[aviavinash]

Well, hold on a minute – while the idea of a DIY zero-emission electricity supply is intriguing, I can't help but wonder about the practicality and potential drawbacks. Are there any hidden environmental costs in the production of the materials needed for such a setup? And what about the initial investment – is it feasible for the average person?

[pfdietz]

By "build your own" it means "run this somewhat idealized simulation to see what it would cost at scale". You are not going to be building utility-scale renewables or storage.