Friday, March 05, 2021

Energy Density

Some wonder why I am so confident that battery technology will never justify our transitioning away from internal combustion engines? 

The answer is an energy density comparison between batteries and hydrocarbons. Let me offer a few rough calculations:

On a volume basis, I figure gasoline is about ten times more energy dense than batteries. (Replace the batteries in an EV with a full gas tank and you could ravel at least ten times as far.)

On a weight basis, I figure the comparison is more like twenty to one. This, of course, puts the kibosh on air travel by battery. (Even if one could find a way of powering a jet engine with electricity.) 

So, kind reader, even if Mr. Musk could pull a rabbit out of his tuchus and eventually double battery efficiency, we are still parsecs away from energy density parity.


Afterthought: If Tesla could cram twice as much energy into its batteries, would they take twice as long to recharge?



ChillFin said...

You need to absorb more sci-fi. It was not that many lifetimes ago that it was a fantasy to imagine fossil fuels, automobiles, electricity, nuclear power, heavier-than-air flight, space travel, Mars rover, computers, the internet, GPS... Who is to say that we won't have nuclear power cells so small that you never have to charge your devices or your car? You have to imagine what's possible and then do it. I was taken aback when SpaceX launched rockets, then had the booster section come back down under control... to land on a platform... that's in the ocean... successfully.

George W. Potts said...

I also remember how we would have flying cars, cancer cures and invisible cloaks. Not every dream comes true ... particularly when charlatans are involved ... particularly charlatans who can land a rocket booster.

Next time, tell me where I am wrong with my thinking.

George W. Potts said...

And I will add ... there is nothing wrong with dreaming big ... but, before betting everything on this dream, you should have some evidence of its plausibility. The odds of a totally EV world are not large enough to justify anyone’s religious zeal ... let alone the world’s.

George W. Potts said...

And remember cold fusion?

ChillFin said...

Remember the Gartner Hype Cycle? Innovation Trigger -> Peak of Inflated Expectations -> Trough of Disillusionment -> Slope of Enlightenment -> Plateau of Productivity. There are great minds and wealth behind each of these phases. You lived through some cycles. So did I. But some variation of the McGuffin often lifted off. Believe.

George W. Potts said...

As we learned once again with Obama ... hope is not a plan.