Small Hydro Research Articles

Techno-Economic Analysis of Decentralised Small Hydro Power Projects for Rural Electrification: A Case Study of Meenvallom Project in Kerala with the Use of RET Screen Expert Advanced Software

Rural electrification is a fundamental factor of poverty mitigation and rural growth of a nation. In India, electricity has not played an active role in the socio-economic progress of the village. Gross Domestic Product (GDP) is growing by 8%, whereas the involvement of agriculture division is 1.9%. The government of India has encouraged the goal of providing electricity to all villages in various phases. Therefore, the aim of this research was to define the techno-economic analysis of decentralized Small Hydro Power projects in Kerala with the help of RET Screen expert software. The objectives are to explore the potential hydropower to be harvested by Small Hydro Power for rural electrification, to assess financial saving and cost analysis and to investigate the environmental impact of the Small Hydro Power in Kerala. The RET Screen expert is used to assess the economic feasibility of a Small Hydro Power system and to recommend the possibility of installing the technology in the Meenvallom SHP in Kerala. The RET Screen expert is a Clean Energy Management Software developed by the Government of Canada, which is a free-of-charge decision support software for pre-feasibility or feasibility analysis and also ongoing energy efficiency performance analysis (Netscreen Canada). An attempt has been made in this study is to evaluate the features of rural electrification in Kerala and the viability of Small Hydro Power (SHP).

Duck curve leveling in renewable energy integrated grids using internet of relays

Power grids are undergoing deregulation, privatization, and decentralization worldwide. The smart grid allows the integration of clean power renewable energy technologies to the utility grid through mini, micro, and nano grids. Conventional centralized power grids used to rely on fossil fuel-fired power plants which are being replaced worldwide with solar, wind, small hydro, geothermal, biomass, wave, and alternative energy technologies. Installed solar and wind power generation capacity has surpassed 1300 GW in 2020. Solar and wind powers rise during the day and fall during the evening. Consumer demand increases steadily during the evening and peaks after sunset when solar generation becomes zero and wind power falls substantially. Decentralized smart grid faces duck curve limitation on the integration of renewable energy technologies as centralized utilities used to face the peak-hours issue. Smart grid operators have no effective solution of load peaking after sundown except keeping fossil fuel-fired plants on standby to ride through the duck curve. We present a solution to the duck curve problem by integrating smart load shedding devices in micro and nano grids to adjust their demand frugally during peak hours to support the national grid. Information and communication (ICT) technologies that enabled the internet of things (IoT) have been attempted to facilitate smart load shedding in nano grids. ICT enabled voltage transformers (VT) and current transformers (CT) supply signals to heuristic rules based multifunction smart relaying system. Smart meters, instrument transformers, and status monitoring field devices generate a massive amount of data. The research designed an IoT and LabVIEW based software platform to carry out demand-side management. Under frequency (UF) and under-voltage (UV) relaying functions were used to conduct load shedding in nano grids. This nanoscale demand-side management experiment paves the way to ride through utility-scale duck curve setback. This PT/CT data based economic solution performs at nanoscale same as ABB PML 630 load shedding controller. This UF and UV relaying based multifunction relay starts shedding loads when frequency falls below <1% and voltage below 10% of rated values. Our load shedding scheme has successfully functioned on nanoscale 5 kW system. The future study section proposes to integrate big data technologies in-home energy management system (HEMS) through extract, transform and load (ETL) pipeline to import data from PT/CT and circuit breakers (CB) integrated smart meter to transform it according to requirement by loading data into Hadoop “big data” processing platforms for utility-scale load management with help of day-ahead load and weather-dependent renewable power generation forecasting techniques.

High specific speed Francis turbine for small hydro purposes - Design methodology based on solving the inverse problem in fluid mechanics and the cavitation test experience

The paper is a result of a research and development project aimed at developing a series of types of high specific speed (90 < nsQ < 100) Francis turbines. The inverse flow analysis approach based on the hodograph theory has been employed in order to develop the blading geometry of quality high enough to minimize the subsequent CFD based optimization process. The three-dimensional turbine blades are developed on meridional stream surfaces determined using the VLM methodology. The mass and momentum conservation equations are written in a curvilinear coordinate system, which is adjusted to the streamlines by means of the Christoffel symbols. The solution is found using the method of characteristics. The developed geometry is optimized by means of the genetic algorithm implemented in CFD software. Model tests were conducted in the Institute of Fluid-Flow Machinery of the Polish Academy of Sciences. Satisfactory coincidence between design assumptions, the CFD based performance assessments and those based on the model test results attained, shows reliability of the methodology adopted. Critical cavitation numbers as established according to different criteria have been applied to plot the sigma permissible isolines on top of the efficiency hill diagram. Physical interpretation of some irregularities in diagnostic characteristics is provided.

