Small Hydropower Stations Research Articles

Design of a Straight Bladed Vertical Axis Water Turbine Suitable for Deployment in River Like the Brahmaputra

Turbines are hydraulic machines which convert hydraulic energy into mechanical energy. This mechanical energy is used in running an electric generator that is directly coupled to the shaft of a turbine. These machines convert mechanical energy into electrical energy. The generation of hydro-electric power is the cheapest as compared to the power generated by other sources such as oil, coal, etc. Power generated by Small Hydro Power (SHP) station is not only cheap, but also environment friendly. Despite its dual advantage, the SHP has however remained untapped all over the world. Things are now changing surely but slowly, with more and more focus on SHP. Hydropower being the cleanest source of electrical energy from environmental considerations needs to be tapped as early as possible. The authors of this paper are motivated by the water current available in the river Brahmaputra, Assam, which may be suitable for establishing Small Hydro Power stations. A design of a prototype of a straight bladed vertical axis water turbine which is based on the theories of vertical axis wind turbine is proposed here. Encouraged by the existing theories of vertical axis wind turbine, the authors propose a mathematical analysis and design of a prototype of vertical axis water turbine which may be suitable for Small Hydro Power Station. Future scope of this work is also mentioned.

A socio-environmental vulnerability map to evaluate the sustainability of small hydroelectric power stations in Southeastern Brazil

It is understood that hydroelectricity generation through small hydropower stations is a sustainable alternative. However, in order to assess their sustainability, it is necessary to evaluate the socio-environmental vulnerability of a given region. This paper aims to analyse the socioenvironmental vulnerability from the impact of a small hydropower plant in Sao Luiz do Paraitinga, a municipality which is 180 km away from Sao Paulo city, Brazil. The methodology is based on principles of the analytical hierarchy process (AHP) in order to produce the Socio-Environmental Vulnerability Index (SEVI) Map. The results indicate that there is significant overlap between areas that are susceptible to physical processes of environmental vulnerability and those that present the worst social indicators. The results herein indicate a starting point for a more in-depth analysis of the socioenvironmental vulnerability of areas under the influence of small hydropower plants, which requires planning and mitigating actions to address such vulnerability.

Influence of Different Types of Small Hydropower Stations on Macroinvertebrate Communities in the Changjiang River Basin, China

Many studies have investigated the influence of hydropower stations on macroinvertebrate communities, but few have clarified the influence of different types of hydropower stations. A total of 133 samples obtained from seven rivers, on which 45 hydropower stations are located, with the rivers distributed across four provinces (Yunnan, Jiangxi, Fujian, and Hubei) were investigated to study the influence of different types of small hydropower stations on macroinvertebrate communities. Samples were collected during 2011–2012. Results showed that 126 taxa of macroinvertebrates were collected, of which 68.3% were insects. The average macroinvertebrate density and biomass were 966 ± 112 ind/m2 and 17.31 ± 1.54 g/m2, respectively. For dam-type hydropower stations, the intercepting effect of the dam was the main factor affecting macroinvertebrate populations, whereas the influence of hydrological period was nonsignificant. Macroinvertebrate taxa richness exhibited a gradual increase from reservoir reaches to down-dam reaches and then to natural reaches (4.4, 6.5, and 9.5, respectively). The Shannon–Wiener index showed a similar increasing trend (1.06, 1.48, and 1.58, respectively), whereas biomass levels exhibited a decreasing trend (56.3, 25.2, and 6.0 g/m2, respectively). For the diversion-type hydropower stations, hydrological period was the main influential factor, whereas the intercepting effect of the dam was nonsignificant. From wet to dry seasons, increases were observed in macroinvertebrate abundance (5.2 to 8.3), density (322.2 to 1170.5 ind/m2), biomass (24.6 to 40.1 g/m2), and Shannon–Wiener index (1.23 to 2.08).

Experiences in discharge measurements at Small Hydropower Stations in India

As a part of Ministry of New and Renewable Energy (MNRE), Government of India programme for promoting small hydropower (shp) development, efficiency testing and performance evaluation of Small Hydro Power plants is mandatory for receiving financial incentives by plant developer. The task of efficiency testing and performance evaluation of shp plants was assigned by MNRE to Alternate hydro Energy Centre (AHEC) Indian Institute of Technology Roorkee in the year 2003 along with financial support to acquire the required instrumentation and develop expertise. Over 200 small hydro plants (SHPs) of different capacity (1–25 MW) as well as types viz dam toe based, run of river and canal fall based have been tested for efficiency and performance evaluation during the period 2005–2018 in different states of India as per IEC-60041, IEC-62006, ISO -1438-1 and ISO-748 to the extend feasible as per available resources and time. During efficiency testing of hydro plants, it has been found that discharge measurement is very challenging activity as the most of the plant owners did not provide the required space and provisions for mounting/fixing the instruments for discharge measurement. After commissioning of the plants it becomes extremely difficult to select the ideal/suitable locations and providing the provisions for mounting different measuring instruments. Various problems observed during discharge measurement are discussed in this paper and may be helpful for testing in future.

