My Solar Power Dream, Part II

 

By Cecil Hoge

Last month, I wrote a blog post about my experiments with solar power and how I hope solar power in combination with electric outboards will soon be practical to motor our inflatable boats. I would now like to tell about our first introduction of a true solar powered electric motor boat which we presented last month at the Miami Boat Show – Our Sea Eagle 10.6 inflatable boat with a 3 HP 1003 Torqeedo electric motor, and a PowerFilm solar panel mounted directly on our Sea Eagle canopy.

We introduced this particular configuration at the Miami Boat Show because we think this combination of boat, motor and solar panel is particularly practical for yacht owners. This is because yacht owners generally use inflatable boats to go ship to shore and to cruise around scenic harbors. The great thing about this use is that when yacht owners are not cruising around harbors or going ship to shore, their tender is moored by their boat or tied up to a dock. If there is any sunlight, the PowerFilm solar panel is silently and constantly charging up the lithium battery of the Torqeedo motor.

Before the show, Torqeedo—the manufacturer of the electric motor—had a press conference inviting many magazines and press officials to a house in Miami on the Intercoastal Waterway. There Christoph Ballin, the President of Torqeedo, and I demonstrated our new solar panel configuration.

Those of you familiar with this waterway know that it stretches all along the East Coast of the United States, making it a beautiful protected waterway that many boaters use to go up and down the East Coast. Using the Sea Eagle 10.6 with the solar electric package as we did, the real advantages of this kind of boat configuration became readily apparent. Not only was it very quiet and clean and easy to motor through the winds and currents of the Inter coastal Waterway, but the battery was able to simultaneously charge while we were motoring. Because of this, our range (the distance we could travel on the current charge) was extended by the constant input of solar power.

Another truly interesting aspect was the fact that when motoring at a relatively slow speed, the battery power remains constantly fully charged. The solar panel delivers in full sun 45 watts and if you keep the power usage on the Torqeedo to 45 watts or less, you literally are running on solar power alone. This is a slow speed—it is only about one and half miles per hour—but it also allows you to travel without putting any drain on the battery.

One of the many unique characteristics of the Torqeedo electric motor was that it has a computer module showing remaining battery power, speed over land, remaining range at a given speed and the actual wattage in power that you are using at any given time. This allows you to simply set the power usage at 45 watts and chug along for free, or to go faster and monitor your usage and remaining range all the time.

One thing that is sometimes forgotten when discussing the power and speed in an outboard motor, is that to get twice the speed, you need 8 times the power. In other words, the faster you go the much more power you use. Without the benefit a solar panel, the Torqeedo motor goes full speed for 38 minutes, 3/4 speed for over 2 hours and slow speed for up to 10 hours, so the range and time you can go changes dramatically with the power you use. When you add a solar panel, it increases your range and it extends the time you can use the motor.

Personally, the best benefit of using a solar panel is that when the boat is at rest and when there is some sunlight, the battery is always recharging, eliminating any need to plug it into an electrical source when you’re not using it. Unlike rigid solar panels the PowerFilm solar panel uses amorphous solar cells on a flexible but durable fabric material allowing it to charge all the time there is some light. While it charges best in full sunlight, the solar panel still charges in cloudy and waning light conditions. This is a welcome change from rigid solar panels which are much heavier and need a certain light intensity to deliver any charging power. It also means that the PowerFilm solar panel is far lighter than traditional rigid glass solar panels.

The fact that the solar panel charges all the time in most light conditions has some real and unusual benefits for a yacht owner. While the boat owners are at a restaurant enjoying a nice meal or moored and relaxing on their boat, the solar panel is silently recharging the battery of the motor as long as there is some sunlight.

This is very practical in terms of how many yacht owners use their yacht tenders. It allows someone to go to a nearby beach or to a dock or to another boat to tie up—often for several hours at a time—and then get back in their boat and motor back from whence they came. And the truly great thing about this, is the fact that all the time the boat is at rest in sunlight, it is recharging the battery.

