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Small hydropower (SHP) is one of the most critical renewable energy that is well adapted to the rural localities in less developed countries across the world. Most rural communities in Nigeria are off the national power grid and are bedevilled by an inconsistent supply of electricity. The one possible panacea to the rural energy crisis is harnessing the terrain and abundant rivers and streams within their domain. This study aimed to identify and select suitable sites for the SHP dam in the upper Benue river watershed. Ten thematic layers, land use, precipitation, geology, soil, slope, elevation, stream power index, topographic wetness index, drainage density, and flow, were integrated with Geographic information system and Analytical hierarchy process. A composite suitability map created revealed that 7.5% of the watershed is of a very high suitable class, while 17.5% of the watershed is of a very low suitable class. To select an ideal location, a semi-automatic approach was developed to identify narrow valleys by intersecting contour with stream order and the suitability layer. Eighteen (18) potential dam sites were identified after a query operation was done. The developed method was validated using field data which were correlated with the model output using t-Test; paired two samples for the mean. A strong Pearson correlation of 0.71 between the field data and the semi-automatic approach was observed. The approach offers good prospects for dam site selection. Based on a field survey, the potential dam sites are feasible economically and technically for SHP dam construction that will provide cheap renewable energy to millions of inhabitants in the watershed.

The inevitable depletion of traditional energy sources attracts a strong interest in the development of renewable energy technologies around the world. Territorial features and abundance of water resources in Russia have a great potential for small hydropower development, but statistics show that there is no high practical interest in this area. A comparative analysis of the features of the Russian and Chinese energy systems indicates the presence of certain problems in the small hydropower industry of Russia connected with the lack of a strategic understanding of the prospects for the development of the industry at the state level. This situation naturally leads to an increase in investment risks. The purpose of the present research is to determine the conditions that can make the construction of small hydropower plants attractive to investors and lead to the formation of the market of the appropriate technological equipment. Official statistics, planning documents, expert publications in the media and scientific magazines, as well as the author's comparisons of the Russian and Chinese small hydropower regulation measures have been used in the process of analyzing the Russian energy development.

India is a developing nation with 1.35 billion populations living in varied strata of living standards. Therefore, the energy demand is constantly increasing in an effort to accelerate industrial activities and boost the economy. The country mostly meets its electricity demand from fossil fuel. It has large generation capacity but in some remote and rural areas only 53% of the villages get electric supply for less than 12 hours a day. This is because of hilly and mountainous terrains especially in the north and north-eastern regions of the country and absence of utility grid owing to economic reasons. It is estimated that about 15% of country's population do not have access to electricity. With huge hydro potential in the country, especially in the Himalayan States, hydropower generation may be emphasized and pressed in to augment ever increasing energy demand. The emphasis should be on small hydropower (SHP) as construction of large hydropower involves huge capital cost and they are associated with various techno-economic and social issues. The article aims to provide important information for appropriate policy making in developing small hydropower in India.

In this paper, a small hydropower microgrid solution with high applicability is proposed to solve the problem of high line failure rate and long maintenance time, which can improve the reliability of distribution network in mountainous areas. In this scheme, small hydropower and local load constitute a low-cost but efficient microgrid operation to improve the reliability of rural electricity. In this scheme, small-sized hydropower and local load constitute microgrid operation. In case of failure, the scheme makes full use of the independent operation of microgrid to provide qualified power quality to local load. This scheme is easy to realize and does not need additional energy storage, so it has good economy. Firstly, the frequency disturbance characteristics of small hydropower microgrid is analyzed, which lays a theoretical foundation for small hydropower microgrid operation. Then it introduces the island operation mode to grid-connected operation mode transition of small hydropower, including the key technologies such as frequency adjustment strategy in island operation stage. Finally, the simulation studies show the effectiveness of the method.

In general, the seasonal characteristics of small hydropower (SHP) especially the power transmission during the summer flood season would lead to the steady overvoltage of the distribution network. In order to suppress this steady overvoltage, a strategy for coordinated cooperation between generator phase-in operation and shunt reactors which can be called cooperative control is proposed. The distribution network of SHP stations connected to the 35 kV Bantao substation in southern Shaanxi is taken as an example to study the mechanism of overvoltage after the SHP is connected to the grid. A distribution network model with SHP units is established. Based on the model, the effect of separately installing shunt reactors on the node voltage is studied in the case of generator lag phase operation and the influence of the operation mode of SHP unit on the node voltage is also analyzed separately. Finally, the improvement measures of cooperative control between the generator phase-in operation and the parallel reactors are analyzed by simulation. Results are presented to verify the improvement measures that can effectively restrain the overvoltage of the distribution network in the SHP area.

