Grid-wide subdaily hydrologic alteration under massive wind power penetration in Chile

• Published in: Journal of environmental management 2015-05, Vol.154, p.183-189
• Main Authors: Haas, J., Olivares, M.A., Palma-Behnke, R.
• Format: Article
• Language: English
• Subjects: Chile; Environment; Humans; Hydroelectric plants; Hydrology; Hydropeaking; Hydrothermal coordination; Power Plants; Renewable Energy; Reservoir operation; Rivers; Subdaily hydrologic alteration; Variable renewable energy; Wind; Wind power
• ISSN: 0301-4797; 1095-8630
• DOI: 10.1016/j.jenvman.2015.02.017

Hydropeaking operations can severely degrade ecosystems. As variable renewable sources (e.g. wind power) are integrated into a power grid, fluctuations in the generation-demand balance are expected to increase. In this context, compensating technologies, notably hydropower reservoir plants, could operate in a stronger peaking scheme. This issue calls for an integrated modeling of the entire power system, including not only hydropower reservoirs, but also all other plants. A novel methodology to study the link between the short-term variability of renewable energies and the subdaily hydrologic alteration, due to hydropower reservoir operations is presented. Grid operations under selected wind power portfolios are simulated using a short-term hydro-thermal coordination tool. The resulting turbined flows by relevant reservoir plants are then compared in terms of the Richard-Baker flashiness index to both the baseline and the natural flow regime. Those are then analyzed in order to: i) detect if there is a significant change in the degree of subdaily hydrologic alteration (SDHA) due to a larger wind penetration, and ii) identify which rivers are most affected. The proposed scheme is applied to Chile's Central Interconnect System (SIC) for scenarios up to 15% of wind energy penetration. Results show a major degree of SDHA under the baseline as compared to the natural regime. As wind power increases, so does the SDHA in two important rivers. This suggests a need for further ecological studies in those rivers, along with an analysis of operational constraints to limit the SDHA. •Current hydropower operations induce significant hydrologic alteration.•Wind energy portfolios were represented in a grid-wide power operations model.•Massive wind penetration marginally increases hydrologic alteration in some rivers.