Solar panels provide an excellent solution for obtaining the electrical power needed  to support on-board electrical systems.  They are quiet, require little maintenance and are reliable.

While cruising, we take a very conservative approach to using electricity on board our 38 foot sailboat.  Even so, when considering the solar option, I concluded that  using solar panels to supply all our electrical needs would be expensive and would require considerable panel surface area.  With this in mind,  I set out to use solar power to augment the generation of power with the goal that we could be at anchor for three days without running the diesel to charge the batteries.

The 85 watt Kyocera KC85T is rated at 5 amps (17 volts) and measures about 26" by 40".  We can generate about 35 amp-hours on a sunny day on the Great Lakes by adjusting the angle 3-4 times a day for optimum efficiency.  Our energy usage is roughly 55amp-hrs a day at anchor.  Thus we run a deficite of about 20 amp-hours per day.

Here is how we calculated our energy usage per day at anchor.
Equipment            Amps            Amp-hours/day
Refrigeration          5                        20
Instruments            1                         4
Computer               4                         6
Lighting                  2 (avg)                10
Pumps                    5                         5
Other                     1                       10
 (propane monitor, etc.)
                                                ________
Total amp-hours                                55

When under sail we have an additional current draw of 20 amp-hours from our auto-pilot and instruments.

We have a 75 watt alternator on board and a 360 amp-hour battery bank.  Because we typically run the engine several hours on the days we are moving, the battery bank gets charged on those days.  This system works out well for us.

Each cruising boat has different patterns of energy usage and different requirements.  Calculate your usage, consider your sources of power generation and select the size of the solar array you will need.  Based on this, you can determine whether a single panel or multiple panels will be required to meet your needs.

Contact us if you would like assistance in determining the size of panel that will be required to meet your needs.

Top-of-Pole Mount

The top-of-pole mount offers excellent functionality for getting the maximum performance out of your solar panel.  The closer the surface of the panel is to being perpendicular to the rays of the sun the higher the performance (amps output).  Thus, the panel needs to be both tilted and rotated.  I have found that adjusting an 85 watt panel 3-4 times a day will achieve power generation of up to 40 amp-hours on a clear day on the Great Lakes.

A panel mount should be adjustable easily without the use of tools.  Our panel mount provides 13 tilt positions by simply pulling a pin, tilting the panel and replacing the pin.  The panel, which is atop our crane pole can be rotated 360 degrees.  We provide a pole locking mechanism to keep the pole from rotating on a windy day and have found that using the mechanism as a brake to limit free rotation of the pole works well.

As shown in the picture, our pole is mounted to the stern rail away from the boom so there is nothing to cast a shadow on the panel.  Shadows can significantly reduce the efficiency of a solar panel.  The pole is mounted high enough to clear the bimini yet easy enough to reach to adjust the angle to the sun.

My sense is that the 120 watt solar panel is about the maximum size
(31" X 48") to mount on the top of a pole such as ours.  The limiting factor is the strength of the stern rails that stabilize the pole.  A larger panel would require bracing struts from the pole to the deck.  Clearly this is possible but I would recommend mounting larger panels to a frame above the bimini, on dinghy davits or directly to the stern rail.

Pro and Cons:

Top of pole mount
Pros: Easily adjusted for best sun angle, clear of shadows, out of the way.
Cons: Limited size of panel that can be pole mounted.

Bimini frame panel mount
Pros: Can mount large panels, out of the way.
Cons: Cannot easily adjust for best sun angle, often have shadows cast by the boom, back stay or topping lift.

There are many outboard motor lifting cranes available on the market.  Most of them are based on a pole with a horizontal boom or crane attached.  If you have a pole mounted on the stern of the boat, why not be able to use it for multiple purposes such as a solar panel mount, an anchor light mount or an antenna mount?   I started out researching poles made by various manufacturers including Garhauer (my favorite) and concluded many were over designed for what I needed or didn't offer multiple features.  Taking the best of each and adding my own ideas, I built several prototype poles until I came up with a design that fit the needs of the cruising sailor yet could be manufactured for a competitive price.

Here are some of the features I wanted to achieve:
1. Relatively light duty - The unit should routinely lift boating gear up to 100 lbs. yet be robust enough to lift a 250 lb. body from the water. 
Note: If I fall overboard and am impaired, hopefully my first mate (The Admiral), would be able to pull me out and onto the transom platform or dinghy.
2. Easily removable - The unit should be easily removed and stowed.
Note: I did not want to unbolt a bunch of fittings to take the unit down.  The pole simply slides out of two sleeves mounted on the stern pulpit.
3. Easily stored - The unit should easily fold up for storage in a locker.
4. Easy installation - Installation should not require a bunch of holes to be drilled in the boat (holes are a bad thing on a boat) for brackets and supports. 
Note: This design relies on the strength of the stern pulpit only.  It attaches to the one or two horizontal rails on the pulpit. 

Note: We offer three options for the pole base:
   a. A swivel on the bottom with a rubber base and sets on the deck.  This is ideal if the pole is perpendicular to the deck at the pole base.
   b. A ball mounted to the deck with double sided tape or bolts and a mating receiver inserted into the base of the pole.  This is ideal for supporting the pole base at the transom or if the deck is not perpendicular to the pole.  It is also a good solution for boats with a single stern rail.
  c. A slotted base that fits over the outside rail.  This is ideal for boats with limited deck space for the pole base but with an extruded outside rail.  See pole base pictured elsewhere on this site.

5. Support for other equipment - The pole should accommodate mounting brackets for equipment such as a solar anchor light, a solar panel, or an antenna cluster. 

Note: We currently have an 85 watt Kyoceria solar panel mounted at the top of the pole on our boat and it works well.

Design specs:
1. Pole diameter - The pole is made of 1.5 inch OD thick walled stainless steel.
2. Boom - The boom is .375 inch stainless formed into a U channel.  The length may vary depending on the distance from the pole to the motor mount on the stern rail.  The crane is typically 18 inches long.
3. Stern pulpit brackets - The pole is attached to the stern pulpit rails using stainless  brackets.
4. Block and tackle - A 4:1 ratio for the block and tackle is ideal for most lifting jobs.  The line should be long enough to reach the water; typically 50 feet.

Design alternatives to consider:

Transom mount - In some cases, the stern rail may not be strong enough to properly support the crane or may not be configured to support a pole.  In this case, a transom mount may be the best solution.  This will require a bracket bolted to the transom to support the pole and braces from the pole to the stern rail or the deck to hold it in place.  Yes, holes in the boat required.   The Custom Marine Products system will work well in this configuration.

I have seen many such designs with radar units mounted to the top of the pole but few with a crane integrated into the unit.  I like the PYI, Inc. (PYIINC.COM) product and the Garhauer (garhauer.com) product for heavy duty pole based systems.

Hopefully this will give you some ideas of what to look for at the boat shows and what to consider if you build your own or custom order one of our units.

Once you develop your specifications, we can quote you a price for a custom unit.