Liveaboard solar electric boat

[Q Xopa]

Originally Posted by skipmac

Very welcome.

A couple of additional details. Mine is a new, reasonably efficient air con unit. However, as someone previously mentioned, there is some new technology out that has produced some much more efficient systems.

I checked out the one recommended which sounded great but if I recall the details, it was around $5,000 or more vs the $1500 I paid for mine.

The best ones I have seen recently are Carrier 9,000 BTU, 42 SEER at $2,880. But nearly as good Midea 9,000 BTU 40 SEER for $1,499.

So it obviously depends on how much space you want to cool. This is usually a BTU size factor, and how much Insulation which will effect the duty cycle. Those 2 factors are interchangeable.

The guys running these setups say they can do it on a min of 600W Solar, or better and from memory 400Ah of batts.

These air conds start on a surge around 460W max. Then run at around 120W, when the set point is reached.

So on a 12V boat thats 10A for what ever time, say 12 hours overnight x whatever duty cycle you can get with Insulation, shading, room size etc.

So assuming 120Ah, you decide what your battery and system budget is. On a 600Ah bank, for example, that's 20% drawdown.

I havent done this myself, this is only what these guys are saying.

To me this is not an inconsequential size system but it as not as 'NOT DOABLE' as some claim.

Im more than happy to hear better numbers from the guys that say this not doable.

[KP44]

Originally Posted by Q Xopa

The best ones I have seen recently are Carrier 9,000 BTU, 42 SEER at $2,880. But nearly as good Midea 9,000 BTU 40 SEER for $1,499.

So it obviously depends on how much space you want to cool. This is usually a BTU size factor, and how much Insulation which will effect the duty cycle. Those 2 factors are interchangeable.

The guys running these setups say they can do it on a min of 600W Solar, or better and from memory 400Ah of batts.

These air conds start on a surge around 460W max. Then run at around 120W, when the set point is reached.

So on a 12V boat thats 10A for what ever time, say 12 hours overnight x whatever duty cycle you can get with Insulation, shading, room size etc.

So assuming 120Ah, you decide what your battery and system budget is. On a 600Ah bank, for example, that's 20% drawdown.

I havent done this myself, this is only what these guys are saying.

To me this is not an inconsequential size system but it as not as 'NOT DOABLE' as some claim.

Im more than happy to hear better numbers from the guys that say this not doable.

This sounds very do-able; even likely. And it will not take a house-sized array of solar panels, I have over 500 watts of solar on my little stern arch.

Just install the AC in whichever stateroom you want cool and keep the other doors closed or mostly closed.

[Q Xopa]

Originally Posted by KP44

This sounds very do-able; even likely. And it will not take a house-sized array of solar panels, I have over 500 watts of solar on my little stern arch.

Just install the AC in whichever stateroom you want cool and keep the other doors closed or mostly closed.

Personally, I am scepticle and want to hear some intelligent replies, numbers/ references/ experiences, facts, etc from the other camp.

[john61ct]

Do-able, yes, but hardly practical for most.

Remember, for every hour of usage from **storage**, those Ah soon need to be replaced, at the same time the solar is also feeding the aircon usage.

Numbers like 600W panelage and a 400Ah bank (total? additional just for the aircon?) are just silly scammers looking for clicks maybe.

[KP44]

Originally Posted by Q Xopa

Personally, I am scepticle and want to hear some intelligent replies, numbers/ references/ experiences, facts, etc from the other camp.

A little search show 20 to 40 amps at 12 volts. So 250 to 400 watts of power.

I doubt this can cool a big boat or a big cat. But it would make our galley and stateroom pleasant in any weather on our 45' cruising boat.

https://www.cruisencomfortusa.com/marineseries

[Q Xopa]

Originally Posted by john61ct

Do-able, yes, but hardly practical for most.

Remember, for every hour of usage from **storage**, those Ah soon need to be replaced, at the same time the solar is also feeding the aircon usage.

Numbers like 600W panelage and a 400Ah bank (total? additional just for the aircon?) are just silly scammers looking for clicks maybe.

Ok good not disbelieving you, but any chance you can put some actual numbers and facts instead of just strong opinions?

[jmschmidt]

I have a 12-panel battery storage system on my house that augments my 36-panel grid tied regular system. The systems works in concert at day and night and run every thing but the A/C and the main modem. If the grid goes down the batteries with run all our refrigeration including 48" refer-freezer, beer cooler, wine cooler (you know, the important stuff) plus one TV one desktop computer, some lighting circuits, even so shop tools but no house A/C. If the batteries run down at night, which only happens in Dec/Jan months) those circuits auto-switch to the grid. The 12-panel battery storage system would not handle the house A/C. Tried it once and the A/C (only 12,000 BTU)started and stopped two or three time and then shut down. Also had to reboot the modem after every transfer to the grid and back.

[Q Xopa]

Originally Posted by john61ct

Do-able, yes, but hardly practical for most.

Remember, for every hour of usage from **storage**, those Ah soon need to be replaced, at the same time the solar is also feeding the aircon usage.

