Induction vs Gas Cooking

[Dockhead]

Originally Posted by a64pilot

Three meals a day for only 100 AH?
We do this every time, the converts say it takes almost no power at all, others say physics don’t work like that, it’s still heat, and heat takes lots of power. Regardless of the source, a calorie is a calorie.
It really the same argument that goes on for electric propulsion, the faithful say it’s great, can easily do it, others think not.
However I think it boils down to some heat items up for cooking and some cook unprepared items, and the energy requirement varies greatly.
Of course I will get arguments that thats not true from the faithful.

I don't think I've seen any magical thinking from induction cookers, comparable to the electric propulsion fanatics.


I don't think anyone disagrees with anything you said here. Induction cooking is much more efficient than resistance cooking, because -- and this is not magic -- much less of the heat is wasted on heating the air in the cabin. But as you say -- a calorie is a calorie, so however efficient the TRANSMISSION of the heat it, you still have to produce the heat itself. I have by now a lot of experience with induction cooking and the power demand is not trivial. With my battery bank (450AH * 24v) it's a stretch to cook a whole cooked meal on induction (a couple of omlets or something like that is fine, but not a big pot of soup, for example, plus fried stuff, etc.), so I normally fire up the generator. My NuWave will draw 2000 watts continuously for as long as you are intensely heating up something and at least at the beginning of frying something. Simmering takes a lot less power -- maybe 150 watts. Everyone can draw his own conclusion. Or best of all, just take a KillOWatt or similar outlet meter and just measure directly how much power you use to cook an average meal, and figure out from there how hard it will be to produce and/or store such power.



Firing up the generator at meal time is not a burden for me because I have to charge anyway -- so you just time the charging to coincide with the cooking (and clothes washing and whatever other high load tasks you have). So induction cooking works fine on my boat, but YMMV with different cooking patterns, no generator, whatever. There's no magic involved, just banal kW hours.


A lithium battery bank, especially a big one, would make induction cooking even much better, because it's so easy to store and use power, particularly power you might produce incidentally to propulsion. I hesitate to work my lead batteries too hard with loads like this because I don't want to wear them out. But with lithium batteries and their very efficient charging and very high cycle life, the equation may be very different.

[rslifkin]

I agree with generator runtime at mealtime not being a big deal. A morning and evening generator run for cooking keeps my hot water tank hot and throws some extra power in the batteries, so it's useful. Plus, the evening run can be used to cool the boat down a bit at the end of a hot, sunny day with not much breeze to make it more comfortable for sleeping.

[a64pilot]

Originally Posted by Dockhead

CNG is lighter than air and vastly safer than LPG. I would have no problem having CNG on board if it were widely available.


As to electrical power required -- you can do the math yourself based on your own cooking patterns. You do need abundant power on board, in one form or another, either stored or generated or preferably both, to make it work.


I have 450AH * 24v of batteries; I can do a little cooking off batteries on the induction hob but I would not cook a whole meal without running the generator unless the main engine is running.


Induction cooking is probably not practical on a boat without either a jumbo solar installation or a diesel generator.

While I do think a generator is necessary, I believe a Honda will suffice, the little Honda is more capable than we give it credit for, it will charge 100 amps at 12V, 50 at 24 or course and will run a 16K AC apparently with a soft start kit.
The difference between a Honda and a Diesel is output of course, with my Diesel I can charge hard and run an AC or I guess cook, I can do everything with the Honda, just separately. But on the hook it’s used pretty much exclusively to charge the bank and we will use the 2800W inverter for most any 120 VAC needs like running a kitchen appliance or making frozen Dacquri’s etc. as those short term needs don’t really justify cranking a generator, but we will usually Vacuum whenever the generator happens to be running anyway, I just turn off the charger to Vacuum.

I started out trying to source all DC appliances, but pretty quickly realized the quality is usually way lower and the price higher, better to buy high quality AC appliances and use the inverter.

So, in my opinion electric cooking is in the same league as the average non energy recovery watermaker, best if you have a generator, theoretically possible without one, but theories break down in the real world.
The age old answer to Engineers who would say it works on paper is too bad we don’t fly paper airplanes.

