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#1
posted to rec.boats.cruising,rec.boats.building
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Solar Catamaran
Good day, what do you guys (especially the solar cell experts) think of this boat? http://www.transatlantic21.org/ Chris |
#2
posted to rec.boats.cruising,rec.boats.building
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Solar Catamaran
wrote in message ups.com... Good day, what do you guys (especially the solar cell experts) think of this boat? http://www.transatlantic21.org/ Chris Pretty cool, but I sure would think thrice about taking it offshore. |
#3
posted to rec.boats.cruising,rec.boats.building
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Solar Catamaran
wrote in message ups.com... Good day, what do you guys (especially the solar cell experts) think of this boat? http://www.transatlantic21.org/ Chris The specs say two motors using 8kw each for 16kw total and two 5kw arrays producing 10kw total. So they're producing less power than they use. Hmmmmm! I'd say they got problems. Probably have a diesel generator tucked in one of the hulls. Wilbur Hubbard |
#4
posted to rec.boats.cruising,rec.boats.building
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Solar Catamaran
"KLC Lewis" wrote in message et... wrote in message ups.com... Good day, what do you guys (especially the solar cell experts) think of this boat? http://www.transatlantic21.org/ Chris Pretty cool, but I sure would think thrice about taking it offshore. Yes, catamarans like that one with a heavy load of solar panels on top are more prone to turn turtle than a monohull. Since they're going monohull speeds I have to wonder what's with the dangerous catamaran configuration. Also, they need a way to tilt the array so it takes advantage of the sun at all times. The way they have it now they only get peak efficiency at or around local noon. Wilbur Hubbard |
#5
posted to rec.boats.cruising,rec.boats.building
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Solar Catamaran
Does anyone with experience in the efficiency have insight in how well a setup like this can work? (Other than stating the obvious from the specs: Wilbur, 10 kW are 34 hp that would be pretty good, even 17 hp for 24 hr run time. Engine specs would be peak power.) I would like to know what countinous power output one could _really_ expect; with other words, were they cruising or drifting? Thanks! On Mar 26, 3:57 pm, "Wilbur Hubbard" wrote: wrote in message ups.com... Good day, what do you guys (especially the solar cell experts) think of this boat? http://www.transatlantic21.org/ Chris The specs say two motors using 8kw each for 16kw total and two 5kw arrays producing 10kw total. So they're producing less power than they use. Hmmmmm! I'd say they got problems. Probably have a diesel generator tucked in one of the hulls. Wilbur Hubbard |
#6
posted to rec.boats.cruising,rec.boats.building
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Solar Catamaran
what the heck do they do at night? LOL!
On Mar 27, 10:50 pm, wrote: Does anyone with experience in the efficiency have insight in how well a setup like this can work? (Other than stating the obvious from the specs: Wilbur, 10 kW are 34 hp that would be pretty good, even 17 hp for 24 hr run time. Engine specs would be peak power.) I would like to know what countinous power output one could _really_ expect; with other words, were they cruising or drifting? Thanks! On Mar 26, 3:57 pm, "Wilbur Hubbard" wrote: wrote in message oups.com... Good day, what do you guys (especially the solar cell experts) think of this boat? http://www.transatlantic21.org/ Chris The specs say two motors using 8kw each for 16kw total and two 5kw arrays producing 10kw total. So they're producing less power than they use. Hmmmmm! I'd say they got problems. Probably have a diesel generator tucked in one of the hulls. Wilbur Hubbard |
#7
posted to rec.boats.cruising,rec.boats.building
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Solar Catamaran
"mandolin2k" wrote in message oups.com... what the heck do they do at night? LOL! They claim they have a large battery bank for night time use. And they claim they have enough output from the array to both charge the batteries during the day and run the motors. The array output is only 10KW(max). The twin engines use 8KW each for a total of 16KW and if they have to charge batteries too then it seems to we they lack sufficient solar array for the job. Something's fishy here. Wilbur Hubbard On Mar 27, 10:50 pm, wrote: Does anyone with experience in the efficiency have insight in how well a setup like this can work? (Other than stating the obvious from the specs: Wilbur, 10 kW are 34 hp that would be pretty good, even 17 hp for 24 hr run time. Engine specs would be peak power.) I would like to know what countinous power output one could _really_ expect; with other words, were they cruising or drifting? Thanks! On Mar 26, 3:57 pm, "Wilbur Hubbard" wrote: wrote in message oups.com... Good day, what do you guys (especially the solar cell experts) think of this boat? http://www.transatlantic21.org/ Chris The specs say two motors using 8kw each for 16kw total and two 5kw arrays producing 10kw total. So they're producing less power than they use. Hmmmmm! I'd say they got problems. Probably have a diesel generator tucked in one of the hulls. Wilbur Hubbard |
#8
