Once again, you are absolutely right. The cost is huge and the return on the investment is nil.
Thus only those who really want to be green and are willing to take a hit will do it.
In Germany, the government subsidizes every square meter of solar panle with €100. This has reduced the intial capital investment cost enough that their 100,000 roofs program reached its goal in 3 years instead of 7. Same thing is happening in Japan. The technolgies are advancing and it is German and Japanese companies that are making the advances.