A question probably asked, so pardon me if I repeat it.

[wallythacker]

I think the answer is already known but here's my question regardless.

Is it possible to install enough solar and wind using today's tech to run a watermaker part time, say, 10% of the day? along with running a 16.5k btu AC unit 50% of the day, run the fridge and normal devices and maintain a neutral balance on the battery bank?

Maybe I should be asking how many watts (is that the proper measure?) does my power plant need to produce to achieve what I'm requesting?

[LoudMusic]

Originally Posted by wallythacker

I think the answer is already known but here's my question regardless.

Is it possible to install enough solar and wind using today's tech to run a watermaker part time, say, 10% of the day? along with running a 16.5k btu AC unit 50% of the day, run the fridge and normal devices and maintain a neutral balance on the battery bank?

Maybe I should be asking how many watts (is that the proper measure?) does my power plant need to produce to achieve what I'm requesting?

The short answer is Yes. This is all quite possible. You're going to need a lot of solar, a lot of batteries, and a big boat to carry everything.

I think you'll want to track down how much power your devices are going to consume per day. Then figure out how much solar you'll need to produce a little bit more than that per day in the region you intend to use it. Then figure how much battery you'll need to run whatever needs to run through the night when the sun isn't shining.

My recommendation would be to have multiple smaller air conditioners so you can have the option of consuming less energy and cooling a smaller space. Provides inherent redundancy as well.

Also, run the watermaker less often and for longer sessions. They typically have a start up and/or shutdown cycle that uses additional power and water that doesn't end up adding to your freshwater tank. For some that's as much as an hour of service, or 10 gallons of water. You'd be FAR better off to run for 6 hours once a week than 2 hours daily.

[john61ct]

What is your "power plant"?

A higher gph watermaker run off dino juice power run fewer hours per week is much more pleasant than listening to it running for many hours.

If you are regularly burning fuel anyway.

[sck5]

running air conditioning from batteries? That would take one hell of a lot of batteries. And serious acreage for the panels to keep them charged.

[john61ct]

Yes missed that.

Aircon is for shore power, unless you have a large ship with a huge dino juice powerplant.

Nothing to do with solar on a small boat, much less off batteries.

[SV Bacchus]

Go to YouTube, search for "Gone with the Wynns" and see what they did. They dumped all propane and have a full electric kitchen, run their A/C units off batteries as well as watermaker.

It cost them a bunch but what a nice setup.

[roland stockham]

Quite possible on a good sized cat, unlikely on a mono. Not enough room for that many panels. The small A/C units on RV's use about 20a so you would want that plus the load for the rest of the boat so 30-40a. That way, assuming you use the A/C during the afternoons only the A/C is actually going to run from the panels not the batteries during the heat of the day. The problem is going to be that about 5a from a 100w panel is about what you see in real life so do you have room for 5 or 6 100w panels? On many boats the answer is no and you need a generator. If you need A/C for more then 4hr in the afternoon the answer is also probably no.

[CharlzO]

Curious, but a 16k BTU ac unit seems awful hefty for most boats, at least any monohull under say, 40'? I assume the OP has already figured out that this is the size needed, so I'm just curious as to what boat they're outfitting

[skipmac]

Is it possible? Yes.

Is it practical? No.

To get enough solar to run and air conditioner and watermaker and more you would need a pretty large cat or tri AND a whole lot of batteries.

Bottom line, you need a generator to feasibly do what you want.

[2big2small]

What you want is easy to achieve on a monohull of 40’ or larger or on a multihull, except for the A/C. Though it can be done, it’s going to be hard and require a larger boat than 40’ and you may not be able to keep your batteries neutral. You may have to skip the airco some days or run it only shortly during the hottest hours or before going inside.

[SpillTheWine]

Originally Posted by SV Bacchus

Go to YouTube, search for "Gone with the Wynns" and see what they did. They dumped all propane and have a full electric kitchen, run their A/C units off batteries as well as watermaker.

It cost them a bunch but what a nice setup.

I think they did something similar with their motorhome before that.

[mitiempo]

Watermaker isn't a problem, especially an efficient one from Spectra.

A/C is no go from batteries, needs a gen. Anchor out instead of tying up in marinas and the breeze will keep you cool, A/C not needed.

[CatNewBee]

Do not want to post everything twice, but you can lookup my thread 1000Ah LiFeYPO4 and all electric galley. Its a Lagoon 400S2 40ft catamaran with large solar array.

Bottom line it is somehow doable to run fridges, freezer, electronics and the waterheater out of solar only when the sun is shining and recharge what you consumed during the night before whithout needing dino juice.

If you not run the water heater, you may run either the watermaker or a washing machine or one A/C unit for some time ( 1..2h ) to cool down one cabin before sleeping and get the energy recharged by solar. On good days youbwill have probably excess energy from 2pm to sunset, what you can invest in A/C or other stuff. One A/C unit can be run off the solar array alone, but you have other loads that need power too, so the battery will drain slowly.

You can save 120Ah/day if you are contious about energy saving and turn off the inverter when not needed. See the details in my thread.

I also have a 7kW generator on board, if I need more than my LFP can provide, the battery can be recharged with up to 350A with all I have (2x 40A legacy charger, 220A nominal Victron Quattro charger - delivers 180..200A, 100A solar), so in best case the battery is full again from empty in 2.5...3h, having 2-3kW extra juice for A/C, hot water, watermaker, washing machine or galley during the charging.

If you are savvy and not use everything everyday, solar only will work for a long time. I tested it for 2 weeks without any other power source inclusive cooking and baking in the galley and running all fridges / freezer on the coldest setting, but you cannot run A/C all day long then.

[SV Bacchus]

Originally Posted by SpillTheWine

I think they did something similar with their motorhome before that.

You're right and if I'm not mistaken they took some of that technology off the motorhome when they sold it and then installed it on the cat. But I could be wrong.. have been before.. probably will be again some day..

[CatNewBee]

Originally Posted by SV Bacchus

You're right and if I'm not mistaken they took some of that technology off the motorhome when they sold it and then installed it on the cat. But I could be wrong.. have been before.. probably will be again some day..[emoji3]

actually, they took it off and sold it separately, the motorhome was kind of test vehicle / promotion or leasing, I do not know, if the company got it back or if they sold it.

But on the cat they put on new batteries (different brand) and new solar panels, not sure about the inverter.