Paul T. Yillia (Dr. techn.) is a Research Scholar with the Water (WAT) Program at the International Institute for Applied Systems Analysis (IIASA). Previously, he was Lead Policy Specialist at Sustainable Energy for All (SEforALL), leading and undertaking several key actions to incorporate the Water-Energy Nexus within the overall SEforALL Global Action Agenda and supporting the overall operational process to guide countries align their energy policy/plans with the SDGs. Dr Yillia is a visiting scholar at Vienna University of Technology, where he previously held a full-time position as Research and Teaching Scholar, supporting applied research and exchange of knowledge and skills on water science and technology, especially with developing countries and countries in transition. Prior to that, he undertook various assignments in the Netherlands with UNESCO-IHE Delft Institute for Water Education, UNDP Cap-Net, University of Sierra Leone and Egerton University where he held various research and capacity building responsibilities within the framework of international development co-operation. He has undertaken several consultancy assignments with various governments and international organizations, including UNOPS, UNF, UN-Water, UN-Environment, UNESCO and UNIDO.