Structural changes of global power generation capacity towards sustainability and the risk of stranded investments supported by a sustainability indicator

"Global power plant capacity has experienced a historical evolution, showing noticeable patterns over the years: continuous growth to meet increasing demand, and renewable energy sources have played a vital role in global electrification from the beginning, first in the form of hydropower but also wind energy and solar photovoltaics. With increasing awareness of global environmental and societal problems such as climate change, heavy metal induced health issues and the growth related cost reduction of renewable electricity technologies, the past two decades have witnessed an accelerated increase in the use of renewable sources. A database was compiled using major accessible datasets with the purpose of analyzing the composition and evolution of the global power sector from a novel sustainability perspective. Also a new sustainability indicator has been introduced for a better monitoring of progress in the power sector. The key objective is to provide a simple tool for monitoring the past, present and future development of national power systems towards sustainability based on a detailed global power capacity database. The main findings are the trend of the sustainability indicator projecting very high levels of sustainability before the middle of the century on a global level, decommissioned power plants indicating an average power plant technical lifetime of about 40 years for coal, 34 years for gas and 34 years for oil-fired power plants, whereas the lifetime of hydropower plants seems to be rather unlimited due to repeated refurbishments, and the overall trend of increasing sustainability in the power sector being of utmost relevance for managing the environmental and societal challenges ahead. To achieve the 2 °C climate change target, zero greenhouse gas emissions by 2050 may be required. This would lead to stranded assets of about 300 GW of coal power plants already commissioned by 2014. Gas and oil-fired power plants may be shifted to renewable-based fuels. Present power capacity investments have already to anticipate these environmental and societal sustainability boundaries or accept the risk of becoming stranded assets."