Induction vs Gas Cooking

[Dockhead]

Originally Posted by noelex 77

The extra efficiency of lithium is nice, but it is only a very small factor.

The efficiency factor only effects power that is charged and then discharged from the battery. The high demand appliances are typically run during the day and most of the power is supplied directly from the solar panels rather than making the round trip via the batteries, so is not subject to these losses. It is also important to understand that lead acid batteries only lose efficiency when they approach 100% SOC.

If you want to look at efficiency numbers. The efficiency of the solar panels makes far more difference. Spend a little more money here and you can squeeze more watts our of the same sized panel. This will make a significant difference.

I think the efficiency of the batteries also makes a huge difference. It is true that LA is more efficient during bulk phase but only at the optimum charge rate -- normally about 0.02C. Charging slowly it's very inefficient, as it is also during absorption phase. Also you have to consider the whole charging cycle as you practically use it, not just the optimum phase.


So long and short of it, I guess you waste 20% or maybe even 30% of your power with LA compared to lithium, if you look at the whole cycle in pracftical terms, and you lose even more efficiency from your operating constraints, not being able to take power out whenever you want, not being able to delay charging, etc.. I think if you want to store power and use it later for heavy consumers like electric cooking, lithium will be a huge advantage. As you say it's less important if you have a huge solar installation and have excess power, but if you have a more modest solar installation, or if you are producing power by running a gennie, the advantages are huge.

[noelex 77]

Originally Posted by slug

After a hard week of so of sailing ....garbage needs to be emptied, boat washed, tanks filled , batteries charged , hot water heated , provisions replenished , laundry done and a good nights sleep off watch

A good cruising boat can easily and comfortably manage all the above at anchor. Many of the threads on Cruisers forum are focused on how to accomplish these tasks easily.

We usually only tie to the dock once every two years (to redo anti fouling and other maintenance, where the boat needs to be out of the water). We last tied up almost a year ago.

We don’t smell, I promise .

Originally Posted by slug

Tied to the dock is the best way to accomplish this

, and .

Some prefer to be tied to a dock and if this what you like then . There are no rules dictating the way you should be cruising in a yacht. Do what you enjoy, but don’t think life at anchor needs to be hard, or you need to forgo any of the facilities or comforts you have mentioned.

We much prefer to swing at anchor, preferably spending most of the time in a deserted part of the world. Of course that is our choice.

[noelex 77]

Originally Posted by Dockhead

I think the efficiency of the batteries also makes a huge difference. It is true that LA is more efficient during bulk phase but only at the optimum charge rate -- normally about 0.02C.

Slow charging produces a higher battery efficiency for lead acid batteries. This is exactly what most yacht solar systems do.

Originally Posted by Dockhead

Charging slowly it's very inefficient, as it is also during absorption phase.

It is a very common misconception that charging slowly produces long absorption times. The opposite is true charging slowly produces shorter, not longer absorption times.

Lead acid battery efficiency is excellent during the bulk phase, especially the early part of the bulk phase, is less in the absorption phase, but with solar charging the slow rate produces short absorption times. We are typically in absorption only 20-30 mins a day. On days of poor solar production where battery efficiency is more critical, the time in the absorption phase is even less. This is quite different to generator based charging where absorption times are typically a couple of hours.

Lead acid battery efficiency becomes very bad during the float phase, but by then the batteries are fully charged (or almost fully charged) so battery efficiency is irrelevant.

Originally Posted by Dockhead

So long and short of it, I guess you waste 20% or maybe even 30%

These numbers are way too high. I am not even sure a generator based charging system have these values, but for a solar based boat overall power efficiency (considering much of the power is supplied directly from the panels) is much better than you are suggesting.

Battery efficiency is a very small factor for a boat using predominantly solar charging, especially considering lead acid battery efficiency is at its best when it is most needed when solar power generation is low.

It is a more important factor for boats predominantly using a generator based charging system, although the real advantage of lithium with these boats is the very high charge acceptance rate.