Synergies of river and land circulation in towns with small rivers: The case of Poitiers (France)

AbstractThe development of waterfront archeology since the 1970s has motivated the study of the synergies between cities and rivers. The increasing number of excavations in city waterfronts with its inception in Northern Europe, emphasize the complexity and value of riparian areas. These city‐river synergies shed light on such natural and cultural complexity, which requires a multidisciplinary approach and highlights the dynamics of a changing, hybrid and multifunctional riverine area. Although this interdisciplinary field of research has recently been growing, archeological research in France is focused primarily on large hydro systems with respect to smaller ones. This paper focuses on two secondary watercourses—the Clain and the Boivre—surrounding the city of Poitiers in Western France. Studying river and land circulation of the city in a longue durée perspective highlights the importance of small rivers in waterway traffic, as well as their archeological potential. These findings call for a reconsideration of the rich heritage of small rivers in future urban development projects, taking into account the sensitivity of small hydro systems to environmental changes.This article is categorized under: Human Water &gt; Human Water

Energy generation by small hydro power plant under different operating condition

Energy is the basic input for the economic development of a country. The growing demand for energy generation has resulted in dependency on fossil fuels. The price of fossil fuels and security of energy supply has been a concern in India and other countries which can be overcome by the exploitation of the large potential of hydro power and renewable energy sources. India has vast potential in the range of small and medium size hydro power projects. Hydro power stations have an inherent ability of instantaneous starting, stopping, load variation and helpful in improving reliability of the power system. Operation of small hydropower system is the systematic procedure to obtain the maximum energy generation under different operating conditions with proper operating strategy. In the present paper, the operating strategy have been developed by analysing energy generation based on water availability. Different combinations of discharge for different units have been considered.

Solar energy forecasting using intelligent techniques: A step towards sustainable power generating system

The rapid advancements in the technology, increase in comfort levels, movement of population to urban areas, depletion of fossil fuels and increasing greenhouse gas emissions have invigorated the use of renewable energy resources for power generation in the last few years. The major renewable energy resources which have potential to fulfill the requirements includes solar energy, wind energy, small hydro and biomass etc. Among these major resources, solar energy-based technology is considered as one of the fastest growing technology because of its various advantages and ubiquitous availability of the resources. However, there are certain challenges in the utilization of solar energy for power generation because of various uncertainties in the atmosphere. As a result, the power generated from solar based power plants is fluctuating in nature which is not desirable. Therefore, the utilities are adopting the smart grid approach which has ability to integrate the solar power plants efficiently and the solar energy forecasting is one of the essential tools for this new model. In this paper, AI based techniques are utilized to forecast solar energy using high quality measured solar irradiance data. The forecasting accuracy of the developed models is evaluated based on statistical indices such as absolute relative error and mean absolute percentage error. The results obtained from the developed models are compared to observe the forecasting ability and performance with the high-quality measured data and found accurate.

Integration of small hydro turbines into existing water conduit of an irrigation dependent power plant – A case study

Hydro energy is one of the richest and most useful renewable energy sources in the world. In an irrigation-based storage reservoir, agricultural to hydro power water transfer is important. A tradeoff between irrigation and power generation is essential in order to achieve optimal social benefits. Most of the irrigation based hydro turbines employ the reaction type turbines due to the advantages of low/medium head and high discharge through the irrigation canals. The release of water through irrigation gates is affected during the lower release of water for irrigation, flora and fauna and drinking. The power units are of reaction type hydro turbines could not able to tap the energy during the lower release due to the restriction on operational limitations, the turbine may subject to cavitation and leads to noise and vibration causes subsequent fatal failure of parts and catastrophic accident on the plant. This condition leads to reasonable generation loss to the power generating units. A pilot study on Dhom (2x1 MW) irrigation dependent hydroelectric plant, Mahagenco, Satara, Maharastra has been conducted in order to tap the water during the lower release and flood scenario from the reservoirs. The modification has been suggested in the existing layout of penstock section at main inlet valve. This paper emphasizes on utilizing untapped energy by integrating small hydro turbine into the existing water conduit in an irrigation dependent hydro power plant. Incorporation of inline hydro power units with existing water conductor system would yield additional power generation of 2.592 Million units of energy per year. Further, the plant capacity factor could be increased from 0.315 to 0.463. The additional power generation can be used for internal loads of the power house.

