On 2003 Jan 2, a family friend (who owns a crane) erected a 15 meter tower for my Bergey wind turbine.
The voltage at the controller varies widely from nothing up to 20 V over short periods (30 seconds) as gusty winds drive the three blades. The controller has a dc-dc converter to increase the voltage to 27 V for charging the nominal 24 V battery (four 6 V golf cart batteries, series). Some days, the delivered energy is sufficient to run our refrigerator and some lights, but today, the wind is dead and we had to return to the grid. As a senior project, some students are being invited to design a digital data recording system of energy delivered each week (i.e. the highly variable instantaneous energy [V(t).A(t)]dt, integrated over each week and accumulated over several years to disclose seasonal variations and the merits of expanding from a maximum of about 1.8 kW (30 V x 60 A) for the Bergey turbine to about 10 kW, the minimum power of interest for sale of energy to electrical cooperatives. For comparison, the large Danish turbines operate at a nominal power of 1500 kW at a capital cost of about $1.0/W. Gene.
