Dr Prest is a Senior Lecturer in law specialising in environmental law with interests in administrative law and litigation and is a Member of the IUCN Commission on Environmental Law.

He is a Member of the Executive of the Australian National University's Energy Change Institute a cross-campus inter-disciplinary network devoted to energy issues. His primary expertise is in national level sustainable energy law and policy for deep decarbonisation. Apart from his research interest in international climate law, his main research focus is in comparative review of national and sub national law and regulation for energy and transport sectors.

His research has a strong focus on comparative environmental law, with an emphasis on renewable energy and climate change law, examining the legal and policy barriers to increased investment in renewable electricity generation. His work applies a comparative law approach to critically analyse key policy choices and legislative models in the field of domestic energy and climate law, drawing upon Australian, EU, Indonesian, and Japanese experience in the last decade.

His current research is united by the following common themes: (1) barriers and drivers of renewable energy investment and comparative international analysis of renewable energy law; (2) questions of regulation of competition between firms in the electricity market and the influence of regulatory frameworks on the impact of disruptive technological innovations; and (3) a series of international and/or local industry based case study approaches. The latter include: (i) renewable energy incentive laws; (ii) the influence of land use planning law on wind energy projects; (iii) regulation of mercury emissions from conventional generation; and (iv) legal frameworks to encourage emerging renewable energy technologies including storage and micro-grids, solar thermal power with storage. Other projects include (v) law and policy for electric vehicle charging infrastructure (vi) law reform to promote hydrogen energy transition (vii) Japan-Australia energy dialogue (iv) barriers to renewable energy investment in Indonesia.