This paper will focus on the application of lithium-ion energy storage solutions (ESS) for offshore oil and gas (O&G) installations. It will discuss the benefits that can be achieved by integrating energy storage in hybrid power plants, using the West Mira semisubmersible installation in the North Sea as a representative case study. West Mira will be the world's first modern drilling rig to operate a low-emission hybrid (dieselelectric) power plant using lithium-ion batteries. The integration of energy storage with the power supply and distribution system of a drilling rig represents an important step towards improving the environmental sustainability of the offshore oil and gas industry by reducing emissions and paving the way to harnessing clean but intermittent renewables, such as offshore wind. Offshore rigs have highly variable power consumption for drilling and dynamic positioning. By incorporating energy storage, it is possible to reduce the runtime of combustion engines and also keep them operating on an optimized combustion level. The installation of an ESS on West Mira will result in an estimated 42% reduction in the runtime of on-platform diesel engines, reducing CO2 emissions by 15 percent and NOx emissions by 12 percent, which is equivalent to annual emissions from approximately 10,000 automobiles. The batteries on West Mira will be charged from the rig's diesel-electric generators and used for supplying power during peak load times. In addition, they will serve as backup to prevent blackout situations and provide power to the thrusters in the unlikely event of loss of all running machinery.