I too would love to see CNG replace Propane, but it’s not going to happen unfortunately. You just have to treat propane like a pet snake I guess and respect that it’s trying to kill you and not give it a chance

[MountainKing]

Originally Posted by mvweebles

Biggest challenge I see for swapping out a Princess electric stove is keeping an oven in the mix. One of the high-end toaster ovens such as Breville SmartOven is a good option. Guessing that 85%-90% of cooking is stove-top. Induction and a decent battery bank could keep you in good shape.

I was thinking of something like this :Samsung 1.2 cu. ft. PowerGrill Duo Countertop Microwave with Power Convection and Built-In Application in Black

Mounting it on the gimbals for the current stove and set an induction cooktop on top of it. I do have to measure the current oven it would replace and see if it's actually feasible. Once I can get to my boat...

[Dockhead]

Originally Posted by MountainKing

I was thinking of something like this :Samsung 1.2 cu. ft. PowerGrill Duo Countertop Microwave with Power Convection and Built-In Application in Black

Mounting it on the gimbals for the current stove and set an induction cooktop on top of it. I do have to measure the current oven it would replace and see if it's actually feasible. Once I can get to my boat...

I would ditch my crap gas oven in a second for one of those.


My boat was built with a Panasonic full-size built-in microwave with grill, which certainly does not use more power than one of the modern ones with convection oven. I have made a few attempts to find one which will fit in the hole of the existing one, and haven't managed to find anything, but I will keep trying.


Not gimballed but still really really useful. I think I use the microwave more than the stove as it is. It's used multiple times a day.

[a64pilot]

It’s been decades ago, but We loved our micro-convention oven. It would cook a Thanksgiving turkey in an hour and a half, as opposed to almost all day in a conventional oven.
This was in an old house we were renting that the gas oven was unsafe, sometimes you would open the oven door, and when the air went in, a huge ball of blue flame came out.
So we didn’t use the gas oven.

We don’t really have room for a microwave, and I keep asking but the Wife doesn’t want one. About all we did with one in the house was cook bacon and reheat foods, but then that was with a whole lot more people to feed, up to seven for a few years when the Daughter and her kids lived with us.

[rslifkin]

Originally Posted by MountainKing

I was thinking of something like this :Samsung 1.2 cu. ft. PowerGrill Duo Countertop Microwave with Power Convection and Built-In Application in Black

Mounting it on the gimbals for the current stove and set an induction cooktop on top of it. I do have to measure the current oven it would replace and see if it's actually feasible. Once I can get to my boat...

I've been looking at that same microwave to replace my current 1980s one. Should fit with minimal modification to the hole and would give me something resembling a standard oven.

[a64pilot]

Just from a quick glance it wouldn’t be hard to take a dual burner induction meant to be built in and build a cover that would replace the butcher block on our current stove that is a cover over the stove, the cut out required is 19.7” by 10.7” 19.7 width of course and it will just fit on ours, that would leave the function of the gimbal, allow electric cooking and easily be removable to keep the gas function.
Have to watch power consumption cause I believe it could easily exceed 15 amps if you don’t.

[Pete7]

Originally Posted by Dockhead

I have by now a lot of experience with induction cooking and the power demand is not trivial. With my battery bank (450AH * 24v) it's a stretch to cook a whole cooked meal on induction (a couple of omlets or something like that is fine, but not a big pot of soup, for example, plus fried stuff, etc.), so I normally fire up the generator.

Without a generator, I don't think it's a solution for smaller yachts who use the oven and grill regularly, which we do alot. We sold the Honda genny after installing solar.
We would also need to add probably two more house batteries or buy another small petrol generator. This has to be compared to the butane or propane cost and availability. Other than every country seems to have different sized tanks and valves It's certainly available throughout Europe everywhere, for home, camping, caravans and yes boats. The risk needs to be managed, and precautions taken, but 4.5kg of butane or 3.9kg of Propane (similar sized cylinders) for £18 is cheap enough.

However, we do like the slow cooker and use one regularly, draws 110w heating and half that once up to temperature. Home made rice pudding is so much nicer that the tinned stuff and joints of meat really tasty for those who are like a bit of roast beef, yum

I do see the appeal for those in hot climates, I guess they don't eat roast dinners with two veg and roast potatoes. Up here that's just what is needed after a cold days sailing.

Pete

[noelex 77]

Originally Posted by bensolomon

Is induction cooking a reasonable choice for a modest cruising boat of 37 feet? How much extra battery and dokarvwould be needed. I hate having CNG on board.

