Toyota Motor Corp. is secretly developing a vehicle that will be powered solely by solar energy in an effort to turn around its struggling business with a futuristic ecological car, a top business daily reported Thursday.

The Nikkei newspaper, however, said it will be years before the planned vehicle will be available on the market. Toyota's offices were closed Thursday and officials were not immediately available for comment.

According to The Nikkei, Toyota is working on an electric vehicle that will get some of its power from solar cells equipped on the vehicle, and that can be recharged with electricity generated from solar panels on the roofs of homes. The automaker later hopes to develop a model totally powered by solar cells on the vehicle, the newspaper said without citing sources.

The solar car is part of efforts by Japan's top automaker to grow during hard times, The Nikkei said.

In December, Toyota stunned the nation by announcing it will slip into its first operating loss in 70 years, as it gets battered by a global slump, especially in the key U.S. market. The surging yen has also hurt the earnings of Japanese automakers.

Still, Toyota is a leader in green technology and executives have stressed they won't cut back on environmental research despite its troubles.

Toyota, the manufacturer of the Lexus luxury car and Camry sedan, has already begun using solar panels at its Tsutsumi plant in central Japan to produce some of its own electricity.

The solar panels on the roofs add up in size to the equivalent of 60 tennis courts and produce enough electricity to power 500 homes, according to Toyota. That reduces 740 tons a year of carbon dioxide emissions and is equal to using 1,500 barrels of crude oil.

Toyota is also likely to indirectly gain expertise in solar energy when its partner in developing and producing hybrid batteries, Panasonic Corp., takes over Japanese rival Sanyo Electric Co., a leader in solar energy, early next year.