Fabby Tumiwa is an energy transition strategist and the Executive Director of Institute for Essential Services Reform (IESR). For more than 20 years, Fabby Tumiwa has worked on a wide range of energy policies and regulations. He is an advocate for renewable energy and energy efficiency. He advises Indonesian government agencies, businesses, non-governmental organisations (NGOs), and multilateral development organisations on electricity, renewable energy and energy efficiency, energy finance, and climate change policies. From 2006 to 2018, he served as Indonesia’s delegate to climate change negotiations. He was a member of the various Working Groups under the National Council on Climate Change from 2009 to 2014.

He served as a member of the Indonesia Climate Change Trust Fund (ICCTF) Steering Committee from 2015 to 2019. Fabby Tumiwa is chairman of the Indonesia Solar Energy Association since 2021. He is a Country Adviser of Southeast Asia Energy Transition Partnership (SEA-ETP) and was a member of the Technical Advisory Group (TAG) of Energy Sector Management Assistance Program (ESMAP) of the World Bank in 2022, and currently, he serves as a member of Energy Transition Accelerator High-Level Consultative Group, an initiative by US State Dept, Rockefeller Foundation, and Bezos Foundation.