The remarks come after environmental group Greenpeace issued a statement earlier this week demanding the world's top smartphone maker find a way to reuse rare materials in the discontinued smartphones that Samsung is taking back.
The success of large-scale solar has raised questions about the wisdom of continuing incentives for rooftop installations, which remain far more expensive than most other forms of electricity.
The settlement stems from VW's admission in September that it intentionally misled regulators by installing secret software that allowed U.S. vehicles to emit up to 40 times legally allowable pollution.
As part of the settlements, Volkswagen will to help boost zero emissions vehicles and introduce a program to offset excess diesel pollution from the offending vehicles.
The Japanese company said using ethanol, produced from crops including sugar cane and corn, to generate hydrogen-based electricity inside vehicles would be cheaper than fuel cell technology.