Electric Range without a Generator?

[Adelie]

Originally Posted by zboss

I wonder also.

Once you go with the electric cooktop and maybe one of those new electric instant ovens, you might as well add in heating your hot water from an inverter. Our how water goes from whatever the normal temp is to showering hot in about 20-25 minutes so that is about 700 watts or 58 amps. An engine with properly configured dual 200 amp alternators married to a bank of lithium can easy power the hot water and all your cooking needs.

I’m not sure if the economics though. We are starting the engine anyway to heat the water and our propane only costs us $10 a month.

You can’t do things on a boat the way you do them on land. If you are on a boat and the only concession you make to that is to have a water heater with a smaller tank that won’t work well with a solar electric system.
Ways to make solar electrical water heating work better would be to preheat using a small solar water heating panel on deck and then thru an electric in-line (tankless) water heater.
https://www.chronomite.com/uploads/f...tal-IFSRLF.pdf
$160 or so.
The 1800w 120v version can raise the water temp about 30* at 0.4gal/min. 105-110* is the temp water is what most people find most comfortable showering in. So in tropical areas you water is going to probably come out of your tanks in the 75-80* range and will hit the shower head at 105-110* even if you aren’t preheating the water with solar.
With preheating you should be able to get 0.5gal/min at 110*.

The 1800w is 160amps at 12.5v with 90% inverter efficiency. That’s 2.67amp-hr/min of operation.

A 6min shower will use 16amp-hr. You may think you can’t shower in 6 min but if you use the navy practice of wetting down, shutting off the water to soap up then turning it back on to rinse the actual water flow time can be in the 2-3min range or 6-8amp-hr of power. The added benefit is using less water.

Let’s say 2 people take showers and they use 10a-hr each for 20a-hr total. You need at least 40amp-hr of battery capacity dedicated to this use and 80w of solar panel also dedicated. If you are using a water maker to make the water then additional battery and panel capacity will need to be dedicated.

Also you will need a 2000w inverter which is $200-300.

On a monohull of about 40’ one should be able to add this capacity to their systems.

If you need higher flow rates and/or more temperature gain it could work on a strictly solar system up to a point. What point that was would depend on required flow rate, tank temp, insolation at your location (for both preheating and battery charging), desired final temperature and limits on time of day use (afternoon thru early evening).

If you can compromise your desires somewhat to meet system capabilities you can have solar based hot water showers with not a lot of difficulty and only moderate cost.

[a64pilot]

If you want to do the Navy shower thing, just hang a black plastic camping shower all day and shower in the evening.
However my Wife’s doesn’t, so I run the Honda for 45 min and heat 12 gls of water to the point to where it shuts off automatically, 20 to 30 min. or so and it’s not cut itself off, but there is plenty of hot water for two people to take a normal, not Navy shower.

[Auspicious]

Originally Posted by RonSwanson

They got Lithium batteries, added more solar power, and switched out their range for electric (so they could get rid of the propane all together). I wonder if it can be done without having a generator?

I skimmed the thread TL;DR so may have missed someone else with my question.


Why on earth would you want to do this?


Spend a lot of money to replace propane--the most commonly used, widely available cooking fuel on the planet--with something that might--MIGHT--be as good as what you have as long as everything works, has more failure modes, and has safety shortfalls you are likely not prepared to monitor.

[Adelie]

Originally Posted by Auspicious

I skimmed the thread TL;DR so may have missed someone else with my question.


Why on earth would you want to do this?


Spend a lot of money [A] to replace propane--the most commonly used [B], widely available cooking fuel on the planet [C]--with something that might--MIGHT--be as good [D] as what you have as long as everything works, has more failure modes [E], and has safety shortfalls [F] you are likely not prepared to monitor.

Why? Because the OP’s values, circumstances and his cost-benefit analyses are not the same as yours.

Let’s go thru you points individually:

A. Money wise starting from scratch a propane system seems to be about the same as electric.

Propane:
2 burner stove w/ oven-$950
2 Bottles-$80 (HomeDepot 20# size)
Regulator-$70
Solenoid-$60
20” Hose- $90
I’ll skip the wiring, propane & CO detectors and a vented enclosure.
Total: $1,250 + tax and shipping. Let’s call it $1500

Solar:
175w panel ( delivers about 50a-hr/d) -$180
Trojan T-1275 deep cycle -$240
Victor’s MPPT 75/15- $90
2,000w inverter - $ 200
Countertop induction burner-$100 (w/ pan&skillet)
Microwave convection oven -$190
200amp circuit breaker-$23
2x30’ of 10agw panel cables with MC4s at one end of each -$60
2x13’ 4agw tinned battery cable-2x$37=$74
6xlugs - 3x$5.5/pair=$16.50
I’ll skip the panel mounting.
Total-$1173.5 plus tax and shipping. Let’s call it $1425.

