I have an N95 mini PC (32GB DDR4, 250GB SSD, 1TB NVMe), a 4 disk USB enclosure, an access point, and a 16 port switch plugged into a UPS.

The UPS says 35W for all of it, but I’ve always been too lazy to unplug devices to see how it breaks down. I’m also not sure how accurate the measurements are, especially under a load that low.

I’d be willing to believe the mini PC draws less than the other components at this point.

I recently got a junk M2 MacBook Air (16GB/512GB) with a broken screen for $250. It idles at just 0.2W (!) when accessed via SSH. While it offers zero expandability, lacks wired LAN, and runs on a non-free OS, it's an interesting candidate for an ultra-low-power inference server.