Sectoral Cooperation of the BRICS Countries: Potential and Implementation Priorities

The BRICS countries are increasingly expanding multilateral forms of cooperation, moving beyond political areas to economic ones. This cooperation is based on their interest in using the resources and experience of other partners to the group to develop national economies and promote the export of goods, technologies and services for the benefit of national producers. The purpose of the study is to analyse the potential and identify the most promising areas of sectoral cooperation. It was carried out using the methods of comparative and statistical analysis, historical analogies, deductive and expert assessments. Agreed at BRICS summits, national economic strategies set the priorities of sectoral cooperation. Raising the competitive capacity of the BRICS economies is considered today in the context of productivity enhancement, including increasing energy efficiency, improving logistics, innovating technologies. The most promising areas are cooperation in offshore oil and gas production, nuclear power, construction of small hydropower stations, building transport corridors, including the high-speed networks and equipment of the Northern Sea Route. The sectoral priorities also highlight cooperation in the agriculture sector to address food security problems and in the digitisation of all sectors of the economy to take advantage of the opportunities provided by information and communication technologies.

Reduction of Inrush Current and Voltage Drop by Selecting Optimum Reactors in Induction Generators

Induction generator has many advantages compared to the synchronous generator in terms of robust, cost and easy to maintenance. So the induction generator has been widely applied to small or medium size hydropower station in recent years. The induction generator generates a large inrush current corresponding to the starting current of the induction motor at the moment of grid connection. This inrush current can cause the voltage drop of the grid as well as the consumer load equipment, which may degrade the stability of the electric quality. It is very important to reduce the voltage drop due to the inrush current in order to improve the electric quality and increase the supply of the induction generator. In this study, we propose a solution to reduce the voltage drop and the inrush current by adjusting the parameters of the reactor tap and adjusting the appropriate operating pattern of the water turbine generator. As a result of the analysis, it was confirmed that the voltage drop can be adjusted within the allowable range.

Study of Local Consumption Measures to Yunnan Small Hydropower

Focus on the phenomenon of increasing surplus electricity of small and Medium-sized Hydropower stations in Yunnan Province, After introducing the distribution, capacity, quantity, Production and operation status of YunNan small hydropower and so on. This paper Researched and Analysed the power market、structure of load and energy consumption characteristics to YunNan power system. According to the realities of power source characteristics、structure of load and power market of YunNan power system, the methods that “combination of tobacco with hydropower”、developing electricity consumption for rural residents、market transaction and energy substitution are proposed to promote the local absorption of YunNan small and medium sized hydropower. According to the existing industrial policies and industry data of Yunnan, these measures can effectively promote the local absorption of small hydropower in Yunnan.

SMALL HYDROPOWER PLANTS AS A PART OF ELECTRIC POWER INDUSTRY AND ENERGY MARKET OF UKRAINE

Globalization and sustainable development necessitate joint analysis of technological and environmental trends in energy development taking into account current economic and legal provisions. Based on synthesis of the current state of Ukrainian electric power system in general and hydropower in particular, there have been underscored the importance of comprehensive approach in identifying the key tasks of building the pathway of further electric power industry development. The authors provide the characteristics of today’s organizational and technological structure of the electric power system, including the legal provisions regulating its activity. As currently there are significant legislative changes, particular attention was paid to the review of electricity market. Features of the new liberalized electricity market have been determined in comparison with the current market, and also in connection with renewable energy characteristics. Thus, amendments introduced by the new Law “On electricity market” to the green tariff policy have been detailed with the regard to incentive mechanism for development of renewable energy and liability of electricity producers operating under Green Tariff for imbalances. The article focuses on the analysis of the state and growth potential of small hydropower. Еconomic incentives are systematized according to the current legislation. Also, here is presented the potential for possible growth of small hydropower, namely, quantitative result of the exploration of the technical potential of hydropower resources of small rivers. There have been identified a number of barriers and impediments to the construction of small HPPs. Environmental restrictions to the construction of small hydropower stations have been formulated according to the accurate analysis of various branches of national legislation such as the Land Code, the Water Code, the Law “On the Nature Reserve Fund of Ukraine”, etc., as well as valid ratified documents and other key soft-low instruments at the international level. Additionally, provisions of Сustoms and Tax legislation on small hydropower regarding to incentives for technology development have been defined. Consideration of small hydropower projects successfully implemented on the territory of the country confirms the possibility of the future development of small hydropower.

