> In exchange I’ll give you some unspecified amount of pizza

You mean, in exchange we will have genuine social interactions that you will value much more highly than the electricity bill or the pizza.

Plus you will be able to tease me about my overengineered homelab for the next decade or more.

About the worst I can imagine happening (other than the new-found ability to rockroll someone's TV as a prank) is that said friend might take an interest in how I manage my data and want a hand with setting up a similar thing for themselves.

And that's all fine too. I like my friends quite a lot, and we often help eachother do stuff that is useful: Lending tools or an ear to vent at, helping to fix cars and houses, teaching new things or learning them together, helping with backups -- whatever. We've all got our own needs and abilities. It's all good.

Except... oh man: The electric bill! I forgot about that.

A small computer like what I'm thinking would consume an average of less than 10 Watts without optimization. That's up to nearly $16 per year at the average price of power in the US! I should be more cognizant of the favors I request, lest they cause my friends to go bankrupt.

/s, of course, but power can be a concern if "small" is misinterpreted.

Or find someone else with a similar backup need and then both just agree to have enough space to host remote backups for the other. I would have to increase my ZFS from N to 2N TB, but that would be less work and cheaper than setting up a backup computer for N TB somewhere else.