Lagoon 420 hybrid + modern tech

[ranchero76]

Originally Posted by cwjohm

You are talking a requirement of up to 240KW emergency and 800Kw long term motoring provision, so you would need to spend at least $100K and require carrying capacity of a couple of metric tons in terms of batteries and generator.

Sure, $30-$40K will allow you to spend a month at an island fully covered but you will need a big boat with large diesels to tow you to that island and back again.

Yes, I totally agree that big diesels still needed for long motoring, emergency. My idea is having additional parallel electric motors for everything but long runs.

[StuM]

> charging batteries, cooking, scuba compressor, AC, fridge, freezer, and everything else on boat, including boat moving here and there. Nice.

So lets see:
Charging batteries presumably for those free/silent/maneuring [sic] /short runs in addition to powering all the above, including at night?

Please provide your daily energy budget for these items so that we can see how much solar and battery storage you are actually talking about.

[ranchero76]

Originally Posted by StuM

> charging batteries, cooking, scuba compressor, AC, fridge, freezer, and everything else on boat, including boat moving here and there. Nice.

So lets see:
Charging batteries presumably for those free/silent/maneuring [sic] /short runs in addition to powering all the above, including at night?

Please provide your daily energy budget for these items so that we can see how much solar and battery storage you are actually talking about.

Big modern fridge takes 2.4 kWh per day approx. AC - all depends. Scuba diving - all depends. Both not needed daily. Cooking - 1000W x how many hours you'd be cooking daily. And so on. Real usage will heavily very, but 30-40 kWh LiPo bank and 3kW solar (another 10-15kWh) per day in most cases will cover all needs. IMHO.

[smj]

Originally Posted by ranchero76

Big modern fridge takes 2.4 kWh per day approx. AC - all depends. Scuba diving - all depends. Both not needed daily. Cooking - 1000W x how many hours you'd be cooking daily. And so on. Real usage will heavily very, but 30-40 kWh LiPo bank and 3kW solar (another 10-15kWh) per day in most cases will cover all needs. IMHO.

You would need to tow a barge behind you to cover the weight and square footage needed for 3-4 kW of solar and the necessary batteries, regulators and wiring to run it.


Sent from my iPad using Cruisers Sailing Forum

[StuM]

Originally Posted by ranchero76

Real usage will heavily very, but 30-40 kWh LiPo bank and 3kW solar (another 10-15kWh) per day in most cases will cover all needs. IMHO.

What do you mean by "another" 10-15kWh. That 10-15kWh is all the energy you have available to charge those 30-40kWh of LiPo and concurrently run whatever electrics you are using during the day under your scenario.

And those 30-40kWh of storage will set you back, what? There goes your budget of $30-40,000 before you even look at the solar installation and all the ancillary electronics etc.

Originally Posted by ranchero76

Cooking - 1000W x how many hours you'd be cooking daily

Kettle, toaster, induction plate for the bacon and eggs? More like 5kW while you are cooking breakfast.

[ranchero76]

Originally Posted by StuM

What do you mean by "another" 10-15kWh. That 10-15kWh is all the energy you have available to charge those 30-40kWh of LiPo and concurrently run whatever electrics you are using during the day under your scenario.

And those 30-40kWh of storage will set you back, what? There goes your budget of $30-40,000 before you even look at the solar installation and all the ancillary electronics etc.



Kettle, toaster, induction plate for the bacon and eggs? More like 5kW while you are cooking breakfast.

Yes and no. Initially you'd have 50kWh of energy (40+10). Then you'll start loosing it but only if daily consumption goes over 10kWh. There's some unavoidable usage (fridge, for example, unless it's empty ), and many things that you can manage (like "surviving* without toast for a day, for example ) So YOU will have control and still might have to start genset from time to time.
Regarding these 30-40k of initial investment - I'd consider that to be part of initial purchase. You can buy boat without fancy interior for less money, but nice interior... well, it's nice to have Same goes to "fancy" LiPo+solar+hybrid setup.

[StuM]

Originally Posted by ranchero76

Yes and no. Initially you'd have 50kWh of energy (40+10). Then you'll start loosing it but only if daily consumption goes over 10kWh. There's some unavoidable usage (fridge, for example, unless it's empty ), and many things that you can manage (like "surviving* without toast for a day, for example ) So YOU will have control and still might have to start genset from time to time.
.

