Wright's Law , a lesser known cousin of Moore's Law, states, that in most industries, unit-costs decrease by X percent for any doubling of the production volume. In addition, a growing amount of money and attention focused on a particular product tends to increase the opportunity for internal innovation to be successful, specially where there are high degrees of freedom and substitutability without consumers noticing a difference. Internal innovation tends to be focused on making existing products better or cheaper while external innovation focuses on what customers might actually need or want. Internal innovation is often incremental, low friction and often invisible, while external innovation is often disruptive and requires changes in customer behavior. While the cost of solar, wind or battery technologies has dropped significantly over the last decades, the current research pipeline shows plenty of potential for significant efficiency improvements. If I were a cleantech VC,