Small Hydro Power Turbine Location based on Water Height and Discharges

Small Hydro Power Turbine Location based on Water Height and Discharges

Factors Influencing the Determination of the Gyrosures Potential of Small Rivers

The article examines the main trends in the use of renewable energy sources in the world. The article examines the main trends in the use of renewable energy sources in the world. The use of renewable sources is associated with the depletion of reserves of carbonaceous minerals and a decrease in greenhouse gas emissions into the atmosphere. The article presents the main, according to the authors, reasons for the incorrect determination of the potential of small hydro resources in the Republic of Tajikistan. In recent years, many small hydroelectric power plants have been built, which are ineffective. For this, the authors propose a more detailed study of the watercourse regime and the determination of its potential for the minimum and maximum tributaries and the possibility of its use, the influence of hydrological, socio-economic factors on the determination of the potential of small rivers during the construction of small hydroelectric power plants. Zoning of small watercourses is proposed for a more detailed determination of the watercourse capacity and the possibility of constructing small hydroelectric power stations on them. The influence of altitude above sea level on the output of the rated power of installations of renewable energy sources is considered. As it shows, the experience of operation and the above statistical analysis at the existing small hydroelectric power plants with an altitude of SHPPs above sea level, their nominal capacity will decrease. The decrease in the nominal output power of small hydroelectric power plants with an air-cooling system is associated with the rarefaction of atmospheric air.

Vertical axis wind power plant

The issue of developing technologies using alternative renewable energy sources today is a very urgent task both around the world and in Russia, which is explained by economic, technological, and, most importantly, environmental factors. The climatic and geo-graphical features of our country create all the necessary conditions for the use of such areas as solar energy, small hydro energy, wind energy, etc. But the most promising in terms of energy potential is wind energy, as many regions of our country are located in areas with high average wind speeds. However, there are a number of problems that impede the development of wind energy in Russia, the most important of which is the almost complete absence of wind generators designed and manufactured in our country that could compete with foreign models. The product proposed in the article is an attempt to solve this problem through the use of a new design of a wind wheel and an electric generator, as well as the use of magnetic suspensions.

Generation control of isolated small hydro power plant by using DECSA optimized FPI controller

PurposeIn this work, generation control of an isolated small hydro plant (SHP) is demonstrated by applying optimal controllers in speed governor and hydraulic turbine system. A comparative analysis of application of fuzzy PI (FPI) and PID controller is conferred for generation control (both power and terminal voltage) of an SHP. The controllers are designed optimally by using crow search algorithm (CSA) and novel hybrid differential evolution crow search algorithm (DECSA). The purpose of this paper is to settle the voltage and real power to improve the quality of the power.Design/methodology/approachIn this work, the controllers (PID and FPI) are implemented in speed governor and excitation system of SHP to regulate power and terminal voltage. Differential evolution and CSA are hybridized to enhance the performance of controller to refurbish the power and terminal voltage of SHP.FindingsThe proposed DECSA algorithm is applied to solve ten benchmark functions, and the effectiveness of DECSA algorithm over CSA and DE is demonstrated in terms of best value, mean and standard deviation. CSA and DECSA algorithms optimized controllers (PID and FPI) are used to design SHP with the capability to contribute power and voltage of better quality. The comparative analysis to substantiate the competence of DECSA algorithm and FPI controller is demonstrated in terms of statistical measures of power and voltage of SHP. Robustness analysis is performed by varying all system parameters to prove the effectiveness of the proposed controller.Originality/valueThe proposed algorithm and FPI controller are applied individually to improve the quality of the power of SHP. DE, CSA and DECSA algorithms are implemented to solve benchmark equations. The solutions of all benchmark equations contributed by DECSA algorithm is converged rapidly and having minimum statistical measures as compared to DE and CSA algorithms. The DECSA algorithm and FPI controller are proposed with superior competence to enhance the generator performances by conceding undershoot, overshoot and settling time of power and terminal voltage. DECSA-based FPI controller contributes a noticeable improvement of the performances over other approaches.

Evaluation of different statistical techniques for developing cost correlations of micro hydro power plants

The ministry of India has proposed the SHP (Small Hydro Power) scheme to achieve a cumulative capacity of 6000 MW from small and micro hydro projects (MHPs) till 2022. Initial stage investigation of these projects require accurate investment cost estimates to carry out the feasibility studies. Although many previous research studies developed various cost estimation models for SHPs, they can’t be directly employed for cost estimation of micro hydropower as well without their comprehensive evaluation. Therefore, this paper focuses on estimation of cost correlations for MHPs using different statistical methods to test the viability of these methods and to present a distinctive approach for more accurate cost estimates. This study meticulously analyzes a total of three methods; the former two methods utilize the existing approaches to evaluate each cost component individually in order to derive the respective cost expressions. And, the third method explores the effects of employing multivariate polynomial regression model for the development of cost correlations, which is validated further on the basis of MAPE (mean absolute percentage error). The proposed method yields an MAPE of less than 5% for total project cost of MHPs while it is found more than 20% using aforesaid methods.