The article provides an overview of the current state of energy in the world and in Russia, which focuses on the development of renewable energy sources (RES). An analysis is made of the trend in the production and consumption of energy resources, as well as an assessment of the use of renewable energy in Russia. Incentives for the development of renewable energy sources with the characteristics available in the world are determined. Conclusions are drawn about the importance of developing this industry both in Russia and in the Chechen Republic, as one of its regions. An assessment is given of the development of wind and solar energy in Russia. The current power supply structure of the Chechen Republic is considered, where the indicators of maximum electric power, consumed electric power, and also electric power generation of the republic are given. The analysis of the possibility of using wind and solar energy resources, as well as small hydropower of the Chechen Republic. Options for the development and effective use of renewable energy sources are considered, taking into account the fact that the use of energy resources based on modern innovative technologies, the introduction of new promising alternative sources, and the search for ways to stimulate the use of renewable energy sources, where it is supposed to organize and introduce a tariff policy, is one of the main tasks of energy development which give a complete systemic idea of the scale of the problem of transferring the energy system to innovative rails. Some options are proposed for the most expedient development of the energy system of the Chechen Republic, the construction of small pilot plants using renewable energy sources, with the goal of actual (experimental) confirmation of the predicted calculated values, as well as the gradual mass introduction of plants using renewable energy sources in the private sector with the creation of the necessary tariff conditions for use and construction installations on an industrial scale within the framework of energy private or public companies. Priority tasks have been set for the prospective development of the republic’s energy sector by introducing renewable energy sources.

This article contributes to an emerging body of literature about the micropolitics of the transition to renewable energy by examining how community leaders, in order to protect their territories, contest the energy transition. We present findings from two ethnographic case studies of small hydropower plants (SHPs) in indigenous Mapuche territory. As SHPs up to 20 MW are considered renewable projects by law, Chilean national authorities consider them as a non-invasive eco-friendly solution and, consequently, most of these projects are approved without carrying out an indigenous consultation and, thus, ignoring community leaders’ demands for territorial autonomy. Following a micropolitical ecology approach, this paper analyses community leaders’ resistance towards SHPs in Mapuche territories by discussing three key aspects: 1) access to information, 2) participation in decision-making processes, and 3) changes in community politics. These are different dimensions of the ‘micropolitical life of SHPs’, a heuristic tool, defined in collaboration with community leaders to explore the contentious political dynamics that community leaders experience in their resistance against SHPs on the one hand, and to describe how community leaders’ political practices shape and are shaped by contingent encounters and alliances in specific historical and territorial settings on the other. We conclude that despite the anguish that SHPs cause, community leaders bring about hope that may create possibilities to transform their territories.

As the effects of climate change are becoming severe, countries need to substantially reduce carbon emissions. Small hydropower (SHP) can be a useful renewable energy source with a high energy density for the reduction of carbon emission. Therefore, it is necessary to revitalize the development of SHP to expand the use of renewable energy. To efficiently plan and utilize this energy source, there is a need to assess the future SHP potential based on an accurate runoff prediction. In this study, the future SHP potential was predicted using a climate change scenario and an artificial neural network model. The runoff was simulated accurately, and the applicability of an artificial neural network to the runoff prediction was confirmed. The results showed that the total amount of SHP potential in the future will generally a decrease compared to the past. This result is applicable as base data for planning future energy supplies and carbon emission reductions.

Energy is the prerequisite for social and economic development of a community and country. In Japan, national government is promoting small hydropower (SHP) through a renewable energy policy by providing a high FIT price of 34 yen (≒0.32 US$/kWh) on energy generated from an SHP of less than 200 kW. Until now, the energy generation was controlled by national government agencies, but now independent power generation businesses are growing at the local community level in rural Japan. For the future growth of SHP, it is necessary to make electricity generation at the local community level. Therefore, these local communities will install and manage their renewable electricity by themselves. It will help to make the community self-sustainable and independent from the national government, and at the same time, it will also lead them to achieve the Sustainable Developments Goals (SDGs) target from community-based action. This paper aimed to discuss an SHP development business model in which local community will become the business owner of the SHP. It means “of the community, by the community and for the community”. The community identifies their renewable energy potential and needs, they borrow money from the financial organization or banks, install the power plant and do necessary maintenance and management by themselves. The revenue earned by selling electricity is used to repay the loan, and the rest is used for community development directly (such as local roads construction, agriculture land improvements, community hall maintenance, waterways maintenance, welfare, etc.). This paper also discussed a community-based 50 kW SHP installed in Miyazaki prefecture of Japan as a case study. This SHP is one of the best examples of a community ownership model (Community-based business model). A detailed explanation from planning to investment has been discussed. The local community is getting approximately 112,000 USD per year by selling the electricity, and 162-ton CO2 is estimated to decrease yearly, which will support the achievement of SDGs. Finally, installing this kind of SHP in remote areas will provide managerial skills to the local community directly, plant operation knowledge, and education to local students. Local communities learn the problem-solving skills, which lead them to solve the local problem on a community level by themselves.

