[rohit2412]

But it isn't linear. Price is falling exponentially (15% every year). And adoption will be more rapid as solar suddenly becomes economically viable.

For a benchmark, look at China's adoption. https://en.m.wikipedia.org/wiki/Solar_power_in_China . Not at how many years they too from 20gw to 175 gw, but how much solar became viable for them last year.