Powernap for Hackintoshes?

If you install OS X on a SSD, would you be able to enable power nap on it?

Short answer: no.

Longer answer: Power Nap requires very specific hardware support, both from the EFI system used by real Macs and in the logic board, SMC, and network controller. Much like Airplay Mirroring requires that your system be able to perform h.264 encoding and decoding in hardware, it's not just a matter of what sort of hard drive you have. It's one of those features that is unlikely to ever be fully supported in anything but actual Apple hardware.

Bummer, I was kinda looking forward to that when I build my hackintosh. And you said that Airplay Mirroring is also unsupported?

Airplay Mirroring is supported if you have a CPU/chipset that has the necessary dedicated circuitry in it (late model Sandy Bridge and all (I think, not 100% sure) Ivy Bridge) and a supported GPU. Even on real Macs it's only supported on a small portion of models due to the need for hardware support.

However, there are third-party tools such as AirParrot that accomplish the same thing in software if your hardware is beefy enough to handle realtime h.264 encoding/decoding at that resolution.

Intel chipsets have a feature similar to Powernap built into their hardware that can be turned on (at least on Gigabyte motherboards) and it's probably exactly what Apple uses in OS X as well (the feature was 'introduced' by Intel around the same time).

Is it related to Erp at all?