Effects of Mountain Rivers Cascade Hydropower Stations on Water Ecosystems

China is rich in hydropower resources, and mountain rivers have abundant water resources and huge development potential, which have a profound impact on the pattern of water resources allocation in China. As the main way of water resources and hydropower development, the construction of cascade hydropower stations, while meeting the requirements of water resources utilization for social development, has also brought adverse effects on river ecosystems. Therefore, the impact of the construction of cascade hydropower stations on mountainous river ecosystems, where the minimum ecological flow of rivers must be ensured and reviewed. In addition, this paper proposed the deficiencies and outlooks for cascade hydropower stations based on previous research results

Technological Innovations and Advances in Hydropower Engineering

It has been more than 140 years since water was used to generate electricity. Especially since the 1970s, with the advancement of science and technology, new technologies, new processes, and new materials have been widely used in hydropower construction. Engineering equipment and technology, as well as cascade development, have become increasingly mature, making possible the construction of many high dams and large reservoirs in the world. However, with the passage of time, hydropower infrastructure such as reservoirs, dams, and power stations built in large numbers in the past are aging. This, coupled with singular use of hydropower, limits the development of hydropower in the future. This book reports the achievements in hydropower construction and the efforts of sustainable hydropower development made by various countries around the globe. These existing innovative studies and applications stimulate new ideas for the renewal of hydropower infrastructure and the further improvement of hydropower development and utilization efficiency

Hydro energy in Poland: the history, current state, potential, SWOT analysis, environmental aspects

Energetyka wodna w Polsce.The history of hydro energy in Poland was shown in the article. The first mills were built in the ninth century and the first hydro energy plant was opened in 1896. In 1935, there were 8000 water energy plants and dozen other installations using water energy. War action and nationalisation have caused the crash of hydro energy in Poland. At the moment, there are 761 water energy plants amounting to 994 MW. The Lower Vistula Cascade was described but also use of water for energy purposes in heat plants and waste treatment plants. Technical potential of hydro energy is major. Using already exciting heaps (there are 16,005), it is possible to obtain 14.27 PJ. SWOT analysis has shown that hydro energy in Poland is a well-mastered technology and allows small water retention. Investing in hydro energy in Poland requires a lot of documents. In addition, energetic law is constantly changing. Influence of hydro energy on environment was presented. It was concluded that small hydro energy development is definitely advised in Poland. Small hydro energy stations allow to produce energy and allow small retention in steppe Poland

Short-Term Management Of Hydropower: Definition, Assessment And Disposal Of Operational Flexibility

Modern hydroelectric power systems are largely characterized by variability and uncertainty in water resource obligations. The growing number of operational obligations for flood control, navigation, environmental obligations and ancillary services (including load balancing requirements for renewable resources) further the need to quantify sources uncertainty. The variations caused by these - factors require the hydropower system to have enough up and downward flexibility for control technologies such as dynamic optimal control load-following, unit commitment, automatic generation, to be effective. Therefore, it is increasingly important to adopting operational flexibility to better manage uncertainty and balancing reserves. The objective of this paper is to present and discuss approaches for assessment of the level of the available operational flexibility as a function of dynamic states and control input and how the available operational flexibility can be used by the hydropower producer in a comprehensive optimization reformulation to accommodate business procedures (e.g. operating at high forebay elevations or near zero productive outflow gradients) to drive the system in an efficient, safe and interpretable way. We consider simple metrics such as power capability and its derivatives as indicators for upward flexibility and effective energy storage capability for downward flexibility. Test results based on the Federal Columbia River Power System managed by the Bonneville Power Administration are presented and demonstrate how operational flexibility can be assessed and which role it plays in real-time operation

China’s rising hydropower demand challenges water sector

Demand for hydropower is increasing, yet the water footprints (WFs) of reservoirs and hydropower, and their contributions to water scarcity, are poorly understood. Here, we calculate reservoir WFs (freshwater that evaporates from reservoirs) and hydropower WFs (the WF of hydroelectricity) in China based on data from 875 representative reservoirs (209 with power plants). In 2010, the reservoir WF totaled 27.9 × 109 m3 (Gm3), or 22% of China’s total water consumption. Ignoring the reservoir WF seriously underestimates human water appropriation. The reservoir WF associated with industrial, domestic and agricultural WFs caused water scarcity in 6 of the 10 major Chinese river basins from 2 to 12 months annually. The hydropower WF was 6.6 Gm3 yr−1 or 3.6 m3 of water to produce a GJ (109 J) of electricity. Hydropower is a water intensive energy carrier. As a response to global climate change, the Chinese government has promoted a further increase in hydropower energy by 70% by 2020 compared to 2012. This energy policy imposes pressure on available freshwater resources and increases water scarcity. The water-energy nexus requires strategic and coordinated implementations of hydropower development among geographical regions, as well as trade-off analysis between rising energy demand and water use sustainability

Hydrolink 2017/4. Multi Reservoir Systems Operations

Topic: Multi Reservoir Systems Operation

A two stage Bayesian stochastic optimization model for cascaded hydropower systems considering varying uncertainty of flow forecasts

Copyright © 2014 American Geophysical UnionThis paper presents a new Two Stage Bayesian Stochastic Dynamic Programming (TS-BSDP) model for real time operation of cascaded hydropower systems to handle varying uncertainty of inflow forecasts from Quantitative Precipitation Forecasts. In this model, the inflow forecasts are considered as having increasing uncertainty with extending lead time, thus the forecast horizon is divided into two periods: the inflows in the first period are assumed to be accurate, and the inflows in the second period assumed to be of high uncertainty. Two operation strategies are developed to derive hydropower operation policies for the first and the entire forecast horizon using TS-BSDP. In this paper, the newly developed model is tested on China's Hun River cascade hydropower system and is compared with three popular stochastic dynamic programming models. Comparative results show that the TS-BSDP model exhibits significantly improved system performance in terms of power generation and system reliability due to its explicit and effective utilization of varying degrees of inflow forecast uncertainty. The results also show that the decision strategies should be determined considering the magnitude of uncertainty in inflow forecasts. Further, this study confirms the previous finding that the benefit in hydropower generation gained from the use of a longer horizon of inflow forecasts is diminished due to higher uncertainty and further reveals that the benefit reduction can be substantially mitigated through explicit consideration of varying magnitudes of forecast uncertainties in the decision-making process.National Natural Science Foundation of ChinaHun River cascade hydropower reservoirs development company, Ltd.UK Royal Academy of Engineerin