Renewable Energy Sources

Energy for navigation, refrigeration, lights or other electrical items require a power source, but a boat’s engine, which is the usual choice, will use almost as much fuel to charge batteries as it does when motoring. Idling your engine still produces emissions and pollutants that negatively affect our environment and our health. Running your engine purely for charging batteries can also harm your engine, as it is not designed to run below its rated level.

A renewable source of generation is therefore a suitable alternative and a good safety backup. There are several types of systems you can use including wind generators, solar panels, water generators, or a combination. Some systems can keep your battery fully charged while your boat sits on the trailer, on a mooring or at the dock, or can be used during long journeys while you are underway.

Before choosing which renewable energy system is best for your needs, you first need to establish:

  • What are you trying to accomplish (power navigation, run refrigeration, etc.)?
  • How much electricity do you require?
  • Do you need to modify your boat’s electrical system to meet those requirements?
  • Do you have the appropriate weather conditions (wind, sun, etc.) to “fuel” the generator?

solar power, wind power, renewable energy

It’s always a good idea to consult with a well-trained professional for the best advice and options when dealing with any kind of electricity on your boat. 

Wind: A wind generator has the potential to produce power 24 hours a day whether sailing or at anchor. If there is a strong wind, or you are underway, they can usually put out more current than solar panels. Wind generators, however, can be noisy, require regular maintenance and have the potential danger of rotating blades.

Sun: Solar panels can be used on small and large boats effectively, but will only produce power when the sun shines. The effective charging time is on average 5 to 7 hours per day, depending on where you operate your boat. Solar panels require minimal maintenance, don’t make noise, last up to 25 years or more, and are safe. They do, however, need space and special racks for mounting.

Water: Water-powered generators (hydrogenerators) can also be a cost-effective source of charging your batteries. The motion between the moving hull and the water around you can produce ample amounts of electrical power. There are two main types: towed spinner generators and shaft generators. With both, however, a minimum speed of 4 knots is recommended, as below this speed, the energy generated is negligible. 

solar sails, renewable energy

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