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

[valhalla360]

Originally Posted by Dsanduril

Oh come on, we haven't even started yet on the discussion about which cooking method is a greater contributor to global warming

Dockhead, that is the problem with statistics, they lump everything together and make it difficult to sort out individual cases. But then we haven't seen anything from your side either, other than "some RNLI friend of mine said", and "I posted it elsewhere, somewhere"...

Exactly, so far Dockhead has only provided 3rd hand hearsay to counter documented reports.

As someone who parses automobile crash data for a living, his thoughts on cars being much safer than boats are just silly.

[mako]

Why don't we switch over to a less controversial subject... how about anchors and DD6-71's?

[K_V_B]

Originally Posted by Dsanduril

Ground fault/residual current devices aren't really that old.

RCDs were already compulsury when my parents built their house (in 1972). There was one big one protecting the whole house, and then a separate one for each bathroom, and the kitchen.
But this is Europe...

I think electric safety is well understood, and I think that getting rid of the gas system on a boat has a lot of advantages, if you can make it work.

[Dockhead]

Originally Posted by valhalla360

Exactly, so far Dockhead has only provided 3rd hand hearsay to counter documented reports.

As someone who parses automobile crash data for a living, his thoughts on cars being much safer than boats are just silly.

OK, so we have someone who understands statistics. That's excellent. It's hard to talk to someone who says there were 40,000 people killed in cars last year, and only 300 in boats (say), ergo cars are more dangerous than boats -- ignoring the fact that the population does 50,000 miles (say) in cars for every one mile in a boat. That's like saying that sleeping in your own bed is more dangerous than skydiving, because x thousand die that way, versus 10 skydiving.

If you're a professional then you will understand these basic concepts, so maybe you can explain how you figure cars are more dangerous than boats? Do you have a figure of deaths per million miles? Or how do you figure?

That's the first question.

Now here's another:

What "documented reports" are you talking about? I've seen statistics on fires, but nothing on explosions, not for any country. Nor have I seen statistics for boats with propane on board versus jon boats with outboards etc. Do tell which reports you're referring to.


The data I have is newpaper reports I've seen -- which is hard evidence of a certain number of deaths -- and the statements of an authoritative expert -- which is a very good secondary source. It's not a full statistical survey for sure, but I've not seen anything better. If there is anything, I'd like to see it.

[valhalla360]

Originally Posted by Dockhead

OK, so we have someone who understands statistics. That's excellent. It's hard to talk to someone who says there were 40,000 people killed in cars last year, and only 300 in boats (say), ergo cars are more dangerous than boats -- ignoring the fact that the population does 50,000 miles (say) in cars for every one mile in a boat. That's like saying that sleeping in your own bed is more dangerous than skydiving, because x thousand die that way, versus 10 skydiving.

If you're a professional then you will understand these basic concepts, so maybe you can explain how you figure cars are more dangerous than boats? Do you have a figure of deaths per million miles? Or how do you figure?

That's the first question.

Now here's another:

What "documented reports" are you talking about? I've seen statistics on fires, but nothing on explosions, not for any country. Do tell which reports you're referring to.


The data I have is newpaper reports I've seen -- which is hard evidence of a certain number of deaths -- and the statements of an authoritative expert -- which is a very good secondary source. It's not a full statistical survey for sure, but I've not seen anything better. If there is anything, I'd like to see it.

Per mile makes no sense for this type of comparison. You have a boat that cruises at 6mph vs a car that cruises at 60mph. Then you have the fact that most users are only in the car when it's moving where as your average cruiser may only be underway 1/20th of the time that they are on the boat.

Again, good data has been presented but you insist that they have for some inexplicable and undocumented reason totally ignored explosions. If it's really as bad as you say, that would imply gross negligence if they weren't already including that in with fires.

[K_V_B]

Originally Posted by a64pilot

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?

My back of the envelope calculation looks like this:

Propane/Butane has about the same energy density ad diesel. So one kg of propane equals about 1 kg of diesel. (Diesel weighs about 0.8kg/l)

Now asume you are boiling water:
A gas stove will convert gas in to heat with 100% efficiency, and put about half the heat it produces in the pan above it. So total end-to-end efficiency is approx 50%.