Induction cooking is great, but you do need to produce the electrical power needed. That is tough to do on a 37 foot boat with alternative (solar, wind and hydro) energy if you want to stay away from shore power.

It can be done with a portable gasoline generator, but propane/butane is far more preferable IMHO. It can also be done with a marine generator. In my view, installing, running and servicing a marine generator is worse than the evils of propane/butane, but some disagree.

You can easily and cheaply (providing you have a suitable inverter) test induction cooking by purchasing a portable single hot plate unit. These are inexpensive and even if the experiment is not successful you can use induction when plugged into shore power and therefore saving on propane/butane.

[Dockhead]

Originally Posted by noelex 77

. . . It can be done with a portable gasoline generator, but propane/butane is far more preferable IMHO. It can also be done with a marine generator. In my view, installing, running and servicing a marine generator is worse than the evils of propane/butane, but some disagree.

I agree that the hazards and hassles of portable gasoline generators are worse than those of a good and well managed LPG system. Gasoline vapors create similar risks as leaked LPG, and then you have CO poisoning risks.



I would probably agree with you about a marine diesel generator if the only or main purpose of it is to run electric cooking. Certainly a gas system is an order of magnitude less complex and costly. But if you already have a good marine diesel generator at the heart of an electric-centric boat, then the additional use for cooking is basically free.


If you're on solar, even a largish solar installation, your power budget will be less flexible and you may not be able to afford electric cooking. YMMV. The good thing about a generator is you can increase your power budget by just running it a bit longer.

Originally Posted by noelex 77

You can easily and cheaply (providing you have a suitable inverter) test induction cooking by purchasing a portable single hot plate unit. These are inexpensive and even if the experiment is not successful you can use induction when plugged into shore power and therefore saving on propane/butane.

And I highly recommend this. In the absolute worst case, you've got a great means for cooking when on shore power. I don't know anyone who bought one of these, who regretted it, or took it off the boat.


And gas and induction is not necessarily either/or. In principle, we are "both" on my boat -- at least when both systems are working It's great to have a choice.

[a64pilot]

Originally Posted by noelex 77

You can easily and cheaply (providing you have a suitable inverter) test induction cooking by purchasing a portable single hot plate unit. These are inexpensive and even if the experiment is not successful you can use induction when plugged into shore power and therefore saving on propane/butane.

I keep thinking to try it myself, it’s a little over $50 US from Amazon, but my Propane use is 10 lbs a month and it cost me $10 a refill at the Navy base, but the real issue is it’s another thing to store and storage is at a premium, as it is, I off loaded the sewing machine last year to gain storage and needed it this year, got by by hand sewing, but it would have been nice to have the machine. It’s back aboard now.
However I have accepted having a Honda at least, and they are less maintenance than an outboard, way less. It’s coming up on 1000 hours and still has the original spark plug, just oil changes and if it dies right now, it cost $1 a hour to own purchase wise, but I think it will easily last at least to to 2,000 hours and I’d be real surprised if it didn’t go way longer as it’s a ball bearing crankshaft and of course a steel liner in the cylinder.

The built in generator is way more trouble, requires it’s own thru hull, zincs, water cooled, and is a pain to access and of course cost about six times as much as a Honda.
It has been reliable, but to change the oil I have to empty the Lazarette and climb down in there with it etc.
So cost wise and maintenance wise the Honda is much, much easier.
However a good built in generator ought not be more maintenance intensive than your main engine, but if well maintained it does double your engine maintenance, and if that’s not your thing, then you don’t want one. I’m a Motörhead, it doesn’t bother me, some it does, and many, many sailors just will not maintain an engine, and they have no end of trouble with them because of it. They don’t need another engine to maintain.

It’s sort of the watermaker argument, I wouldn’t cruise without one, but they are complex, expensive and require care, depends on the level of complexity your willing to put up with I guess, cause when you start adding up all these nice to have things, it’s a bunch of money, spares to carry and another thing to perform preventative maintenance on.

[joelhemington]

Originally Posted by bensolomon

Is induction cooking a reasonable choice for a modest cruising boat of 37 feet? How much extra battery and dokarvwould be needed. I hate having CNG on board.

Please forgive my ignorance but WTF is dokarvwould? Even Google doesn't seem to know.

