Integrating Economic and Ecological Benchmarking for a Sustainable Development of Hydropower

Abstract

Abstract:Hydropower reservoirs play an increasingly important role for the global electricity supply. Reservoirs are anthropogenically-dominated ecosystems because hydropower operations induce artificial water level fluctuations (WLF) that exceed natural fluctuations in frequency and amplitude. These WLF have detrimental ecological effects, which can be quantified as losses to ecosystem primary production due to lake bottoms that fall dry. To allow for a sustainable development of hydropower, these "ecological costs" of WLF need to be weighed against the "economic benefits" of hydropower that can balance and store intermittent renewable energy. We designed an economic hydropower operation model to derive WLF in large and small reservoirs for three different future energy market scenarios and quantified the according losses in ecosystem primary production in semi-natural outdoor experiments. Our results show that variations in market conditions affect WLF differently in small and large hydropower reservoirs and that increasing price volatility magnified WLF and reduced primary production. Our model allows an assessment of the trade-off between the objectives of preserving environmental resources and economic development, which lies at the core of emerging sustainability issues.

Effects of water level regulation in alpine hydropower reservoirs: an ecosystem perspective with a special emphasis on fish

“…Based on stable hydrogen isotope data from ten reservoirs in central Virginia, zooplankton may rely strongly on allochthonous (terrestrial) resources, but zooplankton allochthony may not be related to the reservoir age despite successional reduction of the terrestrial particulate organic matter pool (Emery et al, 2015). In essence, as discussed in the following section and exemplified by recent research (Eloranta et al, 2016a;Hirsch et al, 2016), the potential shift from littoral towards more pelagic primary and secondary production can ultimately control the abundance, growth, niche use and competitive interactions among fish populations in alpine reservoirs (Fig. 4).…”

“…Further, the operational regime of existing hydropower plants, and hence water level regulation in existing reservoirs, may be altered to meet future needs for more flexible energy generation and storage (Kumar et al, 2011;Solvang et al 2014). The use of storage and pumped-storage reservoirs to balance volatile production by other renewable energies is also likely to increase in importance (Hirsch et al, 2016).…”

“…Freezing, desiccation and direct physical stress associated with WLR often decrease the abundance and diversity of littoral sessile macrophytes and benthic algae (e.g. Mjelde et al, 2013;Evtimova & Donohue, 2014, Hirsch et al, 2016. These changes at the bottom of the food web are often reflected in higher trophic levels (i.e., benthic invertebrates and fish) via reduced food and habitat resources (e.g.…”

“…Grimås 1964Grimås , 1965Aroviita & Hämäläinen, 2008;Milbrink et al, 2011). Recent empirical studies provide further evidence that WLR can reduce littoral primary production (Hirsch et al, 2016) and induce a pelagic niche shift by generalist fish (Eloranta et al, 2016a).…”

“…Hence, for improved monitoring and mitigation of hydropower impacts, it is necessary to disentangle the ecologically and hydrologically most relevant measures of WLR that connect the hydropower operations to key abiotic and biotic impacts. Examples of WLR measuresnclude the amplitude, timing, frequency and rate of change of water level fluctuations (Bakken et al, 2016) and the relative proportion of affected littoral habitat (Hirsch et al, 2016).…”