Electric Propulsion for Sailboats
Has anyone any experience or any information on using the re-e-power.com unit for propulsion? They have a very interesting and persuasive web site. Any info will be greatly appreciated. From what i can tell their 200+ unit should give me about the same HP as my Nissan 9.8. My major concern is length of available power between charging. There are times when I have not gone out because of weather and spent the day travelling the ICW to my gunkhole destination. Thanks...
Fair winds,
>>ron<<
S/V Serenity
Ron,
The quiet of electric motoring is wonderful. Trolling motors (although relatively inexpensive) will maneuver most small boats but will not overcome tides and currents. The larger electric motors will product the same types of thrust that internal combustion engines (ICE) do. Gasoline and diesel provide a compact source of energy, it is important to define what you want to accomplish with an electric system. The Queen Mary uses electric drive motors but has diesel engines running generators.
The Electric Boat Forum (
http://groups.yahoo.com/group/electricboats/) is a good place to look for information about different ways electric motors are being used to propel boats in general. Go through the archives - most questions have been asked before. Occasionally a thread will go off on an esoteric drift, but most stick to the topics.
Electric propulsion is ideal for sailboats since a sailboat hull is a displacement one and most efficient for battery capacity available. The different designs focus on solving different specific goals. The solutions fall into a handful of categories:
A) Small boat (less than 25') docking/maneuvering in the harbor/tenders using trolling motors (Minn Kota, Motor Guide, etc.). Simple way to add electric power for relatively short time usage. The 12 volt motors won't move any boat past 3 knots. The 24 and 36 volt motors will go as high as 5 knots. The propeller pitch is 4 inches. Cost is from less than $200 to $2000 depending on size and construction.
B) Electric Outboards (several manufacturers) which will perform like an ICE outboard. It is in essence an outboard lower end with an electric motor and controls replacing the internal combustion engine. Cost is $2500 to $6000 and higher - similar to an ICE outboard. These are ideal to replace an ICE outboard especially if the waters are classified as "electric only".
C) Electric motor replacements for ICE inboard. The existing drivetrain is used. Only the motor is replaced. Technology can be much like the electric outboards but can also be sized much larger for larger boats.
D) Electric Pod mounted motors (RE-E-Power is this type) that mount through the hull. These is wonderful if there is no existing inboard system and you do not want to have an outboard mounted motor. Cost is similar to the electric outboards.
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None of the pricing above includes the batteries. When properly maintained, true deep discharge batteries last 5-7 years. There is a higher up-front cost for energy and you need to size your batteries to meet your needs. Recharging can be either from shore (at home or at a slip), solar/wind, or a portable generator.
I have been using an Endura 50 on my O'Day 19 (new from WalMart is <$200 from their on-line store). I consider it a "consumable" expecting 3-5 years use. I prefer using it to the ICE outboard but it has its limits. The ICE outboard does propel the boat to hull speed. But the set of four 6 volt golf-cart batteries provide me with enough battery power to go though the better part of a week without recharging.
I just acquired a Capri 22 and will continue to use the Endura 50 for this season due to the Admiral's influence of the budget priorities. We will be testing the 5 hp Nissan outboard that came with the Capri as to how it moves the boat in the tidal currents of the Piscataqua River in Portsmouth NH.
I will be attempting to answer these questions as a worst case scenario for my boating situation: a) "Will I be able to install enough batteries for the cruise out and in going against the tide both ways?"
b) "If not, would a small generator be able to make up the difference while out sailing?"
The Re-E-Power is on my short list. My wife does appreciate the quiet of electric motor-sailing when the wind does not cooperate with our sometimes fixed schedules.
Search "electric boat motors" on YouTube to view how the different electric motors propel boats at hull speeds. A Honda 1000 or 2000 should fit into the storage space that the fuel tank previously did...
John