Electric cookplate

[Ixneigh]

A friend on a keelboat claims he is running an induction type hotplate off his solar system. He has three hundred watts of solar, three batteries at 100 AH each, and uses the hotplate a total of 30 minutes a day on average. Is there a more efficient or better way to do this? Safety?
I currently use butane camp gas disposable cylinders. Pros/cons over what I have (which is working well for me)
Thank you!

Ix

[Russ]

Living off grid we learn much about energy.

One thing I learned is just how much energy is in fossil fuel. Especially when it comes to making heat.

ANY electric device that makes heat is going to use a LOT of POWER. Induction may be a bit more efficient than standard heating coils, but at 1000w that's still a lot of juice.

They do make 24v induction cook tops. Maybe 12v also. Still 1000w. However, it's probably more efficient than the power loss of inverting to 110VAC.

I guess much depends on that 300w of solar and how much sunshine and what kind of batteries. Newer tech batteries are vastly superior to lead acid. However, you can't get around 1000w of power is a lot of amper hours.

If you can make the power from solar, it probably works for 30 minutes of use or less. I wouldn't expect more than that and that probably will flatten a battery.

What else can your friend tell about his setup?

Years ago on my Hunter, we had a microwave for when at the dock. I tried to run it off an inverter to make coffee and it sucked the battery down so fast. Of course the tech back then was lead acid and I only had the engine alternator to recharge.

[Starscream]

Well, my AI buddy CoPilot says:

"Bottom line
Expect ~20 Ah at 12 V to bring ½ gallon of water to a rolling boil using your 1000 W inverter and an induction cooktop."


I'm redesigning my electrical system and am enlisting the help of Copilot, and I'm astounded by how good it is but also by how confidently it can make a mistake.

[kurz]

I love my Origo3000 with 2 stoves, on a gimbal... Guess what a big thing to get there with Ah... The origo is very compact.

As long as I trailer weight is Important. 3 big batteries, 300w Solar, Inverters, starter lead Battery... You get 100kg or more. And count the $$$

My nespresso machine gets 12V. Works fine for me.

All with 1 Single Battery, also for starting the mercury60, I have Winston LifeYPo4 60A. 100w Solar. Works perfect for years...

Got enough Ah for the Diesel air heater the last night also.

[Be Free]

A friend on a keelboat claims he is running an induction type hotplate off his solar system. He has three hundred watts of solar, three batteries at 100 AH each, and uses the hotplate a total of 30 minutes a day on average. Is there a more efficient or better way to do this? Safety?
I currently use butane camp gas disposable cylinders. Pros/cons over what I have (which is working well for me)
Thank you!

Ix

3 X 100Ah assuming parallel connection starts us with 300Ah usable power (Li) or 150Ah (Pb).
At a nominal 12V that comes to 3600Wh (Li) or 1800Wh (Pb).

Common, portable single burner cook tops are usually 1500W to 1800W.
30 minutes use per day will use 750Wh to 900Wh (with no losses).

A high-quality pure sine wave inverter might be as much as 95% efficient at 80% of its maximum load. Round number: 2000W inverter +/- 10% will get you in the 95% efficient ballpark.

With losses realistically expect to use 900Wh to 1100Wh running the cook top each day.
Whether he is using Li or Pb he can power his cook top through his 2000W inverter for 30 minutes without killing his house bank.

On the solar side he has 300W solar with an average of 6 hours per day of usable sun gives 1800Wh going back into the battery.
There should be no problem bringing a Li battery bank back to full charge most days with these numbers. A Pb battery bank will still work most of the time but it will hit full charge later in the day and will have less reserve for bad weather.

Pro / Con
Keep what you have: What you have works for you and does not require any new equipment. You can buy a lot of propane bottles for the cost of an induction cook top, a 2000W inverter, and heavy enough cable to feed it.
Change: You will not have to keep buying as much propane. Much higher set up costs but close to zero recurring costs. You may need to keep the existing propane setup on board in case of multiple cloudy days or higher than expected cook times.

Recommendation:
Calculate your annual propane costs and replacement costs for any equipment that is close to it's end-of-life. Call it Propane.
Calculate the new equipment costs for converting to induction. Call it Induction. If this number is more than you want to spend on your galley then you have your answer.

Induction / Propane = years to recoup conversion cost.

If the answer is something less than your remaining years sailing then you might consider changing. If not, the numbers don't add up but that does not mean you can't do it anyway. It's your boat.

[Be Free]

Well, my AI buddy CoPilot says:

"Bottom line
Expect ~20 Ah at 12 V to bring ½ gallon of water to a rolling boil using your 1000 W inverter and an induction cooktop."


I'm redesigning my electrical system and am enlisting the help of Copilot, and I'm astounded by how good it is but also by how confidently it can make a mistake.

Two things I've learned about AI answers:

• If it does not sound right it probably is not right.

• Check your units. I've caught AI forgetting to convert units properly on more than one occasion. (see previous item)

[Be Free]

Living off grid we learn much about energy.

One thing I learned is just how much energy is in fossil fuel. Especially when it comes to making heat.
...

In addition to the boat energy budget, where I live being off-grid for hours or even weeks is not unusual. I've learned to think in terms of what my electricity is actually costing me in terms of fuel and wear-and-tear on the generating equipment. These days I turn more lights off and keep the thermostat set higher than I used to even when I'm on utility power.

On your second point: Even different forms of fossil fuel differ. I had someone offer to give me a brand-new Generac generator that would be able to run my whole house (AC included). When I calculated the extra cost for running a generator on propane vs what I spend now to run one on gasoline I graciously declined. Now, if I'd had access to natural gas it would have been a different story.

