For those thinking of fitting a watermaker

geem

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Watermakers are a serious investment for anybody setting off to live aboard full time in the Tropics, sailing an ocean, etc
Many have chosen 12v watermakers as they have a low power demand. They are also complicated pieces of equipment with many moving parts and very expensive. They make comparatively small quantities of water when compared to 230v watermakers with their power hungry large kW motors. Once they get several hundred hours on them they do fail. Parts can be eye wateringly expensive.
With the increase in use of lithium domestic batteries things have changed. The major benefit of lithium is the ability to cook electrically, use the immersion heater, boil the electric kettle and run the 230v watermaker off the inverter.
If you have made the decision to install lithium then the option of a 230v watermaker is now realistic without a generator.
The cost of a 230v watermaker is considerably less than a 12v watermaker, generating the same litres per hour.
A 60 litre/hr 12v Spectra is circa £11,000. A serious amount of cash. If you go 230v you can make at least twice the amount of water per hour for half the cost. If you build your own 230v watermaker, you can save a lot of money on the off the shelf cost. They are simple to build.
You can fit a second inverter as a back up and still be left with plenty of change. 230v watermakers are inherently simpler.
The beauty of the lithium is you have far more efficiency out of your solar. You no longer look to keep the lead batteries topped up. You can use a lot more of the capacity of the lithium bank with no downside. The lithium doesn't need to reach 100% charge state every day to maximise its life. Lithium is happiest at about 50% for maximum life.
The large output of 230v watermakers means run time on the watermaker is low. As a consequence, wear on components is low. We run our 200 litre/ hour watermaker for 15 to 20 minutes per day with two of us onboard. We have no shortage of water.
Our solar panels are 720w. When we had lead batteries our daily production was circa 2kw. It now averages 3.5kw. Same panels, just much more energy efficient. The panels never go off bulk since we don't fully charge the lithium everyday.
The use of a low frequency inverter capable of running large inductive loads is essential. There are cheap and capable low frequency inverters on the market that do the job efficiently. You don't need to go to the big name players with their big name price tags. In the back and beyond, warranty claims are nigh on impossible. Think self sufficiency. Sending a 25kg inverter in the post to Victron from a far flung place to meet the terms of the warranty isn't going to work. Safer to carry a spare or import one at the time.
Your lithium battery needs careful selection. Drop in replacements are improving. There are good guys such as Fogstar in the UK building nice spec batteries but there are many cheap chinese batteries that simply won't work if you want to run inverter loads.
The whole energy equation of battery size, BMS rating, inverter rating all needs working out and selecting as a whole to suit the envisaged loads. That's a whole new post 🙂
 

noelex

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I have now had three watermakers. One conventional model and two energy recovery models (on two differnt boats) over a period of 17 years. During this time they generated all our water except on our current boat that has a very efficient rain collection system, making running a watermaker unnecessary in wetter climates, but still very nice to have in dryer areas.

The post by Geem makes some valid points that should be considered, but the energy consumed by the watermaker still has to be replaced no matter what battery system is used.

The energy recovery watermakers use a fraction of the energy of the models without this feature.

Solar energy in the Caribbean is amazingly high and consistent all year, but if your goal is to cruise further afield you will find producing the energy to drive a non energy recovery watermaker is difficult without a generator especially on a monohull. The ability to cruise areas or seasons with relatively poor solar insolation without a generator is what makes the 12v energy recovery watermakers a popular choice even though, as you point out, they are significantly more expensive.

If you have plenty of solar and plan to cruise areas with good or very good solar insolation, or if you have a generator, the cheaper non energy recovery watermakers are the sensible choice. If this does not apply, you need to do your electrical sums carefully and check you have the energy to drive a watermaker. Often the only option is the more expensive energy recovery option and unfortunately these are not viable for DIY home construction.
 

Trident

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I agree with both of the above to some degree - despite being in some disagreement!

On a cat you can certainly generate enough solar in high latitudes to run pretty much anything except propulsion - we were in port all last year in the UK (ok not HIGH latitudes but not the Med or Caribbean and not optimal performance as we were fixed in an ok direction rather than facing south ) and ran our boat from February to November (well last week of October) on solar alone . This included hot water , full sized domestic fridge and freezer, two lap tops and all electric cooking. We would still have had power left each day to run a water maker for most of that time.

