Pumped Hydro Energy Storage Research Articles

Energy Storage Benefits Assessment Using Multiple-Choice Criteria: The Case of Drini River Cascade, Albania

Albania’s electricity sector lacks energy storage systems (ESS); hence, large quantities of electricity generated during the off-peak time, and excess electricity cannot be stored. On the other hand, the transmission capacity upgrades do not keep pace with the growth in peak electric demand; thus, congestion-related issues occur. Congestion of transmission lines has led to considerable uncertainties. Drin River cascade is located north of Albania. It possesses enormous potential energy that is not used due to a lack of ESS. Security of supply, rational use of renewable energy sources (RES), diversification of the electricity sector, increased competitiveness, sheltering more future RES capacities that can benefit from deferring investment in the existing transmission system, and environmental protection are some of these the main benefits of integrating ESS. Regarding the energy transition, the Albanian government’s endeavor aims to maintain and further develop a flexible, sustainable, secure, efficiently supplied, and affordable energy supply system. The results of the simulation executed by using ES-select software to produce multiple benefits from a single device from the chosen application’s list (App1–App6) showed that the most adequate ESS for storing excess electricity in the Drin River cascade are: compressed air energy storage (CAES-c), pumped hydro energy storage (PHES), and sodium-sulfur batteries (NaS). Integrating such systems in the central or bulk generation makes the circumvented cost in 10 years profitable; therefore, moving towards 2030, it would be extremely difficult to tackle the energy sector’s challenges alone, without integrating the ESS.

Indonesia’s Vast Off-River Pumped Hydro Energy Storage Potential

Indonesia has vast solar energy potential, far more than needed to meet all its energy requirements without the use of fossil fuels. This remains true after per capita energy consumption rises to match developed countries, and most energy functions are electrified to minimize the use of fossil fuels. Because Indonesia has relatively small energy potential from hydro, wind, biomass, geothermal and ocean energy, it will rely mostly on solar for its sustainable energy needs. Thus, Indonesia will require large amounts of storage for overnight and longer periods. Pumped hydro comprises 99% of global energy storage for the electricity industry. In this paper, we demonstrate that Indonesia has vast practical potential for low-cost off-river pumped hydro energy storage with low environmental and social impact; far more than it needs to balance a solar-dominated energy system.

Operational benefit of transforming cascade hydropower stations into pumped hydro energy storage systems

This study evaluates the potential benefit of retrofitting existing conventional cascade hydropower stations (CCHSs) with reversible turbines so as to operate them as pumped hydro energy storage (PHES) systems. We examine the energy generation and storage problem for a CCHS with two connected reservoirs that can be transformed into a PHES system in a market setting where the electricity price can be negative. We formulate this problem as a stochastic dynamic program (SDP) under uncertainty in the streamflow rate and electricity price. We analytically derive an upper bound on the profit improvement that can be obtained from the PHES transformation. We conduct numerical experiments with data-calibrated time series models and observe that the PHES system provides a greater benefit under more limited streamflow conditions or more frequently observed negative prices.

Applicability of Hydropower Generation and Pumped Hydro Energy Storage in the Middle East and North Africa

Energy storage for medium- to large-scale applications is an important aspect of balancing demand and supply cycles. Hydropower generation coupled with pumped hydro storage is an old but effective supply/demand buffer that is a function of the availability of a freshwater resource and the ability to construct an elevated water reservoir. This work reviews the technological feasibility of hydropower generation and also pumped hydro storage and its geographical distribution around the world. There is also an emphasis on installations in the Middle East and North Africa (MENA) in terms of available capacity as well as past and future developments and expansions. A discussion is presented on a project taking place in the United Arab Emirates (UAE) in the Hatta region, which has a water reservoir that would be fit for utilization for pumped hydro storage applications. Once the project is commissioned in 2024, it will provide an estimated 2.06 TWh per year, helping the UAE achieve the goal of relying on 25% renewable energy resources in their energy mix by 2030. These results were obtained by using EnergyPLAN software to project the effect of utilizing various energy resources to face the expected demand of ~38 TWh in 2030.

