There a few things to know about wind turbines. The equation that gives the possible power output from any wind turbine (or any turbine) is as follows,
P = 0.5*density*velocity^3*rotorArea*efficiency
Now, the best designed wind turbines have an efficiency of 0.45.
When buying the wind turbines, keep in mind that RATED WINDSPEED should be the regular wind speed. For instance, most small wind turbine sellers tend to give the power output values at insanely high wind speed (i.e. something that you would expect during storm). On average, the power should be given between 4 to 5 m/s as the average wind speeds in most urban places in the world fall between this. But the seller would try to fool you by saying that it is a 1kW wind turbine etc. Any wind turbine that can be installed on an average house's rooftop canNOT produce 1 kW under normal non-storm conditions.
Similar holds true for solar panels, they should be rated at 700 W/m2 and not 1 kW/m2.
Now, when using small wind turbines, keep in mind that they can only charge battery/batteries which you can use for a few hours (likely 2-3 hours) to run electrical devices (A/C etc are likely to be out of question but again it all depends on your wind turbine and battery size).
If you would like to know more or has any other question, let me know and I can explain further.