THE IMPACT OF EFFICIENT EXPLOITATION OF HYDRO STORAGE ENERGY


By Eng. Malak M Shatnawi, PhD student and Professor Rajnai Zoltan, Obuda University, Budapest, Hungar

Abstract

The electrical system is characterized by fluctuation in demand and generating. This fact amplified with the new global trend toward growing interests to build Renewable Energy (RE) projects, which are characterized by instability. In many cases, the on-peak period is not commensurate with the available generating capacity, which leads to the direction of the expensive source generation and often harmful to the environment.

The purpose of electricity storage is to utilize energy during off-peak hours to generate electricity in the selected area and keep the electricity surplus. The stored water, typically equipped with pumps (turbines) and generators connecting an upper and lower reservoir, is then pumped using naturally available gravitational force to the nearby lake or river.

The methodology will focus on selecting the proper location for a hydro storage project in Hungary, which allows the use of a large amount of water available either from the Danube river or lakes, even if there is enough energy network. Although it depends mostly on the conventional source of energy, this makes the current research very important to achieve the vision of the European Union (EU).

98% of Hungary has an elevation of less than 200 meters above sea level, which limits the number of suitable areas for pilot projects.

Keywords: Pumped water storage; Energy; Hydroelectric and renewable energy; Environment; Sustainability.

 

INTRODUCTION

The continuous electricity demand requires enough generation capacity from different resources such as nuclear, fossil fuel, natural gas, renewable energy, etc. The international trend is to increase utilization of Renewable Energy (RE). Hungary’s trend of RE is rapidly growing and has exceeded the targets set by the EU. Table 1 shows contributions of RE; in 2016 it was 14.2% of the total primary energy, and the target in 2030 is 20%.

Table 1: Estimated trajectories for the sectoral share of renewable energy in gross final energy consumption.
Source: National Energy and Climate Plan of Hungary, 2018 European Commission Report.

Specific measures should be taken into consideration to increase the efficiency of RE because it is well known that RE sources have an interrupted nature; its variation is unpredictable and depends on weather conditions and seasonal changes. The electricity storage will have a significant impact by avoiding the interruptions and poor stability of RE. Also, research in the area of sustainable urban infrastructure shows the need to design and management of engineering systems in light of both environmental and socio-economic considerations. The main challenge for engineers, researchers and scientists to develop practical tools for measuring and enhancing sustainability over its life cycle[5]. It is necessary to analyze the current and future needs, and sustainability analysis should provide data on how the resources were used in the past, how they are being used now and how they will be used in the future[1].

On the other hand, using a non-renewable source for electricity generation, establish significant environmental and social impact due to the greenhouse gases and CO2 emissions. Moreover, they are exploiting non-renewable natural resources, producing waste, which are very harmful[1]. With the increasing integration of renewable energy sources, there is a need to develop technologies that can store power for peak demand periods and help maintain supply and demand in the system. The use of stored renewable energy is particularly attractive over expensive peaking plants. Based on modern technology, there are many energy storage technologies currently available; these technologies include Pumped Storage Hydropower PSH [2][6]. As defined by the United States Army Corps of Engineers, PSH is “a special type of hydropower development, in which pumped water rather than natural streamflow provides the source of energy”[7]. In general terms, PSH is a technology that stores low-cost off-peak energy or excess or unusable energy (perhaps generated from renewable energy sources) for later use.

Figure 1: The Pumped Hydropower System[11].

The Pumped Hydropower System, as shown in Figure 1, consist of the following:

  • Pumped Hydro Power system: it consists of two water reservoir with different elevation connected through hydro energy pump and turbine;
  • Storage Mode during off-peak demand: electric energy gets stored by pumping water from a lower reservoir to the upper reservoir;
  • Generation Mode during on-peak demand: water is released by natural gravity toward the hydroelectric turbine to produce electricity.

The results of this study concluded that according to the topographic features, installing a hydroelectric power system is completely suitable for certain areas in Jordan and Hungary. The paper is organized as follows:
   Section 1 – literature review and history.
   Section 2 – methodology of research.
   Section 3 – remarks and recommendations.

LITERATURE REVIEW

Historically, Pumped Storage Hydropower (PSH) was used in the United States to meet fluctuating power demands in conjunction with nuclear power plants. As renewable energy sources such as wind and solar are increasingly integrated onto the power grid, pumped storage hydropower is again gaining recognition as an effective power storage technology[2]. Countries such as Austria, which have no nuclear power plants, also constructed PSH projects to facilitate the better operation of their key conventional hydropower plants[8]. Hydropower projects considered one of the power grid and internationally recognised as an effective power storage technology. The PSH projects are used for compensation of the variation of the output energy from wind and solar power as well as to store excess or unusable energy from renewable sources, and therefore allow better integration of these types of renewable energy into the power grid[2]. On the other hand, fuel oil and diesel plants are popular for supplying peaking power because their fuel source is generally readily available; however, they have high operating costs and negative environmental impacts. Hydropower is another attractive way of supplying peaking power to maintain its stability where different power plants within the network are turned on and off throughout the day to meet the demand. An example from the United States of how power varies throughout the day is shown in Figure 2[9].