No, you don't have 50kWh initially.
You were talking about "say I spend a month on remote island and spend zero $ on charging batteries, cooking, scuba compressor, AC, fridge, freezer, and everything else on boat, including boat moving here and there. Nice."

Initially you have 40KWh of energy. At the end of the first day you will have added 10kWh and probably used more that that in getting to your anchorage at that remote island. But let's assume you still have that 40kWh of storage when you drop anchor the first evening.

From there on, you are getting that 10kWh per day and can afford to draw maybe another 1kWh from your batteries.

So you use 11kWh per day for the month and your batteries are down to 25% capacity. Good luck clawing your way back out through the reef when that weather comes in at the end of the month.

Interesting that you started off with a list of power hungry devices but now you are reduced to "managing" your usage and using the genset.

And your energy budget of 11kWh per day still has to provide for the 10kW or so that you will need when you are doing that "boat moving here and there".

[cwjohm]

I also assume this fictitious island is not in the Pacific where 50% of the time it is overcast or raining (but still quite warm and humid).

[StuM]

Originally Posted by cwjohm

I also assume this fictitious island is not in the Pacific where 50% of the time it is overcast or raining (but still quite warm and humid).

Don't worry about the warm and humid - he's got AC

[BigBeakie]

Wow, there are some major misconceptions expressed here about EP, but then again, what's new?

Let's try yet again:
- No, you do not need the same energy equivalent in batteries as you carry in diesel.That is an absurd proposition, and you all know it. Strawman arguement if ever I heard one. Yes you need a significant propulsion bank and a means to charge it continuously for continuous motoring on those (fairly rare depending on cruising area and circumstances) when you need to motor beyond the range of your EP bank. Usually this will be a DC genset sized appropriately for the job.

- No, you do not need the same Kw equivalent as your existing diesels unless you want to hoon around at full throttle on a regular basis. So who does that with their diesels anyway? You need the right size electric motors for the job, which is pushing your boat mostly at cruising speeds, and occasionally against wind/waves/current of whatever magnitude is, again, expected for your cruising area.

- Yes, solar is an important strategy to assist in recharging your EP & house bank. Most cruisers spend the majority of time on the hook, so use your time wisely. Do the calculations to determine the size of the array wrt to your energy budget. And yes, you can motor a cruising catamaran on just the solar input, but slowly, so why bother? It's a red herring.

- Regeneration is another very important component. Use the right feathering props and electric motors and systems management. Also helps to have a sailboat that actually sails well, too. Especially in light winds.

- Yes, surprise surprise the "Pacific" does get sunshine. But which part of the Pacific are we talking about, the Aleutian Islands of the Marshall Islands? FYI, most Pacific Island nations are hell bent on installing solar arrays with Lithium storage and dumping their diesel gensets, so I guess they haven't considered all that cloudy & wet weather, eh?

FYI, there are several cruising multihull EP projects happening in Australia and NZ, by some of the best designers & project teams around, such as McConaghy Yachts for example. Of course they foolishly have refused to take notice of the CF collective wisdom that EP for cruising boats can't work, but that's their tough luck, isn't it?

[44'cruisingcat]

Originally Posted by BigBeakie

- No, you do not need the same Kw equivalent as your existing diesels unless you want to hoon around at full throttle on a regular basis. So who does that with their diesels anyway? You need the right size electric motors for the job, which is pushing your boat mostly at cruising speeds, and occasionally against wind/waves/current of whatever magnitude is, again, expected for your cruising area.

And nothing in reserve for when extra speed significantly improves your safety, like crossing bars etc?


Anyway your argument doesn't even make sense. If you size your electrics much smaller than the diesels would be, you WILL need to "hoon around at full throttle on a regular basis" just to match the diesels performance in normal cruising use.

[downunder]

Was at yamba in Northern Nsw last week talking to a chap who had just fitted diesels to his snell 13m Tracey catamaran and was fitting minikeels at the yamba lift out facility.

I indicated he had just ripped out his pod drive electric motors and replaced them with diesels and put them in the dumpster that I could check onu the way out. Unfortunately it was locked so I could not check out the brand of the the electric system.

Spotted in the marina at yamba was the st Francis 50 olvilve
And a Chris white Atlantic 48.

