Evaluation of development potential of pumped hydroelectric storage and geothermal utilization system in abandoned coal mine

Every year in China,a significant number of mines are closed or abandoned.The pumped hydroelectric storage(PHS)and geothermal utilization are vital means to efficiently repurpose resources in abandoned mine.In this work,the development potentials of the PHS and geothermal utilization systems were evaluated.Considering the geological conditions and meteorological data available of Jiahe abandoned mine,a simple evaluation model for PHS and geothermal utilization was established.The average efficiency of the PHS system exceeds 70%and the regulatable energy of a unit volume is over 1.53 kW·h/m^(3).The PHS system achieves optimal performance when the wind/solar power ratio reaches 0.6 and 0.3 in daily and year scale,respectively.In the geothermal utilization system,the outlet temperature and heat production are significantly affected by the injection flow rate.The heat production performance is more stable at lower rate flow,and the proportion of heat production is higher in the initial stage at greater flow rate.As the operating time increases,the proportion of heat production gradually decreases.The cyclic heat storage status has obvious advantages in heat generation and cooling.Furthermore,the energy-saving and emission reduction benefits of PHS and geothermal utilization systems were calculated.

The Economics of Competing Water Uses under a FERC Licensing Agreement: Estimation of Property Value, Recreation, and Hydroelectric Impacts

Reservoirs provide a variety of services with economic values across multiple sectors. As demands for reservoir services continue to grow and precipitation patterns evolve, it becomes ever more important to consider the integrated suite of values and tradeoffs that attend changes in water uses and availability. Section 316 (b) of the Clean Water Act requires that owners of certain water cooled power plants evaluate technologies and operational measures that can reduce their impacts to aquatic organisms. The studies must discuss the social costs and benefits of alternative technologies including cooling towers (79 Fed. Reg. 158, 48300 - 48439). Cooling towers achieve their effect through evaporation. This manuscript estimates the property value, recreation, and hydroelectric generation impacts that could result from the evaporative water loss associated with installing cooling towers at the McGuire Nuclear Generating Station (McGuire) located on Lake Norman, North Carolina. Although this study specifically evaluates the effects of evaporative water loss from cooling towers, its methods are applicable to estimating the economic benefits and costs of a new water user or reduced water input in any complex reservoir system that supports steam electric generation, hydroelectric generation, residential properties, recreation, irrigation, and municipal water use.

On the Origin of the Cavities Present in the Sandstone Formations of the Hydroelectric Development Site of Kakobola and Its Surroundings (Kwilu Province/DRC)

Problems due to underground cavities at the level of soft and polymorphic sandstones, collapses and infiltration of acid waters through the fracture networks have been observed around the Kakobola hydroelectric development, constituting potential risks for the stability of the dam. The objective of this article aims to highlight the major cause that can explain the generating processes of these cavities. Indeed, to do this, the exploration of the subsoil was made possible thanks to the eleven (11) boreholes drilled on the site, the determination of cavities by the method of colored tracers and the petrographic characterization using a microscope. The latter, by means of thin sections, reveals the presence of quartz arenites. The mineralogical characterization of rock materials was carried out using X-ray fluorescence and X-ray diffraction methods. X-ray fluorescence revealed the presence of nickel, zinc and iron. Diffraction shows us an abundance of silica, mainly quartz and its metastable phases, in particular tridymite and cristobalite. It also made it possible to question the presence of carbonated minerals. The drillings enabled us to elaborate the logs and to bring out a geological model of the sector of study. These models were produced on the basis of drilling and observations on excavation. These data also reveal the presence of underground cavities which were also confirmed by the colored tracer method. These cavities would be of natural origin due to the presence of carbonate minerals observed in the rocks and which are attacked by acidic waters attested by the pH 5 measurements of the waters of the Lufuku River. The infiltration of water in rocky materials of low density and through the various networks of fractures and cavities leads to instability of the rock and could damage the hydroelectric development.

