Newbie question here. I am putting together a remote switching box for power circuits aboard a yacht. The design is for a central Raspberry pi to send orders to a few boxes, each controlling a number of circuits distributed through the vessel. Each box will contain an Arduino communicating with the RPi using XBee.
Each circuit will have a typical draw of a couple A with a max of 15 A. Typical switching frequency will be very low with some circuits staying almost always on and others almost always off.
My question is for the actual switching, should I choose relays or MOSFETs? My question is specifically around power conservation which is a primary concern on a sailing vessel. Given the high heat output of the MOSFET, am I correct in assuming these are wasteful components? More so than a relay?