This paper reviews the evidence for linkages between providing improved access to reliable and affordable power and economic growth outcomes. It sets out the potential transmission mechanisms (theory of change) for these growth effects, and assesses the strength of evidence and potential constraints to this narrative. The ability for improved access to reliable and affordable power to contribute to other social and environmental development outcomes is also reviewed, alongside the implications for economic growth when activities are specially targeted to achieve such objectives. Finally, conclusions and recommendations are presented in relation to DFID programming and impact evaluation, together with potential areas for further research.