Question

In which sentence is the underlined clause an adverb clause? The study of solar energy has turned into a science that has a goal of creating renewable energy sources. We can harness solar energy wherever the sun shines. Plate collectors, which capture the energy from the sun, are used to heat water and homes.

Answer 1

It is:
We can harness solar energy 'wherever the sun shines'.
'wherever the sun shines' is adverb clause.

Answer 2

The answer to your question would be that the sentence in which the underlined clause is an adverb clause is the following one: We can harness solar energy wherever the sun shines.

Adverb clauses, also called adverbial clauses, are dependent clauses that function as adverbs. As they are dependent clauses, they must have a subordinating conjunction to connect them to the rest of the sentence. In this case, the subordinating conjunction that introduces the adverbial clause and gives information about place is "wherever".