Under the assumption that the horizontal velocities observed in the sunspot photosphere are caused by Alfven waves, the flux of these waves in the photosphere is found to be equal to 20--50 percent of the missing sunspot flux or 2--3 times the spot's flux of electromagnetic radiation. Since the downward- moving Alfven wave flux is likely to be similar to the upward-moving flux, this observation is consistent with the hypothesis that spots are cooled by their strong emission of Alfven waves.