100% renewable energy in Japan

Low-cost solar photovoltaics and wind offer a reliable and affordable pathway to deep decarbonization of energy, which accounts for three quarters of global emissions. However, large-scale deployment of solar photovoltaics and wind requires space and may be challenging for countries with dense population and high per capita energy consumption. This study investigates the future role of renewable energy in Japan as a case study. A 40-year hourly energy balance model is presented of a hypothetical 100% renewable Japanese electricity system using representative demand data and historical meteorological data. Pumped hydro energy storage, high voltage interconnection and dispatchable capacity (existing hydro and biomass and hydrogen energy produced from curtailed electricity) are included to balance variable generation and demand. Differential evolution is used to find the least-cost solution under various constraints. This study shows that Japan has 14 times more solar and offshore wind resources than needed to supply 100% renewable electricity and vast capacity for off-river pumped hydro energy storage. Assuming significant cost reductions of solar photovoltaics and offshore wind towards global norms in the coming decades driven by large-scale deployment locally and global convergence of renewable generation costs, the levelized cost of electricity is found to be US$86/Megawatt-hour for a solar-dominated system, and US$110/Megawatt-hour for a wind-dominated system. These costs can be compared with 2020 average system prices on the spot market in Japan of US$102/Megawatt-hour. Cost of balancing 100% renewable electricity in Japan ranges between US$20–27/Megawatt-hour for a range of scenarios. In summary, Japan can be self-sufficient for electricity supply at competitive costs, provided that the barriers to the mass deployment of solar photovoltaics and offshore wind in Japan are overcome.

PERFORMANCE EVALUATION OF ADVANCED ENERGY STORAGE SYSTEMS: A REVIEW

Energy systems are progressive and revolutionary for their alternative resources, technical developments, demands, effectiveness and environmental effects. The recently published research's goal is to assess and evaluate the systems that are already in operation and those that will be in the future. Energy can be stored as electrical energy such as supercapacitors (SCs) and superconducting magnetic energy storage (SMES) etc., mechanical energy such as pumped hydro energy storage (PHES), compressed air energy storage (CAES) and flywheel energy storage (FES) etc., chemical energy, electrochemical energy such as batteries and fuel cells etc., and thermal energy. Performance of these energy storage systems (ESSs) have been evaluated in terms of energy density, power density, power ratings, capacitance, discharge-time, energy-efficiency, life-time and cycling-times, and costs. Supercapacitors provide highest power density (>10,0000 W/l), while hydrogen fuel cells provide highest energy density (500-3000Wh/l) among other EESs. Batteries also provide high energy density(200-500Wh/l). The energy efficiency is found highest in SMES system (95-98%), and lowest in TES system (30-50%). Moreover, batteries and supercapacitors have the cycle efficiency above 90%. PHES and CAES seem to be the most cost-effective energy storage systems reviewed in this analysis in terms of $/kWh. In addition, power-based capital cost of supercapacitors is lower (100-300$/kW) compared to energy-based capital cost of supercapacitors (300-2000$/kWh). In comparison with power-based capital costs, the energy-based capital cost of batteries is lower, which is 150-400$/kWh for Lead-acid battery, and <300$/kWh for Li-ion battery. This essay may help researchers in choosing the advanced energy storage technologies for relevant purposes.

Obstacle identification for the development of pumped hydro storage using abandoned mines: A novel multi-stage analysis framework

To achieve the ambitious goals of "emission peak" and "carbon neutrality", China has developed a large number of wind and solar power plants. Access to a high percentage of renewable energy brings great challenges to the stability and flexibility of the power system. Pumped hydro energy storage (PHES) is a proven and economical technology to regulate the peak load and frequency. The development of pumped storage power plants using abandoned mines not only facilitates the effective use of underground space, ecological restoration and local resettlement of workers, but also promotes the large-scale use of renewable energy sources such as wind and light energy. However, in China, this technology is still at the conceptual stage, with few actual cases. Relevant studies have not comprehensively analyzed the obstacle factors faced by PHES and the relationship between them. Based on this, the paper sorts out the relevant obstacle factors from five aspects (economy, technology, construction, geography, and society), combines and improves the Decision-making Trial and Evaluation Laboratory (DEMATEL) and Interpretative Structural Modeling (ISM) methods, constructs an obstacle analysis framework, and explores the influence relationships among obstacle factors. Six key obstacle factors are obtained in this study: uncertain initial capital cost (E1), poor tightness and stability of surrounding rock (T3), construction difficulties (C2), water source problem (G1), insufficient policy drivers (S1), and the lake of demonstration projects (S2). The time-series analysis shows that the effects of E1 and S1 will diminish after 10 years. From the topological hierarchy diagram, it can be found that the impact of transportation problem (C1) will be weakened, and the impact of C2 and S2 on S1 will no longer be obvious with the gradual improvement of the policies. The sensitivity analysis shows that the model constructed in this study is robust and less influenced by the expert knowledge background. In the future, the government should promote the construction of underground PHES by encouraging enterprises’ capital investment, promoting key technology research, establishing information sharing database, and setting up demonstration projects. This study enriches the theory of PHES development in abandoned mines and provides guidance and theoretical basis for future engineering practice.