O good generator is maybe 30% efficient. An induction stove will put about 95% in the pan, a water cooker 100%. Say that here you get a total end-to-end efficiency of 25%.

So you need 2 kg, or 2,5L of diesel to replace 1 kg of propane.

in the UK a kg of propane costs UKP 3.- , a litre of diesel 1.- So from the perspective a fuel costs its propably a wash...

So going all electric, and getting rid of gas means:
- Some extra fuel costs, but they are ofsetted by no longer having to buy gas. For most applications this will be a wash.
- You need to invest in a good inverter and electricity storage. But once you've done that you can take advantage of that in many other ways as well... Run your fridge and freezer on 220V as well for example.
But a big advantage I see is:
- You no longer have the problem sourcing compatible gas bottles...
- You can use multiple sources for electricity...

[Dockhead]

Originally Posted by valhalla360

Per mile makes no sense for this type of comparison. You have a boat that cruises at 6mph vs a car that cruises at 60mph. Then you have the fact that most users are only in the car when it's moving where as your average cruiser may only be underway 1/20th of the time that they are on the boat.

Again, good data has been presented but you insist that they have for some inexplicable and undocumented reason totally ignored explosions. If it's really as bad as you say, that would imply gross negligence if they weren't already including that in with fires.

Fatalities per mile is not the only, and maybe not the best way to parse the data. But as a professional you will understand that the data is only meaningful if it's corrected in some reasonable way for the amount of use.

So if you're going to say that cars are more dangerous than boats, you have to divide the total number of fatalities (or serious injuries, or whatever) by something -- miles, or hours, trips, or days on board, or something. For you as a pro that will be kindergarten stuff. Without that, the numbers are meaningless. For example you could say that driving is far more dangerous than Russian Roulette, because only 10 people were killed that way last year, compared to 40,000 killed in car accidents.

You say "good data has been presented so far", but no relevant data, good or bad, has been presented. If I missed something, I'll be glad to be corrected.

[Dockhead]

Originally Posted by K_V_B

My back of the envelope calculation looks like this:

Propane/Butane has about the same energy density ad diesel. So one kg of propane equals about 1 kg of diesel. (Diesel weighs about 0.8kg/l)

Now asume you are boiling water:
A gas stove will convert gas in to heat with 100% efficiency, and put about half the heat it produces in the pan above it. So total end-to-end efficiency is approx 50%.

O good generator is maybe 30% efficient. An induction stove will put about 95% in the pan, a water cooker 100%. Say that here you get a total end-to-end efficiency of 25%.

So you need 2 kg, or 2,5L of diesel to replace 1 kg of propane.

in the UK a kg of propane costs UKP 3.- , a litre of diesel 1.- So from the perspective a fuel costs its propably a wash...

So going all electric, and getting rid of gas means:
- Some extra fuel costs, but they are ofsetted by no longer having to buy gas. For most applications this will be a wash.
- You need to invest in a good inverter and electricity storage. But once you've done that you can take advantage of that in many other ways as well... Run your fridge and freezer on 220V as well for example.
But a big advantage I see is:
- You no longer have the problem sourcing compatible gas bottles...
- You can use multiple sources for electricity...

In my opinion, that's a very good and useful analysis.

I would just add that this is the worst case scenario --

* When you're on shore power, you're not buying diesel to run the stove and oven
* When you're running the generator anyway for other tasks, you will not be spending the average amount of diesel per kW/h, but the marginal amount, which is far less.

So probably for the average cruiser with average usage, even someone who spends little time on shore power, I guess it's going to be a wash in terms of kg of fuel used.


BUT YOU FORGOT ABOUT COST. 1kg of LPG is more expensive than 1kg of diesel fuel, at least around here. 4.5kg of Calor gas costs 17 pounds here, or 3.77 per kg. But diesel is 0.92p per liter, let's say 1.15 per kg. The gas is more than triple the cost per kg.

Prices are different in different countries, but it looks like for many cruisers, cooking with electricity, even if you generate it all with a generator, is going to be far cheaper than cooking with gas. Certainly will be up here in Northern Europe.

[noelex 77]

I think electric (induction and microwave) cooking is safer than propane. It is also a lot more convenient, especially with a large (preferably lithium) battery bank. Our current boat caries 40 kg (85 lbs) of propane (and their is room for more), but it still a pain swapping these bottles even though our large storage means that we can do this infrequently and when it is most convenient.