On a monohull with less real estate I agree it would be impractical in higher latitudes.
 

penfold

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RO plants are not complicated. They have specific requirements regarding water cleanliness and maintenance which if ignored may result in unhappiness and expense, but are not complex.
 

Trident

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You don't need to go to the big name players with their big name price tags. In the back and beyond, warranty claims are nigh on impossible. Think self sufficiency. Sending a 25kg inverter in the post to Victron from a far flung place to meet the terms of the warranty isn't going to work. Safer to carry a spare or import one at the time.
I assume you mention this as in a previous post I noted I had changed to Victron from the same model you have (3kw) prior to setting off because the spares and repair in far flung places would be an issue with most brands. I did actually speak to Victron prior to this choice and explained it was a critical part of our boat as almost everything is 240v on board and they confirmed they would whilst in warranty not need a return to base - they would send out a new one to us anywhere. Or if I diagnosed the fault then they would send whatever spares needed. I have a cheap back up too to keep the food frozen for a few weeks if needed as it would be silly to go far without.

The Power Star you have, and I had, is excellent but the UK importer don't even know where to get spares and it has a limited warranty. Also, as I just checked, the 3kw version is now £649 whilst my Victron 3kw was only £100 more - but its a small point - the less costly Power Star worked flawlessly for 3 years for me and the even lower cost 3kw bright orange model (LF toroidal sold under 4 or 5 brand names online) that I fitted for a friend that he paid £197 (!!) for is still working fine after almost 4 years too so your point on cost is well made
 

geem

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I assume you mention this as in a previous post I noted I had changed to Victron from the same model you have (3kw) prior to setting off because the spares and repair in far flung places would be an issue with most brands. I did actually speak to Victron prior to this choice and explained it was a critical part of our boat as almost everything is 240v on board and they confirmed they would whilst in warranty not need a return to base - they would send out a new one to us anywhere. Or if I diagnosed the fault then they would send whatever spares needed. I have a cheap back up too to keep the food frozen for a few weeks if needed as it would be silly to go far without.

The Power Star you have, and I had, is excellent but the UK importer don't even know where to get spares and it has a limited warranty. Also, as I just checked, the 3kw version is now £649 whilst my Victron 3kw was only £100 more - but its a small point - the less costly Power Star worked flawlessly for 3 years for me and the even lower cost 3kw bright orange model (LF toroidal sold under 4 or 5 brand names online) that I fitted for a friend that he paid £197 (!!) for is still working fine after almost 4 years too so your point on cost is well made
We paid £350 for ours from Photonic Universe in 2016. We got some seawater in it. Don't ask how. We spoke to the engineer at PU and he diagnosed the failure. A new circuit board for £85 fitted by me. Very happy with the service.
We have friends who have had Victron inverter failure and found it impossible to get support from the Victron dealer network out here. They have ended up just buying new. I hope you are correct that Victron will deal with you direct. I have yet to see that. A failure of our MPPT resulted in them referring us to the local dealer. No help at all. They aren't interested unless you bought from them
 
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noelex

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I agree with both of the above to some degree - despite being in some disagreement!
:)
On a cat you can certainly generate enough solar in high latitudes to run pretty much anything except propulsion - we were in port all last year in the UK (ok not HIGH latitudes but not the Med or Caribbean and not optimal performance as we were fixed in an ok direction rather than facing south ) and ran our boat from February to November (well last week of October) on solar alone . This included hot water , full sized domestic fridge and freezer, two lap tops and all electric cooking. We would still have had power left each day to run a water maker for most of that time.

On a monohull with less real estate I agree it would be impractical in higher latitudes.
Cats have an envious amount of real estate for solar, but it still takes some electrical planning to produce enough energy in the UK during autumn to run all systems, so well done.

With covid we spent a winter in Scotland at anchor and could just manage on solar alone, although we did need to start the main engine and use the alternator for a short run on four occasions during the winter months to supplement the solar production. There is no way we could have run a non energy recovery watermaker even occasionally without very long and frequent engine runs or without buying a generator.

No one (well no one sensible :) ) plans to cruise winter in Scotland (although it is beautiful and we had a great time), but few monohulls have enough solar to run a non energy recovery watermaker in cruising grounds that have even average rather than very good solar insolation. Confining cruising to only the consistently very sunny parts of world is a common plan and if this is the aim a non energy recovery watermaker is the better choice in my view, but if you want to explore further afield you need to figure out where the energy to run the watermaker is going to come from and this usually means an energy recovery watermaker is the only choice (on a monohull) unless you want an expensive bit of equipment with no ability to run it.
 