[Pete7]

Originally Posted by slug

Some folks actually sail

After a hard week of so of sailing ....garbage needs to be emptied, boat washed, tanks filled , batteries charged , hot water heated , provisions replenished , laundry done and a good nights sleep off watch

Tied to the dock is the best way to accomplish this

That's pretty much our approach. By day 5 we are out of water, though in fairness we make no real effort to conserve it and are always washing stuff. Also no need as there is no shortage, quality is highly regulated and it's free. We use the time in harbours (rather than posh marina) to explore the location, do the laundry, showers, cocktails in the local sailing club and top up the fresh provisions, walk the puppy somewhere each day. The difference in price between a local harbour at £20 and a modern marina at £35 a night soon adds up. We choose to spend the savings on nice meats and fish to cook on board. Other than the obligatory fish and chips occasionally we don't eat out.

Staying out longer would involve carrying more water and food. The extra weight is one thing I am loath to add.

Therefore I still think gas for a smaller yacht is the answer. Simple installation, reliable and cheap. Supplement with small electric kettle and a slow cooker, you still have simple systems with redundancy, easy to repair or replace and low up front costs.

However, could we run a single plate induction stove from a house bank of 170Ah FLA powering our 1000w Sterling pure sign wave inverter? I guess the usage would be 30 -40 minutes of cooking (Spag boll, curries, fish, steaks, omelettes etc)

[noelex 77]

Originally Posted by Adelie

The problem is where do you get reliable efficiency numbers? Vendors?

Solar panel efficiency can calculated from the specifications. The number does not indicate the output of the panel in different conditions, but rather the size of the panel in relation to rated wattage.

So a 100w high efficiency panel will not produce any more power (all other things being equal) than a 100w low efficiency panel under the standard test conditions. However, the high efficiency panel will be smaller in area, which is a big help with a boat installation.

As a general rule, high efficiency panels are also better quality and produce slightly more power in average conditions, but this is only a general observation rather than a firm rule.

The formula for efficiency is 0.1 x the specified maximum output of the panel divided by the area of the panel in m ².

Solar panel specifications for the reputable brands is measured under identical conditions and is quite accurate. However, this does not tell you how various panels will perform in different illumination conditions and in the real world as the panel heats up. The temperature coefficient is generally quoted and this is worth comparing, and some manufacturers list the performance at different brightness levels.

The NOCT specifications were commonly included a few years ago, and this is arguably a better way to compare real world output. However, few manufacturers seem to quote this standard anymore.

[Auspicious]

Originally Posted by Seaworthy Lass

What raw meat?

Very narrow-minded. 92% of people worldwide (96% of Americans) are omnivores. If you provision for an omnivorous diet then losing cooking means your available calories not to mention vitamins and minerals are reduced. If you’ve already suffered a system failure your options are now yet more constrained.

Originally Posted by Seaworthy Lass

Anyway, 92% of people may be omnivores, but I doubt all of them eat meat daily, so for a large number it would not be an issue doing without briefly.

You’d be surprised then. Worldwide meat production increased by a factor of five (5) in the second half of the last century. Production continues to increase. Source: theworldcounts.com . Regardless, as I note the issue is not ability to live without meat. The issue is that a system failure that takes out cooking as a result limits options. “Better services in X than Y, but we don’t have the food to get to X. We’ll have to make do.” Then you end up sitting in Y waiting for parts to ship in from X, for example.

Originally Posted by Seaworthy Lass

In my view this is not a good reason to add the complexity of gas if you have sufficient power to cook electrically.

Then you are missing something. Gas is not at all complex. You’re down a path we’ve covered earlier in this thread. Gas is simple. Tank, regulator, solenoid, hose, cooker. List all the things that fail and what it takes to fix them at sea. Do the same for induction cooking. List all the things that fail and what it takes to fix them at all. Induction is hugely complex compared to the simplicity of gas.

If you stay close to services and shipping and stores that may not matter. For off-the-grid cruising and certainly for passagemakers it is a huge deal. What is worse is that users THINK induction is simple so are taking risks not realized.

Originally Posted by Seaworthy Lass

I think not wanting to buy a new set of cookware or to modify what you would ideally like to use are two other poor reasons for installing gas.

You’ve missed the point. It isn’t about buying new cookware. It is about better cookware for many purposes not being an option. You simply can’t beat stainless clad aluminum for even heat distribution. Sure you can make mushroom risotto in cast iron but you’ll be faster and have a better product in stainless clad aluminum.

