For a fridgeputer, you want something like a magnetic N800. You might use it on the fridge to bring up a calendar or to add an item to a shopping list, but you also want to be able to lift it off to show people stuff or to use it on the kitchen table. You don't want to have to unplug it every time you use it.

So a solar solution that provides infinite standby (and maybe even a bit of a recharge) is fine. Then, once every couple of weeks if necessary you plug it in (but still on the fridge).

Probably want something a little larger than an N800 for this use case though.

Regards,
Roger