However, electric cooking on a yacht requires a working generator (or shore power) unless you are on a big cat with room for lots of solar. Unfortunately, generators seem to be one of the components that most frequently give trouble. In addition, they require specialist knowledge and parts to repair (ie they can take a long time to fix in out of the way places). Large yachts get over this problem by fitting two generators, but on our sized yachts this is not viable.

There is no ideal answer (unless you have room for lots of solar), but dependence on a functioning generator is a serious drawback that needs to factored into the pros and cons.

Our new yacht will have propane/butane cooking (with lots of vented bottle storage like our current yacht). With 1kw of solar on the new yacht, we will be able to use some electric cooking to extend the life and therefore reduce the inconvenience of replacing the propane bottles, but it will be a secondary system. Of course your ideal may be different.

[poiu]

Originally Posted by Zanshin

I've got 440Ah (at 24V) of Gel batteries aboard and am a liveaboard 6 months out of the year, never going to a dock between splash and hauling out again. While I'm alone much of the time, I use my espresso machine quite a bit and cook 1-2 meals daily on the stovetop; and also bake bread occasionally. Apart from refrigeration (fridge and freezer), my biggest energy drain is the electric galley.

The energy consumption chart below (click to get a bigger image) shows the last 26 days aboard the boat. I have 750Watts of solar panels and it is generally sunny here in the Caribbean, and this is reflected in the data which shows that I have a pretty good energy consumption household. The 1 hour engine average per day comes mainly from engine runtime while leaving and entering anchorages as I tend to sail almost every day.



This shows that I've got ample battery power for an electric galley (and all the other gadgets such as watermaker, washing machine, etc.); I could even remove 2x220Ah batteries and still never reach the 60% battery charge state. Anything less than 60% will shorten the batteries' lifespan.

A lot of the posts on this thread on the subject of electrical galleys is based on expectations and anecdotal evidence. I've been measuring my energy use closely (using an Arduino processor that I programmed to read the Xantrex monitor and other sources and write everything to an SD data card every 30 seconds, 24x7); so this isn't some wild theory but solid liveaboard evidence.

Nice chart. The volt to capacity relationship doesn't look right though. If I read it right as an example you have 24.5v corresponding to 78% capacity. 50% to 60% would be more what I would expect. I don't know your battery model and its curve though.

[Dockhead]

Originally Posted by noelex 77

. . . However, electric cooking on a yacht requires a working generator (or shore power) unless you are on a big cat with room for lots of solar. Unfortunately, generators seem to be one of the components that most frequently give trouble. In addition, they require specialist knowledge and parts to repair (ie they can take a long time to fix in out of the way places). Large yachts get over this problem by fitting two generators, but on our sized yachts this is not viable. . .

Very good point -- not just the capacity, but the category of reliability of AC power on board. It's been said already but worth repeating that electric cooking is no good for a yacht which lacks high reliability AC power. It's easier to make propane reliable enough, than electrical power, and this would be an overwhelming reason in favor of propane, for anyone who has only a single source of AC power.

But having a generator as a single point of failure is unacceptable for many uses of AC power on board many yachts already. Certainly it is for us. AC power is mission critical. For example, my emergency crash pump is run with AC power.

As originally built in 2000, my boat was delivered with a 2.5kW alternator to back up the 6.5kW heavy duty generator. Until yesterday, when I finally sold it, I had a backup to both of these in the face of a Honda suitcase generator. I sold it because I never needed it and it was just rusting away in the lazaretten -- the low speed heavy duty generator is exceptionally reliable, and for the odd chance of a glitch we've got a backup to that.

Many modern cruising boats, especially larger ones, will have the same category of reliability, or even better.

[K_V_B]

Originally Posted by Dockhead

BUT YOU FORGOT ABOUT COST. 1kg of LPG is more expensive than 1kg of diesel fuel, at least around here. 4.5kg of Calor gas costs 17 pounds here, or 3.77 per kg. But diesel is 0.92p per liter, let's say 1.15 per kg. The gas is more than triple the cost per kg.

Actually I did mention the price difference. :-)

Another interesting titbit: In the Netherlands it is permitted to use red diesel (which is taxed at a lower rate) to run a generator. Even if the electricity is also used for propulsion. That makes an all electric boat even more interesting...

