[KennyBlanken]

There are a bunch of existing spreadsheets that allow you to estimate sizing of the panels and batteries.

You couple that with maps that show 'full hour equivalency' figures for your area, and add in how much extra reserve you want, using calculations based off "I want the system to handle X days of no solar" and "I want the system to be able to charge back to full, given typical household load, within Y days."

A number of folks with off-grid systems have backup generators for the odd "two weeks of rain" situation or a failure of part of the system.

It ends up being fairly efficient because you can size the charger to almost fully load the generator. A fridge uses about 1kWhr/day, which is about 15 minutes of a 3kW generator running...

[Scoundreller]

I just want some big fridge/freezer manufacturer to build a "green fridge" with a 24-48VDC port and include a ~100W panel that anyone could wire up. Auto-switch to 120VAC as needed. Newer fridges run a variable drive motor, so the circuitry required has gone down.

[Shog9]

These exist as camping fridges (ex: https://www.amazon.com/DOMETIC-75-Liter-Portable-Refrigerato... there are also a few different full-size deals floating around. From what I've seen, these are a terrible idea for normal home use: they're eye-wateringly expensive, and for the sake of efficiency you give up a lot of nice features like air circulation and humidity control that are commonplace in far cheaper ordinary 120v AC fridges. Great for short-term use, but if you plan on keeping food fresh for weeks instead of a few days, you're gonna be annoyed.

[timerol]

The heat pump version of this exists, but I'm not aware of a fridge. https://signaturesolar.com/eg4-hybrid-ac-dc-solar-air-condit...