As shares of Berhshire Hathaway Inc. (NYSE: BRK.A, BRK.B) plunged over the past year, it became fashionable to ask whether or not Warren Buffett had lost his touch.

In a move that underscores the potential of China’s auto market – as well as the viability of so-called “green” technology – investing guru Warren Buffett’s MidAmerican Energy Holding Co. will pay roughly $230 million for a 10% stake in BYD Co. Ltd., a Chinese producer of both cars and specialized batteries.