[Ixneigh]

Thank you everyone.
My friend has embraced the LION battery tech. I am not quite ready to make the leap. He also has these huge wires everywhere, so they can be inspected if they get hot. He likes messing around with inverters and things. They take up space on his larger boat. I know he means well when he makes these suggestions about a way to not pay for propane any more. But after reading the comments here, i think i will pass on this one.

Ix.

[Be Free]

Ixneigh

From following your excellent write-ups on your trips I would totally agree that sticking with propane is the best choice for your boat. It is simple, compact, and does not rely on energy sources that can be "fickle". In the example I previously posted, two cloudy days in a row would just about wipe out the house bank just from using the induction cooker unless there was another charging source.

My primary cooking method is the single burner Origo that came in my boat with a small one-burner propane as backup. The most the Origo has been used was an 8 day trip without resupply and two people on board. It worked just fine and (like you) I have no need to change anything in that department.

Full disclosure: My house bank and inverter are more than able to run an induction cook-top but I built it with other uses in mind. Electric cooking on my boat (like inverter powered AC) is just too energy intensive for my taste.

Thanks for a great topic!

[Starscream]

Thank you everyone.
My friend has embraced the LION battery tech. I am not quite ready to make the leap. He also has these huge wires everywhere, so they can be inspected if they get hot. He likes messing around with inverters and things. They take up space on his larger boat. I know he means well when he makes these suggestions about a way to not pay for propane any more. But after reading the comments here, i think i will pass on this one.

Ix.

My $0.02 from 45N lattitude where 95F feels like baking in an oven, and not considering the cost to buy or operate either system:

The amount of heat that escapes into the cabin when using alcohol or propane is much more than that produced by an induction plate. Also, the amount of time invested in watching the pot heat up is much less for induction. These are both big advantages for me, and I would imagine that in FLA one would want to absoutely minimize waste-heat into the cabin, no?

[Be Free]

My $0.02 from 45N lattitude where 95F feels like baking in an oven, and not considering the cost to buy or operate either system:

The amount of heat that escapes into the cabin when using alcohol or propane is much more than that produced by an induction plate. Also, the amount of time invested in watching the pot heat up is much less for induction. These are both big advantages for me, and I would imagine that in FLA one would want to absolutely minimize waste-heat into the cabin, no?

It is early afternoon here in Florida. It is 90F here and 78F where ixneigh lives (he's getting some really nice sea breezes today) and we're still 10 days or so from the official start of Spring. I suppose it boils to to what you are used to. If the water gets below 72F I won't go in without a wet suit but I used to hang out in Germany with some Norwegian girls who would swim in a glacier-fed lake in bikinis (but that's a story for another day).

Speaking for myself, the only time I've paid any attention to the heat coming off my stove was when I was sailing in Winter closer to 30F and what I noticed was that it wasn't doing much to heat up the cabin.

Seriously though, if it's hot enough to uncomfortable I'll have the cabin top and the front hatch open and a wind scoop deployed if possible. One of the "other uses" for my house bank I mentioned in my previous post was the ability to run fans in the cabin (continuously if needed) without putting a strain on the house bank. A little breeze goes a long way toward keeping the cabin comfortable and the cabin is seldom completely closed unless I'm trying to keep heat in. Minimizing waste heat has zero value to me.

[Starscream]

My $0.02 from 45N lattitude where 95F feels like baking in an oven, and not considering the cost to buy or operate either system:

The amount of heat that escapes into the cabin when using alcohol or propane is much more than that produced by an induction plate. Also, the amount of time invested in watching the pot heat up is much less for induction. These are both big advantages for me, and I would imagine that in FLA one would want to absolutely minimize waste-heat into the cabin, no?

It is early afternoon here in Florida. It is 90F here and 78F where ixneigh lives (he's getting some really nice sea breezes today) and we're still 10 days or so from the official start of Spring. I suppose it boils to to what you are used to. If the water gets below 72F I won't go in without a wet suit but I used to hang out in Germany with some Norwegian girls who would swim in a glacier-fed lake in bikinis (but that's a story for another day).

Speaking for myself, the only time I've paid any attention to the heat coming off my stove was when I was sailing in Winter closer to 30F and what I noticed was that it wasn't doing much to heat up the cabin.

Seriously though, if it's hot enough to uncomfortable I'll have the cabin top and the front hatch open and a wind scoop deployed if possible. One of the "other uses" for my house bank I mentioned in my previous post was the ability to run fans in the cabin (continuously if needed) without putting a strain on the house bank. A little breeze goes a long way toward keeping the cabin comfortable and the cabin is seldom completely closed unless I'm trying to keep heat in. Minimizing waste heat has zero value to me.

Clearly sea-breezes and lake-breezes are two entirely different animals At 90F with the alcohol stove on, and all hatches open, I'm doing a human slow-roast.

[Ixneigh]

Yes, great breeze today, quick sail to long key from islamorada gulf side. Hoping to catch a little southerly tomorrow to take me NE to Key Largo oceanside
Its 80 degrees right now.

Ix

[Be Free]

Yes, great breeze today, quick sail to long key from islamorada gulf side. Hoping to catch a little southerly tomorrow to take me NE to Key Largo oceanside
Its 80 degrees right now.

Ix

I wish I was out sailing. I spent all day sanding off old bottom paint and tracking down a problem in my shore power connection.

[Russ]

I wish I was out sailing. I spent all day sanding off old bottom paint and tracking down a problem in my shore power connection.

I wish I was out sailing too. Just took the cover off and waiting for warmer temps.