By Cecil Hoge, President of Sea Eagle Boats, Inc.
Several years ago I wrote a blog story called, “My Solar Power Dream”. In it, I outlined my efforts to create a solar-powered boat that really worked. That experiment was more dream than reality.
At the time, I had put a solar panel on an inflatable sailing catamaran and hooked it up to a lithium battery that powered a Torqeedo electric motor. In the years leading up to that experiment, I had tried a number of solar panels, most of which did very little. On my sailing catamaran, I hooked up a solar panel on the bow between the 2 pontoons with the Torqeedo electric motor at the stern. It worked, but it had a number of problems.
For one thing, the solar panel drooped between the inflatable pontoons. This tended to scoop up water when sailing and hang loosely between the two pontoons. Nevertheless, it did work…kind of. The solar panel did re-charge the battery in the Torqeedo motor, but it took quite a bit of time. If there was sun, it would actually charge the battery fully in about 8 hours, which was pretty good.
But, there were two problems with that:
1. You generally did not get a full 8 hours of sunshine each day.
2. The battery in the Torqeedo motor I was using only held a limited amount of electrical power. Even when fully charged, the Torqeedo battery could only be run for about 25 minutes at full speed. This meant I could go out fairly regularly, but you had to watch your time and how fast you were going because if you wanted to go fast, you would run out of juice pretty quick. And paddling a 16′ inflatable catamaran back to my home one or two miles away was not something I really wanted to do.
About 6 months ago I began working on a new kind of fishing boat. It was designed to hold up to a 6 hp outboard gas motor and 2 fishermen. Our name for this new model is the FishSkiff 16. The first prototype, shown above, was 14′ long and 54″ wide. When I conceived this new model I had no intentions to create a solar-powered version of it. I was looking to create a fishing boat that weighed very little, packed up in a car trunk and motored long distances with small, lightweight gas-powered outboards.
When I got the first prototype, I found out that it did not motor well with a 6 hp outboard. That was because the pontoons were not long enough behind the transom. The problem was that the bow of the boat wanted to ride up at a 20-degree angle at full speed. I can only blame myself for this error since I was the guy who made the drawing of what I wanted our supplier to make. Correcting this problem was simple – all we needed to do was extend the length of the pontoons. And that is what we did.
I must say the longer pontoons behind the boat worked great and looked great. I would note that I also changed the shape of the bow to give this boat a more pointed elegant shape with the drop stitch bow pontoons extending beyond the drop stitch floor. The above picture shows the Sea Eagle FishSkiff 16 rigged with 2 swivel fishing seats.
There was just one problem – I still had the first prototype – what was I going to do with that? That gave me the idea to use that prototype with an electric motor and a solar panel. With a small electric motor, there would be no problem with the shorter pontoons. And that was easy because we had already started selling WaterSnake electric motors two years ago – so I had the motors. In addition, I had developed a working relationship with a solar panel company, Zamp Solar, and a lithium battery company, Relion Battery.
So here is what I did. I got a 100w Flex Solar Panel from Zamp Solar and a 50 amp Lithium battery from Relion Battery. I could have used a regular 12-volt lead acid battery, but I liked the idea that the lithium battery weighed only 15 lbs. while a 50 amp lead acid battery generally weighs 50 lbs. As an older man, I liked the idea of a really lightweight 12-volt battery.
I then put the solar panel on one of our large Sun/Rain Canopies (which of course we already had) and hooked it up with a 12-volt controller to the lithium battery and Voila…I had a solar powered FishSkiff.
That is not quite accurate. This new boat configuration was not truly a solar-powered FishSkiff. What was actually happening was that the solar panel was charging the battery whenever it began to run down (provided there was sunshine). And the battery would power the electric motor whenever I took the boat out for a spin.
