Toyota Motor Corporation, the world’s largest automaker, is planning on installing solar panels on Prius, the world’s first mass-produced gasoline, electric hybrid vehicle, the Nikkei business daily reported. The Japanese company should start the Prius makeover next spring.

The new Prius will include solar panels designed by Kyocera Corp., a company based in Kyoto-Japan, which among other things, is working on increasing its solar cell production in the next few years. The solar panels will be used to supply the 2 to 5 kilowatts needed to power the air-conditioning system.

Prius was first introduced in December 2007 in Japan, and by April 2008, the hybrid vehicle managed to pass the 1 million mark of units sold worldwide. In North America alone, Prius sold in over 591,000 units since it began selling in 2000. The car has now found owners in over 40 countries around the world.

With limited availability, the Prius mid-size sedan sold 11,765 units in June this year, according to a report released on July 1.

According to the company’s own estimations, its Prius hybrids have contributed to a reduction in greenhouse gas emissions of approximately 4.5 million tons in CO2 compared to non-hybrid gasoline-powered vehicle in the same class, with similar size and driving performance.

In 2003, Toyota introduced a second-generation Prius equipped with the Toyota hybrid System II and offering improved environmental performance and power. The hybrid is also one of the first cars to meet the Japanese fuel efficiency standards by 2015, under the Law Concerning the Rational Use of Energy.

In August 2007, Prius G, S and S “Standard Package” have managed 29.6 km/l fuel efficiency with the JC08 test cycle, compared to previous Prius S and S “Standard Package” models, which achieved 35.5 km/l in older 10-15 test cycle.

According to the Japanese automaker, Prius represents their effort to popularize hybrid technology as part of their high-priority environment-management policies. Toyota also plans on selling over 1 million hybrid vehicles annually as early as 2010s.