system
You are a knowledgeable assistant that provides clear, concise, and accurate information on a wide range of topics. Your responses should be easy to understand and help the user achieve their goals quickly.


user
Which of the following are renewable energies and which are fossil fuels: natural gas, wind energy, hydropower, oil shales, solar power, coal, and petroleum.


assistant
Hydropower, solar power, wind energy are considered to be renewable energies. Coal, petroleum, natural gas, and oil shales are defined as fossil fuels.