2 hours ago, SilverNodashi said:

Perhaps you can use the 2.2Kw kettle now?

LOL! I'll try it tomorrow. I am not happy with the performance of the new one anyway!

 

4 hours ago, ibiza said:

LOL! I'll try it tomorrow. I am not happy with the performance of the new one anyway!

 

Why not? Is it purely taking too long to boil the water (due to the fact that it has a smaller element), or does it not reach boiling point (i.e. 100 degrees Celsius)?

You are right, it is just a time the smaller kettle needs to bring the water to the boiling point.

The problem the bigger element causes is it's need more watts and this is the problem in the early morning while the production by the panels is not enough to supply the heater and inverter switches back to grid what I don't like.

On 11/06/2016 at 0:12 PM, krugeran58 said:

Can also try a 12v kettle (150w) 450ml so two cups of coffee/tea. Been using a setup 2x 80watt PV's , 100Ah Batt add plus with 12v car USB charger phones/tables are also charged

Take my money! 

Take my money! 

Hi Jay where did you buy ?

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Would also love to have one!

Where can we buy one of those?

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7 hours ago, Energy said:

Would also love to have one!

 

13 minutes ago, Manie said:

Where can we buy one of those?

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http://www.takealot.com/moto-quip-12v-dc-kettle/PLID28153069

http://www.takealot.com/moto-quip-12v-dc-kettle/PLID28153069

Thanks Viper

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1 hour ago, viper_za said:

http://www.takealot.com/moto-quip-12v-dc-kettle/PLID28153069

The kettle in the pic is plugged into a mains outlet.  The one in the link is 12V.

Necro post, but 4years later and none of the links work anymore. What is everyone using these days? The need is still there. 

I use a single plate induction stove and a stainless steel whistling kettle. The nice thing about that is it has different power settings, so if the sun is shining I put it on full power, and otherwise at a lower power setting.

@DeepBass9 thanks. Out of interest, what are the specs of the plate on high and low settings and how long does it take to boil on low vs high? How many litres? 

3 hours ago, DeepBass9 said:

I use a single plate induction stove and a stainless steel whistling kettle. The nice thing about that is it has different power settings, so if the sun is shining I put it on full power, and otherwise at a lower power setting.

Because of excess electricity we installed a 2 plate Elba countertop hob . With these electric plates the higher settings use more watts .The large 2000w plate is 2000 w on setting 6 , 1100w on setting 5 . LP gas reduce by 60 %

Already on gas, but wife says after moving to solar off grid setup there is just one thing she misses and thats the kettle. Yeah I know, how hard can it be to wait 9mins to boil it on the gas, but OK. Thats the reason I was asking if anything new has come on the market. The induction sounds like an option, but would be interesting what @DeepBass9 comes back with regarding wattage and time to boil. 

3 hours ago, Tsa said:

Already on gas, but wife says after moving to solar off grid setup there is just one thing she misses and thats the kettle. Yeah I know, how hard can it be to wait 9mins to boil it on the gas, but OK. 

There's no shortage of kW in a gas burner. But agreed the kettle takes a long time to boil..

I think the issue is the kettle itself. Electric kettles have the element in the water so are as efficient as you get. Gas burners have the energy on the outside of the kettle.  There has to be more efficient stove kettles somewhere!

18 hours ago, Richard Mackay said:

I think the issue is the kettle itself. Electric kettles have the element in the water so are as efficient as you get. Gas burners have the energy on the outside of the kettle.  There has to be more efficient stove kettles somewhere!

Yup, nail on the head. An electric kettle with the element in the water is damn neat 100% efficient. A pot/kettle on a gas stove is less than half that. Same cost per kwh (roughly) but half as efficient.

I don't have numbers for gas geysers, but of course more effort is made to keep the flame close to the heating pipes, so that would likely be the most efficient way to heat water using gas.

It takes 1.16Wh to heat one liter of water by one degree centigrade (I memorised that, but you can look it up and convert the joules to kwh). Assuming you need to heat one liter from 15C to 100C (85C delta), that is just about 100Wh, so a 1kw element will take 6 minutes to do that. Since most kettles are just a tad over 1 liter (ours is 1.7 for example), 9 minutes sounds about right.

