Hand-held watermaker

[Buck Turgidson]

Solar and towed hydrogenerator. Doesn't sound like Stingos set up was optimal for energy efficiency.
I have found over the years that 12v energy reclaim watermakers are complex and not great for reliability. The energy intensifier pumps wear out and rely on fine tolerances to work. The benefit is they dont use much energy. You still need to run them for long period as they don't make much water. The low amp draw is needed for hours at a time and this has in conflict with the same demand for battery charging after night time fridgefreezer amp draw and if you are sailing, electronic instruments, autopilot etc. Friends who have them confess that they use their engine often to charge the batteries whilst running the watermaker to make, on the face of it small amounts of water.
We use a diesel gent set to make over 200 litres per hour. We only need to run the gen for 15 mins per day. If we didn't have a genset we would run the watermaker hp pump from the engine and fill the tank to the brim every few days. Often this can be done whilst entering/leaving an anchorage. No draw on the batteries, some battery charging whilst you make water and also a tank of hot water into the bargain.
The benifit of a simple hp pump like a Cat 247 is they are bullet proof. With just a needle valve and gauge and a couple of valves plus a LP feed pump, there is little to go wrong the can't be easily fixed anywhere in the world

All of that.
Of course it depends on your boat and needs. I was looking to fit out my twister for some serious long distance sailing (put on hold due to stuff) so I looked at solar charging requirements for water and nav gear (fridge/no fridge changes a lot of the equation) vs lots of extra tankage. It's a tuff call but no chance of a genset so engine charging at dawn and making water while the batteries are floating afterwards was my conclusion. Needed 120-160 watts of solar on a sunny day by my calculations.
I will come back to it when the time is right but I really don't expect any magical new technology in this field.

 

[geem]

All of that.
Of course it depends on your boat and needs. I was looking to fit out my twister for some serious long distance sailing (put on hold due to stuff) so I looked at solar charging requirements for water and nav gear (fridge/no fridge changes a lot of the equation) vs lots of extra tankage. It's a tuff call but no chance of a genset so engine charging at dawn and making water while the batteries are floating afterwards was my conclusion. Needed 120-160 watts of solar on a sunny day by my calculations.
I will come back to it when the time is right but I really don't expect any magical new technology in this field.

We used to run with 340w of solar and with a small efficient fridge. The solar was barely enough even here in the Caribbean. We also have a Duogen that would make lots of power over night when sailing and contribute some in wind mode at anchor. Once we increased to 740w of solar it was a game changer. We still make water with the genset based watermaker but batteries get an easy life. They never drop below 80% charged and we have spare capacity for making ice and domestic hot water off the solar panels once the batteries are on float.
If you are single handing on a small boat then the Katadyn/PUR will do the job but you will need to run for probably 3 hours per day. The unit needs flushing in fresh water if you don't use it everyday. That uses up precious product water.
I suspect you won't have enough room in the engine compartment to run an engine driven HP pump so you are probably limited to 12v unless you go with a Honds suitcase generator and a Cruise RO type watermaker. These are better value than a Rainman and seem well liked by their users.

 

[Deleted member 478]

If that was the case how on earth do the Vendee globe sailors get round the world using them? I think your step may not have been optimal.

No where near enough solar, as simple as that.

 

[mullet]

Quenchsea have brought out a new model which looks as if it works passively by being sunk sufficiently deep in seawater that the depth provides the pressure needed for RO. Interesting idea and inexpensive but not much use to me on the East Coast. Sharing in case it is of interest to anyone, no connection etc.

QuenchSea Reel

 

[AntarcticPilot]

Not much use unless you're off the continental shelf! And how much drag does a line at least 300m long create?

 

[mullet]

And how much drag does a line at least 300m long create?

Indeed. I suspect it'll be more of interest for survival than daily use. And possibly no use if underway - much forward way and it would need to more like a 500m line to actually submerge the device to 300m.

