Most efficient: the energy-recovery systems
These reuse the brine's pressure to drive the inlet, which removes the high-pressure pump altogether. They cluster in a band no conventional system gets near, and they are the right answer for a solar-powered boat without a generator.
| System | Power | Output L/hr | Draw W | Wh per litre | Price |
|---|---|---|---|---|---|
| Zen 30 Schenker | 12/24V DC | 30 | 110 | 3.7 | $6,300 |
| Zen 100 Schenker | 12/24/48V DC or AC | 100 | 400 | 4.0 | $9,600 |
| Ventura 150 Deluxe Spectra | 12/24V DC | 24 | 108 | 4.5 | $6,000 |
| Ventura 150 Connect Spectra | 12/24V DC | 24 | 108 | 4.5 | $7,400 |
| Newport 400C Spectra | 12/24/48V DC | 64 | 288 | 4.5 | $14,500 |
| Zen 50 Schenker | 12/24V DC | 50 | 240 | 4.8 | $7,800 |
The cost is the price tag and the output. These are premium systems, and the smallest of them makes less water per hour than a conventional unit at half the price. You are buying watt-hours, not litres.
Best output per dollar: conventional pumps
If your engine or generator runs daily anyway, efficiency per litre matters much less and these become excellent value. The large-membrane models are the ones to look at, because on a fixed-power pump the membrane pack decides everything.
| System | Power | Output L/hr | Draw W | Wh per litre | Price |
|---|---|---|---|---|---|
| Portable AC 140L Rainman | AC 240V | 100–154 | 1,250 | 9.8 | $5,329 |
| Modular AC 140L Rainman | AC 240V | 100–154 | 1,250 | 9.8 | $5,460 |
| Frame AC 240L Torrent, manual Rainman | AC 240V | 180–264 | 2,800 | 12.6 | $12,089 |
| Frame AC 140L, manual Rainman | AC 240V | 100–154 | 1,250 | 9.8 | $7,685 |
Same pump, more membrane area: these are the efficient end of the conventional camp.
Least efficient: worth knowing before you buy
These are not bad products — they are small-membrane versions of the same platform, and on a generator they do exactly what they promise. But their energy per litre is the highest in the table, and a cruiser cross-shopping on price alone would never know it.
| System | Power | Output L/hr | Draw W | Wh per litre | Price |
|---|---|---|---|---|---|
| Modular AC 70L Rainman | AC 240V | 50–77 | 1,250 | 19.7 | $5,299 |
| Portable AC 70L Rainman | AC 240V | 50–77 | 1,250 | 19.7 | $5,296 |
| Modular AC 75L Rainman | AC 240V | 55–82 | 1,250 | 18.2 | $4,522 |
| Portable AC 75L Rainman | AC 240V | 55–82 | 1,250 | 18.2 | $4,402 |
Which camp are you in?
| Your boat | What to prioritise | Where to look |
|---|---|---|
| Solar only, no generator, long passages | Watt-hours per litre | Energy recovery, under 6 Wh/L |
| Generator or engine runs daily | Litres per hour and price | Large-membrane conventional systems |
| Occasional coastal use, want it off the boat between trips | Portability and simplicity | Portable units, petrol or AC |
| Charter or liveaboard with high daily demand | Output, with efficiency as a tiebreak | Over 100 L/hr, framed systems |
What this list does not yet cover
Several brands have verified Australian dealers but no published output-and-draw figures we have been able to source, so they are absent from the ranking rather than guessed at. That includes Blue Water Desalination, Dessalator, Parker Sea Recovery, Stella Marine, LEDI and CITOR. If you sell or install one of these and have published specs, we will table them with your dealership named as the source.