Propane, the kiss of death

[Adelie]

Originally Posted by Chotu

But something is missing here. The efficiency of whatever is making electricity really drops the induction and microwave much lower.

I use an electric oven in the boat as well as a microwave, so I’m not pro-anything. Just continuing your example through to the end.

I investigated the relative efficiencies of propane/butane vs induction towards the goal of figuring out how much electricity would be needed to replace propane for cooking. In the end I created a chart indicating your average daily draw estimated from your propane tank weight and number of days it usually lasted you. I included inverter efficiency at 90% if I recall.

If the electricity used is generated by solar, wind or regen, the "fuel' is essentially free. The costs of the panels, turbine or regen are not, but they can be amortized over time. For panels there are also issues of what area can be installed on the boat which is related to efficiency.

My goal was to characterize the scope of what was involved. Based on what I learned, for about $3k you could set up a system using lead acid batteries. You would not need to invest all at once, you could add panels, controllers, batteries, inverter and cabling over time gaining system capabilities you could use immediately and install the burners and oven at the end.

If you use a generator or the main engine to provide the power source, then, yes there is an efficiency hit.

[Adelie]

Originally Posted by David Ess

My quote doesnt even mention sailboats, just...boats. And re sailboats and gensets, sure , tiny ones dont, but any decent sized sailboat does. On the safety of electrical induction stoves, it indeed DOES matter, if that is a point of discussion. And re the "tens of thousands ".....of successful applications, I admitted that was true of propane and wood and coal already. But of all types, elec induction is both the safest, plus has all the other attributes others have mentioned above.

Anything over about 30' is decent sized, I can stand upright inside and there is enough room for every member of my family to have a berth.

You are arguing that induction is safest from first principles but the systems are too complex to evaluate that way. Wait for the insurance statistics in about 10yr.

[Adelie]

Originally Posted by Dockhead

You're absolutely right. There are lots of advantages of induction (and microwave) over gas cooking, and I maintain safety is a huge advantage of induction over gas for most boats. But efficiency is NOT an advantage of induction, if you are powering it with a generator. It certainly takes more fuel if you're converting it first into electrical power then back into heat. However brilliant the last conversion stage is, with induction, you've still got a generator which is only 30% or so efficient in doing the first stage. And if you're using generated electrical power stored first in batteries, then it's even worse.


I don't think this is really important since we are talking about small amounts of fuel. And the advantage over gas is that the fuel is drawn from your main tank so you don't have the hassle of providing a separate fuel. But we shouldn't overstate the case by claiming that it's more efficient.

If the electricity is solar produced then the efficiency of the generator is not an issue.

The amount of fuel is also not the issue.
For some it is the fear of the fuel whether that fear is rational or not makes no different.
For others it's the use of fossil fuels which society in general is increasingly looking askance at.
For others still it is the periodic inconvenience of refilling the tanks. In the industrialized countries refilling can be pretty straightforward. Elsewhere not so much.
For others it's the increased sense of independence even though they have an increased dependence on a more complex system.

[Don C L]

Originally Posted by Adelie

Farymann had a 7hp 1 cyl that weighs 141lb, but their website hasn't been updated since 2010 so I assume they're defunct.

Yanmar has a 9hp that is 157lb.
Betamarine atomic-4 replacement is 14hp at 200lb. Since the A-4 is about 325lb I think you would be about 125lb ahean and $10k behind.

The original drawing for the Columbia shows a small outboard in a well behind the rudder. You could beef that up and replace with a 6,8 or 9.9hp high thrust at 61,107&102lb for $1700, $3000 ,$3700

Ha! yeah I was talking about a diesel genset. I have to wrestle my outboard around when I take it off for servicing, but that's only 100lbs. (I got the 9.8) I think the whole discussion is really about the amount of risk one is willing to tolerate and how much trust one has in their own risk reduction. As Jim said, driving down the highway (or on just about any street here in LA) is FAR more risky than all of these fuel choices IMO.

