The blog states:
For Example, a high efficiency 360W+ panel could cost $300 or more while a common 300W panel will typically cost closer to $150. This equates to roughly $0.50 per Watt compared to $0.90 per Watt. Although in the case the leading manufacturers such as LG, Sunpower and REC the more expensive panels have higher performance, lower degradation rates and generally come with a longer ‘manufacturer’ warranty period, so it is often a wise investment.
If I have enough roof space…
And I spend $300, I can get either:
1 of the high efficiency 360W panels, for a total of 360W output, or
2 of the standard efficiency 300W panels, for a total of 600W output
After 25 years, the 360W panel may output 330W, while the 300W panels may output just 240W for a total of 480W for the two.
So, it would seem it is a better deal to buy the cheaper (less efficient panels)…
For the same $$ amount, I generate more output power even after 25yrs.
I am thinking the panel companies are heavily discounting their older production panels and charging a premium for the newer more efficient panels.
Unless I do not have the roof space, it would seem the “lower $/W panel” is a better choice as long as I still generate more power out of them at the 25 year mark… That is, premium is only justified when roof space is not enough.
Am I doing the math wrong somewhere? Any other costs to take into account (I figure I need to buy extra micro-inverters, if that is the setup I am going for)…