They are still using Peltier Thermal Electric Coolers (TEC) so the efficiency is probably not very good compared to a compressor system. They seem to be targeting electronics cooling and medical systems which are pretty big markets, more space constrained but not as demanding for efficiency as a boat refrigeration system. They aren't publishing any efficiency numbers which probably means it's not any great leap above the existing TECs. From what I can see they are offering a more integrated system than other TEC coolers with better control which may lead to improved efficiency but still not close to what you will get from a compressor.