From The Seattle Times:
Cardinal Giovanni Lajolo, who runs the Vatican City state, said Wednesday that the pope would certainly prefer an electric popemobile to a traditional one. But he says one has to be offered.
His comments came during a presentation of a book on the Vatican's use of solar energy. The Vatican in 2008 installed photovoltaic cells on the roof of its main auditorium and a year later installed a solar cooling unit for its main cafeteria.
The technology has won awards and garnered Benedict a reputation as the "green pope."