The current used in Fuerteventura and throughout the Canary islands is 220 Volts AC 50Hz and plugs have two round pins as found on the European continent.
Traveller's from the USA will require a voltage converter, however the better hotels do have provision for 110 Volt appliances like shavers.
If you are coming from the UK, you will require a plug adapter and this is best bought in the UK as they are hard to find in the Canaries.
You may also want to bring a torch with you. Although power cuts are not frequent, they do occur sometimes.