QU-BD Heated Bed - Second PSU? (1 reply)

I'm finishing up my Prusa i3 build with RAMPS 1.4 and a 225mm x 225mm silicone heated bed from QU-BD. I need to decide on how to power it.

Will I need a relay to power the bed since it's 24v?

How powerful would a single PSU need to be as opposed to two separate ones?