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Trident

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We paid £350 for ours from Photonic Universe in 2016. We got some seawater in it. Don't ask how. We spoke to the engineer at PU and he diagnosed the failure. A new circuit board for £85 itted by me. Very happy with the service.
We have friends who have had Victron inverter failure and found it impossible to get support from the Victron dealer network out here. They have ended up just buying new. I hope you are correct that Victron will deal with you direct. I have yet to see that. A failure of our MPPT resulted in them referring us to the local dealer. No help at all. They aren't interested unless you bought from them
Yes others have mentioned this on the forum - though Irish Rover who had an MPPT failure managed after a run around to get hold of the boss of Victron through the Victron forum on their site, who immediately sorted it. As a Victron dealer I specifically asked the question of head office and perhaps it was that status that got me an assurance or perhaps its what the head office tell everyone but only time will tell and I hope I never need to find out.

Photonic Universe have always been a great company to deal with but I must say that I had not got the impression from them that parts were easily available for the inverters so I'm please to hear your story.

On the plus side my Victron does have the blue tooth app so I can see exactly what is being generated at any given moment (sometimes quite alarmingly different from what's expected - I have two identical Quick calorifiers with the same 800w elements but one uses 880w and the other 1020w when in use. My 800w microwave uses 1100w most of the time) and its a lovely shade of Blue :D On the down side, the size of it made fitting much more tricky than the PU one which sat on a shelf above the batteries and I didn't have a set of scales to hand but I'm bugging**ed if Victron are actually accurate about their weights - the Victron was supposed to be 1 kg heavier and felt considerably more.

My shoulder may still require surgery after trying to put a "30Kg" 5kw Quattro in a boat last year!
 

geem

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:)

Cats have an envious amount of real estate for solar, but it still takes some electrical planning to produce enough energy in the UK during autumn to run all systems, so well done.

With covid we spent a winter in Scotland at anchor and could just manage on solar alone, although we did need to start the main engine and use the alternator on four occasions during the winter months to supplement the solar production. There is no way we could have run a non energy recovery watermaker even occasionally without very long and frequent engine runs or without buying a generator.

No one (well no one sensible :) ) plans to cruise winter in Scotland (although it is beautiful and we had a great time), but few monohulls have enough solar to run a non energy recovery watermaker in cruising grounds that have even average rather than very good solar insolation. Confining cruising to only the consistently very sunny parts of world is a common plan and if this is the aim a non energy recovery watermaker is the better choice in my view, but if you want to explore further afield you need to figure out where the energy to run the watermaker is going to come from and this usually means an energy recovery watermaker is the only choice (on a monohull) unless you want an expensive bit of equipment with no ability to run it.
I don't disagree. It why I said Tropics in my post.
We have a diesel generator that is getting its first run today. It's not been run for 2 weeks. I am running it just to run it, so it's making water. At a later date we may remove it but I will replace it with a high output 24v alternator. I have one onboard to fit. 155A at 24v so huge charging abilty for lithium if I fit a Wakespeed regulator. I guess circa 80A continuous at 24V.
 
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Kelpie

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I agree that if you have a beefy 240v system already in place, it makes sense to use it to run the water maker.
We're finding the Caribbean surprisingly rainy, compared to the Med. So slightly lower solar output. However it's working out better for us, because we don't have a water maker but we do collect rainwater.
We're pretty frugal with water, it's now a month since we last filled the 370l tank, and we're about half full. The rainwater extends our time between fills but we don't put it in the main tanks for fear of contamination.
 

geem

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We have a rainwater collection system on our boat. We fitted fabric gutters to the over boom sun cover. Our record is 500 litres in 2 hours in a tropical downpour in Curacao.
It's worth noting how dirty rainwater is. We use a 1 micron filter in a 10" clear housing to filter rainwater before it goes in the tank. That filter gets really grubby, really quickly. It's a very good idea not to put rainwater in your tank without good filtration
 

