From that perspective, you've got a finite amount of energy that's being consumed at any point of time and by that logic, you'd be better served to use the solar energy for something else in your household that would've needed the grid, because a cloud provider will almost certainly only need a fraction of the electricity you'd need to keep the static files served.

So, by doing that you've effectively reduced your absolute energy footprint.

But these projects aren't about reducing your energy footprint. They're about having a local webserver that's running on solar energy. Or in the authors words: At its heart, this project is about learning and contributing to a conversation on a greener, local-first future for the web