Why Batteries will Never Compete With Fuels

There is a lot of hype about electric cars, but they will never replace fueled vehicles. This is because batteries have 10x-100x lower specific energy density.

Hydrogen has a specific energy of 142Mj/kg, or about 40kwhr. Burned in an internal combustion engine, this produces 4kWhr of usable power. The best batteries today are about 200W/kg. That is a factor of 20x less per mass.

The amount of chemical intensity and waste of batteries is large. Just burn hydrogen instead as an ecological solution. If we consider the electricity of producting hydrogen from water - the process is 60% efficient. So about 2x worse for hydrogen than charging batteries. But that still leaves hydrogen at 10x more energy dense, and many factors cleaner, than any mobile battery technology.

This doesn't mean that batteries won't be useful. They can, for example, be used in slow moving, autonomous solar vehicles and many other applications. But in general, battery tech is high on the hype curve.

It is likely that a fusion of nanotech with hudrogen will complete this discussion, such as with nanotubes that store hydrogen. So you have hydrogen 'batteries.' These will not be electrochemical batteries - just chemical storage.

So to sum up - electrochemistry cannot compete with chemistry for energy storage from the environmental perspective.

If this assessment is wrong - I'll be the first to admit - MJ.