[P-40]

Maybe plants are more efficient at converting solar energy into usable power.

Plants can take solar energy and convert it to a storable medium very efficiently. We can't quite do the same yet.

[Yardstick]

Plants can take solar energy and convert it to a storable medium very efficiently.

That's what I figured. It's easy to store corn energy. Just fill a silo with corn or fill a tanker with ethanol. No batteries required.

Here's another question for you (if you don't mind):

Since plants store energy as carbohydrates, why isn't it a simple process to convert them into hydrocarbons? After all, they're both just carbon and hydrogen bonded together. Why do we have to turn the carbohydrates into alcohol, which has the disadvantages of low btu's and being water soluble? Why not just turn the starch into oil (or gas)?