Computational Analysis on Numerical Simulation of Internal Flow Physics for Pump as Turbine in Renewable Small Hydro Energy Generation

Energy contributes significantly in almost all aspects of human life as well as economic activities and plays a crucial role in the infrastructural development of a county to alleviate poverty. Generating energy from a renewable source such as small hydropower through the application of pump operating as a turbine mode called Pump as Turbine is one of the best alternatives to provide clean and inexpensive energy. Using Pump as Turbine helps in generating reasonably priced hydroelectric power for communities in underdeveloped counties. This study investigates the effects of internal flow behaviour and performance of Pump as Turbine under different rotational speed and flow rate. The rotational speed is an essential physical parameter as it affects the Pump as Turbine operation. A model-specific speed centrifugal pump model with head 32 (m), flow rate of 12.5 (m3/h) and the rotational speed of 2900 rpm, has been selected for the study. Numerical simulations have been conducted using the k-ω turbulence model to solve three-dimensional (3D) equations. The pump mode experimental data were used to confirm the results for better analysis. The results predicted that vortex and turbulent kinetic energy increase per rotational speed increase. Also, at the higher rotational speed, very high recirculation of flow is detected at the blade suction chamber, although the pressure side has a smooth flow. This study provides beneficial information which will serve as a reference to help improve PAT performance along with selecting PAT for a small hydropower site. Future works will consider the impact of blade thickness and cavitation in Pump as Turbine.

System for assessing the sustainability conditions of small hydro plants by fuzzy logic

AbstractThis work presents a system for an integrated evaluation of the implementation of small hydroelectric power plants (SHPs), based on a soft decision tree. The method generates the enterprise's sustainability index, where economic, environmental, and social aspects are considered in its interactions, with indicators measured in the field, sectoral indexes, and final index generated by fuzzy logic rule blocks. The methodology used to select the indicators and indexes followed four phases. First, a fuzzy expert system (FES) was developed in the form of a soft decision tree. Then, the array of suggested variables and weights were submitted to expert analysis using the Delphi methodology, and their assessments were collected. The third phase was the improvement of the system, taking into account the obtained considerations. In the fourth phase, the system was applied to a case study based on the installation of an SHP in the southern region of Brazil. The results obtained in the case study showed the sustainability of the enterprise. The presented method can have a significant contribution in supporting decisions regarding the licensing of hydroelectric projects.

Investigating the state of renewable energy and concept of pump as turbine for energy generation development

Access to consistent and clean energy is a key challenge faced by several countries globally; especially in Asian and African countries. Most of the communities within these and other regions in the world are faced with continuous energy crisis, causing most of these economies to cripple. It is estimated that billions of people worldwide are living without access to clean and reliable source of energy. Renewable energy is the biggest source of energy and it characterizes the basis to steer the energy system in the direction of sustainability and supply security. Several countries globally are blessed with rich renewable energy resources that have not been fully developed. These renewable resources have the potentials to change the status quo of power generation and consumption in these countries. In this study, the status of renewable energy generation and storage was identified and discussed. A specific centrifugal pump model with radial volute and 6 impeller blades having inlet and outlet diameter of 104 mm and 160 mm respectively. The operational parameter of the head is 16 m, flow rate is 12.5 m3/h, rotational speed is 2900 r/min and efficiency is 56% were selected to carry out numerical simulations in the study. Using the centrifugal pump to operate as turbine (PAT), is one of the best alternatives for small and micro hydro generation since it helps in meeting energy needs. Furthermore, it can also help improve economic growth due to its cheapest source of power generation as well as providing sustainable energy source that will create more employment opportunities to improve the socio-economic environments of the people. Moreover, PAT method are also advantageous because of its low cost in acquisition and maintenance. The characteristics of PAT have been discussed numerically to analyze pressure and velocity distribution at different rotational speeds. The study concludes that PAT is the best alternative for energy generation.

A brief review on the Gorlov helical turbine and its possible impact on power generation in India

This article reviews the various technologies in crossflow hydro turbines and the viability of installing Gorlov helical turbine in possible potential sites. The article also shares insight into the small hydro project and its current situation in India. Various approaches in simulation for the cross-flow turbine are also evaluated. Also, various design approaches to Gorlov helical turbine are outlined with simulation. Much care is taken to introduce various experimental data regarding the output characteristics of the Gorlov helical turbine.