Hydropower is the energy generated by transforming the force of water into electrical energy. To take advantage of this power, large hydraulic infrastructures are built that are suitable for extracting the maximum potential from this renewable, emission-free, and domestic resource. The goal of this chapter is to have an overview of the worldwide research trends related to hydropower. All publications indexed in the Scopus database with this term in the title, abstract, or keywords are studied, obtaining more than 23,000 records. The subject categories have been analyzed, and the most important ones were: Engineering, Environmental Science, Energy, and Earth and Planetary Sciences. With regard to the temporal evolution of the number of publications, two periods have been detected, up to the year 2000 and after that; the latter period has an exponential growth. In terms of countries, it has been observed that this ranking is led by China, the United States, Germany, the United Kingdom, India, and Brazil. The main institutions with at least 200 publications were 15, all from China except one from Norway. Study of the keywords made it possible to detect nine clusters that were considered significant and that establish the research trends in this field: Small Hydropower, Energy Optimization, Rock Mechanics, Dams & Reservoir, Engineering, Fish, Hydrology, Simulation, and Agriculture. In short, this book chapter provides a global overview and new research opportunities in the field of hydropower.

Small hydropower (SHP) plays an important role in the Baltic States as a reliable and efficient source of electricity from renewable sources. This study presents the historical development, current status, and possible trends for the future development of SHP in the Baltic States with insights into the legal background and development policies for SHP in Estonia, Latvia and Lithuania. For the assessment of hydraulic structures in the Baltic States, the historical data was used supplemented with data from hydropower associations, the national departments of statistics, electricity transmission systems operators, etc. The currently recommended best practice for SHP development is the utilisation of existing sites with available infrastructure. These include old water mill sites and existing dam sites, which, in the Baltic States, number more than 1500. The majority of these sites have their power potential attributed to micro-hydro (

Small hydropower plants utilizing unharnessed energy in existing irrigation systems are a prominent source of renewable energy. In Japan, land improvement districts play a key role in the management of irrigation systems, but face serious problems in terms of management sustainability and require participation from non-farmers. The purpose of this study was to examine the effect of residents&rsquo, involvement in small hydropower projects on their environmental awareness and understanding of the projects&rsquo, multifunctional regional value. We administered a questionnaire survey to 238 households in three areas: Itoshiro, Kashimo and Ibigawa. The respondents were categorized into four groups: participation, recognition, knowledge and control. Based on the degree of respondents&rsquo, involvement in small hydropower projects, inclusive relationships between their involvement and awareness were revealed. These relationships suggest that the trigger of resident involvement is a key factor in developing sustainable small hydro facilities within existing irrigation systems.

In the context of the need for an increasing share of renewables in electricity mixes, the paper presents the existing RES mix, PV and wind, for partially covering the electricity consumption of a research institute, ICSTM, and proposes a solution for completion with a third form of RES, a small hydropower plant. Moreover, it is envisaged to include the proposed small hydropower plant as a new real-scale laboratory attached to ICSTM. The method includes the presentation of an existing proposal for increasing installed capacity in new PV panels and propose to install an SHPP to a weir situated a few hundred meters from the institute. The hydropower potential for two possible arrangements is assessed and some types of turbines suitable for this location are presented. The main results demonstrate that building an SHPP is a better solution for completion of PV and wind as source of electricity for ICSTM. The main conclusion of the paper is that by installing new RES capacities, ICSTM can build a real-scale laboratory for new technologies, at the same time fully covering its own electricity consumption and even supplying a green electricity mix into the national power system.

There was an unprecedented growth of SHP (small hydropower) in Japan during recent years because the government has provided a high FIT (USD 0.32/kWh) for SHP development projects of less than 200 kW. The public and private sectors are committed to harnessing this natural energy to achieve the renewable energy goal as well as to improve local communities social and economic conditions. This paper will discuss about renewable energy initiatives by a food corporation enterprise (FCOOP) based in Fukuoka prefecture of Japan to reduce their net carbon emissions. A detailed approach for social enterprises-based SHP development has been discussed which will be a role model concept for other social enterprises in Japan and in the world that are willing to reduce CO2 emissions. Also, this kind of project connects urban stake holders with local community where resources are available and it leads to development of the local community living standards. As a demonstrated example, a case study of a 20 kW SHP installed in Japan by a FCOOP has been discussed.

