This chapter examines MMC-HVDC transmission systems for delivering power from large-scale new energy bases. The discussion covers technical requirements for DC transmission, differences between phase-locked and power synchronization in renewable energy bases, key technical considerations for DC power delivery, and three hybrid DC transmission systems: the LCC-MMC series, the LCC-MMC with D-MMC, and the LCC-MMC with FHMMC. The chapter concludes with a comparison of these three hybrid DC transmission topologies.