I find it interesting and encouraging to see some lateral thought being applied to watermakers. I'm of the minimalist school of boating - I like to keep things simple and compact (28' boat and not terribly beamy): low power consumption, small battery bank, no fridge. I'd love a small, inexpensive, low-power device that would allow me to carry less water. Don't think we are there yet but I'm keeping an eye on the market.

 

[Deleted member 478]

... I'd love a small, inexpensive, low-power device that would allow me to carry less water. Don't think we are there yet but I'm keeping an eye on the market.

Rain catcher?

 

[mullet]

Rain catcher?

I’ve been known to block the deck drains and open the filler cap of the water tank. Need a proper downpour to wash the deck clean first though.

 

[geem]

I’ve been known to block the deck drains and open the filler cap of the water tank. Need a proper downpour to wash the deck clean first though.

We have a rain collecting sun cover. We fitted gutters to it and 1" pipes. It runs through a single 10" filter housing with a 1 micron filter installed. It's a real surprise how dirty that filter gets. The thought of not having all that crap in the tank really makes you appreciate the filter.
Our record water collection was 500 litres in two hours in a tropical downpour in Curacao

 

[mullet]

Crikey!

 

[AntarcticPilot]

Indeed. I suspect it'll be more of interest for survival than daily use. And possibly no use if underway - much forward way and it would need to more like a 500m line to actually submerge the device to 300m.

I find it interesting and encouraging to see some lateral thought being applied to watermakers. I'm of the minimalist school of boating - I like to keep things simple and compact (28' boat and not terribly beamy): low power consumption, small battery bank, no fridge. I'd love a small, inexpensive, low-power device that would allow me to carry less water. Don't think we are there yet but I'm keeping an eye on the market.

Bottom line is that removing salt from water inevitably requires a lot of energy - you're going from high entropy to lower entropy, and the energy to do that has to come from somewhere, unless you're friends with Maxwell's Demon! The interesting bit here is using the pressure difference between the top and bottom of a hose rather than a pump. But I'd like to see the details, as I can't see how a continuous operation could work. I don't mean it can't work - I mean I don't understand it.

 

[roaringgirl]

Solar and towed hydrogenerator. Doesn't sound like Stingos set up was optimal for energy efficiency.
I have found over the years that 12v energy reclaim watermakers are complex and not great for reliability. The energy intensifier pumps wear out and rely on fine tolerances to work. The benefit is they dont use much energy. You still need to run them for long period as they don't make much water. The low amp draw is needed for hours at a time and this has in conflict with the same demand for battery charging after night time fridgefreezer amp draw and if you are sailing, electronic instruments, autopilot etc. Friends who have them confess that they use their engine often to charge the batteries whilst running the watermaker to make, on the face of it small amounts of water.
We use a diesel gent set to make over 200 litres per hour. We only need to run the gen for 15 mins per day. If we didn't have a genset we would run the watermaker hp pump from the engine and fill the tank to the brim every few days. Often this can be done whilst entering/leaving an anchorage. No draw on the batteries, some battery charging whilst you make water and also a tank of hot water into the bargain.
The benifit of a simple hp pump like a Cat 247 is they are bullet proof. With just a needle valve and gauge and a couple of valves plus a LP feed pump, there is little to go wrong the can't be easily fixed anywhere in the world

My experience differs from that of your friends. We have a 12v watermaker with energy reclaim. I believe the design of the seals in the Clarke pump was changed at some point to make them more reliable. Ours was used to supply all the watery needs of 4+ crew for 2+ years sailing from Scotland to NZ. The only problem I've had with it was a leak in a pipe. We have 750W of PV, a Rutland 1200 windgen and a Watt&Sea hydro-generator. We run the WM for a couple of hours a day normally, to keep the tanks topped up. It draws 8A.

When at anchor the solar is sufficient to make sure that most days we get back up to float. Underway the hydro-gen means we're constantly full, day and night. (Fridge, nav equipment, electric autopilot, watermaker etc...).