Recent advances of energy storage technologies for grid: A comprehensive review

AbstractEnergy storage is an idea that dates back over two thousand years. Engineers, investors, and politicians are increasingly researching energy storage solutions in response to growing concerns about fossil fuels' environmental effects as well as the capacity and reliability of global power systems. Various energy storage technologies are explored in depth in this study, with a focus on their application to the energy storage of electric grids. Specific consideration is paid to a few chosen technologies including flywheel energy storage, pumped hydro energy storage, compressed air energy storage, thermal energy storage in molten salt, hydrogen energy storage, battery energy storages, and capacitor and supercapacitor energy storage. Furthermore, this article delves into the concept of energy storage, focusing on a comprehensive examination of various deployments of these technologies around the world. Some of the barriers to commercial adoption of energy storage technologies, as well as the future, are covered in the article’s conclusion.

Short-Term Assessment of Pumped Hydro Energy Storage Configurations: Up, Down, or Closed?

Short-Term Assessment of Pumped Hydro Energy Storage Configurations: Up, Down, or Closed?

Multi-Objective Generation Scheduling of Hydro-Thermal System Incorporating Energy Storage With Demand Side Management Considering Renewable Energy Uncertainties

Atmospheric pollutants mainly produced by thermal power plants compel to utilize green energy sources such as renewable energy sources and hydroelectric plants in a power system. But due to blinking behavior of sources of renewable energy and due to very high rate of outages, it has a detrimental consequence on overall grid. Demand side management (DSM) programs decrease cost and improve power system security. This study proposes non-dominated sorting genetic algorithm-II (NSGA-II) to solve multiobjective scheduling of generation for fixed head hydro-thermal system integrating pumped hydro energy storage and sources of renewable energy taking into consideration the outage and uncertainty in presence of DSM. Numerical results of the test system attained using the proposed technique were compared with strength pareto evolutionary algorithm 2 (SPEA 2).

Feasibility of pumped hydro energy storage in a river cascade - case study of the Meuse

The Meuse river in the Netherlands has been made navigable by the construction of a cascade of seven low head weirs. Because of environmental regulations, hydropower facilities exist at only two weirs. This implies the full hydropower potential of the Meuse cascade is not utilized. By using pump-turbines the river sections upstream of the weirs could be additionally usable as energy storage reservoirs and could improve and ensure river navigability under changed climate conditions. The main goal of this study is to assess the possible utilization of the full energy storage- and hydropower potential of the Meuse cascade within Dutch environmental regulations. The novelty of this study is the evaluation of the concept of using canalized river sections for pumped-storage purposes within conditions of fluctuating discharge and -water levels throughout the year. In order to meet the goal of the study the relatively fish-friendly Archimedean screw has been selected as pump-turbine. Next a conceptual design of a pumped-storage hydropower plant equipped with screws has been compiled. By using this design, the assessment of utilizing the hydropower- and energy storage potential of the cascade has been carried out by constructing and applying a numerical model. The study shows it is possible to utilize the full hydropower- and the majority of the energy storage potential of the Meuse cascade. The cumulative installed turbine capacity for the cascade turns out to be 81 MW. The Annual Energy Yield (AEY) from regular hydropower alone is 225 GWh. In addition, the yearly surplus power that can be processed for energy storage purposes is 137.2 GWh, of which 77.2 GWh is returned to the grid by a round-trip efficiency of 56.25 %. In total 302.2 GWh can be delivered to the grid which can power up to 75.000 households. The specific cost is relatively high: roughly 15,000 euro/kW. The method developed here can be applied to evaluate the storage- and hydropower potential of other canalized rivers as well, such as the upper Mississippi.

