You want to be extra rigorous about making the best possible thing you can. Find everything that's wrong with it and fix it.

A battery by definition is a collection of cells. So the cell is a little can of chemicals. And the challenge is taking a very high-energy cell, and a large number of them, and combining them safely into a large battery.

I'm extremely confident that solar will be at least a plurality of power, and most likely a majority... in less than 20 years.

If anyone has a vested interest in space solar power, it would have to be me.

Well, my motivation behind Tesla is really to do as much good as possible for the environment and the electric-vehicle revolution. I think there is still a lot of work to do and if we were to sell to a big company, I'm not sure it would progress at the same pace.

Does the logic connect? What are the range of probably outcomes? You want to figure out what those probabilities are and ideally be the House. It's fine to gamble, as long as you're the House. Also, listen to critical feedback, particularly from friends. Generally they will be thinking it but they won't tell you.

There are really two things that have to occur in order for a new technology to be affordable to the mass market. One is you need economies of scale. The other is you need to iterate on the design. You need to go through a few versions.