110 vs 230 for universal power

[Jammer]

Originally Posted by noelex 77

One rainy day I will have to do some experimentation. We boil a lot of water (for drinks and showers) generally via solar so the efficiency is important. I note the article actually quotes typical efficiencies of 80% (electric kettle) and 85% (induction) so the difference may be hard to pick in practice.

I ran the experiment a year ago and got 73% on induction and 86% on the electric teakettle.


I don't think the difference is significant and I'm not even sure it's outside of measurement uncertainty. One fact to consider is that the electric teakettle presents a pure resistive load to the inverter, while the induction hob is, to some extent, a reactive load that will lead to more power dissipation in the inverter. Probably only a few % difference on what comes out of the battery.

[s/v Jedi]

Originally Posted by Jammer

I ran the experiment a year ago and got 73% on induction and 86% on the electric teakettle.


I don't think the difference is significant and I'm not even sure it's outside of measurement uncertainty. One fact to consider is that the electric teakettle presents a pure resistive load to the inverter, while the induction hob is, to some extent, a reactive load that will lead to more power dissipation in the inverter. Probably only a few % difference on what comes out of the battery.

The electric tea kettle is an inductive load… the base with cord is magnetically coupled with the kettle bottom.

[Jammer]

Originally Posted by s/v Jedi

The electric tea kettle is an inductive load… the base with cord is magnetically coupled with the kettle bottom.

I suppose they vary. The ones I have, have contacts. There is a center pin and a ring contact, which carry current.

[goboatingnow]

Originally Posted by Jammer

I suppose they vary. The ones I have, have contacts. There is a center pin and a ring contact, which carry current.

Yes all mine are like that the element remains in the kettle and there is a pin and ring contact. Never seen an inductively coupled one.

[valhalla360]

Another one who's not seen an inductive kettle (120v or 230v). I'm sure they make them but I don't think they are common.

But still not seeing it being life altering to get boiling water in 25seconds vs 30 seconds.

[s/v Jedi]

Originally Posted by valhalla360

Another one who's not seen an inductive kettle (120v or 230v). I'm sure they make them but I don't think they are common.

But still not seeing it being life altering to get boiling water in 25seconds vs 30 seconds.

I am thousands of miles away from the one I checked out (has a center pin in the base like big version of toothbrush chargers) and did away with ours more than ten years ago, I accept that the numbers showing induction 5-10% more efficient are based on simple resistive element electric kettles. So how to explain this then?

For the remark about if it matters to boil a little quicker or not: no, you don’t get it, it is about the energy consumption. You may need an additional solar panel for the water kettle.
The reasons for us to switch to the good old kettle are reduced energy consumption and the water boiling in stainless steel instead of plastic. I did find stainless kettles but they still had plastic parts as well.

[valhalla360]

Originally Posted by s/v Jedi

I am thousands of miles away from the one I checked out (has a center pin in the base like big version of toothbrush chargers) and did away with ours more than ten years ago, I accept that the numbers showing induction 5-10% more efficient are based on simple resistive element electric kettles. So how to explain this then?

For the remark about if it matters to boil a little quicker or not: no, you don’t get it, it is about the energy consumption. You may need an additional solar panel for the water kettle.
The reasons for us to switch to the good old kettle are reduced energy consumption and the water boiling in stainless steel instead of plastic. I did find stainless kettles but they still had plastic parts as well.

2000w@230v for 25 seconds = 1500w@120v for 33 seconds (feel free to adjust based on the volume of water being heated but it will come out with a pretty similar ratio)

Both will boil water and consume pretty darn close to the same KWH (about 0.013kwh). And keep in mind, the only thing you can save is the difference in efficiency, not the total amount. Even if you are correct about being 10% more efficient (and I'm not sure I buy that see below), it's 0.0013kwh you are saving.

It's not going to cause you to need an extra 150w of solar panels (figure around 0.6kwh/day of production) to boil water your favorite hot drink.

As far as which is more efficient, you have to consider the way stoves work vs kettles:
- A traditional electric stove, heats up a resistance coil until it's hot enough that the heat transfers to the pan which then heats up. As there is limited contact area, this is a major source of energy loss. Once the pan is heated up, it starts transferring heat to the actual food.
- Induction transfers heat from the "burner" to the pan electromagnetically (ie: via induction). Then the pan heats and transfers the heat to the food. That electromagnetic transfer does lose some power but is still more efficient than direct heat of burner to heat of pan transfer. Hence the 5-10% improvement.

With a kettle, it's different. There is no interim step. The resistance coil is immersed in the water and directly transferring the heat to the water. An induction kettle, has an extra step transferring the power from the base to induction plate which costs power.

[s/v Jedi]

Originally Posted by valhalla360

2000w@230v for 25 seconds = 1500w@120v for 33 seconds (feel free to adjust based on the volume of water being heated but it will come out with a pretty similar ratio)

Both will boil water and consume pretty darn close to the same KWH (about 0.013kwh). And keep in mind, the only thing you can save is the difference in efficiency, not the total amount. Even if you are correct about being 10% more efficient (and I'm not sure I buy that see below), it's 0.0013kwh you are saving.

It's not going to cause you to need an extra 150w of solar panels (figure around 0.6kwh/day of production) to boil water your favorite hot drink.

