While the Obama administration slowly plots the addition of solar panels to the White House roof, it appears that the Vatican is abandoning their plans for something similar on the iconic Popemobile.

Last December, Pope Benedict XVI expressed interest in replacing his current gas-guzzling transport with something much greener; preferably one that cruised via sun power.

"If one proposed an electric Popemobile that was efficient, safe and a reasonable size, what interest would he have in preferring a petrol Popemobile?" said Cardinal Giovanni Lajolo, who runs the Vatican City state; considered the greenest in the world.

Germany-based SolarWorld, which installed 2,700 photovoltaic cells on the roof of the Vatican's main auditorium and a solar cooling unit for its main cafeteria, immediately offered their services. "It's really no problem," the firm's marketing chief Milan Nitzschke told the AP, saying that electric cars can go from 0-100 kph in three seconds.

It appears, however, that fears remain within the Vatican over the dependability of a fully electric vehicle to escape threats has prompted a compromise. According to the site Whispers in the Loggia, officials have signed with Mercedes-Benz to develop "a hybrid variation on its M Class SUV that'll be able to run some 16 miles (30km) emission-free thanks to a rechargable lithium-ion battery."

OK, so it's not fully electric, but points anyways to the Vatican for pressing for something more efficient than the current two petrol SUVs. While a Mercedes rep denied any plans to create the vehicle, a spokesman for the Vatican says that he expects the new vehicle to be delivered by the end of this year or early next.

Michael d'Estries ( @michaeldestries ) covers science, technology, art, and the beautiful, unusual corners of our incredible world.

Vatican shelves solar-powered Popemobile plans
Officials opt for hybrid Mercedes that can travel 16 miles on electric power alone.