I need guidance on selecting a panel type.

[CarpeSol]

The Research Vessel Carpe Sol Project ( www.rvCarpeSol.com ) is constructing a 36 foot yacht hybrid electric boat that will be powered by 48 volt batteries that will be recharged by solar panels, wind turbines and shore power. Once completed the yacht will tour North American waterways to promote renewable energy technologies for the marine industry. I am trying to determine the most efficient and practical, commercially available solar panels for this application. High efficiency is important because of the limited space available on the boat. Any advice on the pros and cons of different types of panels as well as specific manufacturers and models would be appreciated. Please reply to me directly at hw AT rvCarpeSol.com
Thanks for your input.

[ Mod note - It's suggested all replies be done on THIS message forum, so all can share and learn. If you want a personal reply, my consulting fees are $80/hr. Mike ]

[leonscorpio]

CarpeSol,

I don't mean to be a downer but it seems to me that this forum is for everyone to benefit from the information, so asking one to respond to your email alone is not conducive to the forums reason for existence.. I could be wrong though, as I am not the owner of this forum.

Thanks.

[russ]

@ CarpeSol - Leon is correct - the idea is to spread information for all. Placing email addresses in posts is discouraged as bots will sometimes pick them up and you get buried with spam.

Good luck on your joy ride but if you think it is anything else you are fooling yourself and trying to fool others.

What type of 'research' will this vessel be carrying out?

The 'true greens' will love the journey and worship at your feet (That 2% of the population). To anyone else will it matter? I think not.

[CarpeSol]

My apologies Leon. I am new to the whole blogging experience and only wanted to ensure I received any replies. Now that I learned that I get notified of responses and won't miss any, I understand asking for a direct reply is unnecessary. Chalk it up to a learning curve.

Russ - Thanks for the tip on bots. I am approaching the project from the perspective and interests of a boater. There are numerous DIY kits to convert sailboats to electric power and one manufacturer has produced a hybrid elecrtic/diesel boat but has failed to find a market for it, so he has not built a second hull with that power system. As a boater, I and everyone I speak with is wary of spending hundreds of thousands of dollars on an unproven technology. The purpose of the Research Vessel Carpe Sol is to travel ten thousand miles or more over the course of a few years to demonstrate the real-world experiences and economy of powering long-range, live-aboard boats with renewable energy sources. The research aspect of the vessel will be fulfilled by the complete set of data that will be available on a realtime basis related to the true power requirements and costs associated with this new and unproven utilization of electric power for cruising boaters. As I speak with individuals and corporations in the boating community, everyone is enthusiastic to see the project completed; so I know it will be followed by and impact a great number of interested parties. Parties that will, over the next few years be making purchasing decisions that could help bring about the beginning of a shift away from fossil fuels and towards clean-energy fuels in the marine sector.
Simply put, the mission of the RV Carpe Sol is be a catalyst to help change the mindset of the the boating public regarding electric boats by documenting the long-term benefits.

[Mike90250]

The big problem is power density. Solar panels only capture a small fraction of the sun's energy.

Also, here's another project, at sea, with solar PV power.
http://www.planetsolar.org/index.en.php (Just 15 days out at THIS moment)
better write up:

http://www.inhabitat.com/2010/02/26/worlds-largest-solar-powered-boat-unveiled/

So with 500sf of PV, they only expect average 8 knots.

The very best PV panels are only couple % better than the average panels, so I'd say it's best to not burn the $ on only a few extra watts.

[CarpeSol]

Mike90250... Thanks for your input.

I understand your argument that it isn't worth the large cost difference to get only a couple of extra watts. But setting aside the cost difference, I am trying to get some opinions and real-world experiences on whether Monocrystalline, Polycrystalline, Nanocrystalline, Amorphous, or Thin Film would be best for this application. Then there is the issue of composition; Cadmium Telluride?; Copper-Indium Selenide?; Gallium Arsenide?; DSSC?; Organic Polymer?; Silicon thin film?; or some other type? Are any of the infrared panels, that I understand work better under diffused light, worth considering? Another area of interest for me would be specific manufacturers and their reputations for quality of product and customer service.

Regarding Planet Solar - I am well aware of it and they have a great project. The 8 knot speed is actually determined by the hull speed of the ship and is not a restriction imposed by the number of solar panels. Essentially, you determine the hull speed which is a function of the square root of the waterline length multiplied by a factor typically in the range of .8 to 1.4 that is determined by the hydrodynamics of the hull form. That math gives you the speed at which the boat can move through the water efficiently, Any increase in speed over the hull speed will require exponentially more power.

The purpose of the solar panels on the RV Carpe Sol is to be one of many sources of power to recharge the battery bank that powers the motors and all of the boat's other electrical needs.

[Mike90250]

How long will your project need to survive ? 3 months, 8 months, 3 years ?
Less than a year, thin film/amphorus would work for that long. Longer, I would avoid it.
The "gold standard" cells, are just the silicon slices, mounted in a frame. The thin slices and "string ribbon" are the same chemistery (silicon) mostly, but thinner and more fragile.
For marine use, few panels are rated to handle the salt mist that will be present. The moisture levels, front and backside water splash, hot sunny panels vs cold water splash, and waves, all make for a tough enviroment. Again, it's how long you need these to last, 6 mon - 1 year, most anything will last. More than a year, you will weed out the weak panels. And don't over estimate how much power the panels will produce and contribute to your project.

added:
Here's a good overview: http://en.wikipedia.org/wiki/Solar_cell

Sunpower has the most efficient commercial cells, but their process requires a positive ground system to keep the cells at full power.

[CarpeSol]

The Research Vessel Carpe Sol will cruise the North American waterways for three to five years promoting the use of electric power for live-aboard cruising boats.
I am hoping that some of the members of this group will have experience with the various manufacturers and be able to provide the guidance to help me "weed out the weak panels" as you put it.
Regarding over estimating how much power the panels will contribute - my situation is that I have a finite amount of space that can be utilized for the solar panels and they will have to be mounted in a flat horizontal position facing directly towards the sky. Neither of which is ideal. That's the reason I am interested in getting the most efficient panels available. Any electricity not generated by the panels will need to be supplied by a pair of wind turbines or when absolutely necessary, a bio-diesel generator. Typically, the boat will travel for 30 to 60 miles in one day and then remain tied to a dock or anchored out for one or two days before moving to its next destination. During the times at rest the Carpe Sol will be harvesting power to recharge its batteries for the next trip.
It will take about a year to construct the boat, do you anticipate any major changes in the technology between now and next fall?

[Mike90250]

nothing new on the horizon (for purchase) in the next year. I would suggest you begin sizing your loads, and planning the battery bank and battery management system. I'd also strongly suggest using AGM tyep batteries, as they can handle abuse better than others, except for overcharge, which is managed by your charge controller. Plan on a 48V dc battery system, and highly efficient inverters (sure sine 300W) and DC-DC convertrers for your loads.