Obviously if there are already parts of either system already on the boat then costs go down.

B. I agree that propane is more widely used among cruisers.

C. The only place propane is more widely available than sunlight is in the polar areas during winter. On the other hand polar areas are not normal cruising grounds. And even in the polar areas propane availability will be severely limited.

D.
Induction heats as fast or faster than propane.
Induction creates a lot less extra heat to overheat the boat interior.
For heating cups of water for tea or coffee a microwave is way faster than a teapot.
A convection Oven will cook significantly faster than a regular oven of any type.
Some breads and pastries they don’t cook properly in a convection oven. Research and experience may show how to alleviate this.

E. Failure modes:
Propane
1. Bottles corrode
2. Locals won’t refill the tanks you have. Have to buy new tanks.
3. Don’t have a fitting to match the local refilling location.
3. Regulator fails
4. Hoses leak
5. Detector fails
6. Burner valve fails.
7. Thermocouple valve fails
8. Stove Burner fails.
9. Oven burner fails

Electric
1. Solar panel fails.
2. MPPT controller fails
3. Battery loses capacity
4. Battery fails
5. Inverter fails.
6. Hotplate fails.
7. Microwave fails.


F. Safety shortfalls
Propane:
1. CO build up
2. Grease fire on the stove.
3. Propane leak and explosion
4. Burner or valve fails and you have to heat food in the oven or on the stove that you would normally use the other for.
5. Something doesn’t work on the supply side and you have to eat cold food
Electrical:
1. Electrical fire
2. Hotplate or microwave fails and you have to heat food in the oven or on the stove that you would normally use the other for.
3. Something doesn’t work on the supply side and you have to use regular house bank for cooking so have restricted cooking power.
4. Inverter fails and you eat cold food.

While there seem to be more failure points for an electrical system the consequences appear a lot worse for propane.

The odds of a safety problem with either are fairly low and probably impossible to quantify.

Overall my guess is that most people are used to propane and are comfortable with the attendant risks but really haven’t thought about an electrical system and don’t know anybody that has one so they are dealing with the unknown.




If I already had a propane system I would probably stick with that if money were an issue. Overtime I would add parts to make an electrical system as a backup.

Starting from scratch I would probably go with the electrical system with a butane countertop burner and a GoSun solar cooker for backup.

[Auspicious]

Originally Posted by Adelie

Why? Because the OP’s values, circumstances and his cost-benefit analyses are not the same as yours.

That may well be the case, but your analysis is faulty.

The OP shows an existing boat, apparently a Tayana 37. He describes shifting to electric cooking as an "upgrade" so presumably has gas cooking already. That takes $1500 off the table in your cost comparison.

Not nearly enough solar or battery capacity in your price list to support electric cooking. Your listed inverter is too small. For apples to apples you'll also want two burners and the electrical capacity to run both burners and the oven simultaneously; otherwise you are reducing performance and should account for that.

Let's go back to what you skipped.

On propane, the wiring is power to the solenoid. Pulling wire can indeed be a challenge; this is small gauge wire with lots of flexibility. Gas detectors are trivial. A vented locker can be a big pain to retrofit but many people quite safely hang tanks from the pushpit. None of that is relevant to the Tayana 37 which already has all that stuff.

For electric you neglected securing the oven and (single) burner so you can actually go sailing. This is non-trivial. The little glue-down straps from West Marine don't count. In addition you neglect the value of gimballing. Don't any of y'all actually cook? Or sail?

To your point 'B' that propane is more widely used among cruisers, while true is not what I said. Propane is the most commonly used cooking fuel on the planet. That means it is available just about everywhere. Might you have to actually *look* or *ask* where to get it? Sure.

Your point 'C' that sunlight is even more available is true but misleading. It presupposes adequate PV solar panels (not in your estimate), mounting (big expense on most but not all boats, usually including an arch and/or hard rails and outboard mounts - certainly going to be expensive to fit adequate solar on a Tayana 37) and sufficient battery bank capacity.

Re point 'D,' Induction heats as fast as propane but not faster. If a new induction burner is heating faster than the large burner eye on a marine propane stove it is time to clean the burner.

