Method for raising floating body for spar-type offshore wind power generation facility

A method for raising a floating body for a spar-type offshore wind power generation facility to be performed to raise the floating body the spar-type offshore wind power generation facility from a floating sideways position to an upright position by injecting ballast water at sea, the method comprising:

• decentering a center of gravity of the floating body for the spar-type offshore wind power generation facility by means of a center-of-gravity decentering means;
• after the decentering of the center of gravity, injecting ballast water to start to raise the floating body for the spar-type offshore wind power generation facility from the floating sideways position toward the upright position, and subsequently stopping the injection of the ballast water at a predetermined amount so as to stop the floating body for the spar-type offshore wind power generation facility in an inclined state before reaching the upright position;
• and
• after the stopping of the injection of the ballast water, gradually re-injecting the ballast water to raise the floating body for the spar-type offshore wind power generation facility to the upright position,
• wherein the center-of-gravity decentering means is a weight detachably attached to an outer surface of the floating body for the spar-type offshore wind power generation facility, and the weight is attached so as to be above a surface of the sea in the upright position of the floating body for the spar-type offshore wind power generation facility.