Currently, I agree with the above posts. Thunder is the sound produced by a lightning strike. However, the one thing I have learned having made it this far is to never say never. Maybe a technology will be developed in the future that would employ thunder, or other types of sound waves, in the production of electricity.
Thunder is the sound of lightning. So it can't really be harnessed to produce electricity. If you mean lightning, scientists have not figured out a profitable, efficient way to harvest significant amounts of energy from lightning, because it is so sporadic and unpredictable.