Electrical Design of a Clean Offshore Heat and Power (CleanOFF) Hub

Abstract: This paper presents an innovative offshore solution where oil & gas platform clusters are powered by a wind farm and a hydrogen hub. The results show a feasible off-grid design as an alternative to conventional electrification solutions. To address the challenges of design and operation of such a system, a power system model of the equipment and control was developed in a power system simulator called Process Power Simulator (PPSim). Power fluctuations in the wind farm are modelled using a state-of-the-art method encompassing turbulence and wakes. Various operation scenarios were used to evaluate the system design and find the right equipment size. An expensive component to over dimension is the battery energy storage system (BESS). The BESS power rating and energy capacity were found by running a combination of scenarios with extreme and natural wind variations, and contingencies. The control strategy and ramp rates of electrolyzers have significant impact on both system performance and design. A ramp rate in the order of seconds as opposed to minutes will decrease the required BESS size by 60-70%. Choosing synchronized control of the electrolyzers can further reduce the BESS size by 15-20%. The simulations also revealed challenges to achieve self-sufficiency of hydrogen and potential design improvements are suggested.