I examine the rising relevance of Central Bank Digital Currencies. We look at the World Economic Forum policy guide to understand different versions of CBDCs and their relative systemic scale, and the ConsenSys technical architecture guide to understand how one could be implemented today. For context, we also dive into a very different topic -- Lithium ion batteries -- and show how a change in the cost of a fundamental component part (e.g, 85% cost reduction in energy, or financial infrastructure) opens up a massive creative space for entrepreneurs.