Induction Cooking and AC on DC

[Jdege]

The house I'm living in was built in 1950. I had a crack develop in the heat exchanger in 2016 and had a new furnace put in.

The old furnace had a squirrel cage air blower, driven by an electric motor. That motor ran probably more than 2,000 hours/year, every year, for 66 years, with zero maintenance. That's something like 130,000 hours. With no maintenance. And it didn't fall, it was still going strong.

Most of the owners owned a car, and few of those cars were run as often or as long as that electric motor. How many cars were driven until used up, during those 66 years? How many quarterly oil changes?

Electric motors are far better than internal combustion, more durable, more reliable, more efficient, provide much better torque across all rpms, and hence need much simpler transmissions, if t need a transmission at all.

Everything about electric is better than internal combustion - except fuel storage.

Batteries suck.

But - batteries have improved immensely over the last five years. And have become much less expensive. And solar panels as well.

After all those improvements? Batteries still suck. But they don't suck as bad as they used to.

I have real doubts about whether we'll ever see an electric automobile that will be able to replace internal combustion in many of the use cases where they're currently used.

But pushing an efficient shape like a sailboat through the water at low speeds? For that they work.

And as for cooking? I don't think that we'll see electric driven by batteries and solar replacing commercial kitchens anytime soon. But for me, on my boat, coming for myself and an occasional guest? I've run the numbers, and it works for me.

In fact, for the last couple of weeks I've been doing all of my cooking with my Instant Pot, my induction cooktop, and my combination microwave/convection oven/air fryer. So I'm pretty sure it will work for me.

Come spring I'll move my three cooking devices, a portable fridge/freezer, and my LiFePO4 power station onto the boat, and we'll see how it works.

[kiwin]

I think you have this backwards. I have two electric cars. I drive long distances often. BEV's are superior in almost every way to ice vehicles, and the world's cars will be electric soon. I can't see many boats going battery electric soon if ever. My boat has 1800w of solar and 1200AH of LFP but the range using diesel is at least 1100 miles ...

[Jdege]

Originally Posted by kiwin

BEV's are superior in almost every way to ice vehicles, and the world's cars will be electric soon.

When I see a battery technology that can recharge in 90 seconds I'll believe that.

[Statistical]

Originally Posted by kiwin

I think you have this backwards. I have two electric cars. I drive long distances often. BEV's are superior in almost every way to ice vehicles, and the world's cars will be electric soon. I can't see many boats going battery electric soon if ever. My boat has 1800w of solar and 1200AH of LFP but the range using diesel is at least 1100 miles ...

Yeah cars don't require a lot of energy per mile to cruise (coasting at highway speeds) boats do especially for a boat in the size and expected speed for long distance cruising.

Cars also have much lower range requirements as most people don't make 3-30 days passages in cars. Running out of energy (fuel) in a car is less critical and oppertunities to refuel are plentiful.

So boats require more energy per mile and there is an expectation of higher miles in range. That exponentially more energy which needs to be stored. It isn't impossible but it is far more challenging.

[Pete7]

Originally Posted by Jdege

I have real doubts about whether we'll ever see an electric automobile that will be able to replace internal combustion in many of the use cases where they're currently used.

But pushing an efficient shape like a sailboat through the water at low speeds? For that they work.

Actually, I disagree with both of those.

Many cars make short journeys each day sitting in car parks. In addition, once a car is up to the road speed, maintaining that speed requires very little energy. The yacht in contrast has to move water which is heavy, out of the way for every metre it progresses. That takes energy.

But for the fact that even a small electric car in the UK costs £25k, we would buy one and then have solar panels on the house to charge it up. For half the year it would be free motoring. Sadly the upfront costs don't currently stack up, but they might one day.

On the yacht we do try to make best use of the sails. Solar provides the majority of electrical needs with balanced electric and gas cooking. So diesel costs are quite low, about 90L a year.

The real problem is heating in higher latitudes. At 50'N we have run the heating in August before now to warm and dry out the boat after a gale and for this diesel heating is the obvious choice at the moment. However, it might be possible to significantly increase the battery capacity with the newer 48v server rack type storage or power wall systems becoming popular to provide electric heating and cooking.

[RLMM]

I have a Princess single burner glass cooktop and a Panasonic Genius microwave, I've sent them messages to advise me when they have an induction unit to drop in, (and what's the difference in consumption)
I like the idea of new lithiums, Group 31 150 AH maybe? for the house bank and increasing my solar to 500 watts.
I do have my BBQ for steaks, small green bottles work well. I'm usually entertaining myself. But people do come by, and I love it.
All ideas welcome.

[PirateFoxy]

Originally Posted by Jdege

When I see a battery technology that can recharge in 90 seconds I'll believe that.

This is one of the issues for us. We work from home so don’t do the daily commute - most of our driving ends up being longer distances where having to stop and wait for ages while the car recharges would just be annoying, especially when trying to manage weather like heavy rain that makes driving difficult. We’re quite happy with our hybrid in this regard - it gets fantastic gas mileage and when the tank gets low it doesn’t take a long time to fill up and get back on the road.

