ALTERNATE ENERGY SYSTEMS:
I have had solar
and/or a combination of solar
on my boats since the 70s. Based on this experience (with a lot of trial and error), this is what I now suggest to my clients.
IF your boat
lends itself to it, (as our Searunners do), go all solar. Solar panels
last much longer than wind
generators, and is a much more reliable source of power, giving several decades of use. When we returned to the U.S. after our first big cruise
on Delphys, we swapped out our wind unit for another big solar panel, and have never regretted it.
Having said that... If one must have wind for logistical reasons, here are some tips: There are dozens of brands out there, so choose a quiet, powerful, & reliable one. Many brands are totally silent, but "whimps" in their output. Still, in a 24/7 windy area, they are a good supplement to your needs, considering how quiet they are. They are however, only a supplement to your needs. A really good brand that gets a bit larger, a bit heavier, and just slightly louder, but produces really usable amounts of energy, is the KISS brand. It sells for a good price
too! The brand that I would be sure to avoid, is the Air-X brand and its brothers. They create a "circle of noise" around your boat that's easily the size of a football field, and even if the noise
doesn't bother you, your neighbor may feel differently. (Making friends is half the fun of cruising, you know)...
IF you have a wind unit on the back, do not use it as a combination with solar on a tower, like so many monohullers do. Our Searunners are far more sensitive to un-centralized weight, so the amas, bow, stern, and up the mast
, must all be kept light, to lessen pitching motion. Also, due to the shadows it creates, the wind unit back there, will at least cut in half the daily output of that aft solar panel, partially negating its usefulness. I have done numerous experiments to determine this... Dark shadows from close objects, even small amounts of it, knock the panel right out.
IMO... wind only makes since on a narrow monohull
that can't accommodate solar, and the wind generator
should be on a pole at the stern. It would mostly be used at sea, and would just be a supplement for the primary source of power, the alternator
FOR TOTAL ENERGY SELF SUFFICIENCY ON A TRIMARAN
Our boats lend themselves to this with solar, more than any other type of boat.
The starting point, is to build a bulletproof wiring
harness... with crimped, then soldered, (just a TINY drop), then heat shrunk eye connections, to well fastened (every 8") double jacketed, tinned boat wire. The wiring
harness is the most time consuming part of the system, and should NEVER need replacement. Almost all of the 99% who do not do this process, get increasing resistance after 10 years, and after 25 years, need to be completely re-wired. This may require tearing out a lot of the interior
, and is best avoided!
Next... Equip the boat from stem to stern with the most energy efficient version of everything. This means use LED and/or fluorescent bulbs, and use DC to DC "transformers" for low V. gadgets... like computers
, TVs and such, rather than inverters. Super insulate your refrigerator
with 7" of foam, or use the equivalent R value in vacuum panels
. Etc, Etc.
Except when doing multi day passages, (when our consumption
doubles), we use about 35 amp/hours daily. This is with our boat equipped with all the comforts of home, like making water
daily, and even watching a movie
When making multi day passages, we run the engine
for 45 minutes once daily, at around 5 AM. This is when the batteries are at their lowest, and best able to use the 38 A. from our standard Hitachi alternator
. Then over the day, the solar panels
bring us the rest of the way up to 100%, slowly.
Anchored out, the long slow solar charge is most compatible with the slow acceptance characteristics of mostly charged wet batteries, and we are "all full" with a 3 stage charge, by 11Am. If it is quite dark and overcast, it might take all day, and I may need to tilt the aft panel, but we still get to 100% charged.
With our two 6V. in series Trojan L-14s (=340 A.h.), and only using 35 A.h. out of them, it is a very shallow cycle indeed, so the acceptance rate is low. More power would be of no use! Also, with this shallow cycling, the V. remains higher, making everything work better/longer, and with good batteries, you may get 15 years out of a pair of them. With the addition of HydroCaps, they only need water
a couple of times a year, however I check them on the first day of each season to be safe.
This ample storage
capacity covers you for days of total black out cloudiness, OR unusual power usage, as well. Like most folks, we spent 95% of the 12 years we were full time liveaboards, at anchor
. During this 95% of the time, we were totally "solar" self sufficient, 99% of the time. We NEVER had a single
breakdown or flat battery
A good battery monitor
, like our Link 10, is essential, and due to topping up the batteries daily, the meter re-zeros itself daily, and stays spot on accurate. With the meter, I can first turn off all power sources in, (Solar) and then a glance, I can tell the consumption
of any device on the boat, or if there is a phantom load, or a device left on.
You need an amount of power (in proven A.h. production on a perfect day), that is 2X your normal anchored out consumption. This way, you are covered, even on VERY cloudy days, when their output is only about 1/2. Overcast but BRIGHT, white out days, surprisingly... are great for solar production too, producing 90+ %.
I started with three panels
and a wind generator
, with the 3 panels in parallel going through an A. meter, as well as a separate meter for the alternator, and third for the wind unit. When I removed the wind unit and installed another aft panel, (articulating on a VERY light weight rack), I ran the new 110W. panel through the now available (previously wind) A. meter, by itself. This way, when it's cloudy and I want to tilt the panel at dusk, I know the sweet spot from my wife watching the meter.
The panel that is holding up best now, (@ 17 years old), is the BP. Ironic, isn't it. This one is still perfect, and while the other 3 are visually "wearing" a bit, output is as good as always, and I expect 30 or more years out of them.
mount panels need to be above the deck
for good ventilation, (rather than bolted directly to the deck), and with sloping end Starboard rails, so that toes and lines don't get hung up on sharp corners. This has served perfectly. Just don't step on them! I have, however, placed a foot there by mistake, with perhaps half my weight, and gotten away with it.
By having the 4 panels (totaling 280 W.) all spread out, 3 of the 4 are usually unshaded. Each has a Schottky diode in the + wire, before they get wired in parallel, (which is just before connection to the 4 stage Trace charge controller). The best wet battery charge controllers, btw, are for the self sufficient cabin
The "Schottky" one way diodes, are to prevent loss from some panels back feeding into the shaded ones. The slight V. loss here, is acceptable for the benefit. These are not to be confused with the "bypass" diodes that come with the panel, which serve only to prevent backfeeding within a panel.
These tips will make a solid alternate energy system that holds up for decades, and really serves its purpose. The hundreds of folks that bitch & complain about solar, have too consumptive a boats, with too small a solar array, as well as insufficient batteries, poor regulation & monitoring, and too much resistance. They're doing it wrong!
Done correctly, the "perfectly reliable", environmentally conscious, and blessedly silent solution, is solar.
For readers from way back, I apologize for repeating myself...