We'll come to your exciting interpretation of the data in a minute, but let's begin with the basics: I said "The costs of solar power have plummeted -- more than a hundred-fold decrease since 1977". You replied with some stuff that gives the impression that you're disputing that fact without ever quite disputing that fact, I guess because you accept that it is true that prices have plummeted. So I'm really not clear what the point of your post is:
- it took a lot of investment to bring solar prices down? I mean, I'm sure it did, most energy sources require huge amounts of investment just to produce without any benefits in $/W reductions over time, and it doesn't affect the fact that prices have indeed come down
- some kind of prediction that solar costs can't fall further in the future? I mean, if you think that, you're a braver analyst than me
And finally, your interpretation: How on earth did you conclude that there were two major price drops in the last 60 years?? Which data could possibly support that interpretation? According to the first chart I linked to, prices dropped every year from 1977 (~$77/W) through to 1989 (~$6/W) -- but you talk about a "change in the early 80s". The rate of change in the early 80s is slower than the rate in the late 70s, which doesn't tie up with your narrative. From 1989, prices stayed steady for about 10 years and then fell significantly through to 2008 (~$4/W) -- a near-halving. From 2008 to 2013, they fell even more significantly to under $1/W.
It takes really determined squinting to look at a chart showing 36 years of significantly declining prices with a decade-long plateau in the middle and describe that as "two major price drops". Had there been a 3 year period of price declines, a 30 year period of plateau, and a further 3 year period of declines, then that would be a reasonable characterisation.