We are we seeing electric stove tops on blue water cruisers?

[Ungvar]

An electric stove on a boat sounds like the cats pyjamas to me. No messing around with propane and the associated plumbing, or cursing your diesel for making your boat unbearably hot, or messing around with alcohol which I hate less than propane and diesel.

There are some generators out there that are advertised as silent running. They aren't exactly silent, but I worked for a while with a 15kW John Deere that was pretty darn quiet.

Plus no open flames



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[Zanshin]

I have an electric galley aboard (4 elements, plus oven) and the propane lines leading to the galley are capped and not attached to my propane in the aft cockpit; that has been re-routed to lead 4 feet away to my BBQ. I opted to go without propane because of the potential danger of explosion and because I believe I can use my batteries more efficiently.

Several years ago I lost a friend to a gas explosion. This was in Germany and some idiot at a construction site on my street did a positive pressure test on a new house's gas system by using pure oxygen directly from a welding kit rather than a low-pressure air tester. This blew the seal to the street and forced oxygen into the gas mains! I arrived after the street had been evacuated but got to watch in horror as the house two away from mine had a dull thud and the window glass popped out, then the house next to mine got the same treatment.

After the fire department thought the danger was over, they had my friend lead them in the basement of his block to identify the gas mains and it exploded while he was in there. 60% burns and it took 3 days for him die. No gas on my boat, if I can avoid it.

[K_V_B]

Originally Posted by Dockhead

That's also very true.

When you're on shore power, then obviously electric cooking is a far better way to do it, since you don't even have to deal with the power source.

That's on top of all the other advantages. Even circumnavigators spend most of their time at a dock somewhere.

I recently came across this here:





(more here, but all in German for the moment: e-cooking – tom logisch )
Basically an electric stove, with one induction plate, a watercooker with base fixed to the top, and a microwave oven. Designed to run of a 3KW inverter. The whole thing is 50cm wide, so should fit on most boats.

Interesting concept. But some will say that it has only one hotplate. But that is in my opinion not a huge problem. It's easy to have a separate hotplate that you just plop up on the countertop when cooking while at anchor or in the harbor. Underway I mostly just heat up stuff I prepared beforehand, and make tea. This would be ideal for that.

[Fuss]

Originally Posted by Dockhead

As a matter of systems design, it's better to concentrate all of your critical functions on one power source, then make the single power source as reliable and redundant as possible.

Having only one way to generate electrical power is nuts.

We have a heavy duty low speed 6.5kW generator, plus a 2.5kW heavy duty alternator on the main engine, either of which can easily power the whole boat (including electric cooking if we had it).


We've been stuck more than once run out of propane in a country with incompatible bottles, or with a fault in the gas system we couldn't fix without parts we didn't have. But we've never been without electricity.

Thats right that if the generator fails you should be able to replace it with the main engine alternator and inverter, otherwise you have no generator backup.

To have no gas onboard and cook with electricity you need roughly the following
...
maybe around 10000 watt hours of batteries
around 400w of solar
around 5kw generator
around 4000 watt main engine alternator, 5000 would be better.
around 3000 watt inverter that can handle some overload.
some form of electricity generation while sailing

a 2 element induction cooker
a combination microwave, grill and fan oven
a very efficient fridge and freezer
an energy efficient method of making hot water for coffee, tea or soups.
an electric egg cooker
a bbq

This setup would mean that you would not miss the gas at all and you would have multiple backups and 4 ways of generating electricity.

You could of course use a cut down version of this and sometimes you would miss the gas.

[Dockhead]

Originally Posted by Fuss

Thats right that if the generator fails you should be able to replace it with the main engine alternator and inverter, otherwise you have no generator backup.

To have no gas onboard and cook with electricity you need roughly the following
...
maybe around 10000 watt hours of batteries
around 400w of solar
around 5kw generator
around 4000 watt main engine alternator, 5000 would be better.
around 3000 watt inverter that can handle some overload.
some form of electricity generation while sailing

a 2 element induction cooker
a combination microwave, grill and fan oven
a very efficient fridge and freezer
an energy efficient method of making hot water for coffee, tea or soups.
an electric egg cooker
a bbq

This setup would mean that you would not miss the gas at all and you would have multiple backups and 4 ways of generating electricity.

You could of course use a cut down version of this and sometimes you would miss the gas.

