Would you buy blocks of ICE ?

[ebaugh]

Originally Posted by nimblemotors

Thanks, all that solar IS for the electric propulsion! Hybrid gas motor too.
But what to do with it all the power once I'm anchored is the question. I could try to manufacture fuel, but making and selling ice (and ice cream) seems easier, safer, more fun and I'd get to meet lots of people.

My experience, only in the eastern and western Caribbean, is most cruisers are pretty self sufficient energy wise. But YMMV.

I'd use the excess to power AC in the master sleeping cabin....

[Sea Frog]

Originally Posted by J Clark H356

4kw of installed solar is not that much. I have a 5kw Northern Lights generator and it runs my H356 just fine with all the same stuff you ar talking about, but 4 kw would be too small for my boat. I don't have gobs of excess power! With AC on a 50 foot boat, I think you will find it too small - you will not produce 4KW of power from a 4kw system. You need to look into power efficiencies of real life systems before you put all your eggs in the solar basket!

Totally agree on efficience matters. AC may be pretty power-hungry - or not. I have decided on MAR-IX inverter system which is very energy-efficient. Besides, you really don't need to cool down all the boat at once - usually it is a pilothouse/galley in the daytime, and master sleeping cabin in the night. With proper heat insulation and heat rejection tech, and inverter AC, I believe you will be able to fit into 4 KW with everything, unless you cool down all the boat with all cabins and so on (can't imagine why one would want to do that).

This is what I will be doing with mine:

1. All windows glazed with 3M "night vision" film with highest heat rejection factor (up to 72%) (or similar)
2. 3mm insulation on the hull, and 5mm on overheads, with Mascoat Marine-DTM insulation paint.
3. Solar reflective paint on the deck.
4. I am seriously considering using high-quality heat exchanger for ventilation, to further increase energy saving. This will be installed at least in master cabin and run off the CO2 sensor, keeping air always fresh AND reducing energy losses.
5. Of course, efficient freezer with extreme insulation, LED lights everywhere, efficient inverters, efficient electronics, that's obvious.

With all above, I hope that 3-4 KW solar (plus wind) will produce enough juice to feed all the stuff. Will it? We'll see!

[Teknav]

How about selling ice cream? Most of us have a sweet tooth to satisfy. A small ice cream maker can use up your excess power output.

Mauritz

[tropicalescape]

Originally Posted by Teknav

How about selling ice cream? Most of us have a sweet tooth to satisfy. A small ice cream maker can use up your excess power output.

Mauritz

Now Maruritz,I know you are old enough to remember hand cranked ice cream machines..So get cranking we dont need no stinking electric machine..Thats a good idea for the make money while crusing gang,sell ice cream!lol

[Teknav]

Hiya Tropic! I was in Guadeloupe - French Antilles, a few years ago. At the base of a volcano, which I was about to hike, was a lady with her son making ice cream; by hand. I saw her preparing a batch of coconut ice cream; a mount of coconut shreds were just made for the ice cream. I bought myself 3 scoops, and on the way back from the hike I bought about a gallon to take with. It was the BEST hand-churned coconut ice cream I ever tasted! <I am hungry now for some ice cream.>

Mauritz
Going to behave now...watching my diet while eating choc choc chip ice cream!

[nimblemotors]

Originally Posted by tropicalescape

Now Maruritz,I know you are old enough to remember hand cranked ice cream machines..So get cranking we dont need no stinking electric machine..Thats a good idea for the make money while crusing gang,sell ice cream!lol

Selling ice cream, good idea, why didn't I think of it??

Making ice cream is not energy intensive, keeping it ice cream and not cream is.

[pdf27]

Not sure of the legality on selling it, but set up your own floating brewery?
Braumeister - 50L | MoreBeer

With my serious hat on, you're better off using it to cut down your spending before you try to make money from it. That means cooking with electricity not propane, possibly a big freezer if that helps save money on food, that sort of thing. Look at what you actually spend money on and figure if there is a way to reduce that with the free power first.

[Bash]

Folks, is it just me, or did the whole world slip a decimal point while I was out sailing?

To produce four kilowatts of power, you would need twenty 200-watt panels. The combined size of that array would be roughly 3,000 square feet. That's 30' wide and 100' long.

I realize that catamarans have more space for panels than monohulls, but....

[J Clark H356]

Bash: This whole thread makes no sense. You are closer to the reality of this than those who have found uses for his excess power. There will be no excess power because he won't produce anywhere near 4000 watts or 4kw. If he did, it wouldn't be enough to power a 50 foot boat with HVAC. It would take at least two 16,000 btuh HVAC Units to cool it and the would require 3200 watts to run and a lot more to start. Add lighting, refrigeration, electronics, etc. and you have an 8 to 10kw load. If solar would do that, the generator business would be done for. He hasn't done the math correctly and doesn't account for the conversion efficiencies from solar to battery to AC or DC use. Insulative paint is worth virtually nothing in terms of heat gain nor is the window film an effective heat gain retarder. I wish him well, but this is not a realistic approach as the amount of panel space will likely exceed the surface area of his vessel.

Last year on a project I was involved in, we installed a 15kw system on a roof at a fixed optimum angle for Tennessee. The most it has produced in a single day is 10kw of power and only for a few hours in the middle of a blue bird day. The system cost $90,000 and took a significant amount of square feet. TN produces about 80% of the solar energy available in Arizona, so it isn't as much a lack of available solar energy as it is efficiency in converting solar energy to power. The system has produced about 20,000kw of power in a year or an average of 54.8 kw per day or 2.16kw per hour (average). This system is almost 4 times larger than this poster plans on installing - 15kw versus. 4kw. It is optimized, whereas a sailboat will not be. It is also new, and will degrade to 85% within 10 years, thus these are real, new actual results, not theory. On this basis, his average will be 4/15 or .266 x 2.16kw = .57kw per hour or 570 watts. Reduce this for moving, lack of optimum angle, clouds, etc. and you see the impracticality of running any substantial electrical load with solar at the level he is contemplating.

I wish what he is proposing would work. If it would, Solenda and the other solar projects we taxpayers have invested millions in would serve the world in a most beneficent way. Sadly, this is not the reality of solar, thus the market has dealt this industry a very harsh reality. A major breakthrough in efficiency is needed to make this industry viable.

[Marmenorman]

Bash,
That's why I would like to see any pics!

[bobconnie]

We have a 5.5 KW genny, on a 51 ft boat, and I sat down and tryed to figure out where I could put enough solor panals to do the job for us ! and ya know, theres just not enough room on a mono hull anyway ! Ive got 2 of them at 100 watt that take care of the batts most of the time ! so we don't have to run the engine or genny to keep the batts up, at least most of the time ! If it's bad cloudy or raining it wont do it, but it works most of the time down here ! In fact the only time we run the genny is when the heat outside is 90 degs or better, then the AC is nice to get some sleep !! We have all the fridge and feazer space we need, and the watermaker is 12 volt and is pretty volt friendly! I guess we are lucky even if we use a little more diesel ! LOL

[pdf27]

I'm looking at fitting a 4kW system to my house (in the UK) and I really don't think my roof is going to be big enough. Most are 3.2m x 8m (12'7" x 26'3"). Predicted output is ~3000 kWh/year (~36,000 Amp-hours/year at 12V, or an average of ~4 Amps).

One additional problem that I don't think has been mentioned yet - shading. PV really hates one panel being shaded, to the extent that if part of one panel is shaded you won't get anything from the rest of the string. Rigging/masts/sails will do that.
Incidentally, this is one reason why yachts tend to have lots of small panels rather than one big one - you can design the system to be much more tolerant of partial shade.