Original sentence: In addition, some claim that perpetual motion machines or other devices capable of extracting significant and usable power from pre-existing energy reservoirs for little or no cost exist but are being suppressed by governments and special interest groups (such as the fossil fuel and nuclear industry), and  that suppression has been going on for some time.Many free energy claims, such as perpetual motion or extracting zero point energy, are impossible according to currently accepted physical laws
Edited sentence: Free energy claims, such as extracting zero point energy, are impossible according to currently accepted physical laws