In reality you need less battery power and less generating capacity, to cook perfectly well with electricity.

You really only need a minimal generator, if you have a power boost inverter which can shave off the peaks. In that case, you only need to generate the average power required, not the peak power.

And no need to size battery bank like that -- a normal battery bank (mine is 420 amp/hours x 24v) is plenty if you run the generator during intensive cooking.

An electric kettle is already a very efficient way to heat water, but something like a quooker is even better. Convection oven and microwave are both very efficient especially microwave. Induction cooktop adds a great deal of efficiency.

It's entirely feasible without an extraordinary electrical system. 3 or 4 kW of generating capacity, power boost inverter of 3 or 4 kW, and a normal battery bank will do it just fine.

[K_V_B]

Originally Posted by Fuss

maybe around 10000 watt hours of batteries

Reinoud Vader (the CEO of Victron) cooks electrical on his boat. According to his test preparing a hot meal, including desert for 4 persons costs about 1200 - 1400 Wh in energy. So if you are prepared to run your engine/genset once a day you would not need 10kWh.
But having that amount available however is nice. And not all that extrem. Two 160 Ah 24V Li-ion batteries and you're basically there.

For BBQ I would just use a disposable charcoal grill...

[Matt Johnson]

With propane, you know what you've got left (give or take). One 20lb tank is about three months of cooking for us. How many gallons of diesel would you need for the generator to equal the same cooking usage? Most sailboats have small fuel tanks and have to ration the diesel usage already on passage. I can't imagine having to also rely on that small amount to charge as well... wait, yes I can.

We had trouble filling our tank when leaving the Canaries...I didn't want to spend the required $120 for adapter and tank. We had a microwave, electric stove and tea kettle aboard, so figured those will work in it's place. Unfortunately, two weeks of gray and cloudy skies (we had 475 watts of solar), running the autopilot, fridge and all the other electronics caused a seriously low amount of power. Diesel was also being rationed to generate power for mission critical items, so running the engine to make food was out. We were forced to eat a lot of bowls of cold cereal!

Matt

[Fuss]

Originally Posted by Dockhead

And no need to size battery bank like that -- a normal battery bank (mine is 420 amp/hours x 24v) is plenty if you run the generator during intensive cooking.

But this is normal...10000wh = 10000/24 = 415amp hours @ 24v

[a64pilot]

The most energy intensive thing there is, is making heat, regardless of the source.
You can do it of course, but it takes a lot of energy to cook food, whether by propane or electric.
For a simple boat cooking electrically would probably at least triple the requirement for electricity.
The numbers of Solar I see, won't do it even all by themselves, and then you have to define what is cooking? Simmering and or baking is going to require lots more heat than heating up something to eat.
I know I'd have to have more than 1KW of Solar, I think maybe 1.5KW?
There has to be a simple conversion factor, something along the lines of if I use 5 lbs or propane a week, to replace that, I have to generate X amount of electrical power, (you chose the unit)

Obviously battery bank wise, you need just enough to get you from one generator run to the other, worst case.
But going to a full electric boat, does sort of seem that your committing yourself to daily generator runs?

[a64pilot]

OK, here we go

1 Gallon of Propane = 27 kWh (Kilowatt Hours) of electricity - This means that one gallon of propane contains the same amount of usable energy as 27 Kilowatt Hours. Or we can say that 27 kWh equals approximately 91,500 BTU.

Propane Vs. Electricity - A Comparison



The next question would I think be, how many gallons of Diesel do I have to burn to generate 27 KHW? Even then as much of it is being "lost" won't tell all, but be interesting as I saw a lot of discussion on efficiency.


My little Nexgen quotes a fuel consumption of .4 GPH max, I assume that means at max rated output it burns .4 GPH?
To generate 27 KWH at the production rate of 3,500 watts would take 7.7 hours?
If that is correct then 7.7 X .4 = 3.08 gallons.
Those numbers don't show the truth I don't think as we lose a lot of the power, but still it looks like for me at least I have to burn 3 gallons of Diesel to make the heat that 1 gallon of propane provides?

Sorry, I keep editing as I think of things,
the flip side of course is if your running the thing anyway, may as well run it when you want to cook.
So I think the answer is, do you want to be generator dependent, or propane dependent?