EXPRESS ASSESSMENT OF HYDROPOWER POTENTIAL OF THE SMALL RIVERS IN UKRAINE WITH ACCOUNT OF ENVIRONMENTAL RESTRICTIONS

The article is devoted to the development of an express method for assessing the potential of hydropower resources of the small rivers in Ukraine, taking into account the requirements of the current regulatory framework in the environmental and energy sectors, which provides objective information for the development of small hydropower stations at the current stage of alternative energy development. The article determines the environmental restrictions of small hydropower based on the provisions of the current regulatory and legal framework of Ukraine, the criteria for the ecological value of the territory and the principles of preserving the diversity of wild fauna of rivers. Restrictions on the use of water for the production of small hydropower plants take into account the sanitary discharge, the continuous operation of fishers, low water, floods, operational measures to regulate the water flow through hydroconstructions, the regulation of hydroelectric power through the watercourse which allows practically no distortion of the natural hydrological regime and biological state of river below the station. Restrictions on the use of the territory for the construction of small hydropower stations take into account the presence of national natural parks, reserves, and natural monuments, places of deposits of minerals and mineral waters, historical and cultural heritage, special purpose land. Restrictions on the permissible bias of river sections have been introduced with regard to environmental restrictions. The article substantiates the significance of the technical potential of the hydropower resources of small rivers in Ukraine, taking into account environmental restrictions, at the level of 1270 million kWh/year (about 375 MW of installed capacity of small HPPs), and its distribution over the hydrological zones of the country. It is established that the volume of technically achievable potential of hydropower resources, even for the main deep-water small rivers of Ukraine, is within 3–15% of their natural potential. The results obtained are essential for the development of a modern concept of regional programs for the development of small hydropower and the Energy Strategy, implementation of the activities of the National Action Plan for Renewable Energy in Ukraine.

Preliminary Study on Risk Assessment Model for Drought Risk in Small Hydropower Stations

Preliminary Study on Risk Assessment Model for Drought Risk in Small Hydropower Stations

A CVaR-Robust Risk Aversion Scheduling Model for Virtual Power Plants Connected with Wind-Photovoltaic-Hydropower-Energy Storage Systems, Conventional Gas Turbines and Incentive-Based Demand Responses

To make full use of distributed energy resources to meet load demand, this study aggregated wind power plants (WPPs), photovoltaic power generation (PV), small hydropower stations (SHSs), energy storage systems (ESSs), conventional gas turbines (CGTs) and incentive-based demand responses (IBDRs) into a virtual power plant (VPP) with price-based demand response (PBDR). Firstly, a basic scheduling model for the VPP was proposed in this study with the objective of the maximum operation revenue. Secondly, a risk aversion model for the VPP was constructed based on the conditional value at risk (CVaR) method and robust optimization theory considering the operating risk from WPP and PV. Thirdly, a solution methodology was constructed and three cases were considered for comparative analyses. Finally, an independent micro-grid on an industrial park in East China was utilized for an example analysis. The results show the following: (1) the proposed risk aversion scheduling model could cope with the uncertainty risk via a reasonable confidence degree β and robust coefficient Γ. When Γ ≤ 0.85 or Γ ≥ 0.95, a small uncertainty brought great risk, indicating that the risk attitude of the decision maker will affect the scheduling scheme of the VPP, and the decision maker belongs to the risk extreme aversion type. When Γ ∈ (0.85, 0.95), the decision-making scheme was in a stable state, the growth of β lead to the increase of CVaR, but the magnitude was not large. When the prediction error e was higher, the value of CVaR increased more when Γ increased by the same magnitude, which indicates that a lower prediction accuracy will amplify the uncertainty risk. (2) when the capacity ratio of (WPP, PV): ESS was higher than 1.5:1 and the peak-to-valley price gap was higher than 3:1, the values of revenue, VaR, and CVaR changed slower, indicating that both ESS and PBDR can improve the operating revenue, but the capacity scale of ESS and the peak-valley price gap need to be set properly, considering both economic benefits and operating risks. Therefore, the proposed risk aversion model could maximize the utilization of clean energy to obtain higher economic benefits while rationally controlling risks and provide reliable decision support for developing optimal operation plans for the VPP.