[Adelie]

I assumed you had the A4.
Is you 9.9 a High thrust?
Motor well or bracket?

[Don C L]

Originally Posted by Adelie

I assumed you had the A4.
Is you 9.9 a High thrust?
Motor well or bracket?

No room in the well for anything but a Seagull engine... and I AIN'T gonna get one of those! Tohatsu 9.8 high thrust on a bracket.

[Pelagic]

Originally Posted by Dockhead

You're absolutely right. There are lots of advantages of induction (and microwave) over gas cooking, and I maintain safety is a huge advantage of induction over gas for most boats. But efficiency is NOT an advantage of induction, if you are powering it with a generator. It certainly takes more fuel if you're converting it first into electrical power then back into heat. However brilliant the last conversion stage is, with induction, you've still got a generator which is only 30% or so efficient in doing the first stage. And if you're using generated electrical power stored first in batteries, then it's even worse.


I don't think this is really important since we are talking about small amounts of fuel. And the advantage over gas is that the fuel is drawn from your main tank so you don't have the hassle of providing a separate fuel. But we shouldn't overstate the case by claiming that it's more efficient.

When you narrowly define this efficiency in terms of energy to convert to cooking BTU's, I agree .

However, if you look at the big picture and think in terms of
1....Multifunctionality,.... ie the Gen is providing a number of services at the same time.

2...Choices..... A variety of free electrical charging sources from, Alternators when motorsailing, Solar, Wind, then the energy used for cooking is surplus energy, as is when using Gen for watermaker, Aircon etc

3.... Labour ........Convenience to me is part of the efficiency equation, a touch control, 9 power settings and no burner maintenance or major spill cleanup makes cooking with induction more efficient

4..... Byproduct heat.... removing the heat load from the interior if cooking with Gas, makes climate control more efficient.

[noelex 77]

Originally Posted by Dockhead

I don't think this is really important since we are talking about small amounts of fuel. And the advantage over gas is that the fuel is drawn from your main tank so you don't have the hassle of providing a separate fuel. .

This is the main drawback with propane. It is not so much of an issue for a boat cruising a small geographic area, but once you start regularly swapping countries it becomes a huge hassle.

The propane bottles all have different sizes and fittings. Decent sized bottles are too heavy to carry any distance, but the bottles cannot generally be transported on pubic transport or in taxies. Many places will not refill bottles so you need to purchase new bottles and find somewhere to dispose of the old ones. These are just some of the problems.

These issues can be minimised. Adapters, refilling bottles yourself, having large vented lockers that can carry multiple large bottles of various sizes are all good strategies. It is also helpful to incorporate other forms of cooking such as induction and diesel. By using some of these techniques we only need to refill propane every few years at the most. This reduces the hassle, but electric and diesel cooking remove these problems completely.

Rather than a minor and debatable difference in safety, or efficiency the above are the reasons to look for alternatives to propane even if it is not practical to completely replace this on many vessels.

[rslifkin]

Originally Posted by Dockhead

You're absolutely right. There are lots of advantages of induction (and microwave) over gas cooking, and I maintain safety is a huge advantage of induction over gas for most boats. But efficiency is NOT an advantage of induction, if you are powering it with a generator. It certainly takes more fuel if you're converting it first into electrical power then back into heat. However brilliant the last conversion stage is, with induction, you've still got a generator which is only 30% or so efficient in doing the first stage. And if you're using generated electrical power stored first in batteries, then it's even worse.


I don't think this is really important since we are talking about small amounts of fuel. And the advantage over gas is that the fuel is drawn from your main tank so you don't have the hassle of providing a separate fuel. But we shouldn't overstate the case by claiming that it's more efficient.

You hinted at another advantage there: your cooking power can come from multiple sources in an electric setup, which adds some flexibility and redundancy, depending on the boat systems in question. You can power from battery / solar, generator, shore power, engine alternators, etc.

