1
The Physics of Wind Generation
The power output from any wind turbine is largely dependent on two
factors, the prevailing wind speed and the swept area of the rotor.
This intercept area is governed by the length of the air blades - the
longer they are, the greater the potential power of the wind generator.
Unfortunately, it is not practical to fit large wind turbines on yachts, and
machines with rotor diameters of around 1 metre are the norm.
The amount of energy available in a wind stream varies as the cube of
its velocity - for example, there is over 70% more energy available at
12 mph than at 10 mph. Very low wind speeds contain very little energy,
so although a wind turbine may spin, it will produce little or no power.
With increasing wind speed output from the turbine rises exponentially.
Wind is a variable but occasionally very powerful resource, and sensible
sailors tend to avoid its worst excesses. Where possible, sailors will sail
downwind and anchor in sheltered spots, all of which reduces the energy
available to a yacht-mounted wind generator.
Given these constraints, a wind generator is unlikely to keep pace with
all electricity usage on a daily basis. It can, however, make a very useful
contribution to the energy budget.
The DuoGen is different.
By deploying the water mode when you go cruising:
The DuoGen taps into the wind power that the yacht’s whole sail area
intercepts
This is many times greater than that of a yacht-sized turbine
At typical cruising speeds, the DuoGen in water mode produces
enough power to run most if not all of the yacht’s electrics
The DuoGen’s water mode is much more efficient than a wind
generator at sea
and
much
easier to live with.
Please note:
some of the
illustrations in this manual
are of the original DuoGen
model, but the instructions
apply to both DuoGen
versions 2 & 3.
