Chapters 4, 5, and 6 use the conceptual framework and analytical template to make socio-technical analyses of the unfolding low-carbon transitions in UK electricity, heat, and mobility systems. These empirical chapters, which form the bulk of the book, investigate longitudinal multi-decadal developments in existing systems and multiple niche-innovations, analysing techno-economic developments (using many quantitative time-series), actors, strategies and activities (which are often more qualitative), and institutions (addressing both formal policies and informal governance styles). All analyses are longitudinal, going back to the post-war decades for the (sub)systems to trace their emergence, stabilisation, and gradual reorientation. Analyses of niche-innovations vary in longitudinal scope depending on specificities of their emergence and diffusion. Each empirical chapter ends with evaluations of opportunities for niche breakthrough and system reconfiguration and draws conclusions about reconfiguration patterns along techno-economic, actor and policy dimensions. For the electricity system, the book analyses three sub-systems (electricity generation, distribution, consumption) and nine niche-innovations (onshore wind, offshore wind, bio-power, solar PV, energy-efficient lighting, smart meter, smart grids, battery storage, demand-side response).