Figure 2: Power varies throughout the day. Source: (Hultholm, 2014).

PSH projects have been providing energy storage capacity and transmission grid ancillary benefits in the United States and Europe since the 1920s. Like other hydroelectric plants, the pumped storage plants are able to respond to potentially large electrical load changes within seconds. PSH project would be typically designed to have 6 to 20 hours of hydraulic reservoir storage for operation[3]. Pumped storage stations are efficient (round-trip efficiencies reaching higher than 70%); the industry plans to build reservoirs close to existing power plants, (Scientific American 2012) and enough projects are being considered to double capacity[3]. Usually, there are two most common configurations for pumped storage hydropower projects[2]:

Pure/off-stream pumped storage hydropower facilities: the system comprised of a lower reservoir, powerhouse, electrical-mechanical equipment, upper reservoir and a connecting waterway. It’s operated in daily or weekly cycles. Daily cycles are operated at night, typically starting between 10pm or midnight and ending in the early morning hours[10]. Peaking demand is lower on the weekends, which allows projects that operate on a weekly cycle, beginning the working week with a full upper reservoir and ending the working week with a nearly empty upper reservoir. The upper reservoir refilled over the weekend. It is more efficient to use adjustable speed related to pump-turbine and generators units, also been used at several power plants in Japan[8] and proposed for several new pumped storage hydropower projects in the United States. Combined pump/turbines are preferable because they have smaller, less expensive configurations and more affordable electrical-mechanical equipment.

Pump-back facilities operation of PSH projects: These are attractive in cases with a peaking capacity of the facility during periods of low streamflow, as well as cases with traditionally low streamflows, but high peaking demands[7]. Very large dams’ studies have reported real financial risks, cost overruns and schedule spills, in particular for the fragile and poorly managed economies of developing countries. Therefore, in the research, scenarios must be based on projected costs and expected costs since any project becomes economically non-beneficial due to the delay and overlooking sustainability issues as well.

Finally, feasibility study, sustainability, environ-mental and societal impact analysis carried out, and the study of solar PV and battery storage found to be cost-effective. It could be achieved faster with a substantially lower risk of time and budget overruns, as well as less environmental impact[4].

METHODOLOGY

In Hungary the existence of several sources of water such as Danube river and Balaton lake making the situation much easier for PSH.

Figures 3 and 4 show the maps and suitable locations to implement the hydroelectric storage system.

Figure 3: Distribution of water through Hungary[12].

Figure 4: Distribution of electricity power network through Hungary[12].

Figure 5 shows the topography of Hungary, which is almost flat except the Trans Danube; the Figure also shows the water body Danube River and Taz River and lakes.

Figure 5: Topography of Hungary[13] [14].

In the best hydro storage system, the location should have a grid, suitable topography in terms of elevation and water source. The considered locations should be located around the northern part of Danube river and Balaton lake.

Figures 6 and 7 represent the Balaton lake area elevation and profile, the suggested location is at the mountain near Balatongyorok; the Balaton lake elevation is +100m and the mountain is +400m, which leave us with a net difference of 300 m heights in elevation.

Figure 6: View of Balaton Lake using google earth map.

Figure 7: Altitude map of Balaton lake area, using google earth maps.


REMARKS AND RECOMMENDATIONS

  1. Hydropower projects are considered to be sustainable, with low operating costs and quick startup and shutdown capabilities.
  2. Even with huge advantages from using hydroelectric power systems, some disadvantages cannot be insignificant. For example, they require substantial initial financial investment compared with other technologies such as gas power plants that have lower initial capital investments, which make it more attractive to some power suppliers.
  3. Environmental impacts are essential during all stages of a pumped-storage hydropower project.
  4. In-depth studies should be carried out for operation and maintenance. ■