The weakest link (I am told) in our design of WM is the electric pump, so we carry a spare.

 

[geem]

My experience differs from that of your friends. We have a 12v watermaker with energy reclaim. I believe the design of the seals in the Clarke pump was changed at some point to make them more reliable. Ours was used to supply all the watery needs of 4+ crew for 2+ years sailing from Scotland to NZ. The only problem I've had with it was a leak in a pipe. We have 750W of PV, a Rutland 1200 windgen and a Watt&Sea hydro-generator. We run the WM for a couple of hours a day normally, to keep the tanks topped up. It draws 8A.

When at anchor the solar is sufficient to make sure that most days we get back up to float. Underway the hydro-gen means we're constantly full, day and night. (Fridge, nav equipment, electric autopilot, watermaker etc...).

The weakest link (I am told) in our design of WM is the electric pump, so we carry a spare.

I have helped several friends out with Spectra watermakers. Cracked end caps, failed boost pumps, worn Clarke pumps. By comparison 220v/110v systems are inherently simpler and therefore more reliable in my experience. 12v motors on energy recovery type watermakers, especially the higher output ones pull a lot of amps. Finding a high output reliable 12v motors is not easy. They really don't exist.
By comparison, a Cat 3 cylinder piston pump is super reliable. They will do many thousands of hours trouble free. The additional benefit is run hours on 220v watermakers are lower as you can make so much more water in an hour than energy recovery 12v types. We make 200 litres an hour. With two of us onboard we use 1.8 tonnes per month.

 

[roaringgirl]

I have helped several friends out with Spectra watermakers. Cracked end caps, failed boost pumps, worn Clarke pumps. By comparison 220v/110v systems are inherently simpler and therefore more reliable in my experience. 12v motors on energy recovery type watermakers, especially the higher output ones pull a lot of amps. Finding a high output reliable 12v motors is not easy. They really don't exist.
By comparison, a Cat 3 cylinder piston pump is super reliable. They will do many thousands of hours trouble free. The additional benefit is run hours on 220v watermakers are lower as you can make so much more water in an hour than energy recovery 12v types. We make 200 litres an hour. With two of us onboard we use 1.8 tonnes per month.

Mine is a Schenker. It doesn't have a boost pump, it has a 'low pressure' electric pump and an energy recovery Clarke pump. There's no difference in the membranes between a 220V and a 12V watermaker, so cracked end-caps are irrelevant to this comparison - perhaps Spectra got a bad batch? With 6 of us on board, on our last Pacific crossing we ran it every day to make 60-90 litres (2.2T/month) and our batteries were full 24/7. We don't have a generator - I'd have to do some serious thinking about where we could put one. When we set out on this adventure, I wanted to make all the power we needed from renewables - a 220V watermaker powered by a generator is just a way of swapping 1L of diesel for 10L of water. Which means that the ability to make water depends on the ability to run a diesel engine and an inverter, and carry enough diesel - everything is a compromise, and we all make our own choices. Funnily enough, I've spent a significant amount of time helping one of my cruising friends with problems with his 220V watermaker. I'm keen to offer a different perspective so people know that it *is* possible to go the 12V route.

 

[john_morris_uk]

We have an Osmosea water maker It’s a 12v energy recovery system and so far we’ve been delighted with it. 50+ litres per hour for a few Amps. So far it’s been super reliable. Wd can run it off Solar or generator or main engine. At anchor for a few teaspoons of diesel we get full water tanks and hot water.
At the end of our transatlantic we had full water tanks despite 5 onboard showering regularly and dobhi-ing their clothes.

What’s not to like?

