Offshore Wind Grid Integration - A Techno-Economic Comparison of MVDC and HVAC

Traditionally, offshore wind grid integration make use of either High-Voltage AC (HVAC) or High-Voltage DC (HVDC) technology; the final choice is a complex decision-making process considering distance to shore, project cost, and local grid or environment constraints, to just name a few. Recent developments in power electronics, however, spiked interest in utilizing Medium-Voltage DC (MVDC) to integrate Offshore Wind Farms (OWF). Here, the use of MVDC means reduced energy losses compared to HVAC and lower capital expenditure (CAPEX) compared to the HVDC. To quantify the benefits of MVDC compared with HVAC, an integrated techno-economic study is needed to assess how these two technologies compare to each other in the integration of OWF. In this paper, three different OWF topologies are presented, discussed and evaluated based on their energy efficiency, CAPEX, operational expenditure (OPEX), and levelized cost of energy (LCOE). Thus, the objective of this research is not only to perform technical design study deploying the two technologies but also to compare the financial attractiveness between them. Nordzee wind farm (NZW) and Holland Kust Noord (HKN) are used as HVAC study cases and will be adapted for the MVDC implementation scenario.