12v Watermaker - Experiences for article?

[double u]

“Sailing is not green? How's that figured?“
Neither our solarpanels nor our boat grew on trees & we did not earn the money to buy her as subsistence farmers, but maybe your boat did...

[zstine]

Originally Posted by double u

“Sailing is not green? How's that figured?“
Neither our solarpanels nor our boat grew on trees & we did not earn the money to buy her as subsistence farmers, but maybe your boat did...

Yes, I agree there is a carbon footprint to building boats and solar panels. But the lifetime emissions of solar panels compared to a gasoline generator is SUPER Tiny! Just like the lifetime footprint of a sailboat compared to a typical house is SUPER Tiny!

My point is, regarding the OP, Solar is way more green than a generator over it's lifetime (No, not zero carbon). Solar is also cheaper and easier to maintain over a 2 decade life. It's pretty easy to find space for 600-800 watts of solar on a mono and over 1000W on a cat. That's enough power to satisfy your average live-aboard lifestyle, including watermakers, without anything else... It seemed like some were arguing to forgo solar b/c your going to want a generator anyway, so why bother with solar.... My answer is, no you don't need a generator and regardless if you do, solar is still easier to maintain, more reliable when in the middle of nowhere and social responsible. IMO Solar should be the primary power source for any topical or sub tropic sailing boats. Generators a backup

[SV THIRD DAY]

Originally Posted by Paul L

T
Yes, a Spectra is typically about 2x the output per amphour than an average 12v DC system. It is many times more efficient than the typical AC units, as I showed above comparing a 20gph CruiseRo vs a 15gph Spectra.
The pricing for main stream models is higher for Spectra, but not really that much more. Compare a Village Marine vs a Spectra for example.

But since the SM30 outsells the SM20 by 5:1, it's a better water maker to run the number on...simply because you get 50% more fresh water production for the same power usage.

The SM30 will make 33GPH and use 9.3A or 1100W.
When you turn that into a DC power load to compare with a Spectra (which is comparing the fuel economy of Sports car to a Prius) you see the following.
The SM30 load through a typical inverter is 100A DC.
100A/33Gals = 3.03Amps/Gal of water made.
Spectra does it for about 1Amp/Gal.

But it's meaningless and a false comparison because it totally misses the point. You don't buy a piston pump energy hog style water maker because your engineering criteria is getting the lowest Amps/Gal of water produced. You buy a piston pump unit because you already have or plan to have a generator aboard the boat. That decision opens you up (or some would say frees you) from limitations of a low output water maker.

Having just returned from the Annapolis Boat Show, when folks walked into the booth without a Generator or no plans for one (unless they had LiFePO4 batteries), I would send them down to talk to Tellie in the Spectra booth. But the generatorless boat also isn't the norm today for the larger boats. Of the 13 water makers we sold at the Annapolis Show 10 went on boats with Generators and 3 went on boats with LiFePO4 batteries. But never once did I try to convince someone without a generator or plans to have a generator to buy a piston pump energy hog. An important factor in having happy customers is in NOT selling them something that won't fit their needs, even if they want one!

This "efficiency debate" inevitably happens, but doesn't make sense at the end of the day when you get deeper into the buying decisions of an AC vs DC water maker. Why? Well the DC approach cares about efficiency because they make water by taking power FROM the battery bank while the AC water maker does so while putting power INTO the battery Bank.
A Totally different Mindset.

An important point that usually gets missed in the "my approach is better" or the "it worked for me" comments is that as long as you understand the differences and options and make an informed decision to get what works best for YOUR boat....there isn't a Wrong Answer to the AC vs DC water maker question. And that's often what's hard for the Cruiser in Planning, they hear the "I Love my XXX" brand of cruising gear but oftentimes without the context why/how brand "XXX" works for one Cruiser while it wouldn't for another. It's also the value of Cruisers Forum where we can talk a little more about the details behind the decisions.

