To offer an alternative for supplying fresh water to people in distress in tropical seas before rescue or to garrison soldiers on a small reef, a portable solar-photovoltaic atmospheric water generator was designed and tested experimentally, and is composed of a water generating module, a water purifying module, a power supply and control module, and a buoyancy module. The results showed that the best water production rate of 460 mL/h was achieved when Tin = 27, RHin = 92%, Qa = 600 m3/h, with the desalination rate above 99.65%, proving itself a feasible solution as a portable desalination device. The daily water production can reach 5.52 L/d, which is more than twice the minimum quantity of the WHO drinking water standard (2.5 L/capita-day), and the energy consumption can be controlled under 200 W. The influences of major operating parameters on the device performance were analyzed and performance comparisons were carried out with the reported AWG products/prototypes. By integrating with a distress signal launcher and positioning module to shorten rescue time, the device has the potential to be employed as a small rescue platform for people in distress in tropical oceans, carried on board ship as a precaution.

Compared with the common marine renewable energy sources like solar, wind, and wave energy, etc., the hydraulic pressure stored in the deep seawater can output stable and successive energy flow. Thus, it can be directly coupled with the reverse osmosis (RO) process to supply drinkable mineral water for crews of Deep Sea Space Station (DSSS). We proposed a novel submarine RO desalination system driven by the hydraulic pressure of deep seawater (SHP-RO), composed of a desalination branch to generate fresh water and a back pressure branch to ensure the depth independence of the desalination. The influences of the deep sea environment on the RO were analyzed, based on which the pretreatment of the seawater and the preparation of the drinkable mineral water were studied. The turbine-based energy recovery scheme was investigated in virtue of the CFD simulation on the flow behavior in the different turbine series. It was predicted that, when the DSSS was located at the depth of 1100 m and the operating pressure of the RO process was 6.0 MPa, for a drinkable water production rate of 240 m3/d, the recovered hydraulic pressure energy can achieve 39.22 kW·h, which was enough for driving electricity consumers in the SHP-RO system.