Spatial structure, inequality and trading community of renewable energy networks: A comparative study of solar and hydro energy product trades

Renewable energy trade is booming and has formed complicated networks worldwide. However, our knowledge of the spatial structures and evolution of these networks is limited. In this paper, network analyses are used to examine the geographic characteristics of selected renewable energy trades and their evolution based on the United Nations COMTRADE Database from 1988 to 2013. The results show that the networks are expanding to include more and more countries and relationships, and scale of the networks is larger than ever. A tripartite confrontational renewable energy trading system has been forming and is strengthening. Europe, the USA, China and other Asian countries are the main players, and China has overtaken the USA and Europe as the leading player. Inequality and 'small-world' characteristics appear in renewable energy trade. Solar energy trade presents a triadic community structure with Europe, the USA and China as the dominant players, while hydro energy trade presents a smaller and more dispersed structure. The core-periphery structure strongly suggests a trade dependency between hubs and peripheral elements in renewable energy trade. Developing countries should design appropriate incentives and contribute to particular segments in renewable energy value chain to accelerate and benefit from the South-South renewable energy trade.