Large dams have been controversially debated for several decades due to their ­large-scale and often irreversible social and environmental impacts (WCD, 2000). In the pursuit of low-carbon energy and climate change mitigation, as well as improved energy access in energy-poor countries, hydropower is experiencing a new renaissance in many parts of the world, especially in Africa and Asia, despite its vulnerability to climate change (IPCC, 2011). Worldwide, almost four billion people lack access to modern energy services, such as electricity or cleaner forms of cooking, and the majority of them are located in the global South (IEA, 2015). The low rate of electrification in many countries in the global South today, especially in Africa and Asia, has been identified as one of the most pressing obstacles to economic growth and poverty alleviation (IEA, 2015). Full electrification requires increased investments in these regions, including small-, medium- and large-scale on-grid and off-grid electricity generation capacity and networks. China has been identified as the leading global investor in energy infrastructure, particularly renewable energy, in the global South (IISD, 2016). Chinese companies operating as the main contractor were responsible for 30 per cent of new capacity additions in Sub-Saharan Africa in 2010–15. Between 2010 and 2020 total additions will be equivalent to 10 per cent of existing energy capacity (Table 1.1). Projects by Chinese companies cover almost the entire electricity mix, dominated by hydropower. Renewable sources account for 56 per cent of total capacity added by Chinese overseas projects between 2010 and 2020, including 49 per cent from hydropower (Figure 1.1).