This document analyses energy systems in a climate change context. Many energy policies are driven by the need to reduce greenhouse gas emissions. However current mitigation measures fail to take into account the full impact of increased climatic variability. Given energy’s importance in the economy and in the promotion of ecodevelopment, it is vital that vulnerabilities within the energy sector be understood and substantially reduced. The report explains why a metric for the vulnerability and resilience of energy systems is needed and proposes a methodology. It summarises anticipated climate-induced impacts on key energy systems and outlines possible adaptation measures. Observations and analyses from studies of ten Sub-Saharan countries currently applying the developed metric are presented. The report concludes with a series of recommendations to help reinforce the resilience of energy systems. This publication is aimed at decision-makers in government, energy utilities and NGOs.