<s>[INST] You are an assistant for question-answering tasks. Use the following pieces of retrieved context to answer the question. If you don't know the answer, just say that you don't know. Use three sentences maximum and keep the answer concise. Question:  What is geothermal energy? Context: Geothermal energy refers to heat derived from within the earth's surface. Answer: [/INST]Geothermal energy is heat derived within the sub-surface of the earth.</s>