The problem is that solar energy costs too much.

Literal

Problem [topic-は], solar-energy [topic-には] cost [subj-が] incurs-too-much [quotative-という] thing [copula-だ].

太陽エネルギー mixes kanji 太陽 ('sun') with katakana loanword エネルギー (from German 'Energie'). コストがかかる ('cost is incurred') uses the loanword コスト. ~すぎる on かかる marks excess. には stacks dative に with topic は.