 

[geem]

Mine is a Schenker. It doesn't have a boost pump, it has a 'low pressure' electric pump and an energy recovery Clarke pump. There's no difference in the membranes between a 220V and a 12V watermaker, so cracked end-caps are irrelevant to this comparison - perhaps Spectra got a bad batch? With 6 of us on board, on our last Pacific crossing we ran it every day to make 60-90 litres (2.2T/month) and our batteries were full 24/7. We don't have a generator - I'd have to do some serious thinking about where we could put one. When we set out on this adventure, I wanted to make all the power we needed from renewables - a 220V watermaker powered by a generator is just a way of swapping 1L of diesel for 10L of water. Which means that the ability to make water depends on the ability to run a diesel engine and an inverter, and carry enough diesel - everything is a compromise, and we all make our own choices. Funnily enough, I've spent a significant amount of time helping one of my cruising friends with problems with his 220V watermaker. I'm keen to offer a different perspective so people know that it *is* possible to go the 12V route.

We can now make our water from solar. Lithium battery. We only need to run for 15mins per day so not much load.
Many 12v water akers use custom sized membrane housings membranes so you are forced to buy spares from them. The industry standard 40" membranes is the way to go. Often same price or cheaper than shorter membranes but way more output.
I would be very interested to know what help your friend needed with his 220v watermaker. Pump problem? Needle valve or membrane. There isn't much else.
Your Schenker pump might be the Italian coffee machine pump with the very tight impellor tip clearances? Thats what a friends Schenker used. I dont know if they still use those. They brand them as Schenker but they arent. They have a habit of wearing and not making sufficient pressure. From memory they need to make about 100 psi to feed the Clarke pump. When the vanes wear at the tips they lose pressure.

 

[Topcat47]

Ok, it is going back 20 years but I had experience of a military issue emergency manual water maker , like this one, except the barrel was longer. Two of us pumping alternately for 30 mins produced 1 litre of drinkable water. By this I mean you could safely drink it. I wouldn't use it to make tea with tho' as it had an odd taste. The more it was used, the harder it became to pump. my memory isn't precise here but I think it was a reverse osmosis process. it too had a membrane filter. The kit came with three spares.

 

[geem]

We have an Osmosea water maker It’s a 12v energy recovery system and so far we’ve been delighted with it. 50+ litres per hour for a few Amps. So far it’s been super reliable. Wd can run it off Solar or generator or main engine. At anchor for a few teaspoons of diesel we get full water tanks and hot water.
At the end of our transatlantic we had full water tanks despite 5 onboard showering regularly and dobhi-ing their clothes.

What’s not to like?

Long term reliability. Getting bespoke parts in off the beaten track locations. Apart from that they are marvelous. The Clarke pumps and boost pumps do wear out but if yours is new it will be a while before issues are likely.

 

[vas]

my only contribution to this discussion is that initially my RO system (by HRO, bought s/h) had a short membrane (and housing) producing circa 30lt /h. Pump was a decent 3plunger job, so 500euro later and a couple of high press hoses, I do 100+lt /h. Main mod I did was replace the heavy duty 220V motor with a 3ph motor and an inverter so I can do soft start and stop and save the membrane from the shocks. Yes, I know I could use the needle valve but I have fun automating things onboard.

ok, the 30lt/h was a joke, had to run it for ever. the 110lt/h is reasonable for a couple throughout the summer. Haven't filled the tanks with tap water since and have changed my heads to fresh water flushing and got nice smelling heads. Finally, being in the water all year, I make sure I run the watermaker once a fortnight even in port and keep membranes clean and working (touch wood!)

 

[roaringgirl]

I would be very interested to know what help your friend needed with his 220v watermaker. Pump problem? Needle valve or membrane. There isn't much else.

From memory, at different times: lift pump, hp pump, some fitting on the membrane housing, and any number of problems with the diesel generator they have to use to power it: fuel leaks, dead capacitors, bespoke fuel fittings, ECU lockout, shutdown on power draw.

As I said, mine has been providing 4+ crew with all their watery needs for a couple of years straight, the only issue being a leak in a pipe. It is worth noting that even in Fakarava, I got Selden rigging parts from Sweden in 2 weeks, but I carry a spare (coffee maker) pump, just in case.

How do the membrane end-caps fail in service?