scholarly journals A comparative framework to impact assessment of objective function structure and supply/demand scenario on hydropower operation

2021 ◽  
Author(s):  
Negar Gholami ◽  
Hesam Seyed Kaboli
Keyword(s):  
Water Supply ◽  
Objective Function ◽  
Pareto Front ◽  
Analytical Framework ◽  
Electricity Demand ◽  
Critical Periods ◽  
Hydropower Generation ◽  
Peak Period ◽  
Demand Scenario ◽  
Southwest Of Iran

Abstract The structure of objective functions in the reservoir optimization problem indicates the type of attitude to operation. This article presents an analytical framework to improve the structure of objective function by comparing 6 various forms of single-objective and bi-objective problems. Problems 1 and 2 were defined to compare two perspectives of operation, water supply versus energy generation. Problem 3 was also designed to examine the effect of the intra-annual electricity demand which was ignored in problem 2. Comparison of problems 4 and 5 shows the simultaneous effect of realistic water and electricity demand scenarios on finding an optimal Pareto front. Problem 6 considers a supply policy in which maximum hydropower generation in peak months is main strategy to reduce socio-economic tensions. These problems were analyzed for a period of 72 months in the operation of the Dez reservoir in the southwest of Iran. The results of comparisons showed that the average annual water supply in problem1 is 334 Mm3 higher than problem2, while the mean annual hydropower generation in problem2 compared to problem1 increases by 58.9 GWh. Hydropower generation in problem2 compared to problem3 experiences a 31.8% decrease in the peak period and a 111% increase in the non-peak months, it can impose significant problems on the National Electricity Network. The Pareto front for the problem 5 is better than the problem 4 at all points, meaning that the demand coefficient improves the Pareto front. The solutions of problem 6 can result in efficient meet of water and electricity demand in critical periods and incredibly improve practical planning.

scholarly journals Integration of Water Supply, Conduit Hydropower Generation and Electricity Demand

Proceedings ◽  
2018 ◽  
Vol 2 (11) ◽  
pp. 689 ◽  
Author(s):  
Marco van Dijk ◽  
Giovanna Cavazzini ◽  
Gideon Bonthuys ◽  
Alberto Santolin ◽  
Jacques van Delft
Keyword(s):  
Water Supply ◽  
Distribution Systems ◽  
Electricity Demand ◽  
Hydropower Plant ◽  
Hydropower Generation ◽  
Water Utility ◽  
Supply And Distribution ◽  
Constant Output ◽  
The One ◽  
Optimum Solution

South Africa is acknowledged to be not particularly endowed with the best hydropower conditions as it might be elsewhere in Africa and the rest of the world, however, large quantities of raw and potable water are conveyed daily under either pressurized or gravity conditions over large distances and elevations. There exists conduit hydropower generation potential in the water supply and distribution systems belonging to municipalities, water supply utilities and mines. Bloemwater, a water utility, constructed a stand-alone turbine, based on the available pressure and flow which generates a constant output ranging between 55 and 96 kW and when sufficient, supplies the head-office. Initially a manual changeover was utilized to switch between the hydropower and the local electricity supplier when the hydropower was insufficient to meet the demand i.e. switching of the full load from the one source to the other. To maximize the utilization of the hydropower, an automatic change over panel was developed to deal with the variable electricity demand from the office. The office building’s electrical distribution was divided into different distribution boards to allow each sector to be supplied and switched individually with 6, PLC controlled, motorized change-over switches. The PLC constantly evaluates and subsequently executes switching actions so that Bloemwater can utilize the maximum renewable hydropower, but also limits power interruptions to a minimum because of these switching actions. This technical paper describes the development of this conduit hydropower plant by evaluating the interrelationship of water supply, electricity demand and operating cycles, providing Bloemwater with the optimum solution with increased resiliency and sustainability.

scholarly journals Potential Micro-Hydropower Generation in Community-Owned Rural Water Supply Networks in Ireland

Proceedings ◽  
2018 ◽  
Vol 2 (11) ◽  
pp. 677 ◽  
Author(s):  
Irene Fernández García ◽  
David Ferras ◽  
Aonghus McNabola
Keyword(s):  
Water Supply ◽  
Economic Viability ◽  
Hydropower Generation ◽  
Energy Potential ◽  
Supply Networks ◽  
Rural Water Supply ◽  
Energy Demands ◽  
Water Supply Networks ◽  
Hydropower Potential ◽  
Rural Water

