Energy systems engineering - a guided tour

As future energy systems aim to be more efficient, cost-effective, environmentally benign, and interconnected with each other, their design and operation become ever challenging tasks for decision-makers, engineers, and scientists. Sustainability of life on earth will be heavily affected by the improvements of these complex energy systems. Therefore, experts from various fields need to come together to find common solution strategies. However, since different technologies are usually developed separately by their own technical community, a generally accepted unified systematic approach to tackle integrated systems is lacking. With this article, we want to introduce and highlight the power of energy systems engineering as a generic framework to arrive at synergistic solutions to complex energy and environmental problems. Tools of energy systems engineering are numerous, and its application areas cover a wide range of energy systems. In this commentary, we present an overview of state-of-the-art methodologies of energy systems engineering, list its applications and describe few examples in detail, and finally introduce some possible new directions.