
231Energy Demand, Efficiency, and Conservation
since the 1960s, is promising the achievement of lighting efciencies above
150lm/W in commercial installations soon.*
It is important to notice that the pace of efciency improvement within a
technology family gradually trails off. It is also important to note that the suc-
cessful adoption of a new family of technology (orescent, after incandescent,
after re) occurs when the victor offers clear advantages over the vanquished.
Furthermore, the widespread presence of a winning technology does not
rule out the continued use of an older technology if they offer qualitatively
different services. F