i am experimenting with prototype wind turbines and want to record how much power one creates over a period of time
Depends on the type of power or energy. Assuming electrical energy You want to measure energy not power, as power is a rate of energy production. Easiest is to get a watt-meter, but it has to be sized for your voltage and type of output (AC or DC), and you also need a load resistor (or resistor bank if the output is high). The watt-meter, which is actually a watt-hour meter, multiplies voltage by current to get power in watts, and multiplies that by time to get energy. There are other ways, such as thermal, but that only works short term. So you need a watt meter plus a load resistor (or active load), both sized for your wind turbine. So first thing is to determine your voltage and max current output, then size the watt-meter and the load.
