The energy strategic area envisions a sustainable world that can produce enough energy for its consumption, unimpeded by scarce resources and without any impact on the climate. Our research will help pave the way for this challenging transition. Many roads lead to this future. That is why we are exploring a broad spectrum of promising technologies. In the short term, we expect to generate novel technologies for more sustainable use of existing resources. This research focuses on the built environment and fuel technologies. Somewhat further away, our research will deliver novel solar cells and other new energy conversion technologies. In the longer run, our fusion research will contribute to a sustainable transition.