However this is not nearly enough, since we are restricted when it comes to using nuclear power and there is always a constant search for other energy sources.

not 是副词，表示否定，意思是"不"。 nearly 是副词，由 near（接近）加上后缀 -ly 构成，意思是"几乎、差不多"。 not nearly 是一个固定搭配，表示"远远不够、差得远"，用来强调程度上的不足。