The potential of micro-hydropower generation has been evaluated in seven community-owned rural water supply networks (CORWSN) in Ireland. The replacement of the existing infrastructure in place to reduce pressure in the networks with micro-hydropower turbines (Scenario 1) was considered. New potential locations for additional pressure reduction were also considered (Scenario 2). An assessment of the energy potential and economic viability of each site was carried out, including quantification of leakage reduction impacts. While only one of the seven CORWSNs showed two potential sites with power higher than 1 kW, the power generated can still have significant impacts on local energy demands. The estimated total energy saved in Scenario 2 ranged from 0.63 MWh year−1 to 84.5 MWh year−1 according to the micro-hydropower potential in each CORWSN. Furthermore, water savings from 4348 € m−3 to 73,264 € m−3 were estimated due to the reduction of leakage volume after installing micro-hydropower turbines at the potential sites detected in Scenario 2. Thus, the water cost saving associated to the reduction of leakage volume makes the incorporation of this element in the networks feasible.

Biobjective Optimization of Well Placement: Algorithm, Validation, and Field Testing

SPE Journal ◽  
2021 ◽  
pp. 1-28
Author(s):  
Faruk Alpak ◽  
Vivek Jain ◽  
Yixuan Wang ◽  
Guohua Gao
Keyword(s):  
Multiobjective Optimization ◽  
Objective Function ◽  
Pareto Front ◽  
Optimization Problem ◽  
Optimization Problems ◽  
Field Testing ◽  
Efficient Implementation ◽  
Field Development ◽  
Biobjective Optimization ◽  
Single Objective

Summary We describe the development and validation of a novel algorithm for field-development optimization problems and document field-testing results. Our algorithm is founded on recent developments in bound-constrained multiobjective optimization of nonsmooth functions for problems in which the structure of the objective functions either cannot be exploited or are nonexistent. Such situations typically arise when the functions are computed as the result of numerical modeling, such as reservoir-flow simulation within the context of field-development planning and reservoir management. We propose an efficient implementation of a novel parallel algorithm, namely BiMADS++, for the biobjective optimization problem. Biobjective optimization is a special case of multiobjective optimization with the property that Pareto points may be ordered, which is extensively exploited by the BiMADS++ algorithm. The optimization algorithm generates an approximation of the Pareto front by solving a series of single-objective formulations of the biobjective optimization problem. These single-objective problems are solved using a new and more efficient implementation of the mesh adaptive direct search (MADS) algorithm, developed for nonsmooth optimization problems that arise within reservoir-simulation-based optimization workflows. The MADS algorithm is extensively benchmarked against alternative single-objective optimization techniques before the BiMADS++ implementation. Both the MADS optimization engine and the master BiMADS++ algorithm are implemented from the ground up by resorting to a distributed parallel computing paradigm using message passing interface (MPI) for efficiency in industrial-scaleproblems. BiMADS++ is validated and field tested on well-location optimization (WLO) problems. We first validate and benchmark the accuracy and computational performance of the MADS implementation against a number of alternative parallel optimizers [e.g., particle-swarm optimization (PSO), genetic algorithm (GA), and simultaneous perturbation and multivariate interpolation (SPMI)] within the context of single-objective optimization. We also validate the BiMADS++ implementation using a challenging analytical problem that gives rise to a discontinuous Pareto front. We then present BiMADS++ WLO applications on two simple, intuitive, and yet realistic problems, and a model for a real problem with known Pareto front. Finally, we discuss the results of the field-testing work on three real-field deepwater models. The BiMADS++ implementation enables the user to identify various compromise solutions of the WLO problem with a single optimization run without resorting to ad hoc adjustments of penalty weights in the objective function. Elimination of this “trial-and-error” procedure and distributed parallel implementation renders BiMADS++ easy to use and significantly more efficient in terms of computational speed needed to determine alternative compromise solutions of a given WLO problem at hand. In a field-testing example, BiMADS++ delivered a workflow speedup of greater than fourfold with a single biobjective optimization run over the weighted-sumsobjective-function approach, which requires multiple single-objective-function optimization runs.

scholarly journals Forecasting electricity demand in South Africa: A critique of Eskom’s projections

