Suppose that during last summer a part of the country experienced peak winds only during the hours from 5:00 a.m. to 9 a.m. Why was this a significant problem for production of electrical energy via wind power?

a. Morning winds tend to be extremely variable in direction, diminishing efficiency.

b. Maximum energy production does not coincide with maximum energy usage.

c. Energy stored during the night is not fully used up, diminishing storage capacity.

d. Morning dew on the propellors slows them down, diminishing efficiency.