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How to Save With Solar Power
http://mygospel.biz/?p=2639
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Following a recent five-day trip aboard our trawler where we had to frequently start up the genset
to provide electricity to the 115 volt AC freezer to maintain temperatures, I began to mull over
options. We put in an excess of ninety hours on the vessel generator in only five days; time for
another oil change! I put in an inverter soon thereafter and that improved the run time for the
generator drastically, but there was still work to be completed. I nonetheless needed to keep the
batteries fully charged to operate the inverter. Then it occurred to me, why not explore solar
panels for use aboard our yacht. Solar panels have been successfully utilized since the mid
1950s, originally utilized in manned space exploration. They have been dropping in cost since
roughly 2004 when their popularity really went up. And now with the Green pressure going on,
solar panels are as accepted as ever. So I commenced to delve into them and find out how to
purchase and mount one; I was in for a big surprise. You can come across many retail vendors
over the internet that will sell you a solar panel but nowhere could I locate a detailed description of
how to determine what to buy and how to install it; much less on board a yacht. So this piece was
written as I made my way through the progression; therefore is a truly a learn-as-you-go article.
What Exactly is a Solar Panel and How Do They Work?
Solar panels are basically any panel that makes use of the sun's thermal energy to create
electricity. A solar panel can be described as a photovoltaic panel, the name used in the business,
for panels intended to create electrical energy from the emission of the sun. Despite the group of
solar panel being discussed, nearly all solar panels are flat. This is because the surface of the
panel needs to be at a 90 degree incline from the sun's rays for the best angle to soak up the
sun's rays. Solar panels are able to absorb energy from the sun through a collection of solar cells
on their surface. Very similar to how a plant is able to take in energy from the sun for
photosynthesis, solar cells function in a comparable way. As the sun's rays hit the solar cells on a
photovoltaic panel, the energy is transferred to a silicon semiconductor. The power is then
changed into (dc) direct current electrical energy and then passed through connecting wires to
ultimately enter a storage battery.
Kinds of Solar Panels
Types of panels most normally used in yachting uses have either multicrystalline or amorphous
thin-film cells. Multicrystalline panels are the oldest technology obtainable and in addition the
strongest. When sized correctly and paired with suitable batteries, these are the panels to make
use of for operating large loads such as refrigeration.
Amorphous thin film solar panels are only about 50% as effective as multicrystalline panels, but
can be bought in flexible varieties so they can roll or fold, or change to the shape of a boat cabin
top or bimini. They don't often have adequate yield for considerable energy replenishment, but can
be used to lightly charge a battery bank.
How Much Power Can Solar Cells Make?
Normally, we measure solar panels by wattage and that is how we buy them. You can get solar
panels for boats as small as 10 watts to as great as 200 watts or even larger. But it is simpler to
understand when we change watts to amperage. We calculate these values by multiplying the
number of hours the panel is in full sun (usually defined as 5 a day in Florida) by the panel's
wattage. For a 195 watt solar panel the amount produced would be 195 x 5 hrs = 975 watts/day.
We can then figure, 975 watts/12 volts = 81.25 amps per day.
Power Consumption
Before considering which size panel to purchase for your boat, you will need to complete an
energy budget to ascertain what sources of power consumption you have aboard while at anchor.
I use the at anchor scenario as this is the place you will use the most energy; under power and
your trawler can supply its needs without any issues.
Example, if you have 3 inside lights that pull 2 amps each and you keep them on for 4 hours per
night, your consumption would be 3 x 2 x 4 = 24 AH/Day. We are not concerned by running lights
and electronics as they will not likely be running while at anchor.
DC Loads - calculate how many amps hours are used by each appliance
House Lighting
Anchor lights
Refrigeration
Freezer
Electric Toilet
Fresh Water Pump
Sanitation System
Stereo
Other
Inverter Loads
Inverter loads also make use of DC power but they are powering AC appliances and equipment. If
you want to change watts to amps use (12watts/12 volts = 1amp).
Calculate the amp hours used by each appliance
Computer
Microwave
Refrigeration
Freezer
Heater
Hair Dryer
Television
Other
Add up your overall daily energy use AH/per day
Solar Energy Creation
Different sources of power similar to solar panels can replace the amp/hrs pulled from the
batteries. But similar to the power budget that determined your usage you will also need to
compute your re-supply of amp hours. Keep in mind the formula - (12 watts/12 volts = 1 amp). But
be mindful, the formula is only a gauge; complete accuracy can only be where the panel
production is constant and a solar panel might at times function ineffectually due to cloudy skies.
Compare the day by day power use in AH/Day to the solar power creation. Your solar energy
production must be larger than the use. If it is not, pick a bigger wattage panel and recalculate.
Always purchase more solar panel output than you think you will need; some professionals
recommend at least 30% in excess.
