Can I run a watermaker off solar?

Yes, if you match the system to your surplus. An energy-recovery DC system can make 100 litres for a few hundred watt-hours, which one decent panel covers on a clear day. A conventional 240 V system needs over a kilowatt while running and is designed around a generator.

Is a 12V watermaker better than a 240V one?

Neither is better in the abstract. 12 V runs off the bank with no inverter or generator but gives modest output. 240 V gives far more output per dollar but needs a generator or shore power. Choose by what your boat already has.

Do I need an inverter for a watermaker?

Only for an AC system, and it needs to be a substantial one — these draw over a kilowatt. DC systems at 12, 24 or 48 V connect straight to the bank with no inverter.

Does a 48V watermaker use less power than a 240V one?

No. The same model at 48 V and 240 V typically shares the pump and membranes and draws the same wattage. The 48 V version just takes it from the bank instead of the generator, with a quarter of the current a 12 V system would need.

Buying

12V vs 24V vs 240V: which power source for your watermaker?

The voltage decides where the energy comes from, how thick the cable has to be, and whether you can make water without starting anything.

6 min read · checked 5 September 2026

Every watermaker needs to get to roughly 55 to 60 bar at the membrane. How it is powered to do that shapes the rest of the installation more than any other single choice.

The short version

Choosing by what your boat already has

Your setup	Sensible choice	Why
12 V bank, solar, no generator	12 V DC	No inverter, no engine. Modest output, but it runs on sunshine.
24 V or 48 V lithium bank	24 V or 48 V DC	Half or a quarter of the current for the same power: thinner cable, less voltage drop.
Generator or shore power available daily	240 V AC	Highest output per dollar. The genset covers the draw.
Small electrical system, occasional use	Petrol	Takes nothing from the bank. Needs fuel and ventilation.

12 volt

The simplest possible arrangement: wire it to the house bank and go. No inverter, no generator, nothing to start. The constraint is current — a given power draw at 12 V pulls four times the amps of the same draw at 48 V, so cable size and voltage drop over a long run to the machinery space matter more than people expect.

Output is modest by design in this class, so the question is whether your daily litres fit inside a sensible run time. Note that the energy-recovery systems run at 12 or 24 V and make a day's water on a few hundred watt-hours, which is what makes solar-only water realistic.

12 volt systems

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
D100 DUO Dessalatorreported	12/24V DC	100	700	7.0	on request
D60 Freedom Dessalatorreported	12/24V DC	60	550	9.2	on request
D60 DUO Dessalatorreported	12/24V DC	60	550	9.2	on request
Scout SW20 LEDIreported	12V DC	20	200	10.0	on request
Portable 12VDC 34L Rainman	12V DC	26–37	400	12.7	$4,898
Modular 12VDC 34L Rainman	12V DC	26–37	400	12.7	$5,053
Zen 150 Schenker · spec unconfirmed	12/24/48V DC or AC	150	—	not published	on request
Ventura 200 Tropical Spectra · spec unconfirmed	12/24V DC	31	—	not published	$8,200

Under 6 Wh/L · energy recovery

6–12 Wh/L

Over 12 Wh/L

24 and 48 volt

The same DC logic with better electrical manners. At 24 V a given draw pulls half the current of 12 V; at 48 V, a quarter. That means thinner cable, smaller breakers and less voltage drop, which is why larger boats and lithium installations increasingly sit at these voltages.

48 V is worth calling out separately: it lets a full-size high-pressure pump run straight off the bank with no inverter, so you get AC-class output without AC-class infrastructure. The draw is identical to the AC version of the same model — you are changing where the power comes from, not how much is needed.

48 volt systems

System	Power	Output L/hr	Draw W	Wh per litre	Price
Zen 100 Schenker	12/24/48V DC or AC	100	400	4.0	$9,600
Newport 400C Spectra	12/24/48V DC	64	288	4.5	$14,500
Portable 48VDC 140L Rainman	48V DC	100–154	1,250	9.8	$6,240
Frame 48VDC 140L, auto Rainman	48V DC	100–154	1,250	9.8	$12,115
Frame 48VDC 140L, manual Rainman	48V DC	100–154	1,250	9.8	$8,666
Modular 48VDC 140L Rainman	48V DC	100–140	1,250	10.4	$6,421
Zen 150 Schenker · spec unconfirmed	12/24/48V DC or AC	150	—	not published	on request

Under 6 Wh/L · energy recovery

6–12 Wh/L

Over 12 Wh/L

240 volt AC

The highest output per dollar in the table, and the reason is simple: a mains-powered pump can be big without anyone worrying about amps. If your boat has a generator that runs daily, or you spend most nights on shore power, this is usually the value choice.

The catch is that these systems draw over a kilowatt, so running one off an inverter without the engine going will empty a house bank quickly. Treat AC as meaning "needs a generator" unless your inverter and bank are genuinely large.

Petrol

A small petrol engine drives the pump, so the electrical system is not involved at all. Budget roughly 700 ml of fuel per hour. It suits boats with small electrical systems, and it is popular as a portable unit that lives in a locker and comes out on the foredeck for an hour.

The trade is fuel handling, noise and the fact that there is no meaningful watt-hours-per-litre figure to compare it on. It is a different kind of purchase.

The mistake to avoid

Check it against your own bank

Enter your battery capacity, voltage and daily solar surplus, and we will show which systems fit.

Open the sizing calculator

Common questions

Can I run a watermaker off solar?: Yes, if you match the system to your surplus. An energy-recovery DC system can make 100 litres for a few hundred watt-hours, which one decent panel covers on a clear day. A conventional 240 V system needs over a kilowatt while running and is designed around a generator.
Is a 12V watermaker better than a 240V one?: Neither is better in the abstract. 12 V runs off the bank with no inverter or generator but gives modest output. 240 V gives far more output per dollar but needs a generator or shore power. Choose by what your boat already has.
Do I need an inverter for a watermaker?: Only for an AC system, and it needs to be a substantial one — these draw over a kilowatt. DC systems at 12, 24 or 48 V connect straight to the bank with no inverter.
Does a 48V watermaker use less power than a 240V one?: No. The same model at 48 V and 240 V typically shares the pump and membranes and draws the same wattage. The 48 V version just takes it from the bank instead of the generator, with a quarter of the current a 12 V system would need.