Wind power is common onboard cruising vessels, and is a great addition to an 'off grid' cruising vessel.

In its simplest form a wind turbine is nothing more than an alternator with a propellor, but there are some technical considerations.

A basic wind generator has a regulator similar to that of your alternator, and theres nothing wrong with this simplistic approach, the idea is - wind power is so often used in addition to solar power that wind power will do just fine as a bulk charger, and solar will cope easily with all the absorption demands. There are however wind power systems with complex charge controllers that follow an MPPT process and deliver a 3 stage charging process.

If you are skippering a vessel with wind power it's of the utmost importance that you familiarise yourself with its operation, and ensure that all connections are sound and clean. The video in this lesson is a good introduction to wind power, but sound electrical knowledge as covered in level 1 regarding loose connections and voltage drop is vital. Some wind power systems require a dump resister to dispose of the excess power, if this or its cables fail, then serious damage can be done in strong winds.

Separate controller

Wind generators can have the controller separate, so the wiring between the wind generator and the controller will often be 3 phase Alternating current. This is handy for testing as we can use an AC clamp meter to ensure the current in each phase is identical, but you must be very careful as the phase to phase voltage can be very high on windy days, especially if there is no load connected. It's essential to thoroughly read and understand the literature for the wind generator and controller, failure to do so can result in serious damage to the equipment, and potential injury or death. The output of the controller must be connected to the always on busbar.

Below: Wind generator with separate controller, caution the cables between the wind generator and the controller cary potentially lethal voltages!

Internal controller

Wind generators with an internal controller, shown here below, provide you with a 2 wire DC output that is connected to the always on busbar. These tend to be single stage charging where the output is set to a safe DC voltage, similar to the alternator on an engine, the voltage is often 13.6V. A thorough understanding of how your Equipment deals with strong winds is essential, read and ensure you understand the literature that came with the equipment.

Below: This type has all the electronics built in to the wind generator, so the outputs can be wired directly to the always on busbar.

Dump resister or Dump Load

Some setups require a dump resister to act as a load once the batteries are charged. It is important to know, if you have a wind generator, if there are any precautionary steps in strong winds. Some systems must be lashed so the blades can not spin for example, to prevent serious damage, or even a fire.

The octuple rule.

All wind generators use the kinetic energy of the wind. This energy is captured by the turning motion of the blades and consequently transformed into 3-phase AC power. The energy output increases in line with the wind speed, exponentially. This means that doubling the wind speed generates octuple power. This must be especially considered in storm conditions.

Each wind generator should have an output vs wind speed table, so it's good to test the performance every once in a while.