Regarding real long-term trends, I would agree that a logistic curve fits both emergence/maturing and phaseout best, but Marchetti curves seem too simplicistic. In Luís's diary, the oil shocks are named as explanation for deviation; on one hand, methinks a lot more reasons can throw development off the Marchetti track (rule changes being one, see wind power in Denmark), on the other hand, I rather doubt that all significant energy modes will peak at the same market penetration level (50%).

_{*Lunatic*, n.
One whose delusions are out of fashion.}