Yes, this could be simplified. That being said, I get numerical stability issues if I don’t include the year offset; it’s easier to just include said offset.
Admittedly, this is a 2-parameter fit not a 3-parameter fit; I don’t know offhand of a good alternative third parameter to add to the fit to make it more of an apples-to-apples comparison.
As an aside, people fitting exponential trends without including an offset term and then naively extrapolating, when exponential trends with offset terms fit significantly better and don’t result in absurd conclusions, is a bit of a pet peeve of mine.
Pulling the data from this chart from your source:
...and fitting[1] an exponential trend with offset[2], I get:
(Pardon the very rough chart.)
This appears to be a fairly good fit[3], and results in the following trend/formula:
$/MWh=319.67∗e−0.43796∗(year−2009)+37.706[4]
This is an exponentially-decreasing trend… but towards a decidedly positive horizontal asymptote.
This essentially indicates that we will get minimal future scaling, if any. $37.71/MWh is already within the given range.
For reference, here’s what the best fit looks like if you try to force a zero asymptote:
$/MWh=336.02∗e−0.28833∗(year−2009)
This is fairly obviously a significantly worse fit[5].
Why do you believe that solar has an asymptote towards zero cost?[6]
Absolutely, which is one of the reasons why in the absence of wanting clean energy people tend to lean towards fossil fuels.
Nonlinear least squares.
I’m treating the high and low as two different data points for each year, which isn’t quite right, but meh.
Admittedly, just from eyeballing it.
Yes, this could be simplified. That being said, I get numerical stability issues if I don’t include the year offset; it’s easier to just include said offset.
Admittedly, this is a 2-parameter fit not a 3-parameter fit; I don’t know offhand of a good alternative third parameter to add to the fit to make it more of an apples-to-apples comparison.
As an aside, people fitting exponential trends without including an offset term and then naively extrapolating, when exponential trends with offset terms fit significantly better and don’t result in absurd conclusions, is a bit of a pet peeve of mine.