Walter grew up in Guatemala, attended United World College in Italy, and completed his university education in Canada. An expert in thermodynamics, cryogenic engineering, and hydrogen technologies, he began his career in 1996 with Ballard Power Systems, British Gas Investments Canada, and various universities. Walter has also served as a Visiting Scientist at the Canadian Institute for Fuel Cell Innovation and the Fraunhofer Institute for Solar Energy Systems in Germany.

At UBC, Walter has led MéridaLabs, the Natural Gas Futures consortium, the Smart Hydrogen Energy District, and the Transportation Futures Group, along with various partnerships at regional, national, and international levels. He has served as Director of the Clean Energy Research Centre, Senior Advisor to the President and Vice-Chancellor, co-Chair of the Climate Emergency Taskforce, and delegate to COP meetings.
 

Walter is the Associate Dean of Research and Industry Partnerships in the Faculty of Applied Science, where he has increased the research portfolio from $50M to $100M per year in five years. Since 2003, he has secured approximately $49M in funding, leading to publications, patents, living laboratory projects, and new ventures.

He co-founded General Hydrogen Corporation and Rethink Climate, serving as Chair. Walter serves on the Boards of the Canadian Hydrogen and Fuel Cell Association and the Climate Change Advisory Board for Toronto Dominion Insurance. He is a Fellow of the Canadian Academy of Engineering and is fluent in English, Spanish, and Italian.