How do you heat your water with an electric engine?

[Popeye46]

Originally Posted by Rohan

Just curious - those who have switched their engines from diesel to electric, is there another option for heating your water?

I suppose if you still have a marine diesel generator, you could heat the water though that, although it wouldn't do the job as well. You could also use your battery power to heat the water too, but that would drain your batteries pretty quick. So I'm wondering, are there other solutions out there?

Have a look at Whispergen made in Europe. Used in areas where they don’t get strong sun such as the UK. It heats water using a small amount of diesel. It is NOT a diesel engine ànd it’s very quite. No I don’t sell them.
Fair winds and following seas
Popeye

[Dockhead]

Originally Posted by Popeye46

Have a look at Whispergen made in Europe. Used in areas where they don’t get strong sun such as the UK. It heats water using a small amount of diesel. It is NOT a diesel engine ànd it’s very quite. No I don’t sell them.
Fair winds and following seas
Popeye

Whispergen was made in New Zealand, not Europe.


The factory was destroyed in the earthquake of February, 2011 -- ten years ago! And was not rebuilt.



It was a great device, but this tip is more than 10 years out of date!

[Andy Lange]

When I bought my boat last year I was faced with the same question on how to heat up water for showers. As I wanted to stay as green as possible the decision was easy. I use instant water heaters in both of my showers.

The benefit is clear. As the instant water heaters outlets are connected directly to the shower, you are having hot water within 6-7 seconds. The units only switch on when you have water flow, so no heat loss as there is no pre water heating and hot water storage needed.
The instant water heaters are power hungry, however, since they only need to run for 3-4 min per person a day the overall daily power consumption in my case is negligible (less than 2 percent per person/day from the generated solar energy).

I say in my case, because I wanted to go as green as possible from the onset.
I have installed a total of 1600W of solar panels that charge my 4 x 12V 200A/h LIFEPO4 lithium battery bank. That's a total of just over 10KW/h.
I also installed very efficient 2 x 5000W 220V inverters and each instant water heater is connected to a separate inverter, which allows for 2 people to have a shower at the same time without triggering a fuse.
This also allows for electric cooking, running laptops and other power hungry appliances like kettles, media center, editing suite, separate freezer and everything else on the boat.

I don't need (nor have) a gen set, wind turbine (only work when there is wind and too noisy) or a hydro generator (doesn`t work on anchor, where we all sit for long periods when cruising).

I have started to use my system last year in July when I started my circumnavigation in Europe, had always between 2 and 4 people onboard and not once did I have to use shore power, engine power, nor any kind of fossile fuel, even when I had longer spells of over cast or storms. I have done a total of about 10.000NM since and the system runs flawlessly!

The key is to build an efficient system that can easily handle energy peaks from kettles, electric cookers or instant water heaters.

Also having had a look at my little use of the (still original) Yanmar diesel engine, I will definitely get rid of it and replace it with an electric one. In the last 5000NM I only used up about half of a tank of fuel, mainly getting on or off an anchor or short trips, so in my case electric propulsion will work.

In case anyone is interested in more details I`d be happy to post more about my setup.

[Montanan]

Originally Posted by Rohan

Just curious - those who have switched their engines from diesel to electric, is there another option for heating your water?

. . .
You could also use your battery power to heat the water too, but that would drain your batteries pretty quick. So I'm wondering, are there other solutions out there?

Simple enough to use an electric powered heat pump, either an air source of heat, or a water source of heat. A heat pump is essentially a vapor compression air conditioning unit running in reverse mode as compared to the cooling mode. The coefficient of performance will typically be about 3.5 to 1, which is 3.5 times better than using just resistive electrical heating elements which have a COP of 1. Many units provide for both heating and cooling modes. Also one could readily take heat from the condenser of your air conditioning system to heat your water when you are cooling your boats interior.

No difference between the mechanisms of maritime heating and cooling and land based heating and cooling.

All the best.

[Icarus]

Originally Posted by Rohan

Just curious - those who have switched their engines from diesel to electric, is there another option for heating your water?

I suppose if you still have a marine diesel generator, you could heat the water though that, although it wouldn't do the job as well. You could also use your battery power to heat the water too, but that would drain your batteries pretty quick. So I'm wondering, are there other solutions out there?

LPG instant water heater?
Boil water in a kettle?
WEBASTO diesel water heater works on my boat.

[Corbin39dream]

Originally Posted by Andy Lange

When I bought my boat last year I was faced with the same question on how to heat up water for showers. As I wanted to stay as green as possible the decision was easy. I use instant water heaters in both of my showers.

The benefit is clear. As the instant water heaters outlets are connected directly to the shower, you are having hot water within 6-7 seconds. The units only switch on when you have water flow, so no heat loss as there is no pre water heating and hot water storage needed.
The instant water heaters are power hungry, however, since they only need to run for 3-4 min per person a day the overall daily power consumption in my case is negligible (less than 2 percent per person/day from the generated solar energy).

