efficiency:
Look at man's machines today compared to 50 years ago. As the years go by, we develop new ways that produce less heat, less friction and so on. look at the internal combustion engine. It has to be the most inefficient machine we use today. 42% of the energy the comes from burning the fuel is lossed through the exhaust system, 28% through the cooling system and 15% to friction. Thats a total of 85% loss!!! tesla's idea may seem way to impractical and would be way too inefficient but as time goes by, more testing and inovation could and prob will lead to a much much high efficiency. i know that a machine that would send this laser thingy does not run on gasoline (at least i think lol) and would prob not have too many moving parts to cause friction but the heat i believe would be there...