An impulse turbine made of copper alloy surrounded by adjustable neodymium magnets could be used for wind turbines as well as water impulse turbines.

In other words, the turbine and turbine housing itself becomes the alternator motor. It is a fully adjustable turbine/alternator motor in one unit.

The surrounding neodymium magnet array (forming a circular set of magnetic teeth around the turbine as one might see for example in a particle collider) encases the copper alloy turbine. Faraday does the rest.

The alloy composition has to be considered carefully. Pure copper would conduct electricity well but it is too malleable and will bend or fail at high wind or water Fjet (force) values. Copper buckets would also become pitted in hydro applications, increasing friction and reducing efficiency. Stress fractures would occur in high rpm wind applications unless the alloy balance between conductivity and tensile strength is optimal.

Copper wire windings could be wrapped around rotor blades if shaped aerodynamically and the copper is thin and flat enough. You will need to dust off that old equation concerning wire thicknesses and windings for solenoids if you want to look at this is more detail. It is not my primary focus at the moment but it may help someone else.

I considered using teflon coated turbine cups for hydro in conjunction with highly conductive copper alloy (at a guess maybe 97% copper, 0.3% lead, 1% tin, 0.005% aluminium and a zinc balance) for the alloy. This should have good tensile strength but I am not sure about conductivity.

By adjusting the distance between the magnets and the turbine cups (hydro) or rotors (wind) one can vary required torque (rotational force required) to rotate the turbine and therefore control output and RPM to suit the environmental velocity in wind situations and the Fjet value of the water in Newtons in hydro applications.

A combined turbine/alternator assembly also provides a solution to the x =0.5 ratio speed limit problem (of turbine speed in m/s to water jet speed in m/s) so in very high velocity situations, you could reduce the distance between the copper alloy turbine and the magnets in the turbine housing to decrease the angular velocity of the turbine, thus increasing torque and keeping electrical output at maximum efficiency. 

Final thought. Teflon has very very low conductivity, so it just might make an interesting dielectric sandwich with something conductive.