2010 ◽  
Vol 106 (1/2) ◽  
Author(s):  
Roula Inglesi ◽  
Anastassios Pouris
Keyword(s):  
South Africa ◽  
Electricity Demand ◽  
Price Determination ◽  
Demand Forecast ◽  
Electricity Crisis ◽  
Short Period ◽  
New Ideas ◽  
Demand Scenario ◽  
The Impact ◽  
Current Energy

Within a short period, Eskom has applied to the National Energy Regulator of South Africa (NERSA) for the third time since the 2008 electricity crisis, proposing a multiyear price determination for the periods 2010−2011 and 2012−2013. The new application, submitted at the end of September 2009, motivated for the debate of strategies with which the consequences of the proposed price hikes could be predicted, measured and controlled. In his presentation to Parliament in February 2009, Eskom’s then CEO, Mr Jacob Maroga presented the current energy situation in the country, the reasons for the crisis in 2007−2008, as well as the challenges of the future. The purpose of this paper is to contribute some new ideas and perspectives to Eskom’s existing arguments regarding the demand for electricity. The most important issue is the fact that Eskom does not sufficiently take into account the impact of the electricity prices in their electricity demand forecast. This study proposed that prices have a high impact on the demand for electricity (price elasticity of -0.5). Employing similar assumptions for the country’s economic growth as Eskom, the results of the forecasting exercise indicated a substantial decrease in demand (scenario 1: -31% in 2025 and scenario 2:-18% in 2025). This study’s findings contrasted significantly with Eskom’s projection, which has extensive implications as far as policy is concerned.

scholarly journals Examining the Relative Impact of Drivers on Energy Input for Municipal Water Supply in Africa

2021 ◽  
Vol 13 (15) ◽  
pp. 8480
Author(s):  
Pauline Macharia ◽  
Maria Wirth ◽  
Paul Yillia ◽  
Norbert Kreuzinger
Keyword(s):  
Cluster Analysis ◽  
Water Supply ◽  
Energy Input ◽  
Analytical Framework ◽  
Sub Saharan Africa ◽  
Relative Impact ◽  
Water Abstraction ◽  
Municipal Water Supply ◽  
Municipal Water ◽  
The Impact

This study examines supply-side and demand-side drivers of municipal water supply and describes how they interact to impact energy input for municipal water supply in Africa. Several key compound indicators were parameterized to generate cluster centers using k-means cluster analysis for 52 countries in Africa to show the impact of water supply–demand drivers on municipal water supply and associated energy input. The cluster analysis produced impact scores with five cluster centers that grouped countries with similar key compound indicators and impact scores. Three countries (Gambia, Libya, & Mauritius) were classified as outliers. Libya presented a unique case with the highest impact score on energy input for raw water abstraction, associated with largescale pumping from deep groundwater aquifers. Multivariate analysis of the key indicators for 20 countries in sub-Saharan Africa that are either water-secure or water-stressed illustrate the relative impact of drivers on energy input for municipal water supply. The analytical framework developed presents an approach to assessing the impact of drivers on energy input for municipal water supply, and the findings could be used to support planning processes to build resilient drinking water infrastructure in developing countries with data challenges.

The Business of Water

2016 ◽  
Author(s):  
Karen Bakker
Keyword(s):  
Water Management ◽  
Water Supply ◽  
Analytical Framework ◽  
Water Markets ◽  
Water Sector ◽  
Water Privatization ◽  
Five Dimensions ◽  
The Past ◽  
Water Trading ◽  
Market Environmentalism

Over the past three decades, water supply has become big business, and fierce debates have emerged in many countries over water privatization and water markets. This chapter reviews five dimensions of this debate: (1) the privatization of ownership and management; (2) the commercialization of water management organizations; (3) the environmental valuation and pricing of water; (4) the marketization of exchange mechanisms (“water trading” and “water markets”); and (5) the neoliberalization of governance. The analysis offers an analytical framework within which more structured, comprehensive assessments of market environmentalism—which is multifaceted and highly varied, difficult to implement in practice, and by no means hegemonic—in the water sector might be conducted. The chapter concludes with some reflections on the future of this debate.

Storage Ponds Application for Flood Control, Hydropower Generation and Water Supply

2019 ◽  
Vol 10 (4) ◽  
pp. 219 ◽  
Author(s):  
Avin Dadfar ◽  
Mohsen Besharat ◽  
Helena Margarida Ramos
Keyword(s):  
Water Supply ◽  
Flood Control ◽  
Hydropower Generation
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