Case in point - 100 watt solar panel/ 12 volts = 8.3 amp x 5 hours = 41.66 AH/Day production
Installing Your Solar Panel
Now that you have got your solar panel, where do you put it on board your yacht? As we
mentioned before, installing the panel ninety degrees to the sun is best. You will get the best
power production this way. But on yachts, finding a fitting spot is tricky at best. A number of
boaters put them on brackets placed on the rails, others position them on top of the bimini, and I
have seen them positioned on the trawler dingy stanchions. But wherever you decide to mount
them, bear in mind that to get the most out of them they ought to be in the open, away from any
shading from booms, vessel radar arches, or cabin structures. Bear in mind that while at anchor,
the boat will turn to the sun twice daily because of the tides. I opted to mount our panel on the top
of the boat back deck hardtop in a horizontal position. Here it will get the greatest view of the sun
and be clear from the radar arch shade as the boat swings at anchor. The slope toward the sun is
not precisely at ninety degrees but it will have to do. I selected a 195 watt panel so I get almost a
50% reserve ability in my panel to compensate for the small inefficiency of the sun's angle. We got
the panel from Sun Electronics in Miami, sunelec.com as they had the best prices I could find
anywhere on the web. But bear in mind, panels must be shipped using freight as they are heavily
packed to reduce the chance of damage so be sure to calculate those expenses in your
acquisition.
What is the best way to attach the panel to your vessel?
There are a variety of manufacturers of solar panel mounting rails and supports but almost all of
them are made for roof or ground mounting. West Marine does carry a product for mounting small
panels to the rails. A good number of boaters make their own mounts. I found a mount developed
by Sunsei known as a Sunsei Glue Mounting Kit that is attached to the vessel and panel using 3M
5200 Marine Adhesive. The mount allows the panel to be installed with about 2 inches of space
beneath the panel for aeration. I did not need to drill any holes in the hardtop either. You can
locate these mounts at amazon.com.
Wiring Your Panel
Marine electrical wiring is incredibly specialized and hazardous; if you are not comfortable in
performing this part of the task, please check with an experienced marine electrician. Your panel
will be prewired for attaching to your vessel but you will need to provide the connecting cables that
will also be sold by your panel provider; they are known as MC4 cables. The cables will be made
in different lengths appropriate for your needs with a male and female connector affixed; you cut
one connector off.
In addition, you will also require a controller. The controller regulates the power stream from the
panel to your batteries keeping your batteries charged yet stopping over charging. A number of
controllers are easy but others have LED displays indicating the amount of charge etc. The more
fancy features the more costly it will be. Your panel dealer will be able to suggest a controller that
will satisfy your needs. I chose a controller developed by Specialty Concepts. It is straightforward
but does the job. And the people at the company are a big help in aiding you to select the best
model for your panel. When you get in touch with them, they will want to understand which size
panel (wattage) you own and what the voltage is. Check them out at specialtyconcepts.com. I also
got my controller from the individuals at Sun Electronics in Miami.
The individuals at Specialty Concepts have also calculated how heat will have an effect on current
flow and suggest that their controllers not be placed in engine rooms as the heat produced will
diminish the controller effectiveness by roughly 25%. I put mine in the electrical panel under the
lower helm. And finally, you will require the correctly sized cables to go from the controller to your
batteries and a fuse to connect the controller to the battery bank. In deciding on the correct fuse,
you need to locate the short circuit current for your panel and rate the breaker at 125% of that
number. This will give you the amperage of the breaker you will need. Your controller operating
manual will have information on these too.
Owning a solar panel to preserve your batteries would seem like a great plan but you'll want to
have a way to keep an eye on your batteries. I opted to also install a Trimetric 2025RV Battery
Monitor; bogartengineering.com. This smart device is wired into your battery bank to provide a
genuine measurement of voltage going in to the bank, amps being used by your yacht, the percent
full charge on the bank, and the amp hours utilized from the last charge.
Panel Functionality
So we have now installed a 195 watt solar panel in addition to an 1800 watt inverter and a battery
bank with 443 amp hours. We ran our tests this week on the hook with clear skies. I concluded
that our energy consumption is 112.5 amp hours per day. The freezer is the major draw using 60
of the amp hours followed by the refrigerator. Did you know that a standard anchor light pulls 18
amp hours each night? I think I'll check out LED bulbs now.
The battery monitor indicated that our actual draw from the battery bank was merely 65 amp hours
which indicates we received the remaining from the sunlight, an entire 42% was from the sun. Now
we will turn on the genset for around an hour to bring the battery bank up to complete charge.
Paradise Yachts is a Yacht Brokerage offering used yachts to customers worldwide.
Visit our website to view our selection of Used Trawlers, and Motor Yachts for Sale.
National and international sales. We ship Used Yachts and Boats worldwide. Located in Florida,
USA. 904/556-9431
Article Source:
http://EzineArticles.com/?expert=Michael_W._Dickens
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How to Save With Solar Power
http://mygospel.biz/?p=2639
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