Research of the spatial aspects of using renewable energy sources for sustainable development of the territory

The object of research is renewable energy sources as the basis for the development of renewable energy in Ukraine. Problems in the implementation of objects in this industry are the need to apply measures for their safe operation and less profitability of renewable energy sources compared to traditional ones. This is due to the high cost of equipment and significant costs to ensure technological processes. Increasing the share of renewable energy sources in the total energy balance will require government subsidies to the industry. It has been proven that the application of the cartographic approach allows determining the optimal locations of renewable energy facilities from an economic point of view and taking into account a number of equally important factors, in particular, social and environmental impact. The next methods are used: cartographic – when applying modeling techniques for building maps of renewable energy resources; geo-informational – in the process of collecting and processing information about resources, objects and factors for the development of renewable energy; statistical – at the stage of calculating the energy potential of wind energy, solar energy, geothermal and hydrological resources. The maps for the above-mentioned renewable energy directions are presented, recommendations on the optimal areas for the construction of energy facilities are given on the example of Kharkiv region (Ukraine). So, location: wind power plants are recommended in Vovchansk, Kharkiv, Velykyi Burluk regions; solar power plants – in Blyzniuky, Pervomaiskyi, Balakliia, Izium, Lozova and Borova; geothermal power plants – in the south of Barvinkove and Blyzniuky, southeast of Izium, Borova and Lozova districts. Perspectives for locating small hydropower stations within the study area are sections of the Siverskyi Donets, Udy, Berestova, Mzha, Merla rivers. The dependence of the economic efficiency of wind, solar, geothermal energy and small hydropower facilities on factors such as: distance of transportation of energy raw materials and finished energy to consumers; heat loss; cost of investment in the construction of infrastructure (power lines, electrical substations, heating networks).

A Rapid Active Power Regulating Technique for A Virtual Small-hydro Cluster

A rapid active power regulating technique for a virtual small-hydro cluster is studied in this paper. The virtual small-hydro cluster consists of several decentralized small-hydro power stations, which quickly responds to the active power target instructions of real-time dispatch and AGC. Furthermore, the power fluctuation of the delivery cross-section caused by intermittent power source in short-term scale can be efficiently smoothed. When any tie line transmission power reaches its thermal stability limit, the active power target instructions is allocated according to the sensitivity priority of small-hydro power plants to threshold-crossing lines among the small-hydro cluster. When all the tie lines transmission powers are within their thermal stability limits, the active power target instruction is allocated on the basis of the priority of the summation of product of tie line power variations and sensitivity of small-hydro power stations to tie lines. Under the constraint of fulfilling the active power target instructions, the simulation results show that the adopted control strategy and allocation algorithm can effectively decrease the power fluctuation of each tie line.

Analysis and Research on the effect of the Operation of Small Hydropower in the Regional Power Grid

The analysis of reactive power balance and voltage of power network not only affects the system voltage quality, but also affects the economic operation of power grid. In the calculation of reactive power balance and voltage analysis in the past, the problem of low power and low system voltage has been the concern of people. When small hydropower stations in the wet period of low load, the analysis of reactive power surplus and high voltage for the system, if small hydropower unit the capability of running in phase is considered, it can effectively solve the system low operation voltage of the key point on the high side.

Social sustainability assessment of small hydropower with hesitant PROMETHEE method

Small hydropower stations in remote areas promote regional economic development and social progress. Social sustainability assessment which immensely decides the success of small hydropower development has been paid little attention currently. Meanwhile, present methods tend to fail the social sustainability assessment due to following three problems. Firstly, the uncertainty of information cannot be fully described. Secondly, the correlation among indicators lacks rationality. Thirdly, the ranking methods adopted in previous studies are not appropriate for social sustainability assessment of small hydropower. To deal with the above problems, a Preference Ranking Organization. Method for Enrichment Evaluations (PROMETHEE) outranking method using hesitant fuzzy linguistic term set (HFLTS) is proposed. Firstly, the HFLTS is introduced to describe the uncertainty of information. Then, the Analytical Network Process (ANP) method is adopted to measure the correlation between indicators. Moreover, the PROMETHEE method is employed to rank the social sustainability of each alternative. Then an empirical study is carried out to prove that the proposed methodology is effective and practical. Finally, public recognition is discovered as the key indicator by comparative analysis and discussion. This study provides an innovative perspective for the social sustainability assessment of small hydropower and contributes to making more rational and scientific decisions.

Study on the influence of small hydropower stations on the macroinvertebrates community-Take Nanhe River as a case, China

This study take Nahan River as a case to research the impacts of small hydropower stations on macroinvertebrates community. Results showed that a total of 13 macroinvertebrate samples was collected and contained 56 taxa belonging to 18 families and 35 genera. The influence of runoff regulation was more seriously than hydrological period. There were obvious zoning phenomenon of macroinvertebrates between reservoir, downdam reaches and natural reaches. From reservoir, downdam reaches to natural reaches, species abundance increased in turn. There are the least species in reservoir, the most in natural rivers. The reservoirs had the highest biomass and were quite different from those in downdam and natural reaches. However, there was no significant difference between different periods of hydropower station.

Ecological footprint analysis of environmental impacts by cascaded exploitation of diversion-type small hydropower: a case study in southwest china

Cascaded exploitation of diversion-type small hydropower (SHP) offers a source of new energy as well as socioeconomic benefits; however, it inevitably causes environmental disturbance and damage. Previous studies on the cumulative effect of cascaded diversion SHP rarely discussed using quantitative analysis method. In this paper, the ecological footprint analysis approach is proposed to assess the positive and negative impacts of cascaded diversion SHP on environment of a small-scale river in Southwest China. Positive impact is defined as ecological supply footprint (ESF), which refers to vegetation protection by replacing firewood with SHP. Negative impact is defined as ecological loss footprint (ELF), which includes fish and net primary productivity loss, vegetation destruction and soil erosion. With the raising in the number (n>4) of diversion SHP stations, the difference between ELF and ESF increases remarkably, suggesting that the adverse impacts of cascaded diversion SHP accumulate in the study area. Compared with vegetation destruction and soil erosion, the cumulative loss of fish and net productivity is the most important aspect of the adverse impacts which needs more attentions.

The Study on Eco-environmental Issue of Aral Sea from the Perspective of Sustainable Development of Silk Road Economic Belt

The Aral Sea crisis is the most prominent environmental problem in building Silk Road and Economic Belt, which is mainly induced by extensive exploitation of land resources in Aral Sea basin since the middle of last century. The upstream part of Amu Darya River, as the main water source of Aral Sea, is almost entirely located in Tajikistan, thus, the development and utilization of Tajikistan water resources affect the whole Aral Sea basin. The author puts forward oriented-development of green energy under the overall framework of co-building Silk Road and Economic Belt, developing small hydro-power and dam-free hydro-power stations, standardized implementation of agricultural modernization in Central Asia, through high efficiency and water saving agriculture to achieve “returning water to sea”, to reverse drying trend of Aral Sea, to renovate ecological environment, resulting in simultaneous implementation of agricultural production and Aral Sea governance, simultaneous achievement of agricultural harvest and ecological environment improvement of Aral Sea basin. The article makes a scientific proof of reality and feasibility regarding the proposed methods. Green ecological environment and stable social environment will contribute to the sustainable development of Green Silk Road and Economic belt.…

The prospects for Small Hydropower in Colombia

Small hydropower (SHP) has existed for more than a century in Colombia, and is gaining reserved interest as an option to mitigating climate change. In this paper we investigate the prospects for SHP in Colombia based on an analysis of economies-of-scale and learning-by-doing effects. We created an inventory of SHP plants realized in Colombia between 1900 and 2013, and focused on grid-connected SHP stations only. In the economies-of-scale part of our analysis we considered all SHP plants with a capacity lower than 20 MW. However, we exclude plants with a capacity lower than 0.1 MW from the learning-by-doing analysis, given that their cumulative capacity is still too small for a meaningful learning curve estimation. We used an Ordinary Least Squares analysis for estimating the parameters of our economies-of-scale and learning-by-doing models, and observed that infrastructure costs and total costs are mainly driven by economies-of-scale, while equipment costs can also be influenced by learning-by-doing. Our findings suggest that equipment costs for SHP plants with capacities between 0.1 and 20 MW have declined at an average learning rate of 21%. We conclude that both the public and private sectors can benefit from scaling effects for hydropower plants.

Low mortality rate in silver eels (Anguilla anguilla L.) passing through a small hydropower station

In many regulated rivers, silver eels (Anguilla anguilla L.) experience significant mortality as they pass through small hydropower stations (HPS) during their downstream migration. There has been a huge collapse in the recruitment of this species, primarily because of the destruction of river–ocean connectivity with overfishing. The direct mortality caused by small hydro turbines varies between different places and depends on many factors. The aim of the present study was to assess the mortality rate of silvers eels passing through a small HPS equipped with a Francis turbine in a small Pomeranian river using acoustic telemetry. During the experiment, no direct mortality occurred as a result of passage through the HPS turbine. However, three individuals were believed to have suffered from injuries or passage trauma.