An engineer by training, Palmer started her career working on natural-gas pipelines for Pacific Gas & Electric (PG&E), the dominant energy provider in her native northern California, before shifting to their energy-trading division. A few years later, she went to business school and came out with a job with Goldman Sachs, where she “first dabbled in renewables”.

Around 2006-07, the prospect of US cap-and-trade legislation looked bright.