posted to rec.boats.cruising,rec.boats.building
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Solar Catamaran
The max rating of the engines is not the point: IF the panels produced 10 kW for 12 hrs a day straight, and there was not much loss in storage, they could run on 5 kW 24 hours, which is 8 hp, and could work. (I guess...) The question for the real solar experts was how much can one realistically expect, i.e. how much do two 5 kW panels generate on a real day in the real Atlantic, how much is left after storing in batteries, etc.... Or maybe for the long distance cruisers: If you were adrift in this area at this time of the year, would the prevailing winds blow you over in the end? Anyone? ?, On Mar 28, 9:22 am, "Wilbur Hubbard" wrote: "mandolin2k" wrote in message oups.com... what the heck do they do at night? LOL! They claim they have a large battery bank for night time use. And they claim they have enough output from the array to both charge the batteries during the day and run the motors. The array output is only 10KW(max). The twin engines use 8KW each for a total of 16KW and if they have to charge batteries too then it seems to we they lack sufficient solar array for the job. Something's fishy here. Wilbur Hubbard |
#9
posted to rec.boats.cruising,rec.boats.building
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Solar Catamaran
wrote in message oups.com... The max rating of the engines is not the point: IF the panels produced 10 kW for 12 hrs a day straight, and there was not much loss in storage, they could run on 5 kW 24 hours, which is 8 hp, and could work. (I guess...) I can tell you aren't overly familiar with photovoltaics. 10KW represents the max output when the sun is straight overhead and the temp is mild That same 10KW array will produce perhaps 5K when the sun is at a 45 degree angle and even less when the angle is less. The total wattage output of a 10KW array is probably 50-60 KW on a good sunny day, not 120KW per 24 hour day. You can't run motors and charge batteries and run electonics with that paltry output. Something's fishy here... Wilbur Hubbard The question for the real solar experts was how much can one realistically expect, i.e. how much do two 5 kW panels generate on a real day in the real Atlantic, how much is left after storing in batteries, etc.... Or maybe for the long distance cruisers: If you were adrift in this area at this time of the year, would the prevailing winds blow you over in the end? Anyone? ?, On Mar 28, 9:22 am, "Wilbur Hubbard" wrote: "mandolin2k" wrote in message oups.com... what the heck do they do at night? LOL! They claim they have a large battery bank for night time use. And they claim they have enough output from the array to both charge the batteries during the day and run the motors. The array output is only 10KW(max). The twin engines use 8KW each for a total of 16KW and if they have to charge batteries too then it seems to we they lack sufficient solar array for the job. Something's fishy here. Wilbur Hubbard |
#10
posted to rec.boats.cruising,rec.boats.building
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Solar Catamaran
* Wilbur Hubbard wrote, On 3/28/2007 1:17 PM:
wrote in message oups.com... The max rating of the engines is not the point: IF the panels produced 10 kW for 12 hrs a day straight, and there was not much loss in storage, they could run on 5 kW 24 hours, which is 8 hp, and could work. (I guess...) I can tell you aren't overly familiar with photovoltaics. 10KW represents the max output when the sun is straight overhead and the temp is mild That same 10KW array will produce perhaps 5K when the sun is at a 45 degree angle and even less when the angle is less. The total wattage output of a 10KW array is probably 50-60 KW on a good sunny day, not 120KW per 24 hour day. You can't run motors and charge batteries and run electonics with that paltry output. Something's fishy here... Maybe if you washed your hands ??? The engines and performance is no problem, at 5 knots the boat is only being pushed to half of hull speed, so the requirement is only around 4-5 kW. With the efficient hull shape it might only be 3 kW needed. The batteries seem to be able to stash 50 kWh, so that's about 12+ hours worth. The solar output is the bigger problem - the theoretical output of a 10kW panel at 18N in the winter is maybe 65 kW-hours, so pushing the boat and charging the batteries would seem to be problematical. However, this would not be too different from a sailboat getting less than expected winds - it would just slow down a bit. The biggest issue I see is that the "weight" is listed as "ca. 12 tons" which is about double what a lightweight cat would weigh. My cat, without the engines or sailing rig would only be about 8000 pounds. Its possible that the "weight" is really the admiralty tonnage and the actual displacement is much less. This would affect the power needed in a linear fashion, so if the Disp is only 12000 pounds, it could be driven with possibly as little as 2 kW or even less. One more item: although they talk about doing 5 knots, the log is filled with entries showing speeds as low as 3.5 knots, and very few days over 100 miles, even though they had a tailwind much of the time, plus a quarter knot current in their favor. Thus, they may have only been getting 3-3.5 knots worth of power from the system. |
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