Induction vs Gas Cooking

[Auspicious]

Originally Posted by Adelie

48v is what you do if you have electric propulsion.

For contrast, electric cars use somewhere between 300VDC and 800VDC with the overwhelming majority around 400VDC. If I recall correctly, diesel electric submarines run around 400VDC.

[Pelagic]

Originally Posted by s/v Jedi

I just released a new version of our AC power diagram which is related to the all electric galley discussed here. It's here: https://www.cruisersforum.com/forums....php?p=3157072

Thanks Nick.
Just ordered a new Victron Multiplus
24/5000/120 to add to the existing 24/3000/70 and looking at ways to wire it so that I select either or both.

Will start a new thread on that so as not to derail this one

[s/v Jedi]

Originally Posted by Pelagic

Thanks Nick.
Just ordered a new Victron Multiplus
24/5000/120 to add to the existing 24/3000/70 and looking at ways to wire it so that I select either or both.

Will start a new thread on that so as not to derail this one

Post a link to that thread here because I can’t keep up with all the new posts

[CatNewBee]

Have monitored our cooking for a week, we use 120Ah... 160Ah for cooking in average per day, roughly 100Ah for hot water, 100Ah for making water. Miscellanious 12V loads like fridges and freezer, lights, navstation, chargers etc. account for another 200Ah.

It sums up to roughly 8kWh per day consumption.

[Pelagic]

Originally Posted by CatNewBee

Have monitored our cooking for a week, we use 120Ah... 160Ah for cooking in average per day, roughly 100Ah for hot water, 100Ah for making water. Miscellanious 12V loads like fridges and freezer, lights, navstation, chargers etc. account for another 200Ah.

It sums up to roughly 8kWh per day consumption.

Thanks!
How many on board for those numbers

[Adelie]

Originally Posted by Auspicious

For contrast, electric cars use somewhere between 300VDC and 800VDC with the overwhelming majority around 400VDC. If I recall correctly, diesel electric submarines run around 400VDC.

Yeah, but in the case of cars there is a metric butt load of engineering that goes into the systems to make them consumer safe and on the subs there are professional users, not consumer level users.

[Adelie]

So I did the numbers to compare propane to induction cooking in terms of average electrical demand vs propane usage. If you know how much propane you use currently then you can figure out how much your average daily electrical demand will be.

The first chart shows this equivalency. If you are currently using propane to cook on and you know about how long it takes to empty a bottle, you can determine what your average daily electric use would be if you converted to induction.

- For this chart I assumed a 5kg propane bottle and calcualted how much fuel and energy per day that would be for 21d to 60d of use.
-I converted that to an equivalent daily energy use for induction by adjusting for both propane and induction efficiencies at 100% inverter efficiency.
- Then I converted that to average daily demand for 3 different inverter efficiencies.

The 2nd chart shows what the 5kg equivalent refill period would be if you had a different size bottle and knew how long that typically lasted, the, you could determine what the 5kg bottle life would be.
Example: if you have a 7kg bottle that normally lasts 37 days before needing to be refilled, then a 5kg bottle used at the same rate would last about 26 days. Knowing this you could go back to the first chart and determine what your average daily battery demand would be.

I personally tested an induction cooktop and a butane stove to determine their relative efficiencies. See the following post for a more in depth discussion. https://www.cruisersforum.com/forums...ml#post3157686

A bit over a year ago A64Pilot indicted he used a 10lb tank about every 30d.
https://www.cruisersforum.com/forums...ml#post2860268
This works out to a 5kg tank lasting 32-33d. Equivalent induction demand at 90% inverter efficiency would be about 130Ahr/d. He indicated that "... most all meals do involve two burners and the oven run simultaneously.
Usually two vegetables on the burner, and meat in the oven." with little eating out.
If other people want to volunteer their tanks sizes, average refill time and cooking styles I would appreciate that info.

Whatever your cooking style, if you know how long a tank normally lasts you can make a guess at what your average daily electrical demand for electrical cooking would be.

One of the limitations of my analysis is that I haven't measured propane and covection oven efficiencies. I'm thinking about how to measure that. Eventually I will do that testing but I need to figure out the protocol and to get the equipment. If there is somebody in the San Diego area with a propane oven on their boat that is willing to let me use it I would appreciate it. I'm not going to go out and buy an oven just for this testing. I will however be buying a convection oven before long so that side is covered.

[wingssail]

Originally Posted by Adelie

So I did the numbers to compare propane to induction cooking in terms of average electrical demand vs propane usage. If you know how much propane you use currently then you can figure out how much your average daily electrical demand will be.

The first chart shows this equivalency. If you are currently using propane to cook on and you know about how long it takes to empty a bottle, you can determine what your average daily electric use would be if you converted to induction.

- For this chart I assumed a 5kg propane bottle and calcualted how much fuel and energy per day that would be for 21d to 60d of use.
-I converted that to an equivalent daily energy use for induction by adjusting for both propane and induction efficiencies at 100% inverter efficiency.
- Then I converted that to average daily demand for 3 different inverter efficiencies.

