Induction Cooking info and experience.

[krid2000]

Originally Posted by s/v Jedi

For inverter/charger I recommend this one: https://shop.pkys.com/multiplus-ii-pmp122305110
At $1,184 it is a good deal, with good 50A contactors in the transfer switch.

Jedi,

any specific reason you recommend the MP-II instead of the MP-I version?

Thanks!
Dirk

[s/v Jedi]

Originally Posted by krid2000

Jedi,

any specific reason you recommend the MP-II instead of the MP-I version?

Thanks!
Dirk

It’s smaller, lighter, modern design with modern components, I think higher efficiency and they worked out all the initial problems.

I really don’t understand people posting cheap inverters that still kost $500-700 and they don’t have the charger, don’t have PowerAssist etc. While for a couple hundred more you can have it all.

Also, you can not run an 1,800W cooktop on a 2000W inverter. The inverter is actually 2000VA which means it can only supply that power for a correction factor of 1.0 and I don’t think you can find cooktops like that…

[noelex 77]

Electric cooking has always been (and still is) practical for larger boats with lead acid battery banks, but the development of lithium batteries and the improvement in inverter technology, together with the introduction of induction cooktops has enabled smaller yachts to take advantage of this option. The equipment needed is not expensive in boat terms.

The stumbling block for smaller yachts is power generation. The energy used for electric cooking has to be replaced. It does not matter if you cook more slowly using lower wattage appliances, the total energy consumed is similar. The amount of energy needed varies greatly depending upon the cooking style, and the energy production from solar is very dependent on the location and time of year. So use some caution when trying to decide if electric cooking, especially just electric cooking (with no propane back up) is viable.

Unfortunately, I am seeing long distance cruising boats attracted to the idea of electric cooking (as they should be, as it has many advantages) and ditching their propane options only to find that there are times and situations where the power generation is simply not keeping up. This is particularly a risk on smaller monohull boats where the ability to fit large solar arrays is limited.

[Statistical]

Originally Posted by s/v Jedi

Also, you can not run an 1,800W cooktop on a 2000W inverter. The inverter is actually 2000VA which means it can only supply that power for a correction factor of 1.0 and I don’t think you can find cooktops like that…

The better quality ones should be close to 1.0 (like 0.96+) because a power factor compensating rectifier are cheap and common today. All the power is running through a rectifier.

The cheap ones though who knows.

Still even if you have a good one the inverters have to be derated for temps as well and it is just a good idea to have some headroom.

[Pete7]

Originally Posted by s/v Jedi

It’s smaller, lighter, modern design with modern components, I think higher efficiency and they worked out all the initial problems.

I really don’t understand people posting cheap inverters that still kost $500-700 and they don’t have the charger, don’t have PowerAssist etc. While for a couple hundred more you can have it all.

Also, you can not run an 1,800W cooktop on a 2000W inverter. The inverter is actually 2000VA which means it can only supply that power for a correction factor of 1.0 and I don’t think you can find cooktops like that…

Well my battery charger is separate, also we rarely use shore power.

Surely that depends on the make, yes Victron rate in VA but others in W. So a 1500w induction will run quite happily on a 2kW inverter. The real problem is you are likely to burn what ever is cooking if you put 1500w into a pan whilst cooking for two.

[s/v Jedi]

Originally Posted by Statistical

The better quality ones should be close to 1.0 (like 0.96+) because a power factor compensating rectifier are cheap and common today. All the power is running through a rectifier.

The cheap ones though who knows.

Still even if you have a good one the inverters have to be derated for temps as well and it is just a good idea to have some headroom.

Somewhere buried deep in the forum must be my tests that included power factors, number of real power levels vs cycling etc. I lack the incentive to find them again

[Statistical]

Originally Posted by noelex 77

Unfortunately, I am seeing long distance cruising boats attracted to the idea of electric cooking (as they should be, as it has many advantages) and ditching their propane options only to find that there are times and situations where the power generation is simply not keeping up. This is particularly a risk on smaller monohull boats where the ability to fit large solar arrays is limited.

Even if energy production doesn't keep up and you need to supplement it with electrical energy from diesel powered alternator there are still advantages.

1) You simplify logistics. Going from a 3 fuel boat to a 2 fuel boat has advantages for long range cruisers. Likewise going to an electric dinghy motor may also be worthwhile for getting explosive gasoline off the boat and going to a 1 fuel boat.

2) Improved thermal efficiency means less heat in the galley which most people apreciate in a non-ACed galley.

3) Propane combustion releases significant water vapor which increases the humidity in the boat.

4) Propane can just be a pain the butt to find globally. Filling centers may be located a long distance from marina and may use incompatible connectors.

5) There is a low but non-zero risk by having propane onboard. Some people may value the safety of removing an explosive gas from the boat.

