Hybrid tensioning of riser string operating with energy storage device

An apparatus, comprising:

• a drilling riser;
• a vessel;
• a first motion reference unit (MRU) coupled to the drilling riser, configured to measure one or more properties of the drilling riser;
• a second MRU coupled to the vessel, configured to measure one or more properties of the vessel;
• a plurality of wires coupled to the drilling riser;
• a first and second electrical tensioner coupled to the drilling riser via a first and a second wire of the plurality of wires;
• and
• a controller configured to perform steps comprising:
• distributing tension to the first and second electrical tensioners;
• receiving the one or more properties of the drilling riser from the first MRU;
• receiving the one or more properties of the vessel from the second MRU;
• determining a tension based, at least in part, on the one or more properties of the drilling riser and the one or more properties of the vessel;
• and
• controlling the first and second electrical tensioners to adjust a tension of the first and second wires based, at least in part, on the determined tension.