The Rance tidal power station: a preliminary study of its impact on tidal patterns and sediments dynamics in the Rance estuary (France) from 1957 to 2018

2020 ◽  
Author(s):  
Rajae Rtimi ◽  
Aldo Sottolichio ◽  
Pablo Tassi
Keyword(s):  
Power Plant ◽  
Tidal Currents ◽  
Tidal Wave ◽  
Turbidity Maximum ◽  
Estuarine Turbidity Maximum ◽  
Tidal Range ◽  
Lower Estuary ◽  
Power Station ◽  
Tidal Power ◽  
The Impact

<p>The Rance tidal power station (located on the Brittany coast of Northern France), was opened in 1966 as the world’s first and largest tidal power station, with peak output capacity of 240 Megawatts. It is currently the second world’s largest tidal power installation after the Sihwa Lake Tidal power station (South Korea). The power plant is located at the mouth of a small steep-sided ria, with a maximum perigean spring tidal range of 13.5 m and an average fluvial discharge of 7 m<sup>3</sup>/s. The dam is 750 m long and the tidal basin measures 22.5 km<sup>2</sup>. Despite a well-known effect of the plant on the damping of estuarine water levels, little attention has been given to the consequences of the dam in the estuarine environment in terms of hydrodynamics, for instance, the propagation of the tidal wave and tidal currents along the estuary are still little understood. Moreover, net siltation has been reported by several observations, but there is no specific knowledge on the role of the plant on sedimentation. In this study, we analyze the impact of the tidal power station on tidal wave patterns and sediment dynamics in this particular man-engineered system. To this goal, a numerical model based on a two-dimensional depth-averaged approach is implemented to predict the tide propagation and tidal currents along the estuary accounting for the presence of the tidal power station. Three modelling scenarios were performed: the first considering the bathymetry of 1957 (before the plant’s construction), a second scenario considering the bathymetry of 2018 without the presence of the power station and a third scenario considering the bathymetry of 2018 with the power station. Preliminary results showed that, with and without the tidal power station, the upper estuary exhibits a flood dominant behavior, with longer duration of falling water than rising water, and conversely the lower estuary is ebb dominant with shorter duration of falling water than rising water. This analysis also revealed that the tidal power station might switch the flood dominance in the central estuary to ebb dominance. These findings imply a net seaward transport of both coarse and fine sediments in the lower estuary. Therefore, the tidal power station might have a considerable role in modulating the estuarine turbidity maximum and channels’ morphology. Finally, these results are compared with preliminary numerical simulations of suspended sediment transport to further quantify the impact of the tidal power plant on the dynamics of the estuarine turbidity maximum.</p>

scholarly journals The Impact of Hydropeaking on Juvenile Brown Trout (Salmo trutta) in a Norwegian Regulated River

2020 ◽  
Vol 12 (20) ◽  
pp. 8670
Author(s):  
Svein Jakob Saltveit ◽  
Åge Brabrand ◽  
Ana Juárez ◽  
Morten Stickler ◽  
Bjørn Otto Dønnum
Keyword(s):  
Power Plant ◽  
Brown Trout ◽  
Salmo Trutta ◽  
Water Levels ◽  
Regulated River ◽  
Low Flow ◽  
High Survival ◽  
Power Station ◽  
Brown Trout Salmo Trutta ◽  
The Impact

The Norwegian electrical energy supply system is based on hydropower. The now deregulated energy market has led to increased use of hydropeaking production, leading to greater fluctuations in discharge and water levels below hydropower stations. The power station HOL 1, with an outlet to the Storåne River, is a large hydropeaking facility. With over 300 rapid flow increases and decreases per year since 2012, it is a river subjected to frequent hydropeaking. To quantify the stranding risk downstream of the power plant, the effect of a series of different turbine shutdown scenarios was simulated in an earlier study. The residual flow of 6 m3·s−1 and a full production of 66 m3·s−1 were considered as the baselines for the calculation of dewatered areas. A three-year study of juvenile fish density both upstream as a reference and downstream of the power plant was undertaken. There were very low densities or even an absence of brown trout (Salmo trutta) older than young-of-the-year (YoY) below the outlet of the power station, despite high densities of YoY in previous years. This is probably due to the large and rapid changes in flow below the power station. Hydropeaking has less impact on the earliest life stages of brown trout during spring and summer, as well as on spawning and egg development during winter. This is attributed spawning in late autumn occurring at a low flow seldom reached during hydropeaking. The high survival of YoY during the first summer and early autumn is likely due to a lower frequency of hydropeaking and higher residual flows, leaving a larger wetted area.