Sizing and Simulation of a Hybrid Hydroelectricity and Photovoltaic System with Storage for Supplying the Tamagaly District in Mamou,Guinea

The present study is a contribution to the study of hybrid electric power conversion systems in rural areas.The approach adopted uses a methodology for analyzing the complementarity that exists between the two renewable energy potentials(solar and hydraulic)based on their daily,monthly and annual variations.The different analytical formulas for sizing a PV(photovoltaic)field and a small hydroelectric power station are recalled in this work.The HOMER software served as a tool for optimal sizing and simulation of the system.This work focuses on the analysis of the behavior and control of the performances of a hybrid system made up of two renewable energy sources,hydroelectricity/PV with a storage system and a converter.The main results obtained relate to:monitoring of the variation in temperature variation,solar irradiation of the site,as well as the flow of the watercourse.The profile of the village’s annual charges is known.The annual production of electrical energy is 527.936 kWh/year.The hydroelectric plant will provide 155.316 kWh/year,or 29%,and for the PV field(372.620 kWh/year),or 71%.The monthly energy average is 43.995 kWh/month.The average daily consumption is 731 kWh/d with a maximum power of 163 kW.The completion of this project makes it possible to cover all electrical loads in the Tamagaly district,with an annual energy production of 206.783 kWh.This would make it possible to locally limit greenhouse gas emissions in the area.

Allowance of the Emission Quota Using Life Cycle Assessment for the Creation of a National Carbon Market: Framework Developed for Hydroelectric Projects in Cameroon

The lack of synergy between infrastructure financing mechanisms and mechanisms for combating climate change does not favor the definition of sustainable infrastructure in Cameroon. The definition of a sustainable infrastructure could meet the requirements of these mechanisms, thanks to the control of Greenhouse Gas (GHG) emissions during its installation, in relation to a predefined value. However, the promotion of efforts to reduce emissions from new infrastructures is not subject to a local market. This situation is a limit in the implementation of the policies defined in the Nationally Determined Contribution (NDC). This article proposes a framework for promoting reduction efforts for a national carbon market, in favor of hydroelectric infrastructures. Thanks to the Life Cycle Assessment (LCA) environmental assessment tool, we are going to determine the carbon quota for a specific power. The study carried out on the hydroelectric power station of Mekin (HydroMekin) leads us to a reduction effort of 68.2% compared to the threshold defined at 14.057 gCO2eq/kWhe. The framework, developed, contributes to defining the environmental parameters in the decarbonation strategy during the implementation of new hydroelectric infrastructures and the market carbon design elements special to the construction phase of these infrastructures.

Analysis of Flood Risks Upstream from the Imboulou Hydroelectric Dam on the Léfini River, a Tributary of the Right Bank of the Congo River

The analysis of the risk of flooding upstream from the Imboulou hydroelectric dam on the Léfini River in the Republic of Congo-Brazzaville, focused on the evolution of annual rainfall and flow in the study area during the period from 1970 to 2020 before and after the building of the dam in 2005, by applying statistical methods. These methods were used to analyse the spatial and temporal evolution of rainfall and flow at the unique hydrometric station located at the RN2 (National Road N°2) bridge in the village of Mbouambé in the Pool region. This work has shown that rainfall is not the cause of flooding in the Léfini catchment area. The monthly flow coefficient (MFC) showed exceptional flooding from November and December onwards after the dam was built, resulting in a variability of flows, with periods of high and low water. In addition, the annual average flow (AAF) and the maximum average flow (MAF) increased after the dam was built. Maximum average flows (MAF) were higher than annual average flows (AAF) throughout the period of study (1970-2020). The annual and monthly rainfall-runoff relationship showed changes after the dam was built, particularly from 2009 and during the months of November and December. .

Profit-Based Optimal Operation of a Head-Dependent Hydroelectric Power Station in the Bilateral Market

Deregulation and liberalization of electric power industry, among other things, has created new requirements for the market participants. The power system engineer, operator, and, in general, the market participants are being faced with requirements for which they do not have adequate training and the proper software tools. In this framework, among others, a pure hydro-generation company has to operate its hydro units, throughout the operating day, trying to fulfill the market clearing schedule or a bilateral contract, and modify the program in the intra-day energy markets if necessary （or more suitable） as real-time operation is getting closer. In this scenario the objective is to maximize the hydroelectric power plant profit from selling energy in the spot market or by means of bilateral contracts. In this paper the optimal operation of a head-dependent hydroelectric power station in bilateral market-short-term hourly hydro resource scheduling for energy is obtained.