[pcmm]

Originally Posted by rslifkin

You hinted at another advantage there: your cooking power can come from multiple sources in an electric setup, which adds some flexibility and redundancy, depending on the boat systems in question. You can power from battery / solar, generator, shore power, engine alternators, etc.

In that example there are only 2 sources. Shore power or inverter/batteries. Solar just charges your batteries as does the alternator. Away from the dock you only have 1 source. inverter/batteries so no real advantage there.

[Chotu]

What a complex discussion for a simple choice and rightfully so!

Having a boat that is independent from land other than its primary propulsion fuel is a tremendous advantage. This part cannot be overstated.

Then there is the “one fuel” argument. This is why I went with a lot of unconventional choices on my gasoline (outboard) powered boat. To preserve using a single fuel. I have gasoline powered generator systems which makes for an incredible “range” of generator power running off my main tanks. I can see the same advantages going all electric galley.

The part I don’t like is using “settings” to cook. 1-10?? Please. That’s not enough resolution for me to cook well. Are there ones that have more settings?

Cooking is an analog art, not a 1-10 digital experience.

[rslifkin]

Originally Posted by pcmm

In that example there are only 2 sources. Shore power or inverter/batteries. Solar just charges your batteries as does the alternator. Away from the dock you only have 1 source. inverter/batteries so no real advantage there.

A generator (if installed) can substitute for shore power. And in the inverter/battery situations, yes, that counts as 1 source on the AC side, but the "putting power into the batteries" part of that equation has multiple sources.

[David Ess]

Originally Posted by Dockhead

You're absolutely right. There are lots of advantages of induction (and microwave) over gas cooking, and I maintain safety is a huge advantage of induction over gas for most boats. But efficiency is NOT an advantage of induction, if you are powering it with a generator. It certainly takes more fuel if you're converting it first into electrical power then back into heat. However brilliant the last conversion stage is, with induction, you've still got a generator which is only 30% or so efficient in doing the first stage. And if you're using generated electrical power stored first in batteries, then it's even worse.


I don't think this is really important since we are talking about small amounts of fuel. And the advantage over gas is that the fuel is drawn from your main tank so you don't have the hassle of providing a separate fuel. But we shouldn't overstate the case by claiming that it's more efficient.

Yes, quite correct on those points, but you didnt t factor in that they can also be powered by solar, thus efficiency goes way up. Still though, the main point was not efficiency in the thread, but safety as compared to the 'kiss of death' propane gas alternative.

[pcmm]

Originally Posted by rslifkin

A generator (if installed) can substitute for shore power. And in the inverter/battery situations, yes, that counts as 1 source on the AC side, but the "putting power into the batteries" part of that equation has multiple sources.

Agreed but induction still has a single point of failure in the end. Everything depends on the inverter. A generator could be installed but the trend over the last few years has been to get rid of them not to add new ones! generators are becoming very rare onboard (unless you have a really big boat) Not to mention its a very big expense to support cooking!

Propane has the advantage of redundancy. If you have issue with the electrics (and who hasn't) you can simply bypass the solenoid temporarily and keep cooking! I've had to do that before as for some reason propane solenoids don't seem to last very long. If you loose your inverter (and it happens) you loose the ability to feed the crew.

[rslifkin]

Originally Posted by pcmm

Agreed but induction still has a single point of failure in the end. Everything depends on the inverter. A generator could be installed but the trend over the last few years has been to get rid of them not to add new ones! generators are becoming very rare onboard (unless you have a really big boat) Not to mention its a very big expense to support cooking!

Propane has the advantage of redundancy. If you have issue with the electrics (and who hasn't) you can simply bypass the solenoid temporarily and keep cooking! I've had to do that before as for some reason propane solenoids don't seem to last very long. If you loose your inverter (and it happens) you loose the ability to feed the crew.

Agreed on the SPOF for a non-generator boat. It's fine in coastal settings (just head for a marina and plug in until you can make repairs), but for long offshore runs, I'd want either 2 inverters or a generator. Non-redundant systems that can't be band-aided are a concern.