Google Nexus 5 — Use external HDD without additional power source on Nexus 5

Hello everyone,

I was wondering if there is a way to use an external HDD on the Nexus 5 without the y-cable,
needed to provide additional power to the HDD.
Maybe there is a custom ROM with this kind of power management options,
but I could not find any information of this kind on the net,
so it would be nice if I could use your help.

Thank you in advance,

Best wishes

Davide