Induction vs Gas Cooking

[jmh2002]

Is the boat also 24V? 570 Ahr Pb-acid bank and 800W of solar doesn't seem like a lot?

[Adelie]

At 12v you can expect to average 200-250Ahr per day from 800w of panels.

[kefroeschner]

And I should clarify that the '8 kW' inverters are rated in Chinese watts -- really only good for about 3 kW each, but that is enough to run everything we have.



Yes 12v. If we were doing it over we'd go for 24 or 48v, but this works.



800w * 6hr/day * 1/12v = 400Ahr/day, but yeah, I'll go with 200 to 250. That, incidentally, is what a lot of reading indicates is the typical use range for a cruising liveaboard. Another number from Nigel Calder is, if I recall correctly, to figure on 200 watts continuous as the equivalent of the intermittent loads of the typical cruiser. And 800w maximum for an average of 1/4 of the time is 200w.

[Adelie]

Some people don’t get that while cooking on electricity has a very high instantaneous demand, that demand is over very short periods so the total energy consumption isn’t bad.

[noelex 77]

Originally Posted by Adelie

At 12v you can expect to average 200-250Ahr per day from 800w of panels.

These averages are useful, but solar power is very dependent on the location and season. You can consistently produce much more or less than these rules of thumb would suggest.

[Adelie]

That’s why I wrote average.

[noelex 77]

Originally Posted by Adelie

That’s why I wrote average.

Battery capacity is not sufficient to average solar panel output from location to location or from season to season.

The standard deviation for solar production is very high. Average output can be very misleading. Often it will many months, or considerable cruising miles before you can even remotely approach the mean result.

[kefroeschner]

But to get back to the OP's question ... Induction, by all means. Yes it takes the same amount of energy to cook a given amount of food, no matter how supplied. But, the real difference is how much of the energy being consumed actually gets into the food? If you have a gas stove, cook something and put your hands around the edges of the pot -- ouch! There is a lot of heat just going into the air. Same with old style electric stoves, but not quite as bad. Do the same thing with an induction stove and there is virtually no heat going around the pot and up into the cabin air.


The other issue is safety. We would just rather not live with a potential fire-bomb.


Finally, there is ecology. We need to kick this addiction (as G W Bush called it) to fossil fuels.

[kefroeschner]

Noelex and Adelie are both right. And there are times when it seems the sun has just gone. Like now. Fourth day of overcast and rain with more to come. In Florida. So, some supplement to PV is extremely desireable, per Noelex. The most practical now seems to be windpower.



I recall a report by Don Street on an ARC where he asked, "How any hours did you need to run your engine to charge batteries?"


Those with wind generators only --about 4 hours per day during the crossing.
Those with solar panels only -- about the same.


Those with both -- virtually never.


It's just belt and suspenders.

[noelex 77]

Solar and wind are both synergistic and antagonistic.

They are synergistic because at the times and places of low solar production there is often reasonable wind power. They are antagonistic because often on a sailboat the only practical location for a wind generator is in a position where it will shade the solar panels. Shade on solar panels has a far more significant impact than can be reasonably imagined.

[s/v Jedi]

Originally Posted by kefroeschner

Noelex and Adelie are both right. And there are times when it seems the sun has just gone. Like now. Fourth day of overcast and rain with more to come. In Florida. So, some supplement to PV is extremely desireable, per Noelex. The most practical now seems to be windpower.



I recall a report by Don Street on an ARC where he asked, "How any hours did you need to run your engine to charge batteries?"


Those with wind generators only --about 4 hours per day during the crossing.
Those with solar panels only -- about the same.


Those with both -- virtually never.


It's just belt and suspenders.

The problem with those numbers is that they are for the average boat. Someone who switches to solar decisively, does not belong to that avg group anymore and wind energy makes zero sense for them.

[GoneDiving]

Originally Posted by noelex 77

This is a great set up, but for anyone thinking of duplicating the above it will only work in areas of reasonably good solar insolation.

It is important to understand this limitation and ensure it matches your cruising plans.

Another thing for boats with low powered inverters to consider is that, for our cooktop at least, any setting above 800w draws that amount of power continuously while settings below 800w do not. The hob pulses 800w on and off to give an average 400, 600w etc. So even if you do most of your cooking at 600w, you still need to be able to support 800w.

I'm not sure if this is applicable to all models or just our cheap version??

[noelex 77]

Originally Posted by GoneDiving

Another thing for boats with low powered inverters to consider is that, for our cooktop at least, any setting above 800w draws that amount of power continuously while settings below 800w do not. The hob pulses 800w on and off to give an average 400, 600w etc. So even if you do most of your cooking at 600w, you still need to be able to support 800w.

There is a need for a reasonable sized inverter.

If you have the ability to generate sufficient electrical power to support induction cooking, even part time, you are likely to have a suitable sized inverter. If not, it is easily fitted.

The main stumbling block is a mismatch between the electrical power consumed and the power produced.

Unfortunately, I think some boats are planning to use full time electrical cooking via alternative energy such as solar and wind when this is not sustainable given the realties of their cruising plans and the available alternative energy production.

If you have a large solar array and plan cruising areas of reasonable solar insolation it can be done, but often “Their eyes are bigger than their bellies” as my father would say.

[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

[Auspicious]

Originally Posted by Dockhead

So I have received a 5 page email from a famous professor via my niece, on the systems design and risks questions which Auspicious and I were discussing.

/snip/

2. Risk of parallel systems, like gas and electricity, is additive. Eliminate gas and subtract that risk. Simple subtraction like I thought.

Hmm. I must be remembering something because I do remember lower order risks being subsumed. I accept the expert input but I'll keep looking for what I think I remember.