Electricity is pretty expensive where I live, but solar opportunity is fairly good. Selling power back to grid is nowhere near as cost effective as using solar directly.

So, I could see a compelling use case of, "I want my laundry done by X o'clock. Start the wash when it'll be mostly on my cheap solar."

But yeah. I would never buy one unless it supports local-only/VLAN-restricts-internet-access usage.