SMES systems offer grid-level energy storage at about 98% efficiency. You could also move nuclear reactors to the middle of the desert because no one wants them in their backyard, then losslessly transport their power back to the grid. Same for bringing power from solar and wind installations. These are just two examples with immediate commercial application. The economics of energy production shift when you eliminate 15% of the cost and distance limitations. That would have a big impact on decarbonization. Longer term, josephson junctions replace transistors in processors.