Cheers

[john61ct]

Originally Posted by SV THIRD DAY

You don't buy a piston pump energy hog style water maker because your engineering criteria is getting the lowest Amps/Gal of water produced. You buy a piston pump unit because you already have or plan to have a generator aboard the boat.
..
This "efficiency debate" inevitably happens, but doesn't make sense at the end of the day when you get deeper into the buying decisions of an AC vs DC water maker. Why? Well the DC approach cares about efficiency because they make water by taking power FROM the battery bank while the AC water maker does so while putting power INTO the battery Bank.

That is indeed the crux of the matter.

With the caveat that "AC / genset" really should be generalized as "ICE power" sources, the key factor being high amps input, as opposed to

lower-amp "alternative" sources like solar, wind, hydro.

DC gensets and/or high-output alternators being included in the former group.

An LFP bank being helpful in capturing that high-amp output. If large enough, gives you the option of time-shifting the running of high-amp loads, no longer needs to be concurrent with the energy input.

At which point, the choice between high-gph, vs energy-efficient low-gph WMs, becomes,

do you want infrequent short runtimes, or frequent, long runtimes?

and issues like space occupied and portability.

______
And nitpicky, amps should be Ah in some of these sentences. . .


> The SM30 will make 33GPH and use 9.3A or 1100W.

> The SM30 load through a typical inverter is 100A DC.

are both fine, instantaneous or average measure of power rate

But these:

> 100A/33Gals = 3.03Amps/Gal of water made.
Spectra does it for about 1Amp/Gal.

all need to be measured - as "static" energy quantities - in Ah or Wh per gallon.

**if** you actually care about energy efficiency, which in using high-amp ICE sources is largely irrelevant

[SV THIRD DAY]

Originally Posted by john61ct

That is indeed the crux of the matter.

With the caveat that "AC / genset" really should be generalized as "ICE power" sources, the key factor being high amps input, as opposed to

lower-amp "alternative" sources like solar, wind, hydro.

DC gensets and/or high-output alternators being included in the former group.

An LFP bank being helpful in capturing that high-amp output. If large enough, gives you the option of time-shifting the running of high-amp loads, no longer needs to be concurrent with the energy input.

At which point, the choice between high-gph, vs energy-efficient low-gph WMs, becomes,

do you want infrequent short runtimes, or frequent, long runtimes?

and issues like space occupied and portability.

______
And nitpicky, amps should be Ah in some of these sentences. . .


> The SM30 will make 33GPH and use 9.3A or 1100W.

> The SM30 load through a typical inverter is 100A DC.

are both fine, instantaneous or average measure of power rate

But these:

> 100A/33Gals = 3.03Amps/Gal of water made.
Spectra does it for about 1Amp/Gal.

all need to be measured - as "static" energy quantities - in Ah or Wh per gallon.

**if** you actually care about energy efficiency, which in using high-amp ICE sources is largely irrelevant

It's more than a water maker run time decision, you have the complexity and cost of an energy recovery proprietary pump vs an off the shelf pump. Also for the larger boats that want to live afloat like they live on land, you just can't make enough water with a DC water maker to keep the Wife on that 48ft Cat happy! And if mamma ain't happy....no body's Happy....

[john61ct]

Yes, ability to repair in primitive locations can be critical for many.

Not going to touch that "keeping mama happy" factor 8-)

[69Datsun510]

I've been researching watermakers, Cruise RO S30, Little Wander 145/180, and Spectra units. I'm looking to set my 2013 L400S2 for cruising. I currently don't have an onboard gen set or decent house battery amp hours. I do have a Honda 2000i, I plan to have as a back up to my power system.

One thing I don't think I read on this thread, is the noise and fumes from any generator. I don't like either, and only put up with it on my weekend sailboat because I didn't have solar, and often wasn't able to plug in.

With my L400, I don't want to spend the money on installing a large onboard diesel gen set, its expensive, and involves lots of maintenance. I'd rather spend the money on a large solar array, I have the ability to do so with a Cat, add 4x 1000Ah Winston Thundersky cells batteries, about 3000Ah, inverters for the AC stuff, and DC from the batteries.

So, solar is free, no fuel to shuttle or pay for, no noise, no fumes, and have my Honda for back up should my solar fail or not produce enough. Plus the Honda is easily replaced and lighter, then an onboard gen.