[Auspicious]

Jeepers. Spend a little time on billable work and people go on and on.

Originally Posted by roland stockham

There is also the safety aspect, gas is potentially the most dangerous system on a boat. induction does look good if you can provide enough electrical power.

Absolutely not. Insurance statistics are very clear. The most common source of fire is electricity. Overloaded circuits (undersized wire), loose connections, bad connector choices (the ubiquitous ANSI/SAE J563 aka cigarette lighter plugs), poor wire materials choices. How often do you hear about a propane installation leading to explosion? Even power boats at gas docks are more demonstrably more dangerous and electrical fires outstrip them. LPG (propane and butane) is the single most common cooking fuel on the planet. Adding thousands of watts of consumption to the most dangerous system on the boat (electricity) is problematic. The insurance industry statistics look backward at real-world data and haven’t caught up with induction yet.

Originally Posted by mvweebles

Guessing that 85%-90% of cooking is stove-top.

Not in my practice. Granted I love to cook. Lots of things go in the oven: lasagna, tuna noodle casserole, bread, bacon, roasts (could do on a stove top in a Dutch oven but size is a factor), any casserole, chips. I can’t begin to think of everything that goes into the oven. I'll ask for opinions from some cooking groups I'm part of.

Originally Posted by Dockhead

CNG is lighter than air and vastly safer than LPG. I would have no problem having CNG on board if it were widely available.

And there is the rub. CNG is not widely available. Also worth noting that the storage pressure is quite high. I don’t have data for the relative merits. No question that lighter-than-air is attractive on general principles.

Originally Posted by Dockhead

I can do a little cooking off batteries on the induction hob but I would not cook a whole meal without running the generator unless the main engine is running.

Which is a limitation of induction. It’s worth thinking about failure modes as well. What happens if the alternator regulator fails (happened on my latest delivery). Solar charger? Something gets dropped on the glass top? Water gets into the hob? With propane the most common failure is an ignitor problem (bad battery, failed point) – solution: match to light the burner; next is clogged burner – solution: 10 minutes with vinegar and a toothbrush; next solenoid turns into a rusted mess – solution: female-to-female hose nipple and two hose clamps (you have those secured in your propane locker, right?).
Induction is a solution looking for a problem. It’s more fragile, more expensive (capital and running costs), and carries more risk. The only things it has going for it are that it is better than resistive heat and slightly less heat in the cabin.

Originally Posted by a64pilot

While I do think a generator is necessary, I believe a Honda will suffice, the little Honda is more capable than we give it credit for, it will charge 100 amps at 12V, 50 at 24 or course and will run a 16K AC apparently with a soft start kit.

Honda are the first to tell you that generator is not appropriate for marine applications. It’s in the manual. There are modifications that make it better but don’t address all the shortfalls. Beyond that, if propane worries you what makes slopping gasoline around on the boat better?

Originally Posted by a64pilot

This was in an old house we were renting that the gas oven was unsafe, sometimes you would open the oven door, and when the air went in, a huge ball of blue flame came out.

Why didn’t you just clean the burner? Check the vent for mouse nest?

[noelex 77]

Originally Posted by Dockhead

But if you already have a good marine diesel generator at the heart of an electric-centric boat, then the additional use for cooking is basically free.

Agreed. If you need a marine generator installed for general electrical production then I would ditch the propane/butane and move totally to induction and microwave cooking.

In this case a back up system in case the generator fails is wise. Cold food quickly loses its appeal and many food supplies are unusable. There are back up options such as a large alternator system on the main engine, or even a small camping stove etc etc, so this is not difficult to arrange.

We use are induction cooking when excess solar power is available, cooking on the diesel heater in the depths of winter, and propane/butane cooking for the rest of the time. This versatile system allows the best option to used, minimising the drawbacks of each. For example, we carry several years supply of propane/butane, reducing the hassle of finding refills or replacement bottles. As the propane/butane system is not used and turned off at the bottle for much of the year, the safety and explosion risk is minimal.

Our solution would not suit everyone, but it is important to realise that efficient, cheap alternative energy combined with induction cooking has opened up alternatives that were not viable until recently. However, be aware that electric cooking uses a great deal of electrical power and unfortunately it is easy to install a sytem that will not be viable once shore power is disconnected.