Numbers like 600W panelage and a 400Ah bank (total? additional just for the aircon?) are just silly scammers looking for clicks maybe.

Yes, true they are not stating otherwise that those numbers are bare minimums. But they are nothing like what you have suggested previously.

As to if its practical for most, well I guess that sounds to me like a personal choice. We get what yours is. You have stated air cond is in your opinion an opulent waste of resources. That's fine, you do you.

'Most', hmmm. Going off how many offices, cars, houses have air cond I would say 'most' seem to see air cond as normal.

Yes also agree that you need to also recharge the batteries. Not suggesting otherwise.

I dont know if you actually bothered to watch these videos you are referring to as Silly scammers? It doesnt sound like it. If you had you would see they, as opposed to yourself, are referencing manufactuers spec sheets, their actual useage numbers etc.

Feel free to post some actual numbers, or something that could pass for a loose fact even, or not?

[john61ct]

2500W of panels as a minimum starting point for a small volume well-sealed and insulated space in mild weather, maybe 6-10 hours a day

will of course wildly vary not just by those factors, but also by thermostat setting and aircon efficiency

50Ah usable storage for each hour aircon used when panels not feeding most of the aircon directly.

Both over and above what the boat would require with aircon fed from shore power / ICE sources only.

And all this assuming ideal insolation conditions low latitudes.

ICE will need to make up the difference otherwise or proportionally add panels for off-season, higher latitudes, bad weather etc.

Those designing for this practically will likely be using ICE pretty regularly, to the extent they've foolishly allowed their bodies to get acclimated / dependent on aircon.

Remember, the OP's use case was solar **only**, and **propulsion** as well!!

Is **anyone** knowledgeable claiming that enabling this scenario would be a practical project, retrofitting an existing boat suitable for liveaboard cruising?

[Rorzech]

That's a piece of cake! All you need to do is build a barge out of pontoons that you can tow around where ever you go, big enough to mount flat , about 35 Kw solar panels.They will be very low on the water so they won't have a wind problem. After that you'll just need a 400 Kwh LiFePo4 battery bank that will occupy as much space as a bedroom. Plus you'll need to gang together 3 or 4, 3Kw Inverter chargers. Nothing to it ! Get at it ! I can feel all that nice cool air already !

[Rorzech]

42 Seer is pretty amazing! There is a possibility if you have R-20 foam insulation and triple-E windows, that you could make this work. You could add velcro or magnetic Acrylic panels to your existing glass panels. Good planning leads to good results.

[StuM]

Originally Posted by Q Xopa

The best ones I have seen recently are Carrier 9,000 BTU, 42 SEER at $2,880. But nearly as good Midea 9,000 BTU 40 SEER for $1,499.

So it obviously depends on how much space you want to cool. This is usually a BTU size factor, and how much Insulation which will effect the duty cycle. Those 2 factors are interchangeable.

The guys running these setups say they can do it on a min of 600W Solar, or better and from memory 400Ah of batts.

These air conds start on a surge around 460W max. Then run at around 120W, when the set point is reached.

So on a 12V boat thats 10A for what ever time, say 12 hours overnight x whatever duty cycle you can get with Insulation, shading, room size etc.

So assuming 120Ah, you decide what your battery and system budget is. On a 600Ah bank, for example, that's 20% drawdown.

Hmmm!


https://hvacdirect.com/carrier-9-000...praq09aa3.html


Electrical 208/230 V. 1 Phase 60 Hz
Amperage Requirement 15 Amps


By my reckoning, that's over 3 kW or around 250 A @ 12 V.


Not saying it draws that all the time, but it makes that 460W maximum startup surge dubious to say the least.

[peter57]

Originally Posted by Nauti Cat

I’m looking for advice and suggestions on getting a solar/electric catamaran.
I would like to find a boat without engines to put a Torqueedo hybrid system in with solar panels for living on the hook.

And if anyone has experience living on the hook with solar-How much energy needs to be produced per day. I would be in south Florida and Caribbean so would need a/c 24/7 most of the year plus the usual appliances and tv.

Ideal boat would be 40-46’ at 25,000-30,000#, with a beam of 20-28’. Also I’d prefer to use the outboard version of their electric 55kw motors.

I think you missed a zero off of the price for the boat $300,000 would be more like it and add an extra $150,000 for the systems you want to add on the cheap. Thats here in Oz.

[Matt Johnson]

Steve Dashew has had success running a/c off solar.

SetSail FPB » Search Results » solar

Can this be done on a smaller cruising sailboat? I don't know, but it's pretty cool

5440 watts of solar and 1600 amp hour bank at 24v... and only occasionally runs two 12,000 BTU ac units (Not 24/7 at all). But even with all that, he still has to run the generator every few days.


Matt

[StuM]

Originally Posted by peter57

I think you missed a zero off of the price for the boat $300,000 would be more like it and add an extra $150,000 for the systems you want to add on the cheap. Thats here in Oz.

I think he is talking about 20-30,000 pounds displacement, not cost.