The increasing demand for renewable and sustainable energy sources has encouraged the development of small run-of-river plants. Preliminary studies are required to assess the technical and economic feasibility of such plants. In this context, the identification of optimal potential run-of-river sites has become a key issue. In this paper, an approach that is based on GIS tools coupled with a hydrological model has been applied to detect potential locations for a run-of-river plant. A great number of locations has been analyzed to identify those that could assure the achievement of different thresholds of potential power. The environmental and economic feasibility for small hydropower projects in these locations has been assessed and a multi-objective analysis has been carried out to highlight the most profitable configurations. The Soil and Water Assessment Tool (SWAT) has been calibrated to simulate runoff in the Taw at Umberleigh catchment (South West England). The results showed that, in the area of study, different locations could be selected as suitable for run-of-river plants.

As the largest global renewable source, hydropower is a useful supplement to mountainous distribution networks with abundant water resources, and shoulders a large portion of the regulation duty in many power systems. In particular, in the form of decentralized energy sources located to their customers, small hydropower (SHP) improve grid stability by diversifying the electricity system and reducing power loss. The mountainous distribution networks supplied by small hydropower are closed-loop design but open-loop operation, which easily causes the tripping of tie line even further the off-grid operation of small hydropower system. Once the tie line trips, the current countermeasures&mdash, such as hydropower shutdown and load shedding&mdash, do not fully guarantee the reliability of power supply and the utilization efficiency of hydropower. This paper studies the amplitude-frequency characteristics of SHP off-grid, according to the typical integration of hydropower in South China, a SHP on-grid/off-grid model is established based on the Power Systems Computer Aided Design (PSCAD) platform. It is found that due to the inertia of SHP, the amplitude-frequency characteristics of SHP island system are relatively slow, and the process of non-synchronization with the main grid is gradually expanded. The characteristic of SHP has a certain degree of synchronization with the main grid in the initial island operates stage, which helps to find a novel grid connection method. This paper further proposes the strategy of using fast busbar automatic transfer switch (BATS), which quickly connect the trip-off SHP to the distribution network under the condition of permitting distributed energy grid-connected. The PSCAD simulation results show that proposed strategy has a limited impact on the power grid and prove the effectiveness of the method.

Small hydropower (SHP) and pumped hydropower storage (PHS) are ideal members of power systems with regard to integrating intermittent power production from wind and PV facilities in modern power systems using the high penetration of renewable energy. Due to the limited capacity of SHP and the geographic restrictions of PHS, these power sources have not been adequately utilized in multi-energy integration. On the one hand, rapidly increasing wind/PV power is mostly situated in remote areas (i.e., mountain and rural areas) and is delivered to core areas (i.e., manufacturing bases and cities) for environmental protection and economic profit. On the other hand, SHP is commonly dispersed in remote areas and PHS is usually located in core areas. This paper proposes a strategy to take advantage of the distribution and regulation features of these renewable energy sources by presenting two models, which includes a remote power system model to explore the potential of SHP to smooth the short-term fluctuations in wind and PV power by minimizing output fluctuations as well as a core power system model to employ PHS to shift the surplus power to the peak period by maximizing the income from selling regenerated power and minimizing output fluctuations. In the proposed first model, the cooperative regulation not only dispatches SHP with a reciprocal output shape to the wind/PV output to smooth the fluctuations but also operates the reservoir with the scheduled total power production by adjusting its output in parallel. The results of a case study based on a municipal power system in Southwestern China show that, with the proposed method, SHP can successfully smooth the short-term fluctuations in wind and PV power without influencing the daily total power production. Additionally, SHP can replace the thermal power production with renewable power production, smooth the thermal output, and further reduce the operation costs of thermal power. By storing the surplus power in the upper reservoir and regenerating the power during the peak period, PHS can obtain not only the economic benefit of selling the power at high prices but also the environmental benefit of replacing non-renewable power with renewable power. This study provides a feasible approach to explore the potential of SHP and PHS in multi-energy integration applications.