Optimal dispatching of wind-PV-mine pumped storage power station: A case study in Lingxin Coal Mine in Ningxia Province, China

With the gradual transformation of global energy, photovoltaic power generation, wind power generation, and other renewable energy have attracted countries around the world. Western China has excellent wind and solar energy resources, which are highly vulnerable to external factors and have severe limitations. Considering the gradual maturity of storage and energy storage technology of abandoned mine reservoirs, the combination of storage and energy storage technology of abandoned coal mines and wind-solar power generation technology can realize the reasonable allocation of electric energy in the time dimension. This paper studies the regulation capability of the mine pumped-hydro energy storage system proposed by scholars and uses the wind-photoelectric field model to predict the output power of wind farms and solar power stations. Taking the Lingxin coal mine as an example, the optimization algorithm is used to optimize the dispatching ability of the entire PHS joint system. The results prove that the system proposed in this paper can significantly improve the instability of the generation power curve (In terms of variance, volatility decreases to 18.76%), and improve the overall system revenue to some extent (economic efficiency increased by 15.47%). This provides certain technical support for the better utilization of new energy in the future.

Decision-making framework for power system with RES including responsive demand, ESSs, EV aggregator and dynamic line rating as multiple flexibility resources

The carbon emissions emitted from conventional energy sources and the possibility of extinction of these sources in the near future push the states to seek new energy alternatives, namely renewable energy sources (RESs). In this respect, considering the increasing number of RESs thanks to the incentives of more environmentally friendly sources, and new generation loads, it is vital to use flexibility options in order to ensure reliability in the power systems. In this respect, this study deals with the stochastic optimum operating problem in a power system with wind power plants (WPPs), where dynamic line rating (DLR), pumped hydro energy storage (PHESS), common energy storage (CES), demand response (DR) and electric vehicle (EV) aggregator (EVAGG) is considered as flexibility options. With the proposed structure, an effective decision-making approach is presented that can meet all the requirements of power system operation, both technically and economically. Besides, various case studies carry out to demonstrate the effectiveness of the proposed framework in the IEEE 6-bus and IEEE 24-bus test system. According to the results obtained, PHESS has the most effect on minimization of wind spillage and total system operation cost, and when all flexibility options are evaluated, the total cost is significantly reduced, and no-load shedding occurs. The proposed model has a significant effect on reducing the total operation cost.

An Economic Risk Analysis in Wind and Pumped Hydro Energy Storage Integrated Power System Using Meta-Heuristic Algorithm

Due to the restructuring of the power system, customers always try to obtain low-cost power efficiently and reliably. As a result, there is a chance to violate the system security limit, or the system may run in risk conditions. In this paper, an economic risk analysis of a power system considering wind and pumped hydroelectric storage (WPHS) hybrid system is presented with the help of meta-heuristic algorithms. The value-at-risk (VaR) and conditional value-at-risk (CVaR) are used as the economic risk analysis tool with two different confidence levels (i.e., 95% and 99%). The VaR and CVaR with higher negative values represent the system in a higher-risk condition. The value of VaR and CVaR on the lower negative side or towards a positive value side indicates a less risky system. The main objective of this work is to minimize the system risk as well as minimize the system generation cost by optimal placement of wind farm and pumped hydro storage systems in the power system. Sequential quadratic programming (SQP), artificial bee colony algorithms (ABC), and moth flame optimization algorithms (MFO) are used to solve optimal power flow problems. The novelty of this paper is that the MFO algorithm is used for the first time in this type of power risk curtailment problem. The IEEE 30 bus system is considered to analyze the system risk with the different confidence levels. The MVA flow of all transmission lines is considered here to calculate the value of VaR and CVaR. The hourly VaR and CVaR values of the hybrid system considering the WPHS system are reported here and the numerical case studies of the hybrid WPHS system demonstrate the effectiveness of the proposed approach. To validate the presented approach, the results obtained by using the MFO algorithm are compared with the SQP and ABC algorithms’ results.

RETRACTED: Pumped hydro energy storage arbitrage in the day-ahead market in smart grid using stochastic p-robust optimization method

• Individual participation of pumped hydro energy storage (PHES) in day-ahead market. • Use of stochastic optimization to model the day-ahead market price uncertainty. • Stochastic p-robust optimization (SPRO) is proposed to measure the financial risks. • Risk-guaranteed strategy is obtained in comparison with risk-neutral strategy. • Robust bidding and offering strategies for PHES are obtained with SPRO method. Individual operation of pumped hydro energy storage (PHES) as large-scale energy storage needs the bidding and offering curves to participate, as a prosumer, in the day-ahead electricity market. Therefore, in this paper, by taking advantage of stochastic and robust optimization, a new stochastic p-robust optimization (SPRO) method is proposed to deal with the financial risks of the day-ahead price uncertainty. The proposed method compares the profit of PHES with the relative regret to get a risk-controlled strategy. According to obtained results, reducing the robustness parameter (p) from the p=+∞ to p=0.21, the profit, and the maximum relative regret are reduced by $ 2611 and 15.02 %, respectively. In other words, with a 19.11 % decline in profit, the maximum amount of relative regret decreased by 41.30 %. Therefore, it can be shown that by a few reductions in profit, the maximum amount of relative regret decreases significantly. At the same time, the robustness of PHES is guaranteed against the day-ahead market price uncertainty. Finally, the risk-based bidding and offering curves are derived using the results of the proposed SPRO method.

Drivers and barriers to the deployment of pumped hydro energy storage applications: Systematic literature review

Storage technology is recognized as a critical enabler of a reliable future renewable energy network. There is growing acknowledgement of the potential viability of pumped hydro energy storage solutions, despite multiple barriers for large-scale installations. A plethora of articles have been published covering the drivers for and barriers to the widespread diffusion of pumped hydro energy storage, but the literature has yet to coherently categorise and rate the various reported drivers and barriers. Therefore, a systematic literature review of studies published between 2000 and 2020 was conducted using meta-analysis guidelines to analyse, synthesize and consolidate findings covering both the techno-environmental and socio-economic drivers for, and barriers to, the development of pumped hydro energy storage. The study ranked the significance of reported drivers and barriers as well as the lessons learned for both developed and developing countries. The top-ranked techno-environmental driving factor was grid resilience (i.e., grid balancing, energy time-shifting, etc.) and the top-ranked socio-economic driver was revenue generation and rural development (i.e., job and businesses opportunities, infrastructural development, etc.). In terms of barriers, the top ranked techno-environmental barrier was as the lack of good infrastructure (i.e., roads, transmission lines, etc.) near potential sites, and top ranked socio-economic barrier was securing the initial and ongoing capital requirements for a less understand investment category. Overall, this study synthesises and categorises the drivers and barriers to the development of pumped hydro energy storage. Study findings will be useful to both researchers and practitioners seeking to better direct resources and efforts to foster the development of pumped hydro energy in the future. • Reviewed studies between 2000-2020 to determine the PHES drivers and barriers. • Key drivers to PHES deployment are energy storage, revenue and renewables integration. • Key barriers to PHES development are high capital cost and absence of power lines. • Growing interest in closed-loop systems compared to open loop systems. • Feasibility studies using GIS-MCDM were the most reported method in studies.

A Smart Strategy for Sizing of Hybrid Renewable Energy System to Supply Remote Loads in Saudi Arabia

The use of hybrid renewable energy systems (HRES) has become the best option for supplying electricity to sites remote from the central power system because of its sustainability, environmental friendliness, and its low cost of energy compared to many conventional sources such as diesel generators. Due to the intermittent nature of renewable energy resources, there is a need however for an energy storage system (ESS) to store the surplus energy and feed the energy deficit. Most renewable sources used battery storage systems (BSS), a green hydrogen storage system (GHSS), and a diesel generator as a backup for these sources. Batteries are very expensive and have a very short lifetime, and GHSS have a very expensive initial cost and many security issues. In this paper, a system consisting of wind turbines and a photovoltaic (PV) array with a pumped hydro energy storage (PHES) system as the main energy storage to replace the expensive and short lifetime batteries is proposed. The proposed system is built to feed a remote area called Dumah Aljandal in the north of Saudi Arabia. A smart grid is used via a novel demand response strategy (DRS) with a dynamic tariff to reduce the size of the components and it reduces the cost of energy compared to a flat tariff. The use of the PHES with smart DRS reduced the cost of energy by 34.2%, and 41.1% compared to the use of BSS and GHSS as an ESS, respectively. Moreover, the use of 100% green energy sources will avoid the emission of an estimated 2.5 million tons of greenhouse gases every year. The proposed system will use a novel optimization algorithm called the gradually reduced particles of particle swarm optimization (GRP-PSO) algorithm to enhance the exploration and exploitation during the searching iterations. The GRP-PSO reduces the convergence time to 58% compared to the average convergence time of 10 optimization algorithms used for comparison. A sensitivity analysis study is introduced in this paper in which the effect of ±20% change in wind speed and solar irradiance are selected and the system showed a low effect of these resources on the Levelized cost of energy of the HRES. These outstanding results proved the superiority of using a pumped-storage system with a dynamic tariff demand response strategy compared to the other energy storage systems with flat-rate tariffs.

Fully electrified land transport in 100% renewable electricity networks dominated by variable generation

Large greenhouse gas reductions are possible with a fully decarbonised grid and electric land transport. Additional electric load could pose a significant challenge to a grid with high levels of variable and non-dispatchable renewable energy sources. This scenario is not well-examined, nor is the use of pumped hydro energy storage for low-cost energy balancing. In this paper, we investigate the electrification of land transport within a photovoltaics and wind dominated 100% renewable electricity system. Only technologies that are deployed at scale and widely available globally are considered, namely photovoltaics, wind, battery electric vehicles, high voltage transmission, and pumped hydro. As a case study we present an hourly energy balance analysis of the Australian National Electricity Market with 100% renewables and 100% uptake of electric vehicles for land transport. The cost of the system is determined by occasional periods (days-weeks) of low renewable generation, and therefore only weakly dependent on the charging regime. The 40% increase in electricity demand due to electric land transport can be incorporated with a 4%–8% increase in the levelized cost of electricity. An exception occurs if most passenger vehicle charging occurs during the evening peak period, in which case the average price increases by about 18%.

Load frequency control of a m ulti‐source multi‐area thermal system including biogas–solar thermal along with pumped hydro energy storage system using MBA ‐optimized 3DOF‐TIDN controller

In this article, load frequency control has been studied in an unequal three-area system under a deregulated environment. The area 1 comprises thermal and biodiesel units, area 2 has thermal and solar thermal power plant (STPP), and area 3 has thermal with biogas, wind turbine system (WTS) along with pumped hydro energy storage (PHES) units. A new secondary controller called three degree-of-freedom tilt-integral-derivative with filter (3DOF-TIDN) controller has been proposed, and its performance is compared with integral, tilt-integral-derivative with filter, and two degree-of-freedom-TIDN controllers. The investigation reveals 3DOF-TIDN controller provides better dynamic performance in terms of settling time, peak deviation, and magnitude of oscillations in both generating and motoring mode of PHES. The stability analysis has been performed for the proposed system using different secondary controller. The controller parameters are optimized using novel optimization technique called Mine Blasting Algorithm. In this study, real-time OPAL-RT digital simulator has been used to effectually execute the considered power system under various scenarios, and the obtained results are compared with MATLAB/Simulink results. Further, a comparative study of dynamic responses of the system has been carried out considering different mechanical energy storage devices like PHES, flywheel energy storage device, and compressed air energy storage, and the analysis shows that PHES gives superior performances than others. Robustness analysis of proposed controller gains is also conducted, considering different uncertainties.

Combining electric energy storage and deep-lake degassing by means of pumped hydropower

Nowadays, pumped-hydro storage is the most established large-scale energy storage technology, but its implementation is seriously constrained by the availability of favourable sites. The geographical symbiosis between mountainous areas and deep lakes offers good prospects for the detection of such sites. In these areas, the generally meromictic structure of such lakes causes carbon dioxide saturation in the deep waters and, in order to mitigate the risk of lethal limnic eruptions as the world has already experienced, the gas-lift technique is being applied although it has a serious environmental drawback. This paper proposes an innovative and sustainable symbiotic match between pumped-hydro energy storage with the ideal deep lake degassing solution, providing removal of toxic gases from deep layers without polluting the surface waters of the lake. Considering the two Cameroonian “killer lakes” Nyos and Monoun taken as cases studies, the feasibility of the proposed system is analysed as well as conditions for participation in the local power market. As a result, the threat posed by these two hazardous water bodies is transformed into an opportunity to store about 756 MWh of electrical energy. In terms of installed capacity, this can achieve as much as 80 MW available for harnessing variable renewable energy and contributing to peak power supply. Finally, thanks to the number and distribution of deep lakes around the world, the proposed system shows capability to significantly contribute to the global energy storage potential in a context marked by an ever increasing need for flexibility in power systems.