Powerwall 2 including additional hardware and installation sells for something in the order of $600 / kwh, right? I think it's reasonable to assume, that large scale installations like the one in Australia sell for a much lower price. If we can agree on this, that puts an upper limit on the revenue and prices will probably continue to drop. Let's assume sales and price develop like this:
2018: 1 GWh, $600 / KWh
2019: 2 GWh, $500 / KWh
2020: 4 GWh, $400 / KWh
2021: 8 GWh, $300 / KWh
2022: 16 GWh, $250 / KWh
That would be $4 billion in revenue about 5 years from now. Let's apply a 10% net margin and you end up with something like $400 million in earnings per year. With a P/E of 20 that translates into something like $8 billion additional stock value. Let's say in 2022 there are 200 million shares and we arrive at a value per share of $40. Now you'd have to discount that back and adjust for possible risks resulting from tech breakthroughs, macro-economy, competition (hi Asia!), lower margins, rising interest rates and so on. That's even more of a guessing game. Hm ... let's just say $20 a share right now?
To be honest, i think there will be more than 200 million shares by 2022, but i won't mention that at TMC. I'm not THAT stupid! It may also be hard to sell storage at $250 / kwh 5 years from now. I mean you guys are assuming battery costs on the pack level to be well below $100 / kwh for automotive grade batteries by then. Of course, if you plug in different numbers or simply extrapolate that series until 2030 you may end up with any share price you want. But for now i decided that Tesla Energy is no reason to leave the building anytime soon. We'll see, maybe i'll move a bit closer to the exit when Q3 / Q4 approaches ...