A Study for the Optimal Exploitation of Solar, Wind and Hydro Resources and Electrical Storage Systems in the Bormida Valley in the North of Italy

The exploitation of distributed renewable energy sources leads to a low-carbon energy transition, mainly based on the optimal integration of hydro, PV and wind power plants with the remaining high-performance fossil-fuel power stations. In the last twenty years, European Union (EU) countries have shown a significant increase of the power installed in new PV and wind power plants, together with the refurbishment of small and medium size hydro stations. In particular, in Italy, PV and wind energy production has strongly increased and nowadays there are regions characterized by a very green energy mix. In this new scenario, energy storage becomes a viable solution to mitigate the variability of renewable energy sources thus optimizing the network operation. The present paper is focused on the Liguria region, in the North of Italy and in particular on the Bormida Valley where nowadays more than the half of the annual electricity consumption is covered by the renewable energy local production. The paper describes the current energy situation and proposes an optimization tool to investigate the possibility of installing new PV and wind power plants, as well as energy intensive storage units based on sodium-sulphur batteries; moreover, different scenarios are analyzed through the definition of economic and environmental key performance indicators.

Analytical analysis of combined effect of interior guide tube and draft tube on cross flow turbine performance

Cross flow turbine is considered the most appropriate turbine in micro hydro range of small hydro plants. In this range, variation in flow in small streams is very high and cross flow turbines are inherently suitable for such sites. Further cross flow turbines are easy in fabrication and can be fabricated locally. However, the efficiency of cross flow turbine in comparison of other conventional turbines is inferior. It is therefore there is scope to improve its efficiency. Under the present study, theoretical investigation has been performed to improve the performance of cross flow turbine by providing an interior guide tube (having different shapes and different locations) and draft tube in cross flow turbine. The combined effect of interior guide tube and draft tube has been studied. A substantial improvement in efficiency about 3.35% has been totaled.

Economic feasibility analysis of small hydro power projects

The clean development mechanism (CDM) was created with two main goals: help developed countries achieve the greenhouse gas emissions reduction targets set out in the Kyoto Protocol and provide sustainable development to developing countries who host the projects. Sustainable project management shares the same goals as the CDM project, which could be a valuable asset in the development of new projects. Much has been discussed about the effectiveness of the program in achieving those goals and even more in the post-2012 period when the CDM has experienced fewer new projects and lower certified emissions reduction (CER) prices compared to previous years. Based on Brazilian CDM project data, this works aims to analyze the economic aspect of sustainable management by observing the influence of the obtained CERs on the internal rates of return (IRRs) of a small hydro plant (SHP) according to the current CDM scenario, marked by CER prices reaching their lowest historical values. For this study, a spreadsheet was developed to simulate a project’s cash flows and thus determine its IRRs. The results show that using the current CER prices, carbon credits do not significantly affect SHP projects’ IRRs, with increases of less than 0.2% compared to a scenario with no credits. CDM projects may benefit more from optimizing the investment costs or increasing energy production. These results highlight a need to emphasize the sustainable benefits of the CDM program rather than only focusing on the economic return perspective.

Multi-Objective Antlion Algorithm for Short-Term Hydro-thermal Self-scheduling with Uncertainties

ABSTRACT In this paper, a stochastic multi-objective structure is introduced in joint energy and reserve market to allow energy generation companies participating in the short-term hydro-thermal self-scheduling with uncertainties. To solve this problem, an antlion optimization (ALO) algorithm is used. In addition, uncertainties including energy price, spinning and non-spinning reserve prices, output power of the wind, photovoltaic and small hydro units are mentioned. In this study, two methods are used to generate stochastic multi-objective scenarios, namely lattice monte-carlo simulation and roulette wheel mechanism (RWM). After that, the main purpose of the study is described, i.e. making GENCOs able to achieve the maximum profit and the minimum emission by using a multi-objective function considering a stochastic process. To reach this aim, the mixed integer programming (MIP) which includes a set of multi stage deterministic scenarios is employed. However, some special cases should be introduced in the formulation structure of the presented scheduling regarding hydro-thermal units to make the SMO-HTSS problem with wind, photovoltaic and small hydro units similar to the real time modeling. Since optimal solutions are produced in this method, one can allude to the application of the ε-constraint. Nevertheless, in order to select one of the most appropriate solutions among Pareto solutions obtained, the utilization of fuzzy method has been presented. In the end, as shown in this paper, the ALO algorithm is limited to the ε-constraint; some tests are carried out on an IEEE 118-bus test system to verify the accuracy and validity of the proposed method.