[cwjohm]

No, you do not need the same energy equivalent in batteries as you carry in diesel.That is an absurd proposition, and you all know it. Strawman arguement if ever I heard one. Yes you need a significant propulsion bank and a means to charge it continuously for continuous motoring on those (fairly rare depending on cruising area and circumstances) when you need to motor beyond the range of your EP bank. Usually this will be a DC genset sized appropriately for the job.

Nobody stated this. What was stated was you need the same energy equivalent in batteries for 4 hours emergencey 2 motors or 48 hours motoring on 1 motor. To do otherwise is not safe.

No, you do not need the same Kw equivalent as your existing diesels unless you want to hoon around at full throttle on a regular basis. So who does that with their diesels anyway? You need the right size electric motors for the job, which is pushing your boat mostly at cruising speeds, and occasionally against wind/waves/current of whatever magnitude is, again, expected for your cruising area.

Correct. I typically derate required for equivalent diesel HP at 60% as does nearly everyone who understands this technology.

Yes, surprise surprise the "Pacific" does get sunshine. But which part of the Pacific are we talking about, the Aleutian Islands of the Marshall Islands? FYI, most Pacific Island nations are hell bent on installing solar arrays with Lithium storage and dumping their diesel gensets, so I guess they haven't considered all that cloudy & wet weather, eh?

As per usual a half truth. Yes, Pacific Islands are gearing up Solar and Lithium storage to support their diesel gensets, but in NO WAY are they moving to dump them. Diversification of power sources is a smart move.

Of course there are projects involving EP in the marine industry. Why would there not be. This indicates that one day EP will be a proposition for mainstream production yachts but says nothing about the timing as to when EP will be cost effective, practical and safe.

For those that are out sailing today, it is none of those.

[myocean]

Originally Posted by cwjohm

you need the same energy equivalent in batteries for 4 hours emergencey 2 motors or 48 hours motoring on 1 motor. To do otherwise is not safe.

Could you please explain more in detail why this is needed? If you have a genset with a decent tank, why do you need to have a battery lasting for 48 hours on 1 motor?

I like to thank BigBeakie for his valuable comments.

[valhalla360]

Originally Posted by BigBeakie

Wow, there are some major misconceptions expressed here about EP, but then again, what's new?

Let's try yet again:
- No, you do not need the same energy equivalent in batteries as you carry in diesel.That is an absurd proposition, and you all know it. Strawman arguement if ever I heard one. Yes you need a significant propulsion bank and a means to charge it continuously for continuous motoring on those (fairly rare depending on cruising area and circumstances) when you need to motor beyond the range of your EP bank. Usually this will be a DC genset sized appropriately for the job.

- No, you do not need the same Kw equivalent as your existing diesels unless you want to hoon around at full throttle on a regular basis. So who does that with their diesels anyway? You need the right size electric motors for the job, which is pushing your boat mostly at cruising speeds, and occasionally against wind/waves/current of whatever magnitude is, again, expected for your cruising area.

- Yes, solar is an important strategy to assist in recharging your EP & house bank. Most cruisers spend the majority of time on the hook, so use your time wisely. Do the calculations to determine the size of the array wrt to your energy budget. And yes, you can motor a cruising catamaran on just the solar input, but slowly, so why bother? It's a red herring.

- Regeneration is another very important component. Use the right feathering props and electric motors and systems management. Also helps to have a sailboat that actually sails well, too. Especially in light winds.

- Yes, surprise surprise the "Pacific" does get sunshine. But which part of the Pacific are we talking about, the Aleutian Islands of the Marshall Islands? FYI, most Pacific Island nations are hell bent on installing solar arrays with Lithium storage and dumping their diesel gensets, so I guess they haven't considered all that cloudy & wet weather, eh?

FYI, there are several cruising multihull EP projects happening in Australia and NZ, by some of the best designers & project teams around, such as McConaghy Yachts for example. Of course they foolishly have refused to take notice of the CF collective wisdom that EP for cruising boats can't work, but that's their tough luck, isn't it?

There seems to be a pattern on these threads.
- Those telling us that electric is the next big thing talk in platitudes.
- Those responding provide facts and figures.
- When facts and figures don't match the platitudes, we are told those provided facts and figures just don't understand some mystical quality to electric drives or we don't really need power or range.

Reality is you can certainly put together an electric powered boat...even one that runs on solar but it will be expensive and have drastically reduced performance.