Kelpie

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We have a rainwater collection system on our boat. We fitted fabric gutters to the over boom sun cover. Our record is 500 litres in 2 hours in a tropical downpour in Curacao.
It's worth noting how dirty rainwater is. We use a 1 micron filter in a 10" clear housing to filter rainwater before it goes in the tank. That filter gets really grubby, really quickly. It's a very good idea not to put rainwater in your tank without good filtration
Ours goes in to a collection of jerry cans and whatever else we can find. Used mostly for showering, which is probably the single biggest consumer of water.
 

geem

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Ours goes in to a collection of jerry cans and whatever else we can find. Used mostly for showering, which is probably the single biggest consumer of water.
Try having a dog onboard. She gets more showers than us trying to get the sand off her🙂
 

noelex

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I agree that if you have a beefy 240v system already in place, it makes sense to use it to run the water maker.
We're finding the Caribbean surprisingly rainy, compared to the Med. So slightly lower solar output. However it's working out better for us, because we don't have a water maker but we do collect rainwater.
We're pretty frugal with water, it's now a month since we last filled the 370l tank, and we're about half full. The rainwater extends our time between fills but we don't put it in the main tanks for fear of contamination.
The Med is great in summer for solar production, but the winters are nowhere near as good. The Caribbean is more consistent.

When we collect rainwater it is filtered, but then enters a seperate tank. This means we can then use some very fine filters via a pump to make sure it is clean before it enters our main tank. It is a simple system that could be retrofitted to many boats. Even with a watermaker it provides an independent back up.
 
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geem

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The Med is great in summer for solar production, but the winters are nowhere near as good. The Caribbean is more consistent.

When we collect rainwater it is filtered, but then enters a seperate tank. This means we can then use some very fine filters via a pump to make sure it is clean before it enters our main tank. It is a simple system that could be retrofitted to many boats. Even with a watermaker it provides an independent back up.
Not dissimilar to us except our filtration is gravity. 1" diameter pipes off the sun cover run into a tee then 1" to the filter before the tank filler. It's amazing seeing the 1" pipes running full bore into the tank in a heavy rain storm. We don't use the system often but it's convenient when there is little sun about for solar but plenty of cloud about for heavy rain.
 

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I saw a great system on another boat - deck drain at the lowest point with a y piece under - first few minutes of rain and its diverted to overboard to take away any bird muck and dust and then switch over to filling the tank via a gravity filter.

An American with the same system commented that theirs doubled as their main tank fill also, so that when asleep or off the boat they could set it to divert overboard so no one could drug their water to rob the boat or murder them ... it must be very stressful to live in such perpetual fear.
 

geem

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I saw a great system on another boat - deck drain at the lowest point with a y piece under - first few minutes of rain and its diverted to overboard to take away any bird muck and dust and then switch over to filling the tank via a gravity filter.

An American with the same system commented that theirs doubled as their main tank fill also, so that when asleep or off the boat they could set it to divert overboard so no one could drug their water to rob the boat or murder them ... it must be very stressful to live in such perpetual fear.
We have a dog. No way I want to collect off the deck. The sun cover is amazingly effectively.received_231663256251077.jpeg
 
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Marceline

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really interesting thread and thanks for posting

we're a way off getting a watermaker but hoping to do down the line (need a bigger boat first)

could I ask, what makes of energy recovering watermakers do you recommend ?
 

geem

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really interesting thread and thanks for posting

we're a way off getting a watermaker but hoping to do down the line (need a bigger boat first)

could I ask, what makes of energy recovering watermakers do you recommend ?
I am not the person to ask. Having gone from enery recovery on my own boat, to fixing a few on others boats, I wouldn't put another on my boat. With lithium don't think there is a reason to fit one any more.
 

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This again?

Schenker modular 30 (12V):
Power consumption: 96W
Current draw at 12V: 8A
Water production: 30L/h
Water production/Ah: 30/8 = 3.75L/Ah

Rainman (230V):
Power consumption = 2kW
Current draw at 12V (via inverter) = 2000/12 = 166A
Water production = 60L/h
Water production/Ah = 60/166 = 0.36L/Ah

The Schenker we've been using all the way from UK to NZ has let us down once with a cracked low-pressure hose. Across the Pacific it supplied enough water for 6 people to shower every day, and we never had to run the engine to generate power (we have a Watt and Sea towed generator). At anchor, we generate all our power with 700W of solar, and this has been sufficient, at all times except winter in Wellington. If we had to use 10x more energy for each litre of water, we would certainly have run the engine more often to keep up with power demands on board.
 
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