text: how much power can we generate from piezoelectric crystals? lets say we could attach one end of a piezoelectric substance to a musical tuning fork and the other to a fixed point, then we made the fork vibrate, it would make a voltage come out the piezo substance as a force is being applied. how much energy  could be harvested from this (in watts)? lets all assume that the fork is vibrating at 440hz (the first a above middle c in the musical scale). very little, because the current from pizo is very small, ie: in   nano amps,   and since  w= i  *  v  for example:     0.0000001 * 1000 = 0.0001 watts which is very little . so power input is more than power out put,   unless u have lots of free vibration and lots of cheap pizo to make it viable