Essentially, the German says (and I shorten): "one example is the use of inefficient cookers or the installation of biogas units running on household waste." Is it just me, or does that sound illogical? Don't we need to say, "Two examples are inefficient cookers and simple biogas units"?
I don't follow the logic of "one example is X or Y." For me, that would best be expressed as "X and Y are two examples."