How Much Solar Is Needed For A Boat?

ByMathew F Updated On:

There is no cut-and-dry answer to this question because so many factors and variables must be considered. Along with a plethora of numbers, letters, and equations

This may make this seem beyond a non-mathematical enthusiast’s grasp. Still, it can be pretty simple to calculate how much (and how much of what) you’ll need. So there is no better time to go green!

I’ll cover the numerous aspects that need to be considered to yield an accurate answer so you can charge your boat batteries with solar.

Systems On A Boat Requiring Power

Your boat will require some power, no matter what shape or size. Larger vessels cannot rely on just the wind for sailing and have engines to aid this. These days many ships (especially the bigger ones) have other appliances on board that require power.

When calculating how much solar power is needed for your boat to function, you should compile a list of all the appliances (and their power usage) you have on your boat. Then, when you have added the totals, you will know precisely how much solar power you require.

Unlike standard engines on most boats, vessels that use an electric outboard motor do not require the input of gasoline and can supplement their power from solar fittings.

The output of a solar-powered engine will be lower than that of a vessel powered by gasoline meaning your boat will be slower.

Specialized electric motors need to be fitted to boats for this purpose.

The battery is what is going to be powering all your electronics as well as your outboard. A dedicated battery will provide the motor with the power, and a house battery will be responsible for all other electronics. The size of your battery will depend on the following:

  • The size of your engine
  • The voltage of your motor
  • Maximum amp draw of your motor
  • The number of electronics on board that require power

The battery already fitted to your boat can be used if it is a marine deep-cycle battery. But a specialty battery is recommended for all your solar fixtures.

Marine lithium batteries are the best options for your solar power for the following reasons:

  • Superior energy storing for solar systems
  • Faster charger
  • Lower Depth of Discharge (DoD)
  • No maintenance is required
  • Longer lifespan

Lithium marine batteries may have a high initial cost, but they will be cost-effective over time. Here are some brand comparisons to consider.