So, since I believe you can never have enough power, saving as much as you can, while living comfortably, is a priority for off the grid.

So, this thread has helped me rule out the Cruise RO watermaker, and I like very much, but was looking at running the Honda for water, or try out a soft start the AC motor, as an option. I still think using a large enough inverter, the power to run the RO is to demanding on the system overall.

Brings me to the Little Wanderer, similar to the RO system, but can be run off DC battery supply. The Spectra would be my best option for saving power for gallons of water made.

My question is for those who have knowledge or had both, the Little Wanderer and Spectra unit. Which is easier to maintenance, install, get parts for, tear apart and rebuild? Which one is reliable if serviced regularly as need with filters? The best, most reliable HP pumps, will break down, if not looked after. Water keeps the pumps friction down and cools them, to keep the clearances correct.

Any advise would be helpful, Thanks

[Mr B]

Originally Posted by 69Datsun510

I've been researching watermakers, Cruise RO S30, Little Wander 145/180, and Spectra units. I'm looking to set my 2013 L400S2 for cruising. I currently don't have an onboard gen set or decent house battery amp hours. I do have a Honda 2000i, I plan to have as a back up to my power system.

One thing I don't think I read on this thread, is the noise and fumes from any generator. I don't like either, and only put up with it on my weekend sailboat because I didn't have solar, and often wasn't able to plug in.

With my L400, I don't want to spend the money on installing a large onboard diesel gen set, its expensive, and involves lots of maintenance. I'd rather spend the money on a large solar array, I have the ability to do so with a Cat, add 4x 1000Ah Winston Thundersky cells batteries, about 3000Ah, inverters for the AC stuff, and DC from the batteries.

So, solar is free, no fuel to shuttle or pay for, no noise, no fumes, and have my Honda for back up should my solar fail or not produce enough. Plus the Honda is easily replaced and lighter, then an onboard gen.

So, since I believe you can never have enough power, saving as much as you can, while living comfortably, is a priority for off the grid.

So, this thread has helped me rule out the Cruise RO watermaker, and I like very much, but was looking at running the Honda for water, or try out a soft start the AC motor, as an option. I still think using a large enough inverter, the power to run the RO is to demanding on the system overall.

Brings me to the Little Wanderer, similar to the RO system, but can be run off DC battery supply. The Spectra would be my best option for saving power for gallons of water made.

My question is for those who have knowledge or had both, the Little Wanderer and Spectra unit. Which is easier to maintenance, install, get parts for, tear apart and rebuild? Which one is reliable if serviced regularly as need with filters? The best, most reliable HP pumps, will break down, if not looked after. Water keeps the pumps friction down and cools them, to keep the clearances correct.

Any advise would be helpful, Thanks

My little wonder ran perfectly with no problems till I sunk my boat and the motor got drowned beyond repair,
See my posts 12 and 24 to see how I got around the expensive 12 volt motor replacement of it,
The 240 volt pressure washer runs my little wonder from the invertor,
At $90-00 its a throw away job if it ever dies and I just put another one in its place,

[jmh2002]

An interesting move is starting to happen on some boats though (regardless of whether the watermaker is AC or DC powered).

Some boats (mostly cats) with huge Solar capacity are starting to say:

- I don't care as much about watermaker efficiency anymore
- Because after my batteries are full I'm still making so much excess Solar Power during the day
- So I would prefer to make as much water as possible during this period with this free energy

This is starting to be similar to Generator mindset:

- I'm running the Genset anyway (I'm running the Solar anyway?)
- So let's have big enough equipment to Charge Batteries and Make Water in the shortest amount of (genset run) time as possible.

So in the case of the Solar boat with excess capacity, a higher output but less energy efficient watermaker may in fact make more sense. It might even be cheaper too (or the same price but more GPH).

It's food for thought. The decision making process is changing.

