Myles,
I wanted to respond by saying “Thanks for the lesson” but I rechecked pricing and I cannot get down to $2/watt. The products we are trained on are efficient 25 year panels and cost $3/W uninstalled (in BIG quantities). I checked SunForce and they retail at WAY more than that.
(I did find a Evergreen listed for $2.80/W). But my point is……..They are hard to scrounge.
I had to wait a coupla months for the panel I got because I was scrounging it for the Y kids. I got it for free at the suppliers convenience. Yes, I can order gobs of them and have them by week’s end.
And yes, I am a firm believer in PV power and it will get us out from under the thumbs of the Oil Arabs. That is why I am rigging the kids camp trailer with solar power. To show them the way of the future.
And you mod a dang good site. I love this forum. Definitely one of the more active forums around.
Byron the Geek
From: electricboats@yahoogroups.com [mailto:electricboats@yahoogroups.com] On Behalf Of Myles Twete
Sent: Monday, February 14, 2011 1:58 PM
To: electricboats@yahoogroups.com
Subject: RE: [Electric Boats] Re: Setting expectations
Byron-
“Write a check for about $30,000 and you’ll have your 10kW.”
I don’t think solar is really this dismal in the year 2011. Checking the Feb/Mar 2011 issue of Home Power, I see a full page ad from Sun Electronics (Miami and Phoenix offices) which lists prices for 6 different makes of panels including Sun, Suntech, DuPont, NBSolar, Canadian Solar and Evergreen. Prices range from $1.40/watt (DuPont) to $2.25/watt (Evergreen). They even note having modules as low as $0.97/watt available. Note, while we don’t see Solar World or Sanyo or some of the other more common panels on the list, even without solar incentives available, the panels alone are getting pretty cheap. And with multiple sellers on Ebay selling groups of panels together, I don’t understand why you’d have to wait months for a single panel as you’ve mentioned unless it was a vendor/installer who was dragging his feet and blaming it on the supplier. I’m told the reason for the big price drops over the past 2 years is the economic downturn that led to a resulting glut of panels on the market. Not good if you’re a manufacturer, but great for the consumer.
Now, going cheap has its consequences, key among them: Relatively low output per square foot.
To improve the solar power on a boat calls for us not to “cheap out” on the panels we choose since real estate and weight concerns are paramount. Money not being an object and performance being key, the strategy used by Solaraycers would be used: Buy the best solar cells available and integrate them yourself into a light-weight, high performance solar “panel”---think “solar bimini”. As example, many of the winning solar racing teams have used Sunpower’s A300 solar cells, which have over 20% solar efficiency. While expensive ($10/watt or so?), these could yield amazing performance, nearly doubling the output of much cheaper alternatives at a fraction of the weight and bulk. Full cost would include outright costs, availability and much time spent engineering and working a sealed interconnected panel (roof, or bimini). Added benefit would be that it’d be more difficult for someone to steal your solar panels. Downside might be reliability and ruggedness. I still would like to go this way myself with my boat. In that case, with 20% efficiency cells, a 7x9ft bimini could yield 1kw or better of peak power, or here in the NW in the summer, perhaps 4kwh/day. An 8-hr, 40n-mi cruise at 5kts and 4kw could see 12% of its power coming from the sun---unfortunately the $10k+ cost of that power is daunting to me. The first panel I’ll make will be from the several pounds of surplus 11% efficient cells I purchased awhile back…
-Myles
From: electricboats@yahoogroups.com [mailto:electricboats@yahoogroups.com] On Behalf Of Byron Evetts
Sent: Monday, February 14, 2011 5:39 AM
To: electricboats@yahoogroups.com
Subject: RE: [Electric Boats] Re: Setting expectations
Jim,
Dying sailboats (cat or monohull) are a dime a dozen. See craigslist or your local marina. The 10kW of PV panels is a pipe dream. I am doing a solar project for the YMCA Indian Guide and it took months to get a single 180W PV panel for the kids (Too big and the wrong voltage but still the best I could scrounge). Write a check for about $30,000 and you’ll have your 10kW. Oh, and you need a butt load of batts or you’re wasting a lot of generation and only moving in the bright daylight. (and you need about 2000 sq ft of deck space).