Originally Posted by Seaworthy Lass

I have never roasted meat in our oven on board. Not everyone wishes to do this, even omnivores.

Discussed above. Informal empirical survey showed widely distributed use of ovens but more than the naysayers expected.

Originally Posted by Seaworthy Lass

An Omni pan can’t be used on an induction hotplate, but I successfully make foccaccia style bread and pizza (and cake, scones, cookies, etc) on a frypan.

So no sandwich breads, no baguette, again lots of limitations.

Originally Posted by Seaworthy Lass

I have not neglected gimbaling and I don’t think everyone else has either. I would advocate sitting a portable induction hotplate on a gimballed shelf with fiddles added. Installing this is a minor task compared to installing a gimballed gas stove with all the necessary components to supply gas.

Custom gimballed shelf or production gas cooker? I don’t see a big difference in complexity. Fiddles to keep the hob in place are fine, but what about pot holders?

Originally Posted by Seaworthy Lass

How many amp hrs does your fixed fridge use at what temperature setting in freezer mode?

I’d have to look that up (measured, not specced) and I’m not on the boat. In steady state we run about 150 Ah/day for the whole boat at anchor, more underway and more when the Engel is running. I don’t run my fridge in freezer mode. I run my fridge in fridge mode and my freezer in freezer mode. Two boxes, two compressors, Isotherm SP so more efficient than either air-cooled or using a water pump.

Originally Posted by Seaworthy Lass

Auspicious, it sounds very much as if you love your gas system for cooking and could not do without. Rather than trying to persuade everyone that gas or electricity is universally better, how about we simply agree that needs differ and one solution is not optimum for everyone

Because I don’t agree that is what is happening. When someone says something that does not pass engineering muster (like “induction is simpler” or “induction is safer”) I push back. There are lots of places where different strokes applies. Not here. If you want induction because you want it that’s fine, but you should be well aware of the implications and the risks you are taking. Most importantly misinformed opinion should not be presented as fact.

Originally Posted by Seaworthy Lass

I think the bigger issue to consider here is that only a very small percentage of boats could run an electric galley all year around without long daily generator run times. Very few would have sufficient solar power. In my view, that is the biggest stumbling block.

I mostly agree. It is the biggest stumbling block to implementation and getting off the dock. FMEA shows lots of cause for concern out cruising. See above.

Originally Posted by Seaworthy Lass

PS Frozen bread? Really? I consider frozen bread second rate . Bread or pizza is baked fresh daily on board our boat .

There is no substitute for fresh baked bread, in which category I include par-baked frozen finished in an oven. My observation is lots of people don’t bake bread. They decide it is too hard and buy breadmakers which they don’t use. Freezing bread is better than no bread at all.

Originally Posted by Dsanduril

And for those of us not there yet, switching to a more efficient energy storage device than LA batteries can make power available for cooking.

Sure. If you switch to Lithiums for example that choice ripples through other systems on the boat. Charging in particular. One shouldn’t only consider upgrades to alternators, solar arrays, battery chargers, et al but wire sizes also. Moving from a 40A charger to a 120A charger means a hard look at wire sizes. Same for swapping a 1000W inverter for ganged 3000W inverters surely means new wires.

Originally Posted by Pete7

Staying out longer would involve carrying more water and food. The extra weight is one thing I am loath to add.

Too much fuel, too much water, too much food are self-correcting problems.

Originally Posted by Pete7

However, could we run a single plate induction stove from a house bank of 170Ah FLA powering our 1000w Sterling pure sign wave inverter? I guess the usage would be 30 -40 minutes of cooking (Spag boll, curries, fish, steaks, omelettes etc)

Let’s see. 1200W hob running about 800W so as not to overload the inverter. 220VAC to the hob. 12VDC battery bank. 95% efficiency in the inverter. Assume you run your FLAs between 50% and 80% SOC like most cruisers. That means if your batteries are at 80% you have 40 minutes of cook time to draw down your batteries to 50% IF YOU DON’T USE ANY OTHER ELECTRICAL POWER AT ALL. Then you have to put that energy back in. Power level might be lower for curries than the others. Lots more stew time.

