Dolf Gielen has been director of the International Renewable Energy Agency (Irena) Innovation and Technology Center in Bonn, Germany, since 2011.

He oversees the agency’s work on advising member countries on technology status and road maps, energy planning, cost and markets, and innovation policy frameworks.

Gielen, who has worked for the International Energy Agency, the Organisation for Economic Co-operation and Development, and the UN Industrial Development Organization, spoke to Recharge about a new Irena study, Letting in the Light: How Solar Photovoltaics Will Revolutionize the Electricity System.