I know superchargers do exist that are faster, but aiui they’re also harder on the batteries so if you used them all the time you’d have battery life issues which is a $$$$$ problem to repair.

[seandepagnier]

Originally Posted by Jdege

When I see a battery technology that can recharge in 90 seconds I'll believe that.

ultra capacitors. Lithium titanate oxide.

Recharging in 90 seconds is not generally a useful thing to do, just as boiling water in 5 minutes vs 15 minutes has no real advantages. The only argument for this is if your attention span is very short and unable to multitask.

[kiwin]

I drive long distances all the time. Every 3 hours I have to stop for biological reasons. In the time it takes to answer the call of nature and get a coffee my car has charged enough for the next three hours. So no problem there. Also the price of BEV'S is falling fast. In 3-5 years they will be no more expensive than ice cars. And the running costs are significantly less. Like less than half. I am a petrol head since the 1960's. Electric cars are just better.

[PirateFoxy]

Originally Posted by seandepagnier

ultra capacitors. Lithium titanate oxide.

Recharging in 90 seconds is not generally a useful thing to do, just as boiling water in 5 minutes vs 15 minutes has no real advantages. The only argument for this is if your attention span is very short and unable to multitask.

It’s how it fits into use patterns. 90 seconds is faster than it needs to be, but with current technology you either damage your batteries if you do it too often (aiui) or you have to hang around for significantly longer than it takes to fill up a gas tank. That doesn’t fit into how we use our car. If one of us was driving 30-45min every day to sit in an office for 6-8hours then drive 30-45min home, there’d be plenty of time for the car to charge as long as there was a charger at work and at home.

[PirateFoxy]

Originally Posted by kiwin

I drive long distances all the time. Every 3 hours I have to stop for biological reasons. In the time it takes to answer the call of nature and get a coffee my car has charged enough for the next three hours. So no problem there. Also the price of BEV'S is falling fast. In 3-5 years they will be no more expensive than ice cars. And the running costs are significantly less. Like less than half. I am a petrol head since the 1960's. Electric cars are just better.

We tend not to stop that often, I think? We actually evaluated it over a trip once looking at how far we went between stops and how long we stopped, and it just didn’t make sense for us when looking at the numbers. Gotta wait for technology to improve a bit more. We do have a Prius already so we have an idea of how much less you can end up spending on gas even with a hybrid. It really does add up fast when you compare the Prius expenses to those of the Honda Element we have. I usually use the Prius and my partner drives the Element and when we switch I’m always surprised by how often I have to stop for gas. And the Element is not a big gas guzzler.

[seandepagnier]

Originally Posted by Statistical

Yeah cars don't require a lot of energy per mile to cruise (coasting at highway speeds) boats do especially for a boat in the size and expected speed for long distance cruising.

Without using the sails I can go 1 mile using 60 watt hours. It is very rare to not use the sails though. This is a fraction of what most electric cars use, and a lot less than what the solar panels output with full sun.

Cars also have much lower range requirements as most people don't make 3-30 days passages in cars. Running out of energy (fuel) in a car is less critical and oppertunities to refuel are plentiful.

Running out of energy in a boat is not critical at all, the solar and hydro or even wind generators will recharge along the way, so with electric you do not run out, it may run down or run low.

So boats require more energy per mile and there is an expectation of higher miles in range. That exponentially more energy which needs to be stored. It isn't impossible but it is far more challenging.

Comparing boats to cars by mileage is kind of a ridiculous comparison for many reasons. Boats take advantage of currents. They can travel in straight lines. They avoid traffic. cars travel where boats cannot generally unless there is a canal or something.

Because of sail power, the energy needed is actually zero. So in essence boats are much more suitable for electric power than cars.

[markiobe]

But.... surely if the diagonal of the square is less than the diameter of the circle.... then...

...won't a square peg easily fit into a round hole?

😎😎

[markiobe]

The issue with electric propulsion, if you're going a long way offshore, is not the propulsion but energy storage. If you want to have significant range for safety purposes then it's virtually impossible with current tech battery energy density.

We are having a lightweight catamaran built for tropics liveaboard and have decided, atm, to not go electric propulsion. However electric cooking is totally doable with lots of solar and a big battery bank. Loads of advantages, not the least of which is no heat added to the living area and much easier cleaning, plus plus, plus....

[Jdege]

Originally Posted by markiobe

The issue with electric propulsion, if you're going a long way offshore, is not the propulsion but energy storage. If you want to have significant range for safety purposes then it's virtually impossible with current tech battery energy density.

I've been crunching numbers. Given the system I am considering, I should:

• Have a range of 10nm at a speed of 7 knots, or
• Have a range of 80nm at a speed of 3 knots.

Using stored energy.

Except that, if the sun is shining, I should be able to maintain a speed of 2 knots essentially forever. And that's assuming that there's no wind.

I don't think this would work for a charter boat, where you have to be back to the home marina by the end of the charter, regardless. But for a live-aboard, it should work.