Discharge water from fish farms is a clean, renewable, and abundant energy source that has been used to obtain renewable energy via small hydropower plants. Small hydropower plants may be installed at offshore fish farms where suitable water is obtained throughout the year. It is necessary to meet the challenges of developing small hydropower systems, including sustainability and turbine efficiency. The main objective of this study was to investigate the possibility of constructing a small hydropower plant and develop 100 kW class propeller-type turbines in a fish farm with a permanent magnet synchronous generator (PMSG). The turbine was optimized using a computer simulation, and an experiment was conducted to obtain performance data. Simulation results were then validated with experimental results. Results revealed that streamlining the designed shape of the guide vane reduced the flow separation and improved the efficiency of the turbine. Optimizing the shape of the runner vane decreased the flow rate, reducing the water power and increasing the efficiency by about 5.57%. Also, results revealed that tubular or cross-flow turbines could be suitable for use in fish farm power plants, and the generator used should be waterproofed to avoid exposure to seawater.

During the last years, significant changes happened in seasonal river hydrology in Europe due to climate change. Nevertheless, according to the presented analysis, the total water runoff for hydropower generation did not change. The last fact is an important policy implication for small hydropower promotion in Ukraine because it belongs to that region and has similar climate conditions. Having analysed the hydropower potential, the paper describes the main advantages and limitations of implementing small hydropower projects in Ukraine. The cost of electricity generated by a small hydropower plant in Ukraine is determined and compared with the current feed-in tariff. The calculations show that the feed-in tariff is 1.4 times higher than the electricity generation cost, making the implementation of small hydropower plants profitable for investors. Since the state provides sufficient economic support for this sector's development, the financial and non-economic barriers significantly hinder small hydropower plant deployment are considered.

Exploring safe and sustainable hydropower, with regard to the size and scheme, is of particular importance to avoid unsettling the fragile ecology in Tibet. Through emergy analysis, this study aimed to assess and compare the environmental performance and sustainability of three different small hydropower (SHP) schemes that are currently in use, i.e., dam-toe, diversion and hybrid, in the Nagqu Prefecture of Tibet. The results indicate that the main difference among the three schemes is the high emergy cost associated with the sizeable dam and related sediment deposition. Correspondingly, the diversion scheme without the dam component is superior to the other two schemes with respect to environmental performance. Considering the necessity of SHP in sparsely populated Tibet, the diversion scheme is recommended more highly than the other two schemes for new SHP plants that are being planned for construction. Because of the much higher resource cost but smaller installed capacity, all three case plants in Tibet present worse performance than their counterparts in Guizhou Province. These results help to encourage China's policy makers to be conservative and proceed with caution regarding SHP development in the fragile Tibetan ecosystem, although SHP has played and will continue to play an essential role in rural electrification in this unique region.

In order to meet the growing demand for energy, the development of hydropower leads to an increase of the river exploitation by human activities. Thereby, water management has become a major issue in the energy transition. A better definition of the flow release rules is now required to improve the Minimal Flow Requirement (MFR) concept, which has long been used in spite of its environmental inconsistency. In this work, we present a class of non-proportional redistribution rules that broadens the spectrum of dynamic flow releases based on proportional redistribution for run-of-the-river power plants. We adapt the mathematical form of the Fermi-Dirac statistical distribution to engineer a novel class of redistribution functions. In particular, such functions are used to define the fraction of water allocated to the environment depending on the inflow at the intake. The theoretical background as well as the economic interpretation is presented, and the ability to generate variable flow releases carefully discussed. MFR, proportional and non-proportional distribution policies are then applied to a real case study and their respective economic and environmental efficiencies quantitatively compared. We show that non-proportional distribution policies allow for operating conditions actually close to the Pareto frontier, which improve both efficiencies with respect to those obtained from some traditional MFR and proportional policies.

Las centrales minihidráulicas han sido una fuente de energía pionera para la producción de electricidad desde finales del siglo XIX. La crisis del petróleo en los años setenta del siglo XX puso de relieve la necesidad de apostar por las energías renovables, por su carácter autóctono, porque reducían la dependencia del exterior y por su menor impacto ambiental. Este artículo analiza la evolución de la energía minihidráulica en España desde mediados del siglo XX a la actualidad. El análisis del marco legal que afecta a esta tecnología energética y la evolución de la potencia instalada en las últimas décadas han permitido determinar su resurgimiento y desarrollo, así como conocer las limitaciones actuales. Desde la aprobación de la Ley de Sector Eléctrico (1997) se ha incrementado en un 90% el número de minicentrales, un 52% la potencia instalada y un 72% la energía generada. Se ha dado un balance muy positivo, aunque en la actualidad el sector está estancado como consecuencia de las dificultades existentes para la nueva implantación de estas instalaciones, y en especial por las directrices de la nueva Política Energética para las renovables. Small hydro power plants have been a pioneering energy source for electricity production since the late nineteenth century. The oil crisis of the 1970s highlighted the need to focus on renewable energies, as these reduce dependence on other energy producing countries and reducing their environmental impact. This article analyzes the evolution of minihydraulic energy in Spain from the mid - 20th century to the present. The analysis of the legal framework that affects this energy technology and the evolution of the installed power in the last decades have allowed to determine its resurgence and development, as well as to know the current limitations. Since the approval of the Electricity Sector Law (1997), the number of Small hydro power plants has increased by 90%, 52% of installed capacity and 72% of the energy generated. The balance of recent years is very positive, although at present the sector is stalled as a result of the difficulties existing for the new implementation of these facilities, and in particular by the guidelines of the new Energy Policy for renewables.

