.

jazzyjackson | root | parent
Toshiba pioneered a portable fuel cell dock for their laptops in 2003, apparently 100cc of methanol produced 12W for 10 hours. A zippo has just a couple cc of fuel. I do wonder how much the technology has advanced in 20 years.

https://www.global.toshiba/ww/news/corporate/2003/03/pr0501....

kibwen | root | parent | next
Ethanol goes into a boring tank, but to be useful that boring tank has to be pumped into a tanker and driven, using more fuel, to somewhere it can be distributed. That's way more energy-intensive than running a cable, so forget storage, just run the cable and let the grid operator take care of the storage at utility-scale.
AnonymousPlanet | root | parent
The cost for the storage still exists and has to be paid by someone. And extending the power grid at this scale is a several decade long undertaking. These things don't pop up by sheer willpower.
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Someone | parent | next
> Very conservatively solar produces 30-50 times are much energy per acre as corn ethanol.

31 times, according to https://www.pnas.org/doi/full/10.1073/pnas.2501605122. That’s from pril 2025, so possibly slightly outdated, but I don’t think technical advances can have pushed that to “very conservatively 30-50 times as much”.

Depending on what you want to do with the energy, you are right it can easily be 50 times as much of useful work. For example, ICE cars turn over 80% of that energy into heat, electric cars less than 20%. That’s a factor of 4 in conversion ratio.

laxisOp | parent | next
I cant fully trust your numbers but its just feels good if these are accurate.
foobiekr | parent | next
I had never bothered to calculate the miles-per-year before. My very, very modest rooftop solar does in fact throw off 11,000 actual, real world miles per year for my actual PHEV - so very close to your number. That is a fun way to think about things. Alas, much of it actually goes to waste as the car that would be charged is at the office with me.
Gibbon1 | root | parent
My opinion is states like California should enact policies to encourage work place charging. Because that's when the energy mix has the highest amount of solar.
MentalM | parent
> Very conservatively solar produces 30-50 times are much energy per acre as corn ethanol.

Corn ethanol never was about the energy. Corn ethanol needs so after several years of crop failure you just swap that corn with other culture and people do not starving.