[rslifkin]

How frequently it makes sense to dock vs dinghying in for everything depends a lot on where you cruise, I think. In some places, spots to tie up for a night or 2 are cheap or even free (especially if you don't need power). In other places, they're expensive. It also depends on your boat too. Depending on draft and maneuverability in tight spaces, some boats are easy to just stick on any dock (regardless of layout) pretty much anywhere, others are not.

Originally Posted by BlackHeron

WThe few times a year when they are forced to drop the hook in a place like Mile Hammock where there is no other choice or maybe in the Bahamas, they can simply run the generator and to hell with the noise they are making for everyone else. So many do it anyhow in those anchorages. We don't have or need one, but we can sure hear everyone else's.


The thing I laugh the most at is these same people replacing all their lights with LED upgrades. Why bother when you have so much power to literally burn?

Not all of us have loud generators. And even those of us with boats that rely more on a generator often don't run them overnight. For me, it's usually a run in the morning and one in the evening. Noise-wise, mine isn't terribly quiet anywhere in the cabin (no sound shield on it and my engine room sound insulation isn't great), but you pretty much can't hear it on deck. In terms of noise from other boats, if you're off to my port side and not within 50 feet, you won't hear it. Closer than that, you'll hear a slight hum. Off to starboard, it's about the same, but add the noise of water pouring out of the exhaust a few inches above the waterline (it comes out fairly smoothly, not a violent splashing like some). Actual exhaust noise is minimal thanks to a large waterlift muffler.

LED lights, solar, etc. are all ways to cut down on generator runtime. I don't mind running it to cook, heat water, etc. but I hate having to run it just to charge batteries. That can be the difference between running it for 2 hours in a day vs 6.

[Belezar]

This has been an interesting thread. I eat meat usually every day, often every meal, but not red meat every day. Doesn’t mean much and I appreciate veggies tremendously and agree there are some definite positives from a largely vegetable based diet. A great chef from Chicago gave me appreciation for the depth of flavor available. Since I have available power, I will try a induction plate for the hot times in the kitchen, and as a redundancy, but it will still be gas as my go to fuel. At least for now...

[Adelie]

Originally Posted by Auspicious

....

Because I don’t agree that is what is happening. When someone says something that does not pass engineering muster (like “induction is simpler” or “induction is safer”) I push back. There are lots of places where different strokes applies. Not here. If you want induction because you want it that’s fine, but you should be well aware of the implications and the risks you are taking. Most importantly misinformed opinion should not be presented as fact.

.....

There is no substitute for fresh baked bread, in which category I include par-baked frozen finished in an oven. My observation is lots of people don’t bake bread. They decide it is too hard and buy breadmakers which they don’t use. Freezing bread is better than no bread at all.

......

Engineering muster still involves the opinions of the engineer making a judgement. I know, I'm an engineer and a construction inspector and I see widely differing opinions by different engineers about the same topic. In my opinon gas and induction are so different that it is very hard to make an apples to apples comparison.


I don't understand why people don't use their breadmakers more on boats, I measured power consuption on mine and it was 330W-hr for a 2lb loaf.

[Adelie]

Originally Posted by Pete7

....
However, could we run a single plate induction stove from a house bank of 170Ah FLA powering our 1000w Sterling pure sign wave inverter? I guess the usage would be 30 -40 minutes of cooking (Spag boll, curries, fish, steaks, omelettes etc)

Is that 170Ah at 12v or 24v?

I have 320Ah at 12v on a 20' boat.

[bensolomon]

It

Originally Posted by noelex 77

Induction cooking is great, but you do need to produce the electrical power needed. That is tough to do on a 37 foot boat with alternative (solar, wind and hydro) energy if you want to stay away from shore power.

It can be done with a portable gasoline generator, but propane/butane is far more preferable IMHO. It can also be done with a marine generator. In my view, installing, running and servicing a marine generator is worse than the evils of propane/butane, but some disagree.

You can easily and cheaply (providing you have a suitable inverter) test induction cooking by purchasing a portable single hot plate unit. These are inexpensive and even if the experiment is not successful you can use induction when plugged into shore power and therefore saving on propane/butane.

Great idea to get a small induction cooker.

