German carmaker is latest firm attempting to integrate renewables into its supply network. : BMW said Tuesday it had started to source and use aluminum that has been produced using solar energy, a move the German carmaker described as "an important milestone" in its goal to cut carbon dioxide emissions from its supply network. A "triple-digit million-euro contract" will see Emirates Global Aluminium (EGA), an industrial firm based in the United Arab Emirates, provide BMW with 43,000 metric tons of aluminum this year.