4 ms·
Just to continue the discussion: 4,500 Wh/kg is still a 10x improvement on this new state of the art, and over a 20x improvement in current popular battery che
by throw20102010 7y ago
Just to continue the discussion: 4,500 Wh/kg is still a 10x improvement on this new state of the art, and over a 20x improvement in current popular battery chemistries. Gas looks pretty good.
Another thing to consider is the weight of the equipment needed to convert the stored energy into "whatever." For a car, that is the weight of the drivetrain. A typical car engine+transmission weighs 300-600 lbs depending on the size and power of the car. Two Tesla model S (no transmission needed) motors weigh around 150 lbs.
This weight advantage is significant when you realize that 20 lbs of gas weighs 120 lbs. So when considering the density of a "useable system" with all necessary conversion equipment then electric is starting to catch up. Gas still looks best for most cars (also consider the convenience, and price factors), but I'm pretty sure gas will lose within our lifespans.
- Skunkleton 7y agoDon't forget the charging system, and also that as batteries discharge they don't get lighter. Of course none of that matters. We need to ditch fossil fuels.
- antepodius 7y agoDepends on how cheap it becomes to synthesize it from air using electricity, in which case it just becomes an alternate battery.
- ksec 7y agoYou are excluding the weight of battery which far outweighs the saving of Electric Motors.
- throw20102010 7y agoNo, I was including it. Adding 150 lbs to a 1,200 lb battery only reduces the overall energy density by 11%. Adding 360 lbs to a 120 lb tank of gas reduces energy density by 75%. Where gas originally appeared to have a density advantage of 20x, it's now down to a 6x advantage after factoring in powertrain weight. That is what I mean when I say that batteries are catching up if you consider the total weight of the system.