Quote:
Originally Posted by mikalcalvino
Can anyone give me a crash-course of info or links to purchase a solar panel in the 150w range and a compatible charge controller?
Also some info on a trust worthy yet simple wind vane for a boat of my class(28ft)?
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Nice boat, I have a very serious soft spot for Cal's. Also, I like the color scheme.
Currently , there are 2 major competing controller technologies:
MPPT - Maximum
Power Point
Tracking
PWM - Pulse Width Modulation
MPPT will set you back about $250-300 for a 30a/12v controller. At normal or lower temperatures it will put significantly more energy into the
battery than a PWM controller during the BULK phase of
charging. Using an MPPT will make the system less sensitive to shading of the panel by lines. The controller is indifferent to oversized solar arrays. MPPT controllers are physically larger.
A PWM controller will set you back about $125 for the same capacity. For a system that is not used a lot the PWM will A PWM may be damaged by
panels putting out too much voltage. A PWM is considered to be better for the
batteries and they will last longer.
References:
MPPT vs PWM charge controllers by Blue Sky, Morningstar, OutBack and Xantrex
http://www.morningstarcorp.com/en/su...vPWM.01.EN.pdf
Charge Controllers for Solar Electric Systems
What is MPPT? Explanation of maximum power point tracking
Maximum Power Point Tracking Charge Controller
Summary: My sense is that the PWM will be the better buy if you are sailing your boat on weekends or intermittently with the occasional 1-2wk trip. If you are
living aboard or cruising the MPPT will be the better buy, you will need fewer
panels to keep your energy usage in balance. The cost of the panels is not so much the issue as the need to find places to put enough panels.
Some means of equalizing the
batteries is a good idea as it will help extend their lives. If the controller has the ability so much the better, but look at the details of what is required of the panel. See here for a post I did on
equalization:
http://www.cruisersforum.com/forums/...tml#post936039
Regardless of the controller you get a
tracking mount will significantly improve the output of the panels. See here,
Atom Voyages - The Solar-Tracker, for details one method of construction.
You ask about a
windvane which I suspect may really be a question about how to get the boat to steer itself. The answer is more complex than a decision between a
windvane and
autopilot, since there other alternatives.
The other alternatives are:
A)Balancing the
sails to self steer
B) Sheet to tiller
steering
C) Extra crew.
Balancing
sails is tough for sloops on most points of sail so lets ignore that.
Extra crew will whine about always having to steer, you have to feed them, they take up berths and you would have to get a larger
holding tank, so lets ignore that option too.
That leaves
Autopilots
Windvane
Sheet-to-tiller
Assuming you have a tiller the
autopilot will run you $400-700. It will draw a fair amount of
power depending on how well you trim the sails and the seastate. It is not user repairable and they have a more limited life given the
environment the
electronics are required to work in. It follows a
compass course meaning that you need to
monitor sail trim and course more to keep the boat from overtaxing the unit and power supply and to maintain course made good. The autopilot is the only system that will work while motoring and it is usually the only one that works well running in very light winds. Being quick and east to set up autopilots can be used in moderately confined waters while performing deckwork.
Windvanes, new, will run you €849.00 to$4500 plus tax and
shipping while weighing 15-50lb. Some breakages may be user repairable depending on make and model, the nature of the failure and the spares carried. As with the autopilot the boat needs to be trimmed well for the windvane to work well, though my impression is that windvanes are slightly touchier about it. The windvane will follow the
wind meaning that attention needs to be paid
lest the boat go wandering off somewhere unpleasant like the beach. (See here,
http://www.google.com/url?sa=t&rct=j...yP0QbfNfQio7Aw , for an example.) Generally windvanes are at distance made good (See pg73-77 ofhttp://sfbaysss.org/tipsbook/SinglehandedTips.pdf?id=1). Windvane take time to set up and are best used once underway in waters that are not particularly confined. There are plenty of used windvanes to be had.
If you have a
DIY bent you can build your own windvane for $20-50. Details here:
Walt Murray's website | Mister Vee wind vane self steering
http://web.archive.org/web/200606151...Self-Steering/
Also the book "Windvane Self-steering" by Bill Belcher has a long technical discussion about how windvanes work and plans for building your own. This book will set you back about $100.
Sheet to tiller
steering will run you $20-50 in materials and a bit of time assembling the
equipment. I expect the advantages and disadvantages are similar to windvanes, except that you will need several different methods of sheet to tiller depending on exact point of sail. The following links have a fair bit of info on this topic. Being user made, the
equipment is also user repairable, add no significant weight to the boat and are easily stowed. Even the autopilot will add a significant amount of weight as more power is required meaning a larger/heavier
electrical system, though it won't be hung off the back of the boat like a windvane.
Sheet-to-Tiller Self Steering
A Pearson Ariel Page
http://sfbaysss.org/tipsbook/SinglehandedTips.pdf?id=1
The gold standard of sheet-to-tiller info is "Self-Steering Without a Windvane" by Lee Woas. The book is long out of print and prices for used copies are currently running about $100. This book is a giant collection of different methods of sheet-to-tiller for all points of sail.
If I was dirt pour I would start by trying sheet-to-tiller methods.
With a bit more
money I would think long and hard about whether I wanted to ADD a
DIY windvane to the sheet-to-tiller methods.
With more
money still I would ADD a
cheap autopilot.
Next step up would be a used
commercial windvane.
Next a new windvane.
If money were no object I would have a new windvane, plus the beefiest tiller autopilot plus the sheet-to-tiller setups. I really am big on redundancy.