ISO 15001 is an international standard for energy management systems that has been applied across a wide range of company sizes and industries since 2011. The standard provides organizations with a framework for developing a policy and objectives for their energy management system, and for implementing, monitoring, and reviewing their progress toward meeting those objectives. It also describes procedures for identifying and addressing environmental risks and opportunities. An energy management system can increase energy efficiency in businesses and organizations and reduce energy consumption and associated greenhouse gas emissions. Furthermore, with the help of an energy management system, savings potentials in the company can be identified and raised. In order to identify these factors, energy flows in the company and the associated energy sources are first recorded and analyzed. In the next step, ideas for improvement are developed, evaluated for cost-effectiveness and then implemented.