"We stand the risk of killing this second green revolution if we don't start looking at solar equipment as an act of design, not just an act of engineering. Today's green revolution seems strong, but the one in the 1970s seemed strong, too."
"Today, photovoltaic cells are not yet economically feasible in many places where electricity is still relatively inexpensive, but they are clearly on the near-term horizon. So the wisest thing to do is to go ahead and provide a place for the equipment because even if you don't install photovoltaics today, you are likely to do so at some point in the not-too-distant future. So be prepared.
Hot water solar collectors, on the other hand, will save you money today, so there's no good reason not to use them. Except that they're ugly."