Energy-as-a-Service (EaaS) providers and an energy service company (ESCOs) both exist to help make buildings more energy efficient through retrofits and renewable generation. They will work with a customer – a large company, university, hospital, public building, etc. – to identify sources of energy waste to help reduce emissions and cut down on costs. However, there are many differences in how these providers contract, implement and track energy and cost savings for these programs.