REFERENCES

  1. Juliana D’ Angela Mariano1, Francielle Rocha Santos, Gabriel Wolanski Brito, Jair Urbanetz Junior, Eloy Fassi Casagrande Junior: Hydro, thermal and photovoltaic power plants: A comparison between electric power generation, environmental impacts and CO2 emissions in the Brazilian scenario, INTERNATIONAL JOURNAL OF ENERGY AND ENVIRONMENT, Volume 7, Issue 4, 2016 pp.347-356, pp348,354, Journal homepage: www.IJEE.IEEFoundation.org
  2. Brandi A. Antal: Pumped Storage Hydropower: A Technical Review, B.S., University of Colorado – Boulder, 2004, A Master Report Submitted to Department of Civil Engineering University of Colorado Denver, May 2014, pp. 7,9,10,14,23.
  3. Energy Storage Association ESA Pumped Hydroelectric Storage, http://energystorage.org/energy-storage/ technologies/pumped-hydroelectric-storage
  4. Ayobami Solomon Oyewo, Javier Farfan ID, Pasi Peltoniemi and Christian Breyer: Repercussion of Large Scale Hydro Dam Deployment: The Case of Congo Grand Inga Hydro Project Energies — Open Access Journal of Energy Research, Engineering and Policy, Energies (ISSN 1996-1073; CODEN: ENERGA) Received: 27 February 2018; Accepted: 29 March 2018; Published: 18 April 2018, pp 1,6,23,30.
  5. WBCSD. 2000. “Corporate Social Responsibility: Making Good Business Sense”. World Business Council for Sustainable Development.
  6. Ibrahim, H., Ilinca, A., and Perron, J. (2007). “Energy storage systems – Characteristics and comparisons.” Renewable and Sustainable Energy Reviews, Volume 12, 1221-1250.
  7. United States Army Corps of Engineers. (1985). “Engineering and Design – Hydropower.” Engineer Manual 1110-2-1701. Chapters 2 and 7.
  8. Deane, J. B., Ó Gallachóir, B. P., McKeogh, E. J. (2010). “Techno-economic review of existing and new pumped hydro energy storage plant.” Renewable and Sustainable Energy Reviews, Volume 14, 1293-1302.
  9. Hultholm, C. (2014). “Energy Storage: Premises and Potential. http://www.smartpowergeneration.com/spg/ blog/energy_storage_premises_and_potenti et al, (February 2, 2014).
  10. MWH. (2009). “Technical Analysis of Pumped Storage and Integration with Wind Power in the Pacific Northwest. http://www.hydro.org/wp-content/uploads/2011/07/PS-WindIntegration-Final-Report-without-Exhibits-MWH-3.pdf (March 27, 2014).
  11. https://www.andritz.com/hydro-en/hydronews/hn32/11-pumped-storage
  12. https://www.geni.org/globalenergy/library/national_energy_grid/hungary/hungariannationalelectricitygrid.shtml
  13. Source, https://www.revolvy.com/page/Hydrology-of-Hungary
  14. https://www.nationsencyclopedia.com/Europe/Hungary-TOPOGRAPHY.html

ABOUT THE AUTHORS

Malak Shatnawi is a PhD student of Safety and Security Faculty at Obuda University, Budapest, Hungary.
     She is also the head of a technical department at Cities and Villages Development Bank CVDB, Jordan, providing support in all aspects of finance to Local Municipal Councils. She is the deputy director for Municipal Services and Social Resilience Project MSSRP, which is funded by World Bank and other Donors. The aim of the MSSRP Project is to support and finance Jordanian municipalities, affected by the influx of Syrian refugees, in delivering services and employment opportunities for Jordanians and Syrians. The project beneficiaries reached one million, with the target of three million at the end of the project.
     Malak’s main skills gain include conducting technical and feasibility studies, monitoring the performance of municipalities, preparing technical and biding procurement documents. Related tasks: Procurement officer for Regional and Local Development Projects RLDP, Secretary and member in many committees such as procurement, local and special tender committees for projects funded by CVDB, JTZ, JRLDP, JESSRP and JMSSRP.
     Malak holds a BSc and Master’s degree in Civil Engineering from Jordan University of Science and technology.
Contact: Malak.shatnawi@phd.uni-obuda.hu, Mob: 0036 205 143 327

Professor Zoltan Rajnai, is a Dean of School of Security Sciences, Óbuda University, He is is currently a Head of The Doctoral School and also holds the following positions: OE Doctoral School of Security Sciences (Core member), Doctoral School Council, (Discipline) Doctoral Council, (Discipline) Habilitation Committee, OE Doctoral School of Materials Science and Technology, (Discipline) Doctoral Council, OE Doctoral School of Applied Informatics and Applied Mathematics.
     Sample of Research area: security of communication networks of qualified periods, protection of critical infrastructure, information security.
     Professor Rajnai is 
an author of publications http://vm.mtmt.hu/search/slist.php?lang=0&AuthorID=10001163 and a holder of the awards for cooperation in education and research.
     He was a Head of the Organizing Committee of International Scientific Conferences for ten years;  Hungarian leader of international technology-applicability studies; Tivadar Puskás Award winner;        Telecommunication and Informatics Science Association (HTE) Gold Badge.
     Professor Rajnai is a winner of domestic and international applications:
        – 1996 – KHVM Chapter Managed Basic Programs;
        – 2000 – FEFA 2379 (Higher Education Development Basic Programs);
        – 2000 – KHVM Chapter Managed Basic Programs 6/2000;
        – 2000 – General Communications 2/2000/A;
        – 2004 – Complex telecommunications education Establishment of a specialized cabinet system (Ministry of Transport, Communications and Water).
     In 2005 he was a Chairman of the Organizing Committee of the NATO Scientific Conference Fund –  International Scientific Conference (in French “OTAN pour et contre – NATO Pro & Kontra”).
     Professor Zoltan Rajnai’s full biography is available here: https://bdi.uni-obuda.hu/hu/rajnai_zoltan
     Contact: rajnai.zoltan@bgk.uni-obuda.hu


Download the article as a PDF: Malak Shatnawi article – CIP Review online April 2020