This means that most yacht owners will almost never have to recharge their batteries – they will have perpetual power at their disposal, ready to use whenever needed. Of course, if they need to charge the battery electrically this is also easily done since most large boat owners have a diesel generator on board with available electrical outlets. And of course, the battery can always be charged from an electrical outlet at the dock or at home. Since the battery only weighs about 10 pounds this is not the hassle it is with lugging a 40 or 50 lb. lead acid battery.

We are hoping this new solar electric configuration will offer yacht owners a whole new energy free way to have a tender. Not only is this a very green alternative to using a gasoline motor, it is also a very clean way to motor a boat…there is no gas or oil to spill and mess up and stain your clothes or your boat. Solar electric is clean and easy all the way.

Those of you familiar with the hassle and expense of running and handling a small outboard gas engine will especially appreciate using a Torqeedo electric motor. Instead of having to pull a manual start cord and deal with their temperamental starting nature that seems inherent to all small gas outboards, all you have to do put the magnet starter button on the tiller handle and turn turn the handle left or right for forward or reverse. Instead of having to listen to a loud motoring sound of small gas explosions in a small gas engine (how can such little engines make so much noise?), the yacht owner only hears a low whirring sound of the electric motor. And instead of having your gas motor yearly serviced for what seems like half the cost of the engine, the Torqeedo requires almost no upkeep over a 10 year period.

All of the inherent advantages of a Torqeedo are enhanced with the use of a PowerFilm solar panel on our Sea Eagle canopy. Not only is the panel durable and reliable, it is completely out of the way of the boater. This allows full use of the boat while the solar panel recharges the battery of the motor.

Last but not least, I would like to mention why I think the Sea Eagle 10.6 with a 1003 Torqeedo and a PowerFilm solar panel is such a great match for the average yacht owner. The size of this boat, at 10′ 6″, is perfect for most yacht tending situations – it can hold comfortably 4 people. Better still this model has a patent pending exterior drop stitch keel which allows it to steer very precisely. Most inflatable tenders simply slide when you try to turn them. Not so for our 10.6, because of the exterior keel, it turns precisely within a much smaller radius. This is very important for a small boat motoring around docks and crowded moorings where often there are much larger boats paying not too much attention to the smaller craft that may come nearby.

An added feature of our 10.6 when it is using a high pressure drop stitch inflatable floor along with the outside drop stitch keel (you have a choice between plastic floorboards or a drop stitch inflatable floor), the overall boat is much lighter – 43 lbs lighter to be precise. The 10.6 weighs just 93 lbs. with the drop stitch floor, making it practical to be easily carried by 2 people, to be pulled up on a larger boat or to be towed long distances by your larger boat. And again, when used with the drop stitch floor, the boat is far easier to assemble and far more compact to store – two very important features for yacht owners.

Of course, I have to admit that I am prejudiced since we sell Sea Eagle boats and I am the proud president of the company – we think the 10.6 is the best all-around yacht tender on the market. And we think when it is combined with a Torqeedo motor and a PowerFilm solar panel on our Sea Eagle canopy, this package offers the yacht owner a unique and very pleasant alternative to gas powered yacht tenders.

We hope this new introduction of our solar electric Sea Eagle 10.6 – we call it the Ultimate Solar Electric Package – is just the first of many new solar electric configurations using our boats with Torqeedo motors and PowerFilm solar panels.

No one boat and no one kind of innovation can change the world, but many different people and many kinds of innovation, using many different kinds of solar electric boats and solar electric cars and other solar electric products could change world. More than that, I think this change can come only one person at a time. It will not be a government or a single business that changes the world, it will be people, one person at a time, changing to new innovative products, that will change to world.

Later this year, I hope to report to you about other developments using Torqeedo outboard motors with PowerFilm solar panels on other Sea Eagle inflatable boats. The introduction of our solar electric package for our Sea Eagle 10.6 is, I hope, just a small part of my solar power dream and the first step of many to offer alternative choices to the use of fossil fuels and gas motors.