Assessment of Diversity, Distribution, Conservation Status and Preparation of Management Plan for Medicinal Plants in the Catchment Area of Parbati Hydroelectric Project Stage-Ⅲ in Northwestern Himalaya

The developmental activities, particularly the construction of hydroelectric projects are causing a great loss of biodiversity in the Indian Himalayan Region. The Himaehal Pradesh, a part of IHR is well known for the development of hydroelectric projects. The Parbati H.E. Project is amongst the major projects of the State. The different stages of the project are all causing loss of biodiversity of the area. Stage Ⅲ of the Parbati H.E. Project is a run of the river scheme on the Sainj River downstream of Power House of Parbati H.E. Project Stage Ⅱ. The project shall utilize regulated discharge of Parbati H.E. Project Stage Ⅱ and inflow of River Sainj for power generation, and has been contemplated as a peaking station operating in tandem with Stage Ⅱ. The present study has been undertaken to see the impact of hydroelectric project on the biodiversity, particularly on medicinal plants. A total of 104 species of medicinal plants, belonging to different life forms, i.e., trees （23 spp.）, shrubs （22 spp.）, herbs （57 spp.） and ferns （2 spp.） were recorded. The species have been analyzed and studied for their distribution, classification, altitudinal zones, part （s） used, indigenous uses, nativity, endemism and rarity.Different parts of these species, such as whole plants, roots （including rhizomes and tubers）, leaves, flowers, fruits, seeds, stems, barks, spikes, nuts and insect galls are used by the inhabitants for curing various diseases and ailments. 3o species are native to the Himalayan region, 9 species native to the Himalayan region and adjacent countries also and 65 species are non-natives. 9 species are near endemics. Considering the whole Himalaya as a biogeographie unit （sensu lato）, the near endemics are endemic to the Himalaya. Among these species, Zanthoxylum armature is categorized as Endangered and Valeriana wallichii as Vulnerable. Hedychium spicatum, Rhus javanica, Berberis lycium, Thalictrum foliolossum, Salvia lanata, Rubia cordifolia and Bergenia ligulata may be considered as threatened species due to their over exploitation for trade. 90 species are propagated by seeds, 8 species by seeds and rhizomes/roots/tubers, 4 species by seeds and cuttings, and 2 species by sori. A management plan for the cultivation and conservation of the medicinal plants in the dam submergence area, and the commercially viable medicinal plants with high value in the catchment area is suggested.

Socio-economic and Environmental Implications of the Hydroelectric Projects in Uttarakhand Himalaya, India

This paper deals with de the fiasco created by the Tehri Uttarakhand, India, particularly resettlement and rehabilitation tailed analysis of High Dam in in terms of of the local inhabitants. Aspects pertaining to the environmental issues are also discussed. Currently, the river valleys in Uttarakhand state of India are the targets of increasing hydroelectric projects. Virtually all rivers are being exploited for generating environmental friendly power. Having being learned the hard lesson from Tehri Dam, it has been decided to opt for such schemes in which comparatively little submergence hnd tempering with the fragile eco-systems is involved However, our observations suggest that even in such schemes if due care is not taken they may turn out to be a failure.

Engineering geological classification of the structural planes for hydroelectric projects in Emeishan Basalts

The scale and characteristics of rock mass are important indexes of the rock mass structural plane classification. This paper firstly analyzes the spatial distribution characteristics, the structural plane types （original structural plane, tectonic structural plane and hypergenic structural plane） and the associated features of the Emeishan basalts and then studies the classification schemes of the built hydropower structure planes of different rock areas （the east district, the central district and the west district） in the Emeishan basalt distribution area, Southwest China. Based on the analysis and comparison of the scale and the engineering geological characteristics of the typical structure planes in the basalt hydroelectric Stations, the types of structural planes are used in the first order classification. The secondary order classification is made by considering the impact factors of rock mass quality, e.g., the state of the structural planes, infilling, joint opening, extending length, the grade of weathering and strength. The engineering geological classification for Emeishan basalt is proposed. Because there are no evidences of a large structure presenting in study area, the first-order （Ⅰ） controlling structural planes do not appear in the classification, there only appear Ⅱ, Ⅲ, Ⅳ and Ⅴ grade structural planes influencing the rock-mass quality. According to the different rock-block types in bedding fault zone, the second-grade （Ⅱ） structural planes consisted of bedding fault zone is further classified into Ⅱ1, Ⅱ2 and Ⅱ3. The third-grade （Ⅲ） structural planes constructed by intraformational faulted zones are not subdivided. According to the different characteristics of intrusion, alteration and weathering unloading structural planes, the Ⅳ grade structure plane is divided into Ⅳ1, Ⅳ2 and Ⅳ3. According to the development characteristics of joints and fractures, the V grade structure plane is divided into fracture Ⅴ1 and columnar joint Ⅴ2. In all, the structural planes are classified into four groups with nine subsets. The research proposes the engineering geological classification of the structural plane for the hydropower project in the Emishan basalts, and the result of the study has a potential application in similar regions.