I say in my case, because I wanted to go as green as possible from the onset.
I have installed a total of 1600W of solar panels that charge my 4 x 12V 200A/h LIFEPO4 lithium battery bank. That's a total of just over 10KW/h.
I also installed very efficient 2 x 5000W 220V inverters and each instant water heater is connected to a separate inverter, which allows for 2 people to have a shower at the same time without triggering a fuse.
This also allows for electric cooking, running laptops and other power hungry appliances like kettles, media center, editing suite, separate freezer and everything else on the boat.

I don't need (nor have) a gen set, wind turbine (only work when there is wind and too noisy) or a hydro generator (doesn`t work on anchor, where we all sit for long periods when cruising).

I have started to use my system last year in July when I started my circumnavigation in Europe, had always between 2 and 4 people onboard and not once did I have to use shore power, engine power, nor any kind of fossile fuel, even when I had longer spells of over cast or storms. I have done a total of about 10.000NM since and the system runs flawlessly!

The key is to build an efficient system that can easily handle energy peaks from kettles, electric cookers or instant water heaters.

Also having had a look at my little use of the (still original) Yanmar diesel engine, I will definitely get rid of it and replace it with an electric one. In the last 5000NM I only used up about half of a tank of fuel, mainly getting on or off an anchor or short trips, so in my case electric propulsion will work.

In case anyone is interested in more details I`d be happy to post more about my setup.

Hey Andy, I sent you a message with Skype to discuss your solar setup, as I am planning to get a boat soon.It will require a refit to add solar power and hopefully, a new bank of lithium batteries. I am wondering what brands and how much I should expect for a reliable and efficient solar power system. Thanks!

[MAJICDAN]

The golf cart batteries I bought from Sams spring sale for $69 ea, reg pricy$89 each. I have had them for over five years and I load test them every spring. All my batteries fit under the floor. I can buy 22 of them for less than one 120 amp lithium battery.

[AndyEss]

Originally Posted by MAJICDAN

The golf cart batteries I bought from Sams spring sale for $69 ea, reg pricy$89 each. I have had them for over five years and I load test them every spring. All my batteries fit under the floor. I can buy 22 of them for less than one 120 amp lithium battery.

22 golf cart batteries x $89 = $1958

Electriccarparts in SaltLakeCity has 100AH Calb cells at $124 ea or $496 for a 12V nominal battery. Say $600 for 120 AH equivalent to your example.
Your number seems to be 326% too high.

I don’t know about you, but lugging any number of lead acid batteries over a nearly once in a boat ownership LFP install makes my lower back sing in joy.

[AndyEss]

Just went on the Sam’s Club site - your $69 GC2 battery is 6 volt, not 12, so you need two each to equal the LFP I compared it to, so you are 652% off in your example.
Further, the GC2 battery has a 20 A rating of 215 AH. At 5A, it drops to 157 AH. Considering lead acid batteries shouldn’t be drawn down below 50%, while LFP can handle 80% drawdown, makes your analysis closer to about 800% off.

I used the regular, not sale price, because they always won’t be on sale.

[Dockhead]

Originally Posted by Montanan

Simple enough to use an electric powered heat pump, either an air source of heat, or a water source of heat. A heat pump is essentially a vapor compression air conditioning unit running in reverse mode as compared to the cooling mode. The coefficient of performance will typically be about 3.5 to 1, which is 3.5 times better than using just resistive electrical heating elements which have a COP of 1. Many units provide for both heating and cooling modes. Also one could readily take heat from the condenser of your air conditioning system to heat your water when you are cooling your boats interior.

No difference between the mechanisms of maritime heating and cooling and land based heating and cooling.

All the best.

Most marine air conditioning systems are reverse cycle, so can be used as heat pumps. We had a Cruiseair system on the previous boat.


But the coefficient of performance depends on the temperature of the heat source. In Florida with warm water year round it was pretty good; but where I sail now, with water temp in single digits (C) year round, no one uses heat pumps.


They also need a lot of electrical power. Fine at the dock, but off grid you can't practically run a heat pump without a generator, and that's inefficient compared to just burning the stuff in a furnace.

[MAJICDAN]

Was just quoted almost $1800 for one LIFEPO 120 amp battery.
Sams spring gulf cart sale $69 ea
Maybe someday they may be cost effective but today IMHO only race boats, the rich , or foolish would spend that kind of money..
I usually sail 5000-6000 miles a year.
I can not afford to spend that kind of money on batteries.

[Statistical]

Originally Posted by MAJICDAN

Was just quoted almost $1800 for one LIFEPO 120 amp battery.
Sams spring gulf cart sale $69 ea
Maybe someday they may be cost effective but today IMHO only race boats, the rich , or foolish would spend that kind of money..
I usually sail 5000-6000 miles a year.
I can not afford to spend that kind of money on batteries.

First it is Ah and second well you should shop around because that is an asininely horrible price for lithium these days.

