Some cells are getting 47%, which is ridiculous for a generator! The theoretical maximum efficiency for solar cell from the sun as it appears in the sky is about 68%, so that’s pretty good!

However, how expensive is that cell going to be? How much maintenance does it need, and how fragile is the system once deployed? It’s very obvious that PV efficiency has beed skyrocketing recently, and I don’t thinks it’s stopping soon, but a commercial PV panel available today is just breaking 20% efficiency. Luckily, sunshine is quite abundant.