毋庸置疑，洁净能源领域也取得了一些进展 — — 比如风能满足了丹麦20%的能源需求，在西班牙和葡萄牙总能耗中的占比也达到了15 % — —尽管如此，取得成功的秘诀仍然难以捉摸。
Of course, there is some progress – wind power meets 20% of the electricity demand in Denmark and about 15% in Spain and Portugal, for example – but the recipe for success remains elusive.