Preliminary Assessment of a Novel OTEC CWP Design using Sand-Filled Sandwich Pipe Hensa Akbar Al Kautsar, Ristiyanto Adiputra, Bambang Kusharjanta, Aditya Rio Prabowo and Hermes Carvalho E3S Web Conf., 632 (2025) 03006 Published online: 03 June 2025 DOI: 10.1051/e3sconf/202563203006