[motion30]

That is exactly my situation I have a 1740 watts of solar panels so I just run the Watermaker midday and the solar covers the 80amps 12 volt usage

[jmh2002]

Originally Posted by motion30

That is exactly my situation I have a 1740 watts of solar panels so I just run the Watermaker midday and the solar covers the 80amps 12 volt usage

That's awesome

Can you please give some more specific details of your setup? I think it would add another dimension to this discussion. Thanks!

[jmh2002]

I would also say that in the case of a primarily Solar boat like that, but when conditions prevent a full charge during the day (or over the space of a few days) and it finally becomes necessary to run a Genset, the same mindset would apply:

- I want to charge and make water in the shortest possible time

[motion30]

Originally Posted by jmh2002

That's awesome

Can you please give some more specific details of your setup? I think it would add another dimension to this discussion. Thanks!

I have four 435 Watt sunpower high efficiently panels installed. Charging tru two outback 80 amp controllers. I started out with a 110volt sea waterpro Watermaker. Making 23 gal an hr. Added second membrane. To make 35 to 40 gal per hr. Replaced the 110v motor with a 1hp 12 volt motor. with a 12 volt feed pump. It draws 80 amps dc. I have had this setup about 6 months. I only need to run the water about 1 hr a week. .i have a large battery bank of trojan gc. Batteries. 1350 amp hrs. That is a valid point about having continuing cloudy days. In 6 months i have only tun the gen set maybe 3 or 4 hrs. I also make hotwater tru the inverter. These are both optional procedures. So i can usually until the sun shines

[jmh2002]

Sounds like a good setup

And if you only need to run the watermaker once per week that gives you a lot of flexibility between cloudy days, or using more water/electricity and needing to balance where the Solar input will be prioritised.

What was the reason (in your case) for switching to the DC motor? Not enough inverter capacity to power the water heater AND the watermaker at the same time, or?

Maybe this was more economical (or maybe just simpler) than upgrading to a bigger inverter?

What size and type of boat is this, how many people are normally onboard, and where are you cruising (re, how much sun per day)?

[Paul L]

Originally Posted by 69Datsun510

I've been researching watermakers, Cruise RO S30, Little Wander 145/180, and Spectra units. I'm looking to set my 2013 L400S2 for cruising. I currently don't have an onboard gen set or decent house battery amp hours. I do have a Honda 2000i, I plan to have as a back up to my power system.

One thing I don't think I read on this thread, is the noise and fumes from any generator. I don't like either, and only put up with it on my weekend sailboat because I didn't have solar, and often wasn't able to plug in.

With my L400, I don't want to spend the money on installing a large onboard diesel gen set, its expensive, and involves lots of maintenance. I'd rather spend the money on a large solar array, I have the ability to do so with a Cat, add 4x 1000Ah Winston Thundersky cells batteries, about 3000Ah, inverters for the AC stuff, and DC from the batteries.

So, solar is free, no fuel to shuttle or pay for, no noise, no fumes, and have my Honda for back up should my solar fail or not produce enough. Plus the Honda is easily replaced and lighter, then an onboard gen.

So, since I believe you can never have enough power, saving as much as you can, while living comfortably, is a priority for off the grid.

So, this thread has helped me rule out the Cruise RO watermaker, and I like very much, but was looking at running the Honda for water, or try out a soft start the AC motor, as an option. I still think using a large enough inverter, the power to run the RO is to demanding on the system overall.

Brings me to the Little Wanderer, similar to the RO system, but can be run off DC battery supply. The Spectra would be my best option for saving power for gallons of water made.

My question is for those who have knowledge or had both, the Little Wanderer and Spectra unit. Which is easier to maintenance, install, get parts for, tear apart and rebuild? Which one is reliable if serviced regularly as need with filters? The best, most reliable HP pumps, will break down, if not looked after. Water keeps the pumps friction down and cools them, to keep the clearances correct.

Any advise would be helpful, Thanks

It is not just the noise and fumes of a genset, more of an issue is the added heat they put into a boat in the tropics.

I've cruised with both a Village Marine and a Spectra. Had about 2,000 hours (14,000 gals) on the VM when I sold it. Very reliable and parts are available. So far my Spectra hasn't needed any service, but it only has 330 hours (5,000gals).