New Mark Z. Jacobson Study Draws A Roadmap To 100% Renewable Energy. Last August, Mark Jacobson, a renewable energy expert and senior fellow at the Precourt Institute for Energy at Stanford University, was the leader of a study that identified how 139 countries around the world could obtain 100% of their energy from renewable sources by 2050. But that study got some pushback from people who questioned its assumptions. The naysayers said the study relied too heavily on energy storage solutions such as adding turbines to existing hydroelectric dams or storing excess energy in water, ice, and underground rocks. Those criticisms stimulated another piece of work from Jacobson and his colleagues at the University of California at Berkeley and Aalborg University in Denmark. They are now back with a new report they believe thoroughly addresses the concerns brought up by skeptics of the first report. It begins by breaking those 139 counties into 20 regions and proposing energy storage solutions uniquely suited to each region.