Here now you have been quoted one for almost 2/3rds less so you can start using $670 instead of $1,800 when trying to prove a point.
https://www.expertpower.us/products/ep12100-100ah

Seriously that took all of a 30 second google search. Those looking for deals will spend less. Yes lithium is more expensive but your comparison is apples to oranges.

1) The batteries you use as 6V so 12V would require two and thus double the cost.
2) Realistically you will not discharge lead acid below 50% so a lead acid battery bank with the same USABLE capacity will require more batteries.
3) Battery longevity on a lithium iron battery is significantly higher for the same duty cycle. So really you should be comparing 3 sets of lead acid batteries to one lithium.
4) Quoting a price almost 3x what is easily obtaine is also going to make a biased comparison.

Put all four of those together and yes lithium iron is more expensive but not significantly so certainly not your dubious 30x the cost claim. Nowhere close to that.

[Dockhead]

Originally Posted by MAJICDAN

Was just quoted almost $1800 for one LIFEPO 120 amp battery.
Sams spring gulf cart sale $69 ea
Maybe someday they may be cost effective but today IMHO only race boats, the rich , or foolish would spend that kind of money..
I usually sail 5000-6000 miles a year.
I can not afford to spend that kind of money on batteries.

Golf cart batts may well be the best solution for your use case. It's what I use.


However, lithium is superior in many ways, and is actually cheaper than lead for people who use them intensively. Lithium lasts much longer so is cheaper per kWH you cycle through them, than lead.


But not if you buy drop-in lithium battery replacements. Lithium can be cheaper and starts to make sense for more people when your electrical system is configured to use the LiFePo cells.


Building a boat from scratch there's not a lot of cost involved in having the system properly configured for LiFePo, but re-configuring a boat designed for lead might be unreasonably costly especially if you don't do the work yourself.


I was going to switch my boat over last year and then ran out of time and aborted the project. Doing the work myself and with some elements of the system already in place (like proper Victron charger/inverter) it would have made sense from an economic point of view, given the kind of usage on my boat (sometimes off grid for 2 or 3 months at a time).


YMMV.

[sailingabe41ds]

Originally Posted by seandepagnier

What is the point of the electric boat if you burn diesel fuel? This is completely backward way of thinking shows lack of innovation, and essentially misunderstanding of use of energy. Your suggestion to use fuel doesn't pay for the true cost of the fuel, otherwise it would not be affordable compared to alternatives. Suggesting using fuel is essentially suggesting it is ok to not pay the price, which is actually stealing as you deprive others from the world you inherited.



1) evaccuated solar tube. This makes super solar oven as well as can boil water in freezing. With one of these rigged up, it is smaller than a 30 watt solar panel but could give you gallons of hot water in little time most of the time for shower etc. This is like steroids version of solar shower which works even on partial overcast/windy/cold weather.



2) wood stove. This is how you can have space heating and water heat in the winter or overcast/raining. It takes about 10 pinecones to make a hot shower.


3) wind turbine. I have powered a small electric space heater (thru inverter) from a wind turbine in 25knot winds. With backpacking heat pumps available at 250-600 watts and huge battery capacities, this could be even more efficient than ever.


4) electric water heater. This doesn't use too much power if you ensure it is in a vacuum insulated container. A huge waste of hot waters is heating the water hotter than it needs to be and/or not using immediately after. The specific heat capacity of water is 4,200 Joules per kilogram per degree Celsius, so if you need to heat the water 25C and have 2kg (enough for shower) then a 60 watt solar panel can do this in 1 hour. It's not a lot of power.


5) shower loop. This recirculates the water through a filter saving water as well as the energy to heat it. This is really the ultimate option, but I am still investigating using multiple vortex filters to separate oil as well as debris.. so lets hear from others as this option I have not managed to construct yet.





burning fuel is cheating because it's taking advantage of the world's most vulnerable people, the same people who contribute to the problem the least. It's like stealing from a child, or pushing an elderly person out of the way just because you don't want to change and do things a different way. well the choice wont be forever, and the less people who do the right thing now, the worst the consequences in the future for everyone, and in the future governments may just close down cruising (like saudi arabia) if most of the people doing it are part of the problem there will be no choice.

To each his own....I love my fossil fuel. What I do not like is self-righteous folks who tell others how to live their lives and think they are holier than thou.
BTW...I love animal meat and animal products too!

Abe

[carstendenmark]

An idea :
In cold weather you'll run your cabin heater, if you have one.
Would it be feasible to wrap the outside of the exhaust pipe of an "oil fueled" cabin heater with a suitable copper water pipe and let it into a hotwater tank, as a heating coil ?
Just add a small pump. Almost free heat.

I am not religious, not even to the new religion of "Save the World".
But I'm planning to go electric, and will avoid any diesel fumes, after I throw my old Volvo out for good.
A second question for you guys :
Can a standard cabin heater run on corn/palm/coconut/rapeseed/sunflower oil ?
Smells far better than diesel, and you can get it in any small street shop worldwide.