Toyota will allegedly be the first car manufacturer to include solar panels in a mass produced car, as it is preparing to outfit its high-end Prius hybrid car with a solar panel roof. The extra power will be used in the device in which makes most sense: air conditioning.

Air conditioning is mostly used when solar radiation is at its strongest, which means that it will also be able to generate a maximum amount of electric power through the photovoltaic cells. The solar panels are designed, according to several reports in Japanese press, to output as much as 5 kilowatts and are manufactured by Kyocera, but it seems a bit much for the available roof surface. Around 1 kilowatt would be much more realistic.

The solar panels will be fit on top the third-generation Prius to be unveiled in 2009. Despite the rumors published in Nikkei and other news sources, Toyota did not confirm officially the introduction of solar panels in the next Prius, claiming that the company does not comment on future products.

Recently Google.org, the philanthropic arm of Google, unveiled the RechargeIT initiative, a 11-million-dollar programme about three weeks ago. The new initiative aims to reduce greenhouse gas emissions and oil dependence by accelerating the adoption of plug-in hybrid electric vehicles ("plug-ins").

Google kick-started the initiative by ordering the conversion of six hybrid-powered vehicles (four Toyota Prius and two Ford Escapes) into plug-in hybrids whose batteries can be charged through a regular socket.

Google plans to expand the programme to build a fleet of 100 plug- ins that can be rented by its workers and recharged via a carport covered with solar electric panels.