As far as which is more efficient, you have to consider the way stoves work vs kettles:
- A traditional electric stove, heats up a resistance coil until it's hot enough that the heat transfers to the pan which then heats up. As there is limited contact area, this is a major source of energy loss. Once the pan is heated up, it starts transferring heat to the actual food.
- Induction transfers heat from the "burner" to the pan electromagnetically (ie: via induction). Then the pan heats and transfers the heat to the food. That electromagnetic transfer does lose some power but is still more efficient than direct heat of burner to heat of pan transfer. Hence the 5-10% improvement.

With a kettle, it's different. There is no interim step. The resistance coil is immersed in the water and directly transferring the heat to the water. An induction kettle, has an extra step transferring the power from the base to induction plate which costs power.

Not sure where you get your numbers from. A kettle on an induction cooktop consumes 5-10% less energy, period. With my kettle and cooktop the measured difference (actually measured by me) was 10%. You seem to confuse power with energy.

[NPCampbell]

Originally Posted by s/v Jedi

Not sure where you get your numbers from. A kettle on an induction cooktop consumes 5-10% less energy, period. With my kettle and cooktop the measured difference (actually measured by me) was 10%. You seem to confuse power with energy.

An inductive burner is more efficient than a resistive one at heating up the metal container that sits on it (if it's the right type of metal). However, I think Valhalla is likely correct. If you have a well insulated kettle with a resistive element inside of it, then it's efficiency is likely hard to beat because it is heating the contents directly rather than heating up the container or base first.

[valhalla360]

Originally Posted by s/v Jedi

Not sure where you get your numbers from. A kettle on an induction cooktop consumes 5-10% less energy, period. With my kettle and cooktop the measured difference (actually measured by me) was 10%. You seem to confuse power with energy.

I have to question how you did your measurements since you indicated a standard kettle is magnetically coupled to the base when that is not typical.

I understand the difference between power and energy...that's why I was referring to KWH as the unit for comparison.

Doesn't matter if it uses 30w or 3,000w, you need to account for both wattage and duration...ie: KWH.

[s/v Jedi]

Originally Posted by valhalla360

I have to question how you did your measurements since you indicated a standard kettle is magnetically coupled to the base when that is not typical.

I understand the difference between power and energy...that's why I was referring to KWH as the unit for comparison.

Doesn't matter if it uses 30w or 3,000w, you need to account for both wattage and duration...ie: KWH.

I posted citations. When you Google it you find hundreds. kWh is the unit for energy and a kettle on an induction cooktop consumes less energy than an electric kettle. I used a KillaWatt meter to compare the two… more than 10 years ago.

[NPCampbell]

Originally Posted by s/v Jedi

Here’s my recommendation:

Create two 48V house batteries that are 10kWh each that are normally connected in parallel (each with a main switch and BMS). This will power what you want.

Go big on solar; I have 1,875W and it powers everything incl. watermaker and even some A/C.

For setup check my attached diagram. I recommend to use inverter/chargers instead of separate units because they are more powerful at less cost. In the diagram you can easily force a unit into one role: for inverter unit, switch input breaker to OFF and output breakers ON and for charger switch output breakers OFF and input breaker ON.

You can eliminate the genset and you can add a 3rd inverter/charger. I currently run two in parallel mode; all charging is done by solar or DC-DC converter from the engine mounted alternator.

Nice diagram. I wasn't sure what benefit the 32A autotransformers were providing? Are your MultiPlus units not already inverting to AC already? Are the autotransformers just for load sharing between circuits?

[s/v Jedi]

Originally Posted by NPCampbell

Nice diagram. I wasn't sure what benefit the 32A autotransformers were providing? Are your MultiPlus units not already inverting to AC already? Are the autotransformers just for load sharing between circuits?

Most of the diagram is 240V 60Hz only… no 120V. This is why you can use one inverter but still get 120/240 service. The auto transformer takes the 240V, which is the L1 and L2 conductors, and creates a Neutral conductor so that you get 120-0-120 just like in a house in the US.

230V 50Hz wired boats don’t need them.

[valhalla360]

Originally Posted by s/v Jedi

I posted citations. When you Google it you find hundreds. kWh is the unit for energy and a kettle on an induction cooktop consumes less energy than an electric kettle. I used a KillaWatt meter to compare the two… more than 10 years ago.

I found many citations online but when you read them, they were comparing cooking on induction stoves vs cooking resistance coil stoves. That's not the same as comparing a non-powered kettle placed on an induction stove vs an electric kettle with the resistance coil submerged in the water.

I couldn't find any that matched exactly to what is being discussed on this thread.

Logically, what you describe makes no sense as there is no where for the kettle to lose efficiency while there are multiple steps where the induction system can lose efficiency. Given your statement that you apparently found a stand alone kettle that uses induction (magnetically coupled, I think you called it), it's likely not a comparable test. Might have been a cheap early attempt at induction heating.

But regardless, the difference in voltage is not life altering, which was the original point.

[s/v Jedi]

Originally Posted by valhalla360

I found many citations online but when you read them, they were comparing cooking on induction stoves vs cooking resistance coil stoves. That's not the same as comparing a non-powered kettle placed on an induction stove vs an electric kettle with the resistance coil submerged in the water.

I couldn't find any that matched exactly to what is being discussed on this thread.

Logically, what you describe makes no sense as there is no where for the kettle to lose efficiency while there are multiple steps where the induction system can lose efficiency. Given your statement that you apparently found a stand alone kettle that uses induction (magnetically coupled, I think you called it), it's likely not a comparable test. Might have been a cheap early attempt at induction heating.

But regardless, the difference in voltage is not life altering, which was the original point.

I only listed one citation, in post #28. From that citation I attach the measured efficiency: