Pumped Storage Hydroelectric Power Plants Research Articles

Integration study of a reverse osmosis desalination plant in a hydroelectric pumping station

The archipelagos of Macaronesia (Canary Islands, Azores, Madeira and Cape Verde) have isolated energy systems (IES). This makes the island systems dependent on themselves for energy production. In the case of an island like Gran Canaria, energy production is mainly obtained from: a) Wind and solar energy, 19 % of the total energy produced, b) Energy obtained from the burning of fossil fuels in the energy production equipment of the existing power plants. Thermal power plants, 81 % of the total energy produced. It is necessary to find a solution to the current production system, which is already partially obsolete and must be renewed and/or dismantled, in order to avoid "Zero Energy", which implies a change in the production cycle. In addition, the incorporation of the "Chira-Soria" pumped-storage hydroelectric power plant into the Gran Canaria electricity system represents another, even more important, change in the dynamics followed up to now. Basically, this plant, hydraulically stabilized by means of a seawater desalination plant, incorporates energy storage by storing water at high altitude to be turbined under the right conditions. The new situation with this incorporation will be analysed and the option of integrated operation in the overall energy system of Gran Canaria will be assessed.

Research of the optimal design of a jet pump for regulating a Pelton hydro turbine

Hydroelectric power plants (HPP) contribute a significant share to electricity generation in Russia. Considering the prospects for the development of this sector and using the hydropower potential, it is necessary to explore methods for the modernization of hydroelectric power plants. This article explores a new method of regulating active turbines (Pelton) based on altering the nozzle flow rate by using a jet pump that operates with used fluid from the runner. The relevance of this solution lies in the potential to increase the operational lifespan of high-head pumped storage hydroelectric power plants (PSHPP) and enhance reliability by eliminating or reducing the intensity of the regulatory needle's operation in the guide vane mechanism. Based on the hydraulic scheme incorporating the jet pump into the hydroelectric power plants penstock upstream of the guide apparatus, several geometric configurations of the jet pump were evaluated using CFD modeling to assess the energy losses associated with the proposed regulation method.

Optimal scheduling of Egyptian grid with pumped storage hydroelectric power plant

Egypt's national development plan aims at diversifying energy resources and expanding on renewable energy generation technologies. However, the Egyptian national grid needs energy-storage components to stabilize its power supply when coupled with renewable energy due to the intermittent and random nature of them. The optimal power expansion plan has been reached using a production and costing software package electric generation expansion analysis system (EGEAS). Although pumped storage hydroelectric power plants (PSHPPs) have potential to be constructed in Attaqa Mountain, Egypt, it has not been considered in Egypt's optimal power expansion plan. This study proposes an optimal scheduling of Egypt's grid, adding PSHPP as a committed power plant. First, a mathematic formulation of Attaqa PSHPP is presented. Then, to reach the goal of economic dispatch, an optimal scheduling model of national grid is established with the consideration of both respective operation constraints and load requirements. The results of EGEAS simulation module showed that PSHPP operation for 20 years achieves a net fuel cost saving of 795 M$ as calculated from with and without PSHPP conditions at domestic subsidized fuel prices. More than double of this saving, 7778 M$, could be achieved if the net fuel cost savings are calculated at international fuel prices.

Role of pumped-storage hydroelectric power plants and large penetration of electric vehicles in increasing power system flexibility with large share of renewable sources

The European Union's (EU) goals of reducing energy dependence and reducing greenhouse gas emissions (GHG) are to be achieved primarily by increasing production from renewable energy sources (RES). However, due to the features of renewable sources such as unpredictability and lack of availability, it is necessary to increase the flexibility of the systems themselves. In other words, large penetration of RES into the power system requires a substantial increase in the capacity of various energy storage technologies. Pumped storage hydroelectric power plants (HPPs) represent 99% of global installed capacity of energy storage and are widely spread, providing energy storage capacity and transmission grid ancillary benefits in the US and Europe since 1920s, as well as in the rest of the world. Besides, new technologies are considered worldwide, and as one of the most prominent options considered today is the penetration of electric vehicles (EVs) into the power systems. The use of EVs reduces air pollution while connecting them to the smart grids creates the possibility of increasing the flexibility of the power system since vehicle batteries could be used as storage but also as sources of electricity. Using the PLEXOS energy market simulation software, the power system of the Republic of Croatia was modelled in this paper and based on the results of different scenarios, the role of pumped-storage power plants and large penetration of electric vehicles in increasing the power system flexibility with a large share of renewable sources was observed.

Economic aspects of introducing pumped-storage hydroelectric power plants into the mine dewatering system for distributed power generation

The paper examines the pumped hydroelectric energy storage potential of mine dewatering system for power generation in a distributed power system. Based on the water inflows that can be used to fill the drainage basins, the following options for pumped-storage hydroelectric power plants (PSHPP) are considered: when groundwater is discharged from only one mine, one hydraulic turbine is installed on the horizon below the surface; with additional discharge of groundwater from neighboring mines – installation of two or four hydraulic turbines at the drainage stages closest to the surface. Comparison was made with grid only system. It is based on net present value (NPV) and levelized cost of energy (LCOE) criteria. Variable parameters were hydraulic turbine water flow and mine power consumption. Also, for a certain combination of parameters, the optimal mine power system was determined. The area of use of the PSHS is estimated. It was found that the smallest economic effect is achieved when the power generation of one hydraulic turbine is close to the power consumption. The area of expedient use of the PSHPP within the limits of parameter variation is 17.2%, 19.6% (base and peak costs of power). This is because power generation drops when the water flow decreases. It does not cover the needs of the mine and there is a power shortage. Thus, the mine power system autonomy is very low. With an increase in water inflow and the number of hydraulic turbines, first up to two and then up to four units, the area of expedient use of PSHPP increases to 51.5%, 55.9% and 50.6%, 72.8%, respectively. However, with low energy consumption and a low water flow, it is still rational to receive electricity from the grid. This is due to a sharp drop in the efficiency of hydraulic turbines and high costs for maintenance and repair of PSHPP equipment, which are not comparable to the cost of purchasing power. So it was noted that with the base cost of electricity and an increase in the number of hydro turbines from two to four, the area of conditions under which the use of PSHPP is justified even decreased by 0.9%. At peak cost, the area increases by 16.9%. The mine power system autonomy is not achieved. In general, the efficiency of using PSHPP for mine dewatering systems is high, but the feasibility of their use should be studied for specific conditions of use.

Investigation of Unit Commitment Problem in Presence of Pumped Storage Hydroelectric Power Plants: The Case of Kahramanmaras

Investigation of Unit Commitment Problem in Presence of Pumped Storage Hydroelectric Power Plants: The Case of Kahramanmaras

Pumped Storage Hydroelectric Power Plant Design

Pumped Storage Hydroelectric Power Plant Design

A study on transformation of multi-purpose dams into pumped storage hydroelectric power plants by using GIS model

ABSTRACT Nowadays, the continuity of all activities related to industrial production is essential for the sustainability of modern life. In order to achieve this, it is necessary to ensure the continuity of energy demand. For an energy supply to be considered as reliable, a fast and reliable response should always be provided to changing demand. Pumped storage systems can meet these needs due to their ability to store energy at times of high demand. Therefore, in recent years, many countries have increased their investments to transform existing hydroelectric power plants into pumping storage hydroelectric power plants (PHS). In this study, a GIS-based model for the transformation of an existing dam into a PHS system has been developed. The aim of this model is to determine the most suitable second reservoir location for the PHS transformation and to calculate the theoretical hydroelectric energy potential. According to the results of the study, the second reservoir location with a volume of 6,5x106 m3 was determined by transforming the Porsuk dam, which was examined as a pilot area, into a PHS. It is calculated that this reservoir can store 0.664 GWh of energy. This study will make an important contribution to the literature by presenting a holistic model approach by determining the most suitable second reservoir location and by calculating the energy potential on the transformation of existing dams into a PHS.

Assessment of investment technologies for use of hydro-accumulating stations on intermediate channels of irrigation systems and water reservoirs

The article presents data on the cost of construction and economic efficiency of similar objects of pumped storage hydroelectric power plants (PSHPP) in world practice and in Uzbekistan. Development of measures to reduce head losses in intermediate channels of hydraulic systems and increase their efficiency is urgent issues. The authors assess the importance of the data obtained on the example of new design schemes for small hydroelectric power plants and pumped storage power plants of the Tuyamuyun hydroelectric complex, selected as an object of research.

Debris flow prediction and prevention in reservoir area based on finite volume type shallow-water model: a case study of pumped-storage hydroelectric power station site in Yi County, Hebei, China

In recent years, the development of pumped-storage hydroelectricity has seen a very rapid increase, and lots of stations have been proposed to be built in China to adjust the energy structure of production and alleviate electrical energy shortages. The site of pumped-storage hydroelectric power plants is usually chosen in the mountain area, which can conveniently provide headwaters and height difference for the proper functioning of hydroelectric power station; however, geological disasters such as debris frequently flows in the mountain areas, posing great threat to the safety of plants and staff. A large pumped-storage hydroelectric power station will be built in the Taihang Mountains in the northwest of Yi County, Hebei province. To predict the potential scale of debris flow hazard, the shallow-water model based on the finite volume method (SFLOW model) is used. During the work, reconnaissance, geomorphological analysis, and laboratory experiment are carried out for model construction and data input. Then the debris flow designed for 20-, 50-, 100-, and 200-year return periods and the flood caused by dam break are simulated. The simulation study shows that the potential debris flow hazard will greatly harm the reservoir area, and if debris flows destroy the dam, floods could affect the residents of a maximum of 1.21 million square meters downstream. To prevent debris flows, retaining walls in the SFLOW model are set, and the results show that they can effectively reduce the hazard area of debris flow, ensuring the safety of the reservoir area. In general, the SFLOW model can accurately and efficiently solve the problem of fluid flow on irregular terrain and can be applied to similar engineering projects.

Design and evaluation of PV-wind hybrid system with hydroelectric pumped storage on the National Power System of Egypt

National and international policies encourage increased penetration of solar and wind energy into electrical networks in order to reduce greenhouse gas emission. Solar radiation and wind speed variations complicate the integration of wind and solar generation into power systems and delay the transition of these sources from centralized to distributed energy sources. The increased penetration of nontraditional energy sources into the electric grid stimulates the demand for large capacities in the field of energy storage. A mathematical model, which describes the operation of a proposed hybrid system, including solar PV, wind energy, and a pumped storage hydroelectric power plant is developed in this paper. This hydropower plant utilizes seawater as a lower reservoir, and only a tank has to be built in order to reduce the installation cost of the storing system. The pumped storage power plant used for compensation of the variation of the output energy from the PV and wind power plants by discharging water from the upper reservoir, which is previously pumped in the case of surplus energy from PV and wind turbine power plants. The impact of the proposed system on the grid utility is investigated in accordance with the values of energy exchange (deficits and surpluses of energy) between the considered hybrid system and the grid. The optimum design is determined by the pump and turbine capacities, upper reservoir volume, and the volume of water left in the tank for emergencies. Different scenarios of the optimum operations are presented for analysis. The results obtained from the examined scenarios indicate the ability of such a hybrid energy system to reduce the exchange of energy with the grid. This paper indicates the technical feasibility of seawater pumped-storage hydropower plant for increasing the Egyptian national grid’s ability to accept high integration of renewable energy sources.

Use of Pumped Storage Hydroelectric Power Plants in Uzbekistan

This paper studies the features of construction of pumped storage hydroelectric power plants (PSHPPs) in Uzbekistan with consideration for the possibility of using them to cover the drops and peaks of loading, as well as the features of using the water resources in Uzbekistan—the priority provision of agricultural needs. The efficiency of creating pumped storage power plants at local waterways in a complex with solar and wind power plants is shown.

Conditions for economic competitiveness of pumped storage hydroelectric power plants in Egypt

Pumped storage hydroelectric power plants are one of the most applicable energy storage technologies on large-scale capacity generation due to many technical considerations such as their maturity, frequency control and higher ramp rates, thus maintaining following loads in case of high penetration of renewables in the electrical grid. Economic viability of PSHPPs is still questionable when compared with other electricity generation technologies. In this manuscript, the key factors that affect the viability of constructing PSHPP in Attaqa Mountain, Egypt, are defined. An economic comparison between PSHPPs and simple cycle gas turbine power plants has been carried out to identify the conditions at which PSHPPs will have competitiveness as an on-peak solution, over traditional SCGT power plants. This assessment is based on calculating levelized cost of electricity taking into account different scenarios for PSHPP pumping cost and capital cost, and different scenarios for SCGT fuel prices. The results showed the key factors of the best case at which PSHPPs have the highest economic competitiveness over SCGT power plants when fuel prices are non-subsidized. This is only valid provided that the PSHPP’s capital cost should not exceed 4180 $/kW at zero pumping cost.

Optimization of the operating conditions of gas-turbine power stations considering the effect of equipment deterioration

In recent years in most power systems all over the world, a trend towards the growing nonuniformity of energy consumption and generation schedules has been observed. The increase in the portion of renewable energy sources is one of the important challenges for many countries. The ill-predictable character of such energy sources necessitates a search for practical solutions. Presently, the most efficient method for compensating for nonuniform generation of the electric power by the renewable energy sources—predominantly by the wind and solar energy—is generation of power at conventional fossil-fuel-fired power stations. In Russia, this problem is caused by the increasing portion in the generating capacity structure of the nuclear power stations, which are most efficient when operating under basic conditions. Introduction of hydropower and pumped storage hydroelectric power plants and other energy-storage technologies does not cover the demand for load-following power capacities. Owing to a simple design, low construction costs, and a sufficiently high economic efficiency, gas turbine plants (GTPs) prove to be the most suitable for covering the nonuniform electric-demand schedules. However, when the gas turbines are operated under varying duty conditions, the lifetime of the primary thermostressed components is considerably reduced and, consequently, the repair costs increase. A method is proposed for determination of the total operating costs considering the deterioration of the gas turbine equipment under varying duty and start–stop conditions. A methodology for optimization of the loading modes for the gas turbine equipment is developed. The consideration of the lifetime component allows varying the optimal operating conditions and, in some cases, rejecting short-time stops of the gas turbine plants. The calculations performed in a wide range of varying fuel prices and capital investments per gas turbine equipment unit show that the economic effectiveness can be increased by 5–15% by varying the operating conditions and switching to the optimal operating modes. Consequently, irrespective of the fuel price, the application of the proposed method results in selection of the most beneficial operating conditions. Consideration of the lifetime expenditure included in the optimization criterion enables enhancement of the operating efficiency.

Numerical Modeling of the Impact of a Pumped-Storage Hydroelectric Power Plant on the Reservoirs’ Thermal Stratification Structure: a Case Study in NW Spain

Pumped-storage hydroelectric power plants are generally perceived as an environmentally respectful technology. Nevertheless, the pumping of water from a lower reservoir to an upper impoundment, and the return of that water during power generation, can strongly affect the water quality of the reservoirs. In particular, plant operation can alter their thermal structure, deep water mixing, and water circulation characteristics. The objective of this study is to quantify, through the use of 3D hydrodynamic modeling, the potential impacts of a pumped-storage hydroelectric plant on the thermal stability and mixing of two reservoirs in Galicia, northwest of Spain. To this end, three-dimensional hydrodynamic simulations were conducted using the model Delft3D. Two different coupled models, one for each reservoir, were constructed and subsequently tested for several stratification scenarios, according to measured temperature profiles during the spring and summer season. Several reservoir minimum and maximum operation water levels were also considered. Model simulations demonstrated a high level of mixing in the vicinity of the intake-outlet structures, in particular during startup of the power plant, regardless of the water level in the reservoir. Beyond this area, the results showed a limited overall effect on stratification and mixing in the upper reservoir, owing to the relation between the inflow temperatures and the initial temperature profile of this reservoir. A more significant alteration of the thermal structure is expected in the lower reservoir due to its narrow shape and shallow depth at the structure location, as well as the temperature differences between receiving waters and inflow.