Impact of hydroelectric projects on river environment: Analysis of water quality changes in Ningxia Reach of Yellow River

In this paper, the relationship between hydroelectric projects and the river environment is analyzed. Recently, the large-scale regulation of runoff by large hydroelectric projects in the Ningxia Reach of the Yellow River has altered natural runoff processes, causing an increase in the probability of low discharge and an overall adjustment of riverbed evolution and river characteristics. During low-flow years, the combined effects of these two changes can weaken the self-purification capacity and reduce the water environmental capacity of the river. This is one of the main reasons for the recent decrease of water quality in the Ningxia Reach. This research shows that it is necessary to implement river training projects to maintain stable flow paths, not only for adjusting river regimes and for flood control, but also for increasing the self-purification capacity and the water environmental capacity of the river. Methods and proposals for coordinating the operation of hydroelectric projects with the protection of the river environment are presented in the interest of promoting sustainable development.

Perceived ill-health and health seeking behavior in two communities in the nam theun 2 hydroelectric project area in Lao Peoples Democratic Republic

Objective:To compare perceived ill-health and health seeking behavior between two communities affected by the large Nam Theun 2 hydroelectric project in central Lao People’s Democratic Republic(PDR).Methods: Two different affected areas;Nakai plateaubeing remote,sparcely populated and mountainous,and Xe Bang Fai lowland plains,more densely populated and comparatively affluent were included.Data were obtained from two cross-sectional household-based health and socio-economic surveys.Results:We found pronounced differences in the frequency of self-reported fever,cough,headache and myalgia according to location.On the Nakai plateau,45.1%of the individuals with ill-health report(recall period;2 weeks) went to a local health volunteer compared to only 7.2%in the Xe Bang Fai area(P 【 0.001 ).In Nakai,there were disproportionately more illiterates seeking help from local health volunteers when compared to those who attended at least primary schooling(49.2%versus 17.5%,P 【0.01 ).Self-medication with antimalarials was more common in Xe Bang Fai than on Nakai(32.3%versus 7.0%,P 【 0.001).The mean amount of money spent per health consultation was US $ 1.7 in Nakai and US $ 7.2 in Xe Bang Fai.Conclusion:The observed differences in self-reported ill-health and health seeking behavior among these two Lao communities need to be considered when implementing setting-specific mitigation measures as part of the public health action plan of the Nam Theun 2 hydroelectric project.

Effect of Modeling Range on Structural Analysis for Powerhouse of Hydroelectric Power Plant by FEM

In this paper,three different modeling ranges were selected in the structural analysis for a hydropower house.The analysis was carried out using ABAQUS 6.6.The modeling range has a remarkable effect on finite element method(FEM) calculation result at the middle position of typical cross-sections where the concrete is relatively thin,and at the region close to turbine floor.If the ventilation barrel,floor slabs and columns above turbine floor are excluded from FEM model,the maximum rise difference of pedestal structure increases by about 24% compared with that of the whole model.It is indicated that different modeling ranges indeed affect FEM calculation result,and the structure above turbine floor in the FEM model should be included.

Vulnerability assessment of the Satluj catchment for sustainable development of hydroelectric projects in the northwestern Himalaya

Hydropower if scientifically developed is considered to be one of the clean and non-polluted renewable energy sources.But its impacts always exist on physical and social environment of the area.The present study was conducted in the River Satluj basin which is well known for its hydropower potential.The main objective of the study was to understand the vulnerability of the Satluj basin and to develop a strategy for the development of hydropower projects.This basin has been facing many problems relating to construction of haphazard development of hydropower projects.This has led multi-hazards like landslides,floods,earthquakes,etc.Here,vulnerability assessment index was assessed quantitatively and qualitatively.Geographical Information System and people’s perception were used to study these aspects in the basin.The parameters considered for vulnerability assessment were slope,slope profile,relative relief,curvature,slope aspect,soil texture,lithology,river morphometry,precipitation,hydroelectric projects,land use and land cover,mass-movement,flood,geological elements and earthquake occurrences.The highest vulnerability was found in the middle zone,and finally on the basis of parameters analyzed;the hydropower’s development strategy was developed.