[bensolomon]

Originally Posted by joelhemington

Please forgive my ignorance but WTF is dokarvwould? Even Google doesn't seem to know.[emoji3]

Sorry. I haven't figured out how to edit posts when I see spelling errors. Dokarvwould was supposed to be "solar would". How much solar would be needed for an induction stove. I am trying to figure out how I can be all renewable energy, minus the diesel for the engine on my hunter 37.5 legend. I don't think I have enough real estate for solar or storage for that type of battery bank.

[Dsanduril]

In some senses this topic/thread resembles the electric propulsion threads - is there enough electricity available for the described task? I think cooking, using a 95%+ solar powered boat is much closer to reality than propulsion.

The trouble I perceive is that the standard LA battery installation is not well suited to this. For induction cooking we're talking about loads very similar to the anchor windlass, for longer periods of time, frequently when the sun isn't strong. That means the batteries need to perform (if you aren't willing to fire up a generator). For windlasses, many boat manufacturer's now put an interlock between the engine and the windlass controls to attempt to make sure the user doesn't overload both the windlass and the (LA) batteries. That's because with LA pulling .05C or .1C out for long periods is just fine, but once you get to .2C or .3C or somewhere in that range voltage starts to sag, Peukert rears his ugly head, and things start to go off the rails. In the end it may still be cheaper and easier (for many people) to just put in a larger LA bank to keep the C-rate down, but to me it makes a very strong argument for a more efficient storage system so you can readily transfer energy usage away from peak generation times.

[bensolomon]

Originally Posted by Seaworthy Lass

Yes, it is brilliant! The small size makes everything in it easy to reach. Without a freezer attached there is no build up of ice or excess fluid accumulating. It has been dropped under a solid timber bench and a dyneema loop attached to the timber lid so that the fridge lid opens at the same time as the timber lid.

Not being meat eaters, little refrigeration is actually needed on board and I have not been hankering after a freezer. So this system work extremely well for us.

We bought a high quality National Luna aluminium model, but a huge range of sizes will fit into the cavity (up to about double the capacity), so a drop in replacement should be fairly easy to source worldwide. We are not even constrained by timber lid size, the entire bench top unbolts.

SWL

PS We have not been bothered by a lack of generator either, despite everyone’s concerns when we were initially specifying the new build. We have spent two winters at anchor now above 55° N, relying almost purely on our 1000w of solar. The batteries were occasionally topped up a little when we motored in and out of anchorages, but the engine’s alternator has not been needed much. We have chalked up only 178 engine hours after over two years of cruising and 40 of those was prior to delivery during commissioning.

I think it is important to accept though that cruisers’ needs vary dramatically. There are countless threads where people argue until they are blue in the face that only ‘x’ will work or that ‘y’ cannot possibly work. We are all unique individuals with different needs and budgets and there are more ways than one to skin a cat .

The fridge has been installed running port to starboard under the butterfly. Excess space is taken up with storage. Our stainless steel day water tank has been fitted under the fridge (it was designed to fill directly from a watermaker and then spill over into the main tanks) so the fridge is elevated:

The galley is beautiful! Wow!

[Auspicious]

Originally Posted by Adelie

Engineering muster still involves the opinions of the engineer making a judgement.

I agree. That's why it is important to differentiate fact from opinion. That more boats are lost to electrical failure than gas problems is a fact, based on US insurance statistics. It is my opinion (<- note label) that those statistics are applicable worldwide.

Originally Posted by Adelie

I don't understand why people don't use their breadmakers more on boats, I measured power consuption on mine and it was 330W-hr for a 2lb loaf.

Opinion: this is not a purely technical problem. Breadmakers take up space on counters or in lockers. Cleaning, especially on cheaper models, is a pain. The bread looks funny. People are enchanted by the idea of making bread. Less so by the reality. In many cruising concentration points fresh local bread is readily available at low prices. Off the grid and on passage baking bread becomes a ritual that has value to me. I'm a simple baker - pretty much bread, baguettes, and (US) Southern biscuits. My wife makes blueberry muffins and pizza and cakes and scones and a range of things that slip my mind. These mini coffee cake things.

My preference (opinion) is to make bread by hand and bake it in the oven. Contact time is a bit higher. Clean up is easier. I usually make two loaves at a time (or three baguettes) and "feed the freezer" with all but one. We are frequent but not big bread eaters so two or three loaves last a while.