Industrialization could not have happened without abundant, easy-to-store-and-transport fossil fuels (coal, oil and gas). They and the technologies that mined, traded, processed and used them satisfied needs which they also created (including wars). They provided the heat, power and feedstock to run factories, operate transport systems and shape household living conditions (space heating--cooling, appliances). Energy use has exponentially risen in the last two centuries, to an average 2 kW/cap for poor and over 20 kW/cap for rich people, and supply is still dominated by fossil fuels. Modernization has become closely linked to provision of ’modern’ energy carriers (energy ladder). Apart from corporate and state super-profits and power and associated turmoil, it has brought enormous environmental destruction and harm, some of it affecting many generations to come. The most serious impact, climate change from greenhouse gas emissions, is stimulating a transition away from fossil fuels and towards efficient use and non-carbon supply (renewable, nuclear). This process is confronted with the divergence in worldviews, around issues such as risks, use of land and materials, lifestyle changes versus high-tech, role of decentral versus central supply, and private or public ownership.

This chapter methodically discusses the rules of the WTO framework and disciplines relevant to energy, including several outstanding issues treated in case law. It follows the current structure of WTO agreements on goods, services, intellectual property and plurilateral agreements. On this basis, it reveals the where the WTO agreements do not optimally correspond to the realities of the energy sector (eg the goods/services divide). The chapter also highlights outstanding issues in case law and provides a summary table of energy-related disputes to date.

Supplying cities with sustainable energy is a major challenge as this requires deep transformation of the supply infrastructure in order to reduce energy waste and rely on local renewable energy sources.  Building such a sustainable energy system requires a sound understanding of its entire supply chain and conversion steps from resources to final use so as to identify savings potential and prioritise actions. This chapter presents a systematic approach to assess the sustainability of energy systems that enables decision makers to build evidence-based strategies and take informed measures towards carbon neutral cities.