[a64pilot]

Originally Posted by K_V_B

My back of the envelope calculation looks like this:

Propane/Butane has about the same energy density ad diesel. So one kg of propane equals about 1 kg of diesel. (Diesel weighs about 0.8kg/l)

Now asume you are boiling water:
A gas stove will convert gas in to heat with 100% efficiency, and put about half the heat it produces in the pan above it. So total end-to-end efficiency is approx 50%.

O good generator is maybe 30% efficient. An induction stove will put about 95% in the pan, a water cooker 100%. Say that here you get a total end-to-end efficiency of 25%.

So you need 2 kg, or 2,5L of diesel to replace 1 kg of propane.

in the UK a kg of propane costs UKP 3.- , a litre of diesel 1.- So from the perspective a fuel costs its propably a wash...

So going all electric, and getting rid of gas means:
- Some extra fuel costs, but they are ofsetted by no longer having to buy gas. For most applications this will be a wash.
- You need to invest in a good inverter and electricity storage. But once you've done that you can take advantage of that in many other ways as well... Run your fridge and freezer on 220V as well for example.
But a big advantage I see is:
- You no longer have the problem sourcing compatible gas bottles...
- You can use multiple sources for electricity...

I concur, so much so that I'm thinking of going electric myself as I already have what I'm being told is an excess amount of Solar and an on board generator. But until we go, i don't know how excessive the Solar is, not do I know how much actual power we would use cooking, I believe it's more than most people think, and I don't want to have to start the generator to cook. SO I need I think to gather more data before I pull the trigger.
I was thinking about replacing our stove anyway, it's getting to be 30 years old and lighting the oven is a real PIA as you have to get on the floor and get to the pilot light, hold the button in until the thermocouple is hot etc., and of course since you turn the gas off after every use, leaving the pilot light lit is not an option.
I guess now I ought to wait until I know, but how many 22" wide electric stove / oven are there for Marine use?

What I would love to find is a flat glass heated surface and a Micro-Convection oven, we had one of those many years ago and it was great, cooked fast as it was a microwave, but also browned as it was a convection oven too. Only thing you lose I guess is broiling.

[Dockhead]

Originally Posted by a64pilot

I concur, so much so that I'm thinking of going electric myself as I already have what I'm being told is an excess amount of Solar and an on board generator. But until we go, i don't know how excessive the Solar is, not do I know how much actual power we would use cooking, I believe it's more than most people think, and I don't want to have to start the generator to cook. SO I need I think to gather more data before I pull the trigger.
I was thinking about replacing our stove anyway, it's getting to be 30 years old and lighting the oven is a real PIA as you have to get on the floor and get to the pilot light, hold the button in until the thermocouple is hot etc., and of course since you turn the gas off after every use, leaving the pilot light lit is not an option.
I guess now I ought to wait until I know, but how many 22" wide electric stove / oven are there for Marine use?

What I would love to find is a flat glass heated surface and a Micro-Convection oven, we had one of those many years ago and it was great, cooked fast as it was a microwave, but also browned as it was a convection oven too. Only thing you lose I guess is broiling.

Sounds like a great plan, and we will all be eager to see what solutions you find.

They now make combination micro-convection ovens- grills which will do everything including broiling. I have a large built-in microwave oven on my boat which could be replaced with one of these, which I will do as soon as I get around to it. I use one of these on land, and it's the t*ts. Although I prefer cooking on a gas cooktop, electric rules for ovens. And once you use a convection oven you never want to go back.


For your cooktop, be sure to go induction and not just an ordinary glass top (halogen I guess). The large increase in efficiency from induction would be key for boat usage I would think.

[Dockhead]

Originally Posted by K_V_B

Actually I did mention the price difference. :-)

Another interesting titbit: In the Netherlands it is permitted to use red diesel (which is taxed at a lower rate) to run a generator. Even if the electricity is also used for propulsion. That makes an all electric boat even more interesting...

Apologies for missing that


Interesting about red diesel, which even more improves the economics of electric cooking. Is that a common policy? In the UK, you use red diesel for everything including propulsion, but you have to declare which part you use for "domestic" purposes -- heating and generation -- and you don't pay duty on that part.