Electric Planes Require Better Batteries

The best lithium-ion packs today have an energy density of around 200 Wh/kg, which is still enough to power short haul small airplanes. 

At 800 Wh/kg, batteries can power a 737 sized commercial plane for 600 miles. At 1,600 Wh/kg, you can replace 80% of fossil fuel planes with battery powered ones. 

In theory, about 4,000 Wh/kg is possible. In practice, bleeding edge technologies are flirting with 600-1000 Wh/kg.

All according to this Twitter thread.

Of course, better batteries have all sorts of potentially profound, economically disruptive implications. If you can get batteries with double the energy density and half the cost, electric vehicles will capture perhaps 90% of the market share of motor vehicles without meaningful government subsidies relative to gasoline and diesel powered vehicles.

Better batteries also mean laptops and phones that don't need to be charged daily, more off the grid battery packs where generators would be used today, and more.

The other key economic factor is the price aviation fuel, gasoline and diesel fuel, all of which are largely a function of the price of oil and the tax rate on these fuels. Electric vehicles make more sense in California where gas currently costs as much as $5 per gallon (in part, because of a $1.26 per gallon gas tax v. 33 cents in most states), than it does in Colorado where gas currently costs about $2.50 per gallon.