The 2nd chart shows what the 5kg equivalent refill period would be if you had a different size bottle and knew how long that typically lasted, the, you could determine what the 5kg bottle life would be.
Example: if you have a 7kg bottle that normally lasts 37 days before needing to be refilled, then a 5kg bottle used at the same rate would last about 26 days. Knowing this you could go back to the first chart and determine what your average daily battery demand would be.

I personally tested an induction cooktop and a butane stove to determine their relative efficiencies. See the following post for a more in depth discussion. https://www.cruisersforum.com/forums...ml#post3157686

A bit over a year ago A64Pilot indicted he used a 10lb tank about every 30d.
https://www.cruisersforum.com/forums...ml#post2860268
This works out to a 5kg tank lasting 32-33d. Equivalent induction demand at 90% inverter efficiency would be about 130Ahr/d. He indicated that "... most all meals do involve two burners and the oven run simultaneously.
Usually two vegetables on the burner, and meat in the oven." with little eating out.
If other people want to volunteer their tanks sizes, average refill time and cooking styles I would appreciate that info.

Whatever your cooking style, if you know how long a tank normally lasts you can make a guess at what your average daily electrical demand for electrical cooking would be.

One of the limitations of my analysis is that I haven't measured propane and covection oven efficiencies. I'm thinking about how to measure that. Eventually I will do that testing but I need to figure out the protocol and to get the equipment. If there is somebody in the San Diego area with a propane oven on their boat that is willing to let me use it I would appreciate it. I'm not going to go out and buy an oven just for this testing. I will however be buying a convection oven before long so that side is covered.

We use 5kg in 21 days (average) which includes propane instant hot water heater (showers and wash-ups) and propane BBQ, used most nights, all on the same system. Two to three hot meals a day (usually two). Have been for 34 years,

[Auspicious]

Originally Posted by Adelie

One of the limitations of my analysis is that I haven't measured propane and covection oven efficiencies. I'm thinking about how to measure that.

If you have a thermometer with a remote probe you could measure preheat time by timing from cold start to 350F and assess insulation by turning off the power/heat and measuring time to something like 100F.

[Adelie]

Originally Posted by Auspicious

If you have a thermometer with a remote probe you could measure preheat time by timing from cold start to 350F and assess insulation by turning off the power/heat and measuring time to something like 100F.

I want more info on how much energy goes into the system.

Easy with a convection oven, meter the electricity.

For the propane stove, weigh the tank before and after cooking. I might be able to borrow a big scale from work to weigh a 10lb tank. If that doesn’t pan I have a smaller scale but then I need to figure out bout to hook up one of those small 1lb tanks into a full size system.

Also there’s figuring out if having the tank hooked up while measuring the weight is going to skew the results.

Alternatively I need to figure out how much fuel is used to charge the system and how much vents off unhooking the tank. To do this I could weigh the tank, hook it up, unhook without using any fuel and reweigh.

The problem is that if I am repeatedly hooking up and disconnecting the bottle some amount of fuel is going to be vented into the boat and it becomes a potential safety issue, on a loaner boat no less.

If I weigh with hoses attaches then I can determine fuel use for preheat.

One of the potential problems is condensation on the tank. I’ll have to wipe of the tank before every reading.

I’m intending to cook a chicken, bake a loaf of bread and maybe do a sheet of bar cookies, all from ambient temp so a significant amount of testing.

And repeat it all with the convection oven.

If anybody can think of something else to test cook, let me know.

[noelex 77]

My estimation for both induction cooking and water heating (hot drinks and shower water) is around 100-130 Ahrs a day on a 24v house bank (you need to double these numbers for 12v). This is for two people one of whom is a great, and keen cook.

This is very close to CatNewBee’s estimation in post #349. This was 120-160 Ahrs for cooking and 100AHrs for water for a total of 220-260 Ahrs (on a 12v system).

These numbers will obviously vary depending on a number of variables, but at least serve as starting point.

My Pico battery monitor allows for a reasonably accurate measurement of individual loads so I can measure the AHrs consumed cooking specific dishes. I have never bothered, but can do so if anyone is interested.

[CatNewBee]

Originally Posted by Pelagic

Thanks!
How many on board for those numbers

We are 2. at the moment.

With guests on board, water consumption will increase, but not proportional, we would temporary switch back to sea water flush on the heads and may not make as much hot water as we do now. Cooking for 2 or for 4 is not a big difference energy wise.

[Pelagic]

One factor I don't think has been mentioned in the comparison is...
Spills!
Just dropped a carton of 12 eggs on the stove top, while cooking lunch.
Only one didn't crack open.
Very glad it wasn't a gas cooker!

[Dockhead]

Originally Posted by Pelagic

One factor I don't think has been mentioned in the comparison is...
Spills!
Just dropped a carton of 12 eggs on the stove top, while cooking lunch.
Only one didn't crack open.
Very glad it wasn't a gas cooker!

And the risk of burning yourself. With induction everything is cool except the bottom of the pan you are cooking with. A significant plus when cooking at sea.

[olaf hart]

Just to add some perspective here, it took the Irish hunger strikers over 60 days to die with no food...

The thing that matters is clean fresh water...