1997, BSc in Materials Science and Engineering, Cornell University; 2002, PhD in Materials Science (Rhodes Scholar), Oxford University. Formerly: Postdoctoral Fellow, Santa Fe Institute; Fellow, Columbia University’s Earth Institute; with the United Nations; adviser to the private sector on investment in low-carbon energy technologies. Currently, Associate Professor, Energy Studies, Massachusetts Institute of Technology (MIT), USA. Research centres on evaluating the environmental impacts and costs of energy technologies and setting design targets to help accelerate the development of these technologies in the laboratory. This work involves assembling and analysing expansive datasets and developing new quantitative models and theory. Projects focus on electricity and transportation, with an emphasis on solar energy conversion and storage technologies. Has published in journals such as Nature Climate Change, Nature, Proceedings of the National Academy of Sciences, Nano Letters, and Environmental Science and Technology.