I just saw online the 0.9l Mellerware Piccolo 1.3kW kettle, the type that gets used in hotel rooms for coffee nooks. It seems a reasonable balance between lower power consumption, affordable price, everyday usability, availability through major retailers, up to 2 year warranty, and hopefully brandname quality (for what that's worth).The power is not ultra-low but say if you have a 3KVA inverter wired in for backup, this shouldn't be pushing you as as close to the limits as much as a typical big kettle would. Anybody have experience with it?

6 hours ago, plonkster said:

Yup, nail on the head. An electric kettle with the element in the water is damn neat 100% efficient. A pot/kettle on a gas stove is less than half that. Same cost per kwh (roughly) but half as efficient.

So the transfer of heat between the burner to the bottom of the kettle and then the water is not as efficient?

I guess if more surface area (i.e. the bottom of the kettle) is exposed to the the flame the better. What if the kettle is made of a better heat transfer metal (e.g. copper)?   

Edited March 22, 20206 yr by Richard Mackay

You get those gas stoves for hiking that has a heat exchanger on the bottom of the pot (eg Jetboil) that can boil water pretty damn fast. 

4 hours ago, Richard Mackay said:

So the transfer of heat between the burner to the bottom of the kettle and then the water is not as efficient?

Correct. Some of the heat just buggers off into space without ever entering the utensil, and some heat radiates off the utensil/kettle without being absorbed by the water. When you have the element inside the water, there is pretty much just one place for it to go.

4 hours ago, Richard Mackay said:

I guess if more surface area (i.e. the bottom of the kettle) is exposed to the the flame the better. What if the kettle is made of a better heat transfer metal (e.g. copper)?   

Yup. So when using a gas stove, use the right size burner with the right size pot. Re better heat transfer, it again goes both ways. It absorbs heat more easily, but also radiates it more easily. I'm not sure how much of an effect it really has.

20 hours ago, GreenFields said:

I just saw online the 0.9l Mellerware Piccolo 1.3kW kettle, the type that gets used in hotel rooms for coffee nooks. It seems a reasonable balance between lower power consumption, affordable price, everyday usability, availability through major retailers, up to 2 year warranty, and hopefully brandname quality (for what that's worth).The power is not ultra-low but say if you have a 3KVA inverter wired in for backup, this shouldn't be pushing you as as close to the limits as much as a typical big kettle would. Anybody have experience with it?

Does this make any difference? The amount of energy required to boil the water remains the same, so this kettle would impose a smaller load but for a longer period of time.

OK... it does make a difference when managing the momentary load on the system, but in terms of you batteries surely the amount of energy required to boil the water is what the laws of physics says it is, and so that will be the amount drawn from the batteries.

I think part of the solution here, as it always has been, is boiling just as much water as you need. 

2 minutes ago, Bobster said:

Does this make any difference? The amount of energy required to boil the water remains the same, so this kettle would impose a smaller load but for a longer period of time.

Yup, just like this COVID-19 stuff (I believe I'm the first to bring it up... which is amazing, that is all the rest of the world is talking about!), it is about flattening the curve. I can still boil water when the grid is down... but I don't have to buy a larger battery/inverter.

I run my normal 2kw kettle from my inverter. The LFP batteries can handle it 🙂

4 minutes ago, Bobster said:

I think part of the solution here, as it always has been, is boiling just as much water as you need. 

Absolutely. That's again a difference between me and the other short-haired biped in the house: When I need a liter of hot water, I fill it to about the 1.2 liter mark (the markings aren't very accurate). The other user fills it to the top each time... 🙂

 

 

 

2 minutes ago, plonkster said:

I run my normal 2kw kettle from my inverter. The LFP batteries can handle it 🙂

ThIs has got to be an ad for LFP batteries!  (It's fine if the PV panels are pumping power into the system..)

There should be a law against using the most sophisticated energy we have available for heating water!

10 hours ago, plonkster said:

Correct. Some of the heat just buggers off into space without ever entering the utensil, and some heat radiates off the utensil/kettle without being absorbed by the water. When you have the element inside the water, there is pretty much just one place for it to go.

A problem with gas generally is that people just crank that sucker all the way up. You actually want just enough flame to heat the bottom of the pot/kettle. Anything that overlaps and flares around the sides is wasted (the user manual for my stove actually makes that point - but you have to read the manual). Same with gas heaters - you don't need to open the tap on the top of the bottle all the way, just open it enough to give a constant flame. The heater can only burn so much gas at a time.