Circumnavigation completed on solar power

[Astral Blue]

Originally Posted by deckofficer

They paid 10 mil for the complete boat. We, as consumers don't have to pay more than $1.13 per watt.

Consumers are not exempt from designing and building an appropriate propulsion and drive system, and incurring the costs associated with it. $1.13 per watt is a drop in the bucket compared to the overall costs of the project.

The other question is whether a proportionally similar result can be achieved using downward scaling.

[deckofficer]

Just off the top of my head, it is doable. A catamaran than can support 20Kw of panels that had the misfortune of being dis-masted but otherwise sound, could run $100K. Batteries (lithium) are at $0.40 per w/hr and dropping. So to motor 24/7 at a stately speed of 6 kt would require $20K in Panels, $30K in batteries, and $5K for motors and controllers, so $55K. A similar pure sailing version of this size cat would run more, plus the recurring cost of sail repair/replacement.

On and off, I've thought about going this route, as it would allow for a fully electric galley and dinghy. No more propane, gasoline, or diesel.

[Blue Stocking]

The "lets move back into the cave, and discover fire" group always amuses me.

[DotDun]

Originally Posted by deckofficer

As will batteries.

Not for $1.13 watt.....

You were comparing solar panels to sails.

[Astral Blue]

Originally Posted by Blue Stocking

The "lets move back into the cave, and discover fire" group always amuses me.

Questioning the viability of an unproven formula is hardly a primitive endeavor.

[deckofficer]

I've been here before. I remember the hot rodders as a kid resisting OHV designs for their old trusted flatheads. Much later I was told that a hot rod couldn't be fast and economical, so I built an engine that could do both and had a Track-T that can break 30 mpg on a level road yet still run 10.8 @ 132 mph in Astral Blue's back yard, Sacramento Raceway. I have converted a truck to full electric, built one EV from scratch, and bought a new EV. Electrics are here for personal transportation, and given enough surface area on a vessel, solar-electric can propel you to all points, following the summer months for each hemisphere. Did my thesis at CMA on minimum wetted surface vessels, i.e. fast ferries. The concept will work, as proven by the vessel that I started this thread on, question is, will I still have the energy for the project.

[44'cruisingcat]

Originally Posted by deckofficer

I never said it was fast, but it is a minimum wetted surface hull, so it is efficient. I subscribe to the equation of, if you have a $7,500 sail inventory, you better be putting $750 a year aside for repair/replacement. 20KW/hr worth of panels would run about $20K, and that is the end of your expenditures. ......

Batteries? And probably lithiums at that - plenty of dollars there, which will need periodoc replacement. Also most solar panels are rated to be operating at 80% in 20 years, so they don't last forever.

[44'cruisingcat]

Originally Posted by deckofficer

Just off the top of my head, it is doable. A catamaran than can support 20Kw of panels that had the misfortune of being dis-masted but otherwise sound, could run $100K. Batteries (lithium) are at $0.40 per w/hr and dropping. So to motor 24/7 at a stately speed of 6 kt would require $20K in Panels, $30K in batteries, and $5K for motors and controllers, so $55K. A similar pure sailing version of this size cat would run more, plus the recurring cost of sail repair/replacement.

On and off, I've thought about going this route, as it would allow for a fully electric galley and dinghy. No more propane, gasoline, or diesel.

$55k for a rig and sails? Didn't cost me anywhere near that for mine. Not even remotely close. AND I usually sail faster than 6 knots.

And if you're going to cook then you need considerably more solar panels.

[deckofficer]

Originally Posted by 44'cruisingcat

Batteries? And probably lithiums at that - plenty of dollars there, which will need periodoc replacement. Also most solar panels are rated to be operating at 80% in 20 years, so they don't last forever.

Can you link that info on the solar panels? About 5 years ago the University of Nebraska sold a bunch of panels on Home Power Magazine they had used for over 40 years. These poor cells were burned brown from having concentrators used on them and they still produced rated output without the use of concentrators.

I quoted $30K for the lithium batteries, and they are able to cycle 3000 times before they decrease to 80% of capacity. That is good for constant cruising for ten years and normal cruising for my remaining lifetime. Plus they are dropping in price.

[Astral Blue]

Originally Posted by deckofficer

Can you link that info on the solar panels? About 5 years ago the University of Nebraska sold a bunch of panels on Home Power Magazine they had used for over 40 years. These poor cells were burned brown from having concentrators used on them and they still produced rated output without the use of concentrators.

I quoted $30K for the lithium batteries, and they are able to cycle 3000 times before they decrease to 80% of capacity. That is good for constant cruising for ten years and normal cruising for my remaining lifetime. Plus they are dropping in price.

The specs you are giving for LI batteries assume they are being operated under ideal temperatures and cycling intervals. In the real world (and especially in a cruising cat that operates in a variety of climates), the batteries cannot be maintained within ideal temperature ranges. This will severely compromise the life of the batteries. I would be amazed to see 3000 cycles out of a LI battery and see it maintain 80 percent capacity under conditions most cruisers operate.

[Astral Blue]

I'm also curious as to what methods are used to keep corrosion under control in an environment with salinity levels that are adverse to a battery's sustenance.

[deckofficer]

If AGM's with their paste electrolyte have no corrosion issues on a boat, why would you think lithium would? And as far as cycles, if you keep charge and discharge rates within the C rate quoted, then you should get advertised cycles.

Why is it folks shoot down anything that is new, instead of investigating and thinking "why not"? Like I said in an earlier post, plenty of nay-sayers for both my hot rod build and my EVs.

On catamarans, what aren't A-Frame masts used more? I would guess because of the general conservative nature of sailors. I would say the naval architects would love to employ what they learned in school, but they need to eat.

BTW Ed, if you can free up some time, come up to Placerville tomorrow at 5:00 PM, to a rib joint called "Hog Wild" on Main St, west of KFC using the first exit on Hwy 50. I'll give you a ride in a 30 mpg economy car that from a standing start will have you up to 125 mph in 10 seconds. How can you pass up on that?

[44'cruisingcat]

Originally Posted by deckofficer

On catamarans, what aren't A-Frame masts used more? I would guess because of the general conservative nature of sailors. I would say the naval architects would love to employ what they learned in school, but they need to eat.

I'd say A-frames would be used more if they were proven to be superior - ie - in racing. And i doubt if someone building a purpose-built race boat aimed at chasing records, would be conservative if there were real gains to be had.

[deckofficer]

Originally Posted by 44'cruisingcat

I'd say A-frames would be used more if they were proven to be superior - ie - in racing. And i doubt if someone building a purpose-built race boat aimed at chasing records, would be conservative if there were real gains to be had.

Kornati Cup 2009 comes to mind.

http://www.parasailor.co.za/dyn_docu...lor__smg50.pdf