Complex sentence: The Energy Institute, commonly referred to as EI, is the main professional organization for the energy industry within the UK that promotes the safe, environmentally responsible and efficient supply and use of energy in all its forms and applications.
Split into simpler sentences: The Energy Institute, commonly referred to as EI, is the main professional organization for the energy industry within the UK. The purpose of the Energy Institute is the promotion of the safe, environmentally responsible and efficient supply and use of energy in all its forms and applications.