A single 65W peltier cooler is not sufficient to bring 10 litres of liquid coolant down to a good operating range ~0 to 6C within a reasonable time <6 hours for reliable dew-point harvesting in one day of sunlight, currently this process takes over 12 hours. Further the insulated tank currently being used can not keep the coolant at that temperature for more that 48 hours.

Another issue is due to the size of the the condenser coil (no design here, just what I found I could buy off the shelf) the coolant is rapidly absorbs heat quickly and transfers it to the coolant. This is great for sucking moisture out o the air! But it also means a considerably more coolant needs to be cooled and stored. Meaning a bigger tank, better insulation and greater cooling capacity.