[Dockhead]

Originally Posted by Fuss

But this is normal...10000wh = 10000/24 = 415amp hours @ 24v

Well, with lead acid you would need 830 amp/hours to have 415 amp hours of usable power.

But that's a quibble -- I do agree that it's not an absurd battery bank.

But that being said, I've been long term off the grid, living on board much of the year, with no shore power on my mooring, and I've found that 420 amp hours of 24v normal lead acid batteries is more than enough. I just have no problem with power. Electric cooking would be fine even with my present bank. Note real figures posted above about the actual power consumption, which is far less than many people assume.

[Dockhead]

Originally Posted by a64pilot

OK, here we go

1 Gallon of Propane = 27 kWh (Kilowatt Hours) of electricity - This means that one gallon of propane contains the same amount of usable energy as 27 Kilowatt Hours. Or we can say that 27 kWh equals approximately 91,500 BTU.

Propane Vs. Electricity - A Comparison



The next question would I think be, how many gallons of Diesel do I have to burn to generate 27 KHW? Even then as much of it is being "lost" won't tell all, but be interesting as I saw a lot of discussion on efficiency.

Yes but not exactly --

1. Propane stove wastes quite a lot of energy compared to electric induction, which puts nearly all the power into the food, and almost none of it into the air.

2. When you think about the cost to generate the power, think about the MARGINAL cost, not the average cost. That's because you don't generate electricity exclusively for cooking, you're generating for lots of other purposes as well. That means the incremental amount of power you use cost much less fuel if the generator is running anyway. This is the efficiency of using electricity to do multiple tasks.


The real difference is much less, that what would be calculated like that.

[robert sailor]

Maybe in the future but right now only on a minority of boats. Sure propane can be dangerous if not handled properly but so can a bunch of other things, sailing might not be the best pastime for stupid people. Gen sets in my experience has been one of the highest maintenance items aboard a sailboat and I will avoid one as long as I can. Spend money on getting your systems as efficient as possible and run everything on solar or with a combination of wind. Some of my fellow cruiser friends are slaves to their gensets, not interested in going there.

[Dockhead]

Originally Posted by a64pilot

OK, here we go

1 Gallon of Propane = 27 kWh (Kilowatt Hours) of electricity - This means that one gallon of propane contains the same amount of usable energy as 27 Kilowatt Hours. Or we can say that 27 kWh equals approximately 91,500 BTU.

Propane Vs. Electricity - A Comparison



The next question would I think be, how many gallons of Diesel do I have to burn to generate 27 KHW? Even then as much of it is being "lost" won't tell all, but be interesting as I saw a lot of discussion on efficiency.


My little Nexgen quotes a fuel consumption of .4 GPH max, I assume that means at max rated output it burns .4 GPH?
To generate 27 KWH at the production rate of 3,500 watts would take 7.7 hours?
If that is correct then 7.7 time .4 = 3.08 gallons.
Those numbers don't show the truth I don't think as we lose a lot of the power, but still it looks like for me at least I have to burn 3 gallons of Diesel to make the heat that 1 gallon of propane provides?

If you compare induction to propane, you will need probably half of the kWH to do the same time, with induction. There will be no difference for a normal oven, however, but a large advantage of electric oven if it's convection or microwave.

THEN, assume you are combining loads like all cruisers do, and the generator is running anyway (at least for battery charging). That means if you need 25% of generator capacity to run all the electric cooking, don't look at the 1st 25%, but the incremental second or third 25%, which will cost roughly half in fuel, than the first 25%.

Considering those factors, electric cooking should require no more fuel than propane, maybe less.

Then if you go on to consider what percentage of the time you are cooking at a dock when you have shore power, and the advantage is even much greater.

[cruisersfarm]

Originally Posted by valhalla360

I'm not sure what your point is. Fear of electric or fear of propane. Both are irrational if you use common sense when working with them. Both are dangerous if you do stupid things.

This is my point as well.

A few posters have an irrational fear of gas (is it petrol/gasoline that caused these explosions referred to??)

If stupid people blow themselves up through lack of knowledge, does it make anything more or less "safe?"

The same level of ignorance to systems would result in an electrical fire too.. and I don't buy for a minute that boats actually at sea with a real fire are any less deadly than ones that go boom.

The automobile is far more deadly that electricity or propane, but do you get in one, or avoid them out of fear?

The arguments here are irrational.