Discussion of failure modes is not complete with a list. In engineering we do a failure modes and effect analysis (FMEA). Not all failures have similar impact and some cascade. Some of those you list are trivial or design/procurement/installation shortfalls - do better work. Aluminum tanks don't corrode the way steel tanks do. The tank refilling mantra is specious. Buy the right tanks to start with and problems are de minimus. In my experience the hardest place for a world boat to get propane is the US with our arguably mindless OPD requirement and for a CE boat with non-US documentation I can even get EU tanks filled for non-US cruisers. Hoses leak because they aren't routed properly with adequate chafe protection or are very old; replace before going cruising. All your other failures are trivial and subject to field expedients or full on repairs - mostly cleaning. If a burner stops working it is one of three things: the burner is dirty (clean with a toothbrush), the igniter failed (use a lighter until you can replace), or the thermocouple failed (bypass and maintain a watch until you can replace). You left out the most common failure of a corroded propane solenoid which is also easily rectified.

Electric failures on the other hand all have significance. For the first four you lose cooking AND have an impact on other mission critical functions. Why sign up for a more fragile implementation of a function? Let's look at the others you listed. I make the case that having an inverter in a mission critical system on a boat is ill-advised. TV and other entertainment? Fine. Refrigeration, navigation, cooking not so fine. It's one more thing that can fail and take other functions down with it. We aren't talking about values and circumstances here (your words) but simply good engineering.

The failures for electric are significant. The biggest is resistive heat, usually at a high current connection that has loosened due to vibration and made worse by thermal cycling. These are usually buried so there is no sign of impending failure until it is too late. Fire scares the heck out of me.

The hotplate and microwave/convection oven are complex bits of electronics that are not intended for a high vibration environment and certainly not to be doused with water through a companionway or open port. MTBF takes a big hit. Let's not forget water slopping out of your cooking pot onto your ungimballed burner.

Again I have to ask what you eat. "Cold food" may be okay if you eat beans from a can but what about all that raw chicken? Fish? Beef? Heck, raw veg. I don't want salmonella, E. coli, or botulism at sea. People die. Don't people get food safety in Home Ec or Health class in high school anymore?

Let's also not lose sight of the fact that electric cooking pushes the battery bank harder - even with proper sizing of capacity and charging you have more cycles which reduces service life and the high current drain increases failure rates. You haven't lived until you've been halfway through an ocean passage and a battery cell shorts and takes the entire bank with it.

After 30 years of naval architecture, marine engineering, system engineering, and engineering management I've spent the last ten years working on and delivering boats. I spend a lot of time at sea on a lot of different boats. Objective analysis indicates electric cooking is not a good idea on a recreational boat. My personal experience supports that conclusion.

[Simi 60]

Originally Posted by Adelie

Ways to make solar electrical water heating work better would be to preheat using a small solar water heating panel on deck and then thru an electric in-line (tankless) water heater.
https://www.chronomite.com/uploads/f...tal-IFSRLF.pdf
$160 or so.
The 1800w 120v version can raise the water temp about 30* at 0.4gal/min. 105-110* is the temp water is what most people find most comfortable showering in. So in tropical areas you water is going to probably come out of your tanks in the 75-80* range and will hit the shower head at 105-110* even if you aren’t preheating the water with solar.
With preheating you should be able to get 0.5gal/min at 110*.

The 1800w is 160amps at 12.5v with 90% inverter efficiency. That’s 2.67amp-hr/min of operation.

.

Have you or anyone actual experience with these or similar?
Look very very interesting

Our situation is 2 of us on a boat
most of the time tepid showers, in summer cold is fine.
Wash up once or twice a day so need actual hot for that but currently we are running a 180litre HWS on 240v for at least 1.5 hrs a day at 65+ - amps to get to 60c
Next morning, waters at 52c >> repeat.

Thinking the chronomite or similar would use a fraction of the juice in comparison and, the current HWS is 10 years + old so close to use by date.

[Adelie]

Originally Posted by Simi 60

Have you or anyone actual experience with these or similar?

Look very very interesting



Our situation is 2 of us on a boat

most of the time tepid showers, in summer cold is fine.

Wash up once or twice a day so need actual hot for that but currently we are running a 180litre HWS on 240v for at least 1.5 hrs a day at 65+ - amps to get to 60c

Next morning, waters at 52c >> repeat.



Thinking the chronomite or similar would use a fraction of the juice in comparison and, the current HWS is 10 years + old so close to use by date.

I do not have experience with them in my personal residence but I work construction and I see them regularly in jobsite trailers that have bathrooms. That’s how I knew what to look for when searching.

[john61ct]

There is no doubt an all-electric galley run off mostly-solar is an expensive fantasy for a small boat.

Not as unrealistic as aircon, but fueled by the same lack of understanding.

