I't no surprise then that nearly 10% of all homes in China currently have a unit on their roofs along with a high year growth rate. This technology is sweeping China like wildfire, already approaching market saturation in some communities. (Para. 2) I know we are now piching up on tankless water heaters, but it's still a mystery as to why these units haven't become more popular. (Para. 3) The answers might lie in the following: As compared to China, units in America are priced in the thousands. Even with tax credits. they are still priced much higher tha a comparable system you would find in China. (Para. 4) They would be immensely popular since it would help dramatically lower our energy costs while cutting down emissions. (Para. 5)