Suggested ways to improve the economic efficiency of investments in the construction of agro-industrial facilities in rural areas, allows them to increase the level of employment of the rural population, improving sew infrastructure economic activity in rural areas, to strengthen the management system of rural settlement and, most importantly, to improve the quality of life in rural areas.

An analytical approach to assess the mini hydropower potential is proposed on a GIS platform. The mini hydropower potential is defined in terms of a synthetic index that measures the investment feasibility of a given hydropower plant. The investigation of the mini hydropower potential is performed at the catchment scale by integrating: catchment morphometric analysis; setting criteria for locating the weirs and powerhouses; hydrological modelling; engineering analysis; economic analysis and mapping. The integrated approach has been tested on the Arroscia catchment (Italy) where 27 weir sections have been examined thus resulting into 640 evaluated mini hydropower plant alternatives. Hydropower potential results indicate that in 14 over 27 sub-catchments it is possible to select at least a specific powerhouse location where the investment is affordable. The determination of MHP indexes in a simplified framework overcomes the typical problem due to the single prediction of hydropower potential for a specific plant configuration. The comprehensive MHP analysis allows to supports the energy management strategies while ensuring the sustainable water resource management at the catchment scale.

In Turkey the laws published in recent years succeeded in promoting the utilization of renewable energy for electricity generation. After the publication of Renewable Energy Law on 18 May 2005 in Turkey there occurred a boost in renewable energy projects along with hydropower development. Thus, the economically feasible hydropower potential of Turkey increased 15% and the construction of hydropower plants also increased by a factor of four in 2007 as compared to 2006. From this perspective, this paper was aimed to evaluate the small hydropower potential of municipal water supply dams of Turkey and discussed the current situation of SHP plants in terms of the government policy. It is estimated that the installing small hydropower plants to exiting 45 municipal water supply dams in Turkey will generate 173 GWh/year electric energy without effecting the natural environment. For a case study, Zonguldak Ulutan Dam and its water treatment plant has been investigated in detail. © 2010 Elsevier Ltd. All rights reserved.

This paper aims to evaluate the development of small hydropower (SHP) in Turkey and discusses the current situation of SHP plants in terms of government policy, economical aspects and environmental impacts taking EU policy into account. The laws published in recent years in Turkey succeeded in promoting the utilization of renewable energy for electricity generation, but it is considered that those laws are not fully compatible with EU policy. After the publication of Renewable Energy Law (Law No. 5346) there occurred a boost in SHP project along with hydropower development. Thus, the hydropower potential of Turkey increased 15% and the construction of hydropower plants also increased by a factor of four in 2007 as compared to 2006. Investment and operating costs are in favor of SHP development in Turkey as having the lowest costs among European countries (300-1000 €/kW as investment cost and 1 €cent/kWh as operating cost). Turkish governments have taken precautions for environmental issues resulted from renewable energy utilization but these are obviously not adequate. It is concluded that more attention must be paid on environmental issues and monitoring of the facilities must be enabled with further laws or regulations. © 2009 Elsevier Ltd. All rights reserved.

Recently, small hydropower attracts attention because of its clean, renewable and abundant energy resources to develop. Therefore, a cross-flow hydraulic turbine is proposed for small hydropower in this study because the turbine has relatively simple structure and high possibility of applying to small hydropower. The purpose of this study is to investigate the effect of the turbine's structural configuration on the performance and internal flow characteristics of the cross-flow turbine model using CFD analysis. The results show that nozzle shape, runner blade angle and runner blade number are closely related to the performance and internal flow of the turbine. Moreover, air layer in the turbine runner plays very important roles of improving the turbine performance.