Add ICE sources, maybe LFP it becomes more practical, but a very expensive proposition.

A bigger more expensive overall context, then it becomes more appropriate setting aside values of frugality and simplicity.

In the end a matter of choice, preferences and priorities.

And remember some are **very** risk averse about propane on a boat, and that alone will justify herculean efforts to eliminate it.

And some just want a very robust electrickery setup, and an electric galley just fits right into what they want already.

Set aside the why and focus on the how.

[Adelie]

Originally Posted by john61ct

There is no doubt an all-electric galley run off mostly-solar is an expensive fantasy for a small boat.

.....

Add ICE sources, maybe LFP it becomes more practical, but a very expensive proposition.

.....

Set aside the why and focus on the how.

John there is no doubt that you have not bothered to read most of this thread or you would realise it is not a fantasy. If you are going to be dismissive and condescending in tone and word choice expect a similar response.

Neither ICE nor Lion batteries are required for it to be practical. The system will not be quite as powerful but it is practical for day to day cooking. A large slow cooked or long roasted meal is more problematic.

What is required is the space for one extra battery below and the area on deck for another large panel.

That said I will be the first to admit that the system will be more susceptible to the marine environment. To what extent remains to be seen. I am on the road to installing a system like I describe above and will be happy to report back in several years.

[Auspicious]

Originally Posted by john61ct

And remember some are **very** risk averse about propane on a boat, and that alone will justify herculean efforts to eliminate it.

People think all kinds of things. Opinion is not fact. Ill-informed opinion is worse yet. Electricity is not inherently safer than propane. Look at fire statistics. Think about fire on a boat. Think hard.



You can smell leaking propane. By the time you smell a loose electrical connection it is too late.

[OldMan]

Originally Posted by Adelie

John there is no doubt that you have not bothered to read most of this thread or you would realise it is not a fantasy. If you are going to be dismissive and condescending in tone and word choice expect a similar response.

Neither ICE nor Lion batteries are required for it to be practical. The system will not be quite as powerful but it is practical for day to day cooking. A large slow cooked or long roasted meal is more problematic.

What is required is the space for one extra battery below and the area on deck for another large panel.

That said I will be the first to admit that the system will be more susceptible to the marine environment. To what extent remains to be seen. I am on the road to installing a system like I describe above and will be happy to report back in several years.

Please provide more details of the system you are thinking about. With your above detail, 1.5KWh per day for cooking? (assuming the sun shines)

[Adelie]

Originally Posted by a64pilot

Efficiency is sort of irrelevant when comparing fossil fuel items on a boat as compared to electric.
It’s what the electric propulsion people love to bring up.
Reason it’s irrelevant is that a kilowatt of solar panels harvesting power all day can’t likely come up with the power in a cup full of Propane.
Now I have not run those numbers, that is purely made up, but tries to illustrate my point.

Just cuz i was interested I did the math here.
Energy in a gallon of propane is 91330BTU which is equivalent to 26.766 kWh. There are 16 cups to the gallon. So 1cp propane is equivalent to 1.67 kWh.

1,000w of panels will deliver about 250a-hr of power at 12v nominal. That’s 3.000 kWh.

Most folks don’t use a cup of propane per day to cook.

How long does a tank of propane typically last you? How big is your tank?

[john61ct]

Each of us has our own values, preferences and priorities.

They can be debated, but my main point was, implementation details are a better focus that trying to advocate one solution over the other.

Originally Posted by Adelie

A large slow cooked or long roasted meal is more problematic.

What is required is the space for one extra battery below and the area on deck for another large panel.

A long bout of bad weather, sailing far from the equator, desire to bake or cook a stew. . .

And I assume other consumer devices, panels perhaps already max'd out.

Sure, compromises are in order most of the time.

The final decision depends as much on the context of a given boat, as on the mindset of the owner.

[Q Xopa]

Originally Posted by john61ct

Each of us has our own values, preferences and priorities.

They can be debated, but my main point was, implementation details are a better focus that trying to advocate one solution over the other.


A long bout of bad weather, sailing far from the equator, desire to bake or cook a stew. . .

And I assume other consumer devices, panels perhaps already max'd out.

Sure, compromises are in order most of the time.

The final decision depends as much on the context of a given boat, as on the mindset of the owner.

Your last paragraph sounds quite reasonable now, I fully agree with. You seemed to be in pretty dead set against camp a few posts ago.

[john61ct]

Nope, not at all, just that a critical mass of boat size, budget and robust electrickery infrastructure is required before it gets "practical".

With a proportional factor as to how motivated the owner is to avoid propane, as opposed to the frugal/simplicity zeitgeist.