This paper shifts the focus from green niche-innovations to the resistance by incumbent regime actors to fundamental change in low-carbon transitions. Drawing on political economy insights, the author introduces the concepts of power and politics into the multi-level perspective (MLP) of socio-technical transitions. The paper distinguishes instrumental, discursive, material, and institutional forms of power and resistance, and illustrates these with examples from the UK electricity system. It concludes that the resistance and resilience of coal, gas, and nuclear production regimes currently negate the benefits of increasing renewable energy deployment. The paper suggests that policymakers and transition scholars have overly high hopes that 'green' innovation will be sufficient to bring about low-carbon transitions. Future research and policy should pay more attention to the destabilization and decline of existing fossil fuel regimes.This paper shifts the focus from green niche-innovations to the resistance by incumbent regime actors to fundamental change in low-carbon transitions. Drawing on political economy insights, the author introduces the concepts of power and politics into the multi-level perspective (MLP) of socio-technical transitions. The paper distinguishes instrumental, discursive, material, and institutional forms of power and resistance, and illustrates these with examples from the UK electricity system. It concludes that the resistance and resilience of coal, gas, and nuclear production regimes currently negate the benefits of increasing renewable energy deployment. The paper suggests that policymakers and transition scholars have overly high hopes that 'green' innovation will be sufficient to bring about low-carbon transitions. Future research and policy should pay more attention to the destabilization and decline of existing fossil fuel regimes.