WOS: 000251419600005, This study presents the status of and prospects for the current state of small hydropower technologies used to produce electricity and assesses their future prospects. The hydropower currently provides about 20% of the world's electricity supply and more than 40% of the electricity used in developing countries. Norway produces more than 99% of its electricity with hydropower. The hydropower is the leading source of renewable energy, providing more than 97% of all electricity generated by renewable sources. The chief advantage of hydro systems is elimination of the cost of fuel. Hydropower on a small-scale is in most cases "run-of-river," with no dam or water storage, and is one of the most cost-effective and environmentally benign energy technologies to be considered both for rural electrification in less developed countries and further hydro developments in Europe.

WOS: 000246881200008, The hydropower is the leading source of renewable energy. It provides more than 97% of all electricity generated by renewable sources. The main advantage of hydro systems is elimination of the cost of fuel. Hydropower on a small-scale is in most cases "run-of-river", with no dam or water storage, and is one of the most cost-effective and environmentally benign energy technologies to be considered both for rural electrification in less developed countries and further hydro developments in Europe. Multipurpose dams, like Porsuk Dam in Eskisehir, are constructed with the aim of supplying domestic, irrigation and industrial water except electricity generation. Porsuk basin has suitable valley in upstream of existing Porsuk Dam for realizing of small reservoirs. The discharge capacity of Porsuk River is appropriate only to install Small Hydropower Plants (SHPs). For the sustainable management of Porsuk River water, except existing Porsuk Dam, it is required to construct a few new dams on this river. The valley of Porsuk River is suitable to construct concrete faced rockfill dams (CFRDs). For this propose, initially, historical data of inlet and outlet of Porsuk reservoir has been investigated. Historical data have been analyzed on a monthly basis for 32 years. It has been calculated that the electricity generation using this potential is 20.69 GWh/year with 4.2 MW installed capacity from Porsuk Dam. For the evaluation of all the Porsuk River water potential, it is required constructing at least two new dams in the hilly Porsuk basin. It is calculated that the total electricity generation from these two will reach up to 37.79 GWh/year with 2 x 2.8 MW installed capacity

The belief that small hydropower (SHP) systems are sources of clean energy with few or no ecological problems has been driving the rapid expansion of SHP plants in China and elsewhere. This paper presents an evaluation of the ecological impacts of SHP based on an emergy analysis of a plant located in Guizhou Province in southwest China. The results suggest that periodic downstream drying-up of the river is the largest contributor to the induced ecological impacts in terms of emergy cost. In 2010, the ecosystem service losses caused by downstream ecosystem degradation totaled 2.35E+18 seJ, which accounts for 38% of the total emergy utilized in the annual operation of this plant. If such losses could be avoided, i.e., if the SHP operated as designed, SHP projects would produce relatively modest impacts on the environment. When the reaches downstream of the SHP plant are not affected, the environmental loading ratio (ELR) is 2.20 and the emergy sustainability index (ESI) is 0.93; however, the ELR increases to 3.82 and ESI decreases to 0.38 when river drying-up occurs. These results indicate that China should rigorously investigate potential ecological problems of SHP development and proceed with caution rather than readily believing unjustified assumptions.

This article discusses the environmental issues facing small hydropower plants (SHPs) operating in temperate lowland rivers of Lithuania. The research subjects are two medium head reservoir type hydro schemes considered within a context of the global fleet of SHPs in the country. This research considers general abiotic indicators (flow, level, water retention time in the reservoirs) of the stream that may affect the aquatic systems. The main idea was to test whether the hydrologic regime has been altered by small hydropower dams. The analysis of changes in abiotic indicators is a complex process, including both pre- and post-reservoir construction and post commissioning of the SHPs under operation. Downstream hydrograph (flow and stage) ramping is also an issue for operating SHPs that can result in temporary rapid changes in flow and consequently negatively impact aquatic resources. This ramping has been quantitatively evaluated. To avoid the risk of excessive flow ramping, the types of turbines available were evaluated and the most suitable types for the natural river flow regime were identified. The results of this study are to allow for new hydro schemes or upgrades to use water resources in a more sustainable way. Keywords: small hydropower; small reservoirs; natural and altered flow regime; hydrograph ramping; hydro turbines.

The investment in small hydropower plants requires the analysis of hydrological, technical, operational, budgetary, economical and financial aspects. The analysis of each possible configuration demands the joint action of several technicians, consuming substantial time and money. During initial design of the project, simplified procedures are usually adopted which may compromise the quality of the base configuration.In this paper we will present a global overview of the OPAH model, which was developed to surpass these limitations. This global model performs the optimization of project configuration. This model uses non-linear programming optimization to analyze the multipurpose operation of the hydropower plant. It uses a numeric simulation model of unsteady flow under pressure to analyze the hydraulic circuit. It uses an economical and financial simulation model that takes in to account the project risk associated to hydrologic and market variability, the financial capacity of the investor and the fiscal aspects.

