The Role of Large and Small Scale Hydropower for Energy and Water Security in the Spanish Duero Basin

Abstract

Hydropower has been increasingly seen as a two-fold solution to the provision of renewable energy and water storage. However, the massive deployment of both large and small scale hydropower projects has been reported to cause important environmental impacts at the basin scale. This study assesses the differential contributions to regional energy and water security of large (LHP) and small (SHP) scale hydropower deployment in the Spanish Duero basin, as well as associated cumulative environmental impacts. This is performed through a selection of indicators measured in absolute and relative terms. The results suggest that LHP deployment contributes more to energy and water security, performing better in 10 of the 12 indicators. It also shows higher absolute environmental impacts on flow regime and habitat loss. Meanwhile, when analyzed in relative terms, SHP shows greater impacts in all categories as a result of cumulative effects cascading along the rivers system. These findings suggest that optimizing the use of existing hydropower infrastructure would be beneficial for energy, water and environmental security. This could be implemented by substantially reducing the number of low capacity plants with almost no impact on final energy generation, while enhancing the pumping and storage potential of higher capacity plants.After a golden age during the 1940s, 1950s and 1960s, when hydropower was considered the revelation of clean energies, a series of large scale hydropower projects (LHP) were deployed worldwide. However, ever since, the range of associated environmental and social impacts have become increasingly evident, marking the start of a wide debate over its value [6]. More recently, a countertrend towards small scale hydropower (SHP) projects has emerged, each providing similar benefits to the larger infrastructures, but with reduced impacts due to their smaller size, land and infrastructure requirements. This new panacea has prompted both emerging economies with high untapped hydropower potential and countries with limited capacity for large hydropower technology to deploy a mosaic of SHP projects along river and sub basins. Several examples can be found in China, which has developed a strong hydropower basis in recent decades [7,8], particularly in the Yunnan [9,10] and Tibet regions [11]. Other examples in Asia are found in Turkey [12,13], India [14], Thailand [15] and the transboundary Mekong River region [16]. This trend has also played out in Latin America, where SHP deployments are spreading in countries such as Brazil [17,18] and Colombia [19]. Europe has not lagged behind, with around 21,800 operating small hydropower plants [20] primarily concentrated in 10 the UK (120) [21]. However, several studies have raised concerns over the cumulative environmental impacts posed by a large deployment of small hydropower projects [22,23], which can match or outweigh those of large hydropower projects providing an equivalent energy output [6,8,9,12,[24][25][26]. As such, debate centers around whether or not hy...

Environmental Impact of Small Hydro Power Plant—A Case Study

“…This is also a contribution of the presented paper. The environmental implications of small and large hydropower projects were also studied by Henning et al [4,5] and Ferreira et al [6]. Mayor et al [7] assessed the differential contributions to the regional energy and water security of large-and small-scale hydropower deployment in the Spanish Duero basin.…”

Methods in Forecasting Water Used and Electricity Production at Hydropower Plants

“…Water and energy, both become a global main concern. Therefore, hydropower technology has been seen as a twofold solution to the provision of renewable energy and water storage [8]. It provides renewable, low carbon and internal energy beside increases water storage capacity.…”

Securing Environmental Flows Through System Reoperation and Management: Lessons From Case Studies of Implementation

“…This situation-in which a relatively small proportion of hydropower capacity causes a high proportion of the fragmentation of a basin's channel network-is likely common in many basins around the world, particularly those with a legacy of smaller and older dams. In the Duero basin (Spain), small hydropower dams are responsible for most of the disconnection while contributing very little to the total generation from the basin (Mayor et al, 2017). The data from these basins suggest that considerably large restoration gains could be achieved through strategic dam removal with relatively small losses in generation and/or water storage and thus that policy mechanisms that promote dam removal through system-scale relicensing, mitigation, or environmental trading could produce large benefits in terms of restoring free-flowing conditions in rivers.…”