Roatan operates on 120V supply usage and you will find Plug Types A and B, which are U.S. standard American plugs.
Other Tips:
It is standard for Hotels & AirBNBs to charge you additional fees for power usage, especially if you have an AC on site, because power in Roatan is very expensive
Power outages are not frequent, but can occur. Sometimes these are scheduled and sometimes they are unexpected, but our electricity company RECO is great at communicating when power is expected to be restored on their Facebook page.