Integrating renewable and intermittent energy sources into the electricity sector challenges traditional energy systems based on predictability and constant supply. Studies oncomplementarity between climate-related resources from different regions and countries are proving to be an efficient means to overcome the variability of single-source use. Although Rio de Janeiro State (Brazil) has set goals of increasing its use of clean and low carbon energy, there is no study to support the expansion process. Given that, this work aims to assess the complementarity potential of small hydropower plants, wind farms, and photovoltaic panels in the state. Power output estimates have been based on wind speeds, solar radiation and river flow data and without generation technologies assumptions. The Pearson correlation coefficient and linear programming have been used to comprehend and optimize the renewable mix. Daily complementarity has been observed among the energy sources considered, especially between hydro and solar resources. The optimization process showed an improvement of 61% in the total power standard deviation, from the worst—100% hydro power—to the best case—62% of photovoltaic, 21% of wind, and 17% of hydro power. The results highlight the benefits of appropriately joining the three sources and suggest investing in photovoltaic generation.

A small hydropower plant in Spain is studied from an energetic and economic perspective. The viability of the facility is examined using the freeware software RETScreen. Calculated and standard operational data are compared, thereby demonstrating the feasibility of the project from all points of view. The study highlights the growing interest in renewable energies., research project BU019A08 supported by the Department of Culture and Education of the Regional Government of Castilla y León, Spain

WOS: 000223324500002, The aim of this article is to investigate the small hydropower plants (SHPs) in Turkey. Total hydropower potential of Turkey is annually 433,000 GWh. Almost 50% of the total potential is technically exploitable and 29% (122,322 GWh/year) is economically exploitable. The country is planning to make use of the exploitable hydropower potentials (HPPs) of 122,322 GWh/year by 2023. Since the 1960s, more than 700 dams in various sizes have been constructed and 519 dams have already been in operation by 2002. Of these 519 dams, 202 facilities have been constructed as large dams and 317 as small dams. There are now a total of 134 hydroelectric power plants (HEPPs), total installed hydropower capacity of Turkey has reached 12,177 MW, and production has reached 44,034 GWh/year in 2002. About 38% of the total electricity is produced by HEPPs, approximately 98.5% of total hydropower potential is exploited from dams and HEPPs, whose installed capacity is more than 10 MW, and the rest (1.5%) is from run off river and channel HPPs. At the end of 2002, of these 317 small dams, 70 SHPs projects (installed capacity less than 10 MW) have put in operation and 203 SHP projects (installed capacity less than 10 MW) have been developed at various stages in Turkey.

El propósito del presente artículo es realizar una revisión y análisis contextual y de requerimientos básicos a tener en cuenta para implementar proyectos de Pequeñas Centrales Hidroeléctricas, para lo cual se realizó una recopilación de información y una revisión bibliográfica que permitió conocer la situación actual de la técnica a nivel nacional e internacional, así como las tecnologías más eficientes y aptas para su implementación. Por último, se plantean unas etapas y estudios de ingeniería a seguir para lograr con éxito el desarrollo de un proyecto de PCH y se definen las conclusiones pertinentes del análisis realizado. The purpose of this article is to review and analyze the context and basic requirements to be considered to implement projects of Small Hydro Power, which was performed by collecting information and reviewing of the current state of technology in the country and worldwide, as well as the most efficient and suitable technologies for its implementation. Finally, it raises some stages and engineering studies to follow for successful development of an SHP project and defines the relevant conclusions of the analysis.

Key global energy, environmental and sustainability targets are closely related to the development of Renewable Energy Sources (RES). This includes reduction of Greenhouse Gas emissions and safe energy provision in a sustainable manner. The integration of RES in the energy mix needs to overcome the technical challenges that are related to grid's operation. Therefore, there is an increasing need to explore approaches where different RES will operate under a synergetic approach. A straightforward way to achieve that is by optimizing the complementarity among RES systems both over time and spatially. The present article developed a methodology that examines the degree of time complementarity between small hydropower stations (SHPS) and adjacent solar PV systems (SPVS). The methodology builds on an optimization algorithm that associates hydrological with solar irradiation information. In particularly, the algorithm examines possible alterations on the PV system installation (azimuth, tilt) that increase the complementarity, with minor compromises in the total solar energy output. The methodology has been tested in a case study and the outcome indicated that a compromise of 10% in the solar energy output (90% threshold) may result in a significant increase of the complementarity (66.4%).