As the energy transition proceeds and variable renewable power from wind and solar displaces conventional generators, strict operational limits for the grid's voltage, frequency, and inertia must be maintained. To do this, grid operators are increasingly procuring so-called “stability services” and making other enhancements to the grid that ensure stability. In this episode, we take a close look at how Great Britain is undertaking this stability challenge by interviewing Julian Leslie, Head of Networks and Chief Engineer at National Grid ESO, which runs the transmission grid for the country. Not only does National Grid ESO operate the fastest-decarbonizing electricity network in the world, it has also recently achieved several important technical accomplishments for the first time in the world, including implementing cutting edge tools that allow accurate measurements of inertia across its system; using grid-forming inverters to provide synthetic inertia; and using synchronous condensers without an associated prime mover. And in another world-first achievement, the company has actually written the specification for using grid-forming inverters into its grid code. Julian explains all of these technical concepts in today’s conversation and lays out the deliberate strategy that the company is taking to ensure that it can deliver on Great Britain’s decarbonization objectives while maintaining system stability and saving British consumers a great deal of money. This is a highly technical episode with a Geek Rating of 9, so if you want to brush up on grid power engineering concepts first before listening to this one, you could start with our Energy Basics miniseries—in particular, Episode #126 about how power generators and the grid works—then move on to Episode #55 on voltage stability, and then Episode #153 on grid-forming inverters. Then return to this one.