Effectively, I did have a solar-powered boat because whenever I chose to go motoring I had plenty of juice to cruise around for several hours. Now, this kind of system does have some logistical limits. If you go full speed for over an hour and a half, you could run out of power. And then you would have to paddle your way from there until the solar power put in enough juice to resume motoring. A better alternative to that is simply to go a little slower speed (I recommend 3 mph instead 4 mph) and have all the power you need.
And effectively, whenever I went out, I had all the power I needed, primarily because I generally never would go out for more than 3 hours at a time and, if I did, all that I had to do was slow down a bit and run at half throttle. Since the top speed of the boat at full throttle was 4 mph and the speed of the boat at half throttle was 3 mph, slowing down really was not much of a sacrifice.
I now have been using this boat for 6 months and I found that I could go boating 5 or 6 times a week without ever having to recharge the battery. The 100w Flex Solar Panel from Zamp seems to fully charge the Relion 50 amp lithium battery in about 5 hours, presuming there was sunlight. Now that the winter is coming on strong (I am writing this article in December of 2017), going out is more difficult and more unpleasant, not because I was running out of power, but because it was starting to get damn cold.
Cold is not something that generally discourages me. I go paddling and rowing all through the year – at least, as long as our bays do not freeze – it is hard to paddle on ice! However, paddling and rowing is always quite warm because as long as you are warmly dressed and move while paddling or rowing, which you have to paddle or row, you stay warm. Motoring on my solar powered FishSkiff was a different matter. There the boat was moving, but I was not and that meant it can get damn cold when you are not moving. So, I have sharply curtailed my electric motoring in the Solar Powered FishSkiff in December. It is just too damn cold.
That said there is no problem to go motoring in winter other than the damn cold. I have now pulled my solar-powered boat up onto one of my floating docks, where it sits happily above water and ice. The WaterSnake Venom 34 that we sell has a nifty digital monitor that tells the electric current in the lithium battery. The monitor presently reads between 13.6 and 13.8 volts, which means it is fully charged for a lithium battery and I am ready for a freezing cruise if I so desire.
A couple of point about lithium batteries. Not only are they lighter, they can be run down completely and recharged hundreds of times with almost no degradation to the amount of voltage that a battery can hold in the future. This is not true of a lead acid battery, which if you let your charge go below 50%, can degrade the battery permanently and leaves with less future power. Another aspect is the fact that lithium batteries are not affected by cold weather, meaning they hold their charge in cold weather, whereas lead-acid batteries lose their charge in cold weather. This means I can leave my lithium battery out all winter with the secure knowledge that it will stay charged all year.
In summary, I think I can truly say that our FishSkiff 16, when rigged with our little WaterSnake electric motor and with a solar panel can be motored pretty much every day without ever having to recharge the battery or to put gas in the tank.
That truly is A Solar Powered Dream come true!
Additional Information on Outfitting one of our Sea Eagle boats with a solar panel:
BackCountrySolar.com or call 1-970-882-8046 – 9am – 5 pm M-F, Mountain Time.
The cost is $532 for the 100w Zamp Panel with 10 amp waterproof charge controller & 2 lead wires with the fuse – one set of lead wires (15ft) from panel to charge controller and one set of lead wires from charge controller to battery. This set comes preloaded with everything you need. It will recharge any 12-volt battery, be it lithium, lead acid, AGM, Gel or Calcium. Best of all, shipping is FREE.
Please note, if you are getting a Solar Panel set for one of our boats, you will also probably want a canopy to put the solar panel on. If you order this, please let Jerry in our tech department know so he can make sure the canopy had attachment grommets in place for the solar panel.
The following Sea Eagle boats take both our canopy and can be used with an electric motor up to 65 lbs. thrust – FSK16, SE9, STS10, 285fpb, 375fc & 10.6sr.
We would also like to mention that you could also outfit many of our 380x, 420x, 385ft, 465ft, 435ps kayaks and our FishSUP 126 with the Zamp Solar Panel and an electric motor, but those models do not take our canopy so you will have to tie down the panel on those models. Should you have questions on how to do that, call Jerry at 1-800-473-7308 9am-5pm, EST.