Hydraulic model study of the intake-outlet of a pumped-storage hydropower plant

ABSTRACTThe design of intake-outlet structures for pumped-storage hydroelectric power plants requires site-specific location and geometry studies in order to ensure their satisfactory hydraulic performance. This article presents the numerical and physical model studies conducted on the lower intake-outlet of Belesar III power station in Northwest Spain. The proposed location of this structure in a narrow reservoir and at a shallow depth is particularly challenging and required the analysis of both the near-field and far-field flow dynamics in the reservoir. First, the hydrodynamics of the reservoir were studied with a 2D shallow water model. The location of the intake was found to be suitable, with adequate flow conditions in the reservoir even for the lower operating water levels. The intake could be fed with the maximum pumping discharge without being limited by the reservoir’s hydraulics. Second, the flow in the near-field was investigated by complementary use of 3-dimensional numerical simulations and reduced-scale physical modeling. The results allowed the verification of the submergence requirements and the comparison of geometry alternatives. In comparison with the initial design, the final proposed design shows a more symmetrical approach flow into the structure during pumping mode, resulting in a more homogenous flow distribution between the openings and reduced head loss. This study can provide guidance in the application of hydraulic modeling procedures to locate and design intake-outlet structures in existing lakes or reservoirs and to evaluate potential limitations on water levels, inflows and outflows. It can be useful during planning stages of power plants to aim for the shortest possible waterways between the reservoirs while ensuring adequate flow conditions.

Drastic hydrological changes caused by hydroelectrical development in karst: a case of the karst river Zrmanja (Croatia)

This paper has analysed changes in the hydrological regime along the karst river Zrmanja (the Dinaric karst of Croatia) caused by operation of the reversible or pumped-storage hydroelectric power plant Velebit (RHEPP Velebit), which started operations in 1985. The total river length from the spring to the mouth in the Adriatic Sea is 70 km. Discharges along the whole river course are monitored at nine hydrological gauging stations. For all nine analysed stations, the decrease of the mean annual discharges starting from 1985 has proven to be statistically significant. However, it should be stressed that the Zrmanja River natural regime is extremely complex due to a deep, well developed and generally undiscovered subsurface karst morphology and its influence on regional surface and groundwater circulation. The influence of RHEPP Velebit operation on the maximum annual discharges is not statistically significant. Statistically significant decrease on the minimum annual discharges is observed at only one gauging station located at the Zrmanja River downstream of the Razovac Reservoir. At the same time, climatological changes have been monitored in the analysed area. It has been established that there has been an annual increase in air temperature since 1988 and an annual decrease in rainfall since 1983. A general conclusion is that the decrease in the mean annual discharges along the Zrmanja River is mainly caused by the RHEPP Velebit operation and only in a smaller degree by climatological changes. On the basis of the available data it was not possible to separate precisely the influences of these two factors.

Information and communications technology for the construction of underground powerhouse cavern in the Kyogoku hydropower project

This paper presents the outline of observational construction scheme employed for underground cavern construction, and of the Information and Communications Technology (ICT) as a technological tool to facilitate the observational construction. The Hokkaido Electric Power Co., Inc. has been conducting a Hydropower Project in Kyogoku, on the Pepenai and Bihinai tributaries of the Shiribetsu River in Hokkaido, Japan. The Kyogoku Hydropower Plant is the first pumped-storage hydroelectric power plant that was built by the Power Co. It will output a maximum power of 600 MW, with an effective head of 369 m and a maximum water usage rate of 190.5 m 3 /s. The power plant is housed in a large underground cavern of which the dimension is 45.8 m high, 24.0 m wide, and 141.0 m deep. Its total excavated volume is 116,000 m 3 and the maximum cross-sectional area amounts to 1000 m 2 . The geology in the vicinity of cavern belongs to a so-called “Green Tuff” region of the Miocene period, primarily composed of tuff breccia. The geology presents considerable challenges, including a distribution of tuff blocks and two major fault zones with a low uniaxial compressive strength, presumably due to faulting and hydrothermal alteration. Therefore, observational construction method was applied to the project in conjunction with other ICT-solutions, and the actual rock response during excavation was examined in order to ensure the optimum structural support for the cavern and construction safety.