In general though it is a good idea to consider the additional energy consumption and how it will be covered. Measuring propane tank usage over a week is a good start as cooking habits vary dramatically. Some types of meals are just inherently more energy intense.

[BjarneK]

Originally Posted by s/v Jedi

Somewhere buried deep in the forum must be my tests that included power factors, number of real power levels vs cycling etc. I lack the incentive to find them again

Here is my test of a cheap Ikea induction hob:

https://www.cruisersforum.com/forums...ob-276389.html

To quote myself: "The power factor varies from 93 % on the low settings to 98 % on the high settings."

I have not tried it on an inverter yet.

[Pete7]

Originally Posted by noelex 77

The stumbling block for smaller yachts is power generation. The energy used for electric cooking has to be replaced. It does not matter if you cook more slowly using lower wattage appliances, the total energy consumed is similar. The amount of energy needed varies greatly depending upon the cooking style, and the energy production from solar is very dependent on the location and time of year. So use some caution when trying to decide if electric cooking, especially just electric cooking (with no propane back up) is viable.

Agreed, but I am not sure we are cooking more slowly. What we are not doing is constantly using the potential maximum power of an induction hob. I am not sure how you could for anything other than boiling water. Rice and pasta bring to boil, then simmer with a lid on at a lower setting. Curry, again gently bubbling as I would at home by turning down the gas. We do have a gas back up plan on board, just in case

Originally Posted by noelex 77

Unfortunately, I am seeing long distance cruising boats attracted to the idea of electric cooking (as they should be, as it has many advantages) and ditching their propane options only to find that there are times and situations where the power generation is simply not keeping up. This is particularly a risk on smaller monohull boats where the ability to fit large solar arrays is limited.

Absolutely agree. If we were doing long offshore or ocean passages, I would want to use lots of electric cooking to conserve the gas bottles assuming solar could keep up. However, I would keep the gas hob and use gas if necessary. The Jimmy Cornell catamaran experiment should be compulsory studying here.

Slightly different if a smaller yacht is coastal sailing. The dog needing to go ashore is probably the biggest limit, but there are others too. We only have 4/5 days of water at best and we want to stop and go ashore frequently. Helpful we have the perfect coastline and numerous harbours to allow this.

The power generation is a concern. We are away again in September for a few weeks, which will give us some more data of what we can do at the end of a season. Winter is simple, we are going to use a marina / harbour most nights. Cheap winter rates help here.

Is electric a perfect solution on a small yacht? No. Will it work most of the time without limiting our ability to cook properly? probably and that would be a successful goal for us.

Pete

[noelex 77]

Originally Posted by Statistical

Even if energy production doesn't keep up and you need to supplement it with electrical energy from diesel powered alternator there are still advantages.

Needing to run your main engine specifically to provide the required energy for cooking, even occasionally, is a backward step in my view.

This is the problem that some cruising boats that have switched exclusively to electric cooking are complaining about. They won’t starve, but need to run the main engine for charging, sometimes frequently, in areas of poor solar insolation.

Make sure you do your energy calculations carefully (or keep a propane backup), especially on a smaller yacht with limited power generation.

[s/v Jedi]

I would much prefer running a Honda 2200 generator over running the main engine occasionally.

Also, I would prefer that over a propane installation.

[rslifkin]

Originally Posted by s/v Jedi

I would much prefer running a Honda 2200 generator over running the main engine occasionally.

Also, I would prefer that over a propane installation.

Agreed, main engines aren't really a good solution for power production when not moving. Any kind of generator (ideally built in if it's needed more than occasionally is a better solution).



A generator is the original solution to electric cooking from before doing it with solar / battery was a viable option. My boat was built in the mid-80s with an electric stove, as the builder figured that between shore power and the generator they installed, it wouldn't be a problem to power it.

[sailingharry]

Originally Posted by rslifkin

For things like coffee, separate appliances may be more efficient. I've measured our single cup coffee maker as using approximately 50 wh (0.05 kwh) to produce a 16 ounce cup of coffee (power draw is ~420w for a few minutes). I'd call that fairly efficient.

Indeed. A drip coffee maker is (probably) more efficient than even induction. Exactly 100% of consumed power is deposited in the water (excepting losses in the power cord). The only other loss is through the wall of the carafe.

[s/v Jedi]

Originally Posted by sailingharry

Indeed. A drip coffee maker is (probably) more efficient than even induction. Exactly 100% of consumed power is deposited in the water (excepting losses in the power cord). The only other loss is through the wall of the carafe.

We have opted for a Zojirushi coffeemaker for use aboard. I still prefer coffee from our Technivorm coffeemaker but that kne is less practical aboard.

https://www.amazon.com/gp/product/B07B83DGMV

[bensolomon]

Did you make the cabinets below the induction plate? That looks great!