All the utils, parks, etc run them til dead before they surplus them.
QED: Boat=easy. PV panels=hard.
Byron
From: electricboats@yahoogroups.com [mailto:electricboats@yahoogroups.com] On Behalf Of luv2bsailin
Sent: Monday, February 14, 2011 12:17 AM
To: electricboats@yahoogroups.com
Subject: [Electric Boats] Re: Setting expectations
I know I tend to shoot from the hip and toss around ideas just to stimulate discussion if nothing else. It's easy to forget that there are a lot of folks reading these posts and that off the cuff brainstorming comments could be taken any number of ways.
So... where can I find an old dis-masted sailing cat and about 10KW worth of surplus solar panels...
Cheers,
Jim
--- In electricboats@yahoogroups.com, "Eric" <ewdysar@...> wrote:
>
> Jim,
>
> I appreciate your information and your candor. This estimate looks better to me if only because you qualified most of your relevant assumptions; location, power requirements, system size, etc.
>
> Since Bill has stated in other posts that "slow speed (5 to 10mph) is ok" with him, it shows that he has different expectations than most of the members of this group. Almost everyone here considers 5kts as "speeding" under electric power, at least for multihour cruising. He's also looking for about 50 miles under power each day.
>
> So here's the question at hand: On a typical 40' x 14' houseboat, can the boat be driven at speeds above 5kts for 50 miles a day on solar power alone? From my calculations, even on a good day, no.
>
> Taking the question all the way back to Bill's first posts. Is a typical 40' x 14' houseboat a good candidate to convert to electric power alone? Considering that most houseboats that size are delivered with well over 400hp installed, reducing onboard power to 20hp or less will probably make the vessel a hazard to navigation in all but the calmest conditions. A mild 10kt crosswind could make the boat unsteerable. So again, from my calculations, even on a good day, no.
>
> I've had some people here say that I shouldn't discourage other people, that I should let them "follow their dreams". But we're the one of the few sources of information about electric boats that isn't trying to sell something. There's not many other places to turn to for answers. I'll heartily encourage people to push the envelope on what an electric boat can do, but the current conversation isn't even close. I love to proven wrong, and I'm always learning new things when research my answers to discussions here. But in my opinion, given current technologies, Bill's concept as originally stated is a non-starter.
>
> Fair winds,
> Eric
> Marina del Rey, CA
>
> --- In electricboats@yahoogroups.com, "luv2bsailin" <luv2bsailin@> wrote:
> >
> > I forgot to mention that I was using Los Angeles as the location for that 5/2 hour summer/winter figure. Chicago is 4.38/1, Miami is 4.4/2.4. Since NREL uses historical data the typical weather patterns are factored in.
> > Anyhoo, let's say my hypothetical 26x8ft pontoon shantyboat does 5kt on 5hp on a calm day. I've got 200 square feet of brand-new high efficiency panels on the roof. Total peak rated output is 3600W. It's summertime in Miami and I want to take a cruise up the ICW before hurricane season heats up. 3600*4=14,000 is about how much energy I'll be able to get from my PV panels on an "average" day. Let's say about half of that gets wasted between charging batteries and then discharging them to run the motor. That leaves me with 7200 Watt-Hours available for the motor. Converting to "HP-Hours" you wind up with 5HP for a couple hours. So, not accounting for wind and tides, I can cover ten miles a day on pure solar alone. Maybe more if my 50% efficiency number is too pessimistic. It may be, since you'll be sending some of the power directly to the motor during high sun. Hard to say if 5HP-5KT is reasonable either but hey, it's my hypothetical boat so I get to pick the hypothetical numbers.
> > I don't know how this all relates to the hypothetical 40Ft houseboat, being discussed. I suppose it really doesn't much.
> > Cheers,
> > Jim
> >
>
No comments:
Post a Comment