scholarly journals Trends in tidal power development

2020 ◽  
Vol 173 ◽  
pp. 01003
Author(s):  
Alberto Boretti
Keyword(s):  
Tidal Energy ◽  
Electricity Production ◽  
Tidal Range ◽  
Power Station ◽  
Tidal Power ◽  
Power Plant Operation ◽  
Tidal Streams ◽  
Tidal Power Generation ◽  
The 1960S ◽  
Oceanic Currents

Tidal energy has been around for almost 2, 000 years, as the first Tide Mills date the Romans times. Tidal power generation then emerged in the 1960s, with the construction of the 240 MW La Rance power station, a still working example of good renewable energy initiative, permitting electricity production at very competitive costs since now more than 54 years. Unfortunately, apart from the construction in 2011 of a similar plant based on the tidal range technology, the 254 MW Sihwa Lake power station, almost nothing else happened in the real world for tidal energy, apart from very small or demonstration plants. While the future is certainly towards tidal streams/currents technologies rather than tidal range technologies, as tidal currents turbines may also be used for oceanic currents installations, these technologies are still in their infancy, as apart from their theoretical performance, every other aspect of a submerged power plant operation needs further developments.

Simulation for Operation of Tidal Power Plant

2011 ◽  
Vol 109 ◽  
pp. 476-479
Author(s):  
Xiang Bo Ouyang ◽  
Wei Lu
Keyword(s):  
Power Plant ◽  
Simulation Modeling ◽  
Optimal Operation ◽  
Ideal Model ◽  
Power Station ◽  
Tidal Power ◽  
Tidal Power Plant ◽  
Unit Model ◽  
Real Plant ◽  
The Ideal

Simulation is the basis of planning design and optimal operation of tidal power plan. In this paper, a method of simulation modeling is proposed. At first a real plant is abstracted as an ideal model. Then, the ideal model is divided into different unit model by the method of modularization and hierarchy. After every unit model has been verified, we get an accurate model of a tidal power plant. The simulation of jiangxia tidal test power station was presented to prove the efficiency of the proposed method.

scholarly journals HYDRODYNAMIC IMPACTS OF TIDAL POWER LAGOONS IN THE BAY OF FUNDY

2012 ◽  
Vol 1 (33) ◽  
pp. 69 ◽  
Author(s):  
Julien Cousineau ◽  
Ioan Nistor ◽  
Andrew Cornett
Keyword(s):  
Operating Mode ◽  
Tidal Energy ◽  
Tidal Currents ◽  
Water Levels ◽  
Tidal Range ◽  
Bay Of Fundy ◽  
Tidal Power ◽  
Circulation Patterns ◽  
Tidal Hydrodynamics ◽  
Low Head

It has long been identified that the Bay of Fundy, Canada, is one of the world’s premier locations for the development of tidal power generating systems, since it has some of the world’s largest tidal ranges. Several proposals have been made in recent years to find economical ways to harness the power of tides. There is presently considerable interest in installing tidal power lagoons in the Bay of Fundy. The lagoon concept involves temporarily storing seawater behind an impoundment dike and generating power by gradually releasing the impounded seawater through conventional low-head hydroelectric turbines. A tidal lagoon will inherently modify the tides and tidal currents regime in the vicinity of the lagoon, and possibly induce effects that may be felt throughout the entire bay. The nature of these hydrodynamic impacts will likely depend on the size of the tidal lagoon, its location, and its method of operation. Any changes in the tidal hydrodynamics caused by a tidal lagoon may upset ecosystems that are well adapted to existing conditions. The scale and character of the potential hydrodynamic impacts due to tidal lagoons operating in the Bay of Fundy have not been previously investigated. This paper presents the results of a hydrodynamic model developed to analyze, predict, and quantify the potential changes in the tidal hydrodynamics changes (water levels, tidal range, circulation patterns and tidal currents) due to the presence of a single tidal lagoon, or multiple lagoons, operating in the upper Bay of Fundy, Canada. The extent of the changes due to different scenarios involving several number, size and location of lagoons, as well as their operating mode is also investigated. The final purpose of this novel study is to assist with decisions concerning the development of the vast tidal energy resources available in the Bay of Fundy, Canada.

scholarly journals Construction and Operation of Small Hydro Power Plants in the Ukrainian Carpathians: New Challenges for Environment

2020 ◽  
Keyword(s):  
Power Plant ◽  
Environmental Impact ◽  
Impact Assessment ◽  
Environmental Impact Assessment ◽  
Hydroelectric Power Plant ◽  
Hydroelectric Power Station ◽  
Hydroelectric Power ◽  
Power Station ◽  
Hydro Power ◽  
The Impact

Purpose. Analysis of environmental problems and risks associated with the construction and operation of small hydroelectric power facilities (SHEPP) in the Ukrainian Carpathians. Methods. Field studies, statistical, hydrological, hydroecological, analysis and synthesis. Results. Potential environmental risks arising from the construction and operation of SHEPP in the Ukrainian Carpathians are considered. The influence of Yavіrska hydroelectric power station on water discharges in the Stryi river was investigated. The daily water discharges for the two hydraulic sections located above and below the station for low-water (2003) and high-water (2008) years are analyzed. Possible risks in the construction and operation of the hydroelectric power plant for the movement of flood waters, river sediments, the development of riverbed deformations, and others, are indicated. The difference in water discharges between the two hydrological stations is presented, and it is confirmed that in the spring of 2008 and 2003 and the autumn and winter of 2003 and 2008 minimal differences in water consumption were observed as a result of the water retention in the reservoir above the dam of Yavіrska hydro power station for the maximal electrical power generation. The impact of the Yavіrska SHEPP on the biota of the Stryi river during 2014–2015 was analyzed. The obtained results indicate that the main negative factors affecting the communities of river hydrobionts are the creation of reservoir of limnethic conditions in the continuum of the river ecosystem; the accumulation of sediments and dead organic matter on its bottom and banks and the demolition of these sediments on the lower sections of the channel bed; also a decrease of water in the riverbed downstream of the dam after the closure of the floodgates in June. The analysis of the environmental impact assessment reports made it possible to analyze the major environmental threats, which are possible during the building and operation of a small hydroelectric power plant on the Stryi river in the Dovhe village (Drohobych district, Lviv region). Conclusions. To prevent the impact of the projected SHEPP in the Carpathian region it is necessary to prescribe the mechanism of carrying out the environmental impact assessment, to specify the natural-geographical, hydrological and hydro-ecological restrictions on the construction and operation of the hydroelectric power station. It is also necessary to identify sections of mountain (“wild”) rivers with high values of natural landscapes and prohibit the construction of small hydropower facilities.

scholarly journals Estuarine turbidity maximum in six tropical minor rivers, central west coast of India

2017 ◽  
Vol 49 (4) ◽  
pp. 1234-1254 ◽  
Author(s):  
Lina L. Fernandes ◽  
V. Purnachandra Rao ◽  
Pratima M. Kessarkar ◽  
Suja Suresh
Keyword(s):  
West Coast ◽  
Dry Season ◽  
Turbidity Maximum ◽  
Estuarine Turbidity Maximum ◽  
Wet Season ◽  
Salinity Stratification ◽  
West Coast Of India ◽  
Driving Mechanisms ◽  
River Mouths ◽  
The Impact

AbstractUnderstanding patterns of erosion and sedimentation and their driving mechanisms is important for formulating a variety of estuarine management issues (conservation, shoreline protection, navigation, dredging and embanking). Therefore, the present study aims to determine the factors influencing the seasonal distribution and dynamics of suspended particulate matter (SPM) of two meso-(Mandovi and Zuari) and four micro-tidal (Terekhol, Chapora, Sal, and Talpona) river estuaries of Goa, on the central west coast of India. These estuaries exhibited salinity stratification near their mouths during the wet season and well-mixed water columns during the dry season. The SPM concentrations were two times higher in the wet season than in the dry season. Estuarine turbidity maximum (ETM) was a consistent feature in both the seasons at the mouth of the estuaries, except in the estuary of the Sal River. The in situ vertical distribution of SPM volume concentration and mean particle size allowed for a better visualization of the ETM formation and distribution. The gravitational circulation as well as flocculation at the salt–freshwater interface during the wet season and the impact of tidal and wind-induced currents at the river mouths during the dry season were primarily responsible for the formation of the ETMs.

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