1. as the name says most probable wind speed is the wind speed (better: "wind class", a small range of wind speeds: e.g. 9 to 10 m/s) which has the highest probability to occur (e.g. 11% of the year).

2. energy (resp. power) is related to wind speeds by the power of 3: 

E = k h v³

h is the probability of a wind speed (or "wind class"), v the wind speed, k other factors (such as area, air density etc.), so check your probability distribution of wind speeds - due to the power of 3, a high wind speed, even with a relative low probability may have the highest energy contribution during a year.

3. average wind speed is just the arithmetic average, which is not helpful or even is misleading, due to the relation of the power of 3 of the wind speeds to energy (see point 2 above).