Direct or indirect electrification? A review of heat generation and road transport decarbonisation scenarios for Germany 2050

Energy scenarios provide guidance to energy policy, not least by presenting decarbonisation pathways for climate change mitigation. We review such scenarios for the example of Germany 2050, with a focus on the decarbonisation of heat generation and road transport. In this context, we characterize the role of renewable electricity and contrast two rivalling narratives: direct and indirect electrification. On the one hand, electricity directly provides heat and transport, using electric heat pumps, electric heaters, and battery electric vehicles. On the other hand, electricity, heat, and transport are indirectly linked, using gas heat pumps, gas heaters, fuel cell electric vehicles, and internal combustion engine vehicles, in combination with power-to-gas and power-to-liquid processes. To reach climate policy targets, our findings imply that energy stakeholders must (1) plan for the significant additional demand for renewable electricity for heat and road transport, (2) pave the way for system-friendly direct heat electrification, (3) be aware of technological uncertainties in the transport sector, (4) clarify the vision for decarbonisation, particularly for road transport, and (5) use holistic and more comparable scenario frameworks. (C) 2018 Elsevier Ltd. All rights reserved.