Run of River Bulk Hydroelectric Generation from the Congo River without a Conventional Dam

The paper discusses harvesting the Congo River for bulk hydroelectric generation based on run of river, low head generation technology, as employed at the existing Inga 2 power station in the Democratic Republic of Congo. The evolutionary approach builds on existing infrastructure.The results show that the footprint is much smaller than that which employs a conventional dam. The environmental impact is minimized. These collectively will contribute to lower capital costs. In summary, 10,000 cm3/sec of constant river flow will produce 5,000 MW of base power. On average, the constant recorded flow of the river is 30,000 cm3/sec and a total of 15,000 MW of base power generation is possible.

On-Cam Operation of Counter-Rotating Type Hydroelectric Unit

The counter-rotating type hydroelectric unit, which is composed of the axial flow type tandem runners and the peculiar generator with double rotational armatures, has been proposed. In the unit, the front and the rear runners counter-drive the inner and the outer armatures of the generator, respectively. Besides, the flow direction at the rear runner outlet must coincide with the direction at the front runner inlet, because the angular momentum change through the rear runner must coincides with that through the front runner. In this paper, the tandem runners work at on-cam conditions in keeping the induced frequency constant, to provide the hydroelectric unit for the power grid system. The output and the hydraulic efficiency are affected by the adjusting angles of the front and the rear blades. Both optimum angles giving the maximum output or efficiency were presented at the various discharge/head circumstances, accompanying with the turbine performances.

Predispatch of Hydroelectric Power Systems with Modifications in Network Topologies

In this article, the primal-dual interior-point methods are used to minimize costs and losses in a predispatch model for the generation and transmission of direct current (DC) power flow in a hydroelectric system with pre-programmed manipulations;i.e., in cases of preventive maintenance, within a period of twenty-four hours. From the computational standpoint, the effort required to solve a problem with and without manipulations is similar, and the reasons why will be also discussed in this study. Computational results prove these findings.

Optimal operation of cascaded hydroelectric power plants in the power market

An improved network flow algorithm, which includes the minimum cost network flow and the same period network flow, is proposed to solve the optimization of cascaded hydroelectric power plants in a competitive electricity market. The typical network flow is used to find the feasible flow and add the discharge water to different cascaded hydroelectric power plants at the same step. The same period network flow is used to find the optimal flow and add the power output at a different step. This new algorithm retains the advantages of the typical network flow, such as simplicity and ease of realization. The result of the case analysis indicates that the new algorithm can achieve high calculation precision and can be used to calculate the optimal operation of cascaded hydroelectric power plants.

Characteristics Research of Immersed and Waterlogged Subterranean River System of Reservoir Areas of Hydroelectric Stations

The karst immersion and waterlogging is one of the typical and the m os t harmful natural disasters in southern karst areas of China. It is threat to th e local production and life for a long time. In recent years, due to the constru ction of more reservoirs, the disaster became serious. This article takes immers ion and waterlogging of Banwen's subterranean rivers in Yantan reservoir area as an example, researches the daily rainfall's reflection to the water level of re servoir depression, discusses characteristics of immersion and waterlogging of t he valley, analyzes the disaster index in detail, such as water level process, t he highest water level, sensitive rainfall, original waterlogged rainfall and de layed day numbers etc., and provides the reference as a basis to the disaster an alysis.

Study on engineering-hydrogeological problems of hydroelectric project

Engineering-hydrogeological problems arise from the interaction between engineering activities and geological environment, in which rock-soil mass and groundwater are especially important constituents. However, up-to-date research on them is relatively dispersive and simple due to their complexity and lack of comprehensive and systematic study methods. Starting from geological analysis of mechanism to geological model based on geological regularities, the paper predicts the tendency of geological evolvement and puts forward proper measures to solve problems. In this paper, elevated water-sensitive structure in rock-soil mass, which mainly causes engineering hydrogeological problems, and problems in hydropower is discussed based on unique construction in Chinese Western hydropower projects. Engineering hydrogeological problems are reservoir induced earthquakes leakage from reservoir bottom in karst, stability of high slope at reservoir banks, sliding of dam foundation and dam